/* * Copyright 2005 Richard Wilson * Copyright 2006 James Bursa * Copyright 2008 Michael Drake * Copyright 2003 Phil Mellor * * This file is part of NetSurf, http://www.netsurf-browser.org/ * * NetSurf is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * NetSurf is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ /** * \file * HTML layout implementation. * * Layout is carried out in two stages: * * 1. + calculation of minimum / maximum box widths, and * + determination of whether block level boxes will have >zero height * * 2. + layout (position and dimensions) * * In most cases the functions for the two stages are a corresponding pair * layout_minmax_X() and layout_X(). */ #include #include #include #include #include #include #include #include #include "utils/log.h" #include "utils/talloc.h" #include "utils/utils.h" #include "utils/nsoption.h" #include "utils/nsurl.h" #include "netsurf/inttypes.h" #include "netsurf/content.h" #include "netsurf/browser_window.h" #include "netsurf/layout.h" #include "content/content_protected.h" #include "css/utils.h" #include "desktop/scrollbar.h" #include "desktop/textarea.h" #include "html/html.h" #include "html/html_save.h" #include "html/private.h" #include "html/box.h" #include "html/box_inspect.h" #include "html/font.h" #include "html/form_internal.h" #include "html/layout.h" #include "html/table.h" #define AUTO INT_MIN /* Fixed point percentage (a) of an integer (b), to an integer */ #define FPCT_OF_INT_TOINT(a, b) (FIXTOINT(FDIV((a * b), F_100))) typedef uint8_t (*css_len_func)( const css_computed_style *style, css_fixed *length, css_unit *unit); typedef uint8_t (*css_border_style_func)( const css_computed_style *style); typedef uint8_t (*css_border_color_func)( const css_computed_style *style, css_color *color); /** Array of per-side access functions for computed style margins. */ static const css_len_func margin_funcs[4] = { [TOP] = css_computed_margin_top, [RIGHT] = css_computed_margin_right, [BOTTOM] = css_computed_margin_bottom, [LEFT] = css_computed_margin_left, }; /** Array of per-side access functions for computed style paddings. */ static const css_len_func padding_funcs[4] = { [TOP] = css_computed_padding_top, [RIGHT] = css_computed_padding_right, [BOTTOM] = css_computed_padding_bottom, [LEFT] = css_computed_padding_left, }; /** Array of per-side access functions for computed style border_widths. */ static const css_len_func border_width_funcs[4] = { [TOP] = css_computed_border_top_width, [RIGHT] = css_computed_border_right_width, [BOTTOM] = css_computed_border_bottom_width, [LEFT] = css_computed_border_left_width, }; /** Array of per-side access functions for computed style border styles. */ static const css_border_style_func border_style_funcs[4] = { [TOP] = css_computed_border_top_style, [RIGHT] = css_computed_border_right_style, [BOTTOM] = css_computed_border_bottom_style, [LEFT] = css_computed_border_left_style, }; /** Array of per-side access functions for computed style border colors. */ static const css_border_color_func border_color_funcs[4] = { [TOP] = css_computed_border_top_color, [RIGHT] = css_computed_border_right_color, [BOTTOM] = css_computed_border_bottom_color, [LEFT] = css_computed_border_left_color, }; /* forward declaration to break cycles */ static bool layout_block_context( struct box *block, int viewport_height, html_content *content); static void layout_minmax_block( struct box *block, const struct gui_layout_table *font_func, const html_content *content); /** * Compute the size of replaced boxes with auto dimensions, according to * content. * * \param box Box with object * \param width Width value in px or AUTO. If AUTO, updated to value in px. * \param height Height value in px or AUTO. If AUTO, updated to value in px. * \param min_width Box's min width, as given by layout_find_dimensions. * \param max_width Box's max width, as given by layout_find_dimensions. * \param min_height Box's min height, as given by layout_find_dimensions. * \param max_height Box's max height, as given by layout_find_dimensions. * * See CSS 2.1 sections 10.3 and 10.6. */ static void layout_get_object_dimensions(struct box *box, int *width, int *height, int min_width, int max_width, int min_height, int max_height) { assert(box->object != NULL); assert(width != NULL && height != NULL); if (*width == AUTO && *height == AUTO) { /* No given dimensions */ bool scaled = false; int intrinsic_width = content_get_width(box->object); int intrinsic_height = content_get_height(box->object); /* use intrinsic dimensions */ *width = intrinsic_width; *height = intrinsic_height; /* Deal with min/max-width first */ if (min_width > 0 && min_width > *width) { *width = min_width; scaled = true; } if (max_width >= 0 && max_width < *width) { *width = max_width; scaled = true; } if (scaled && (intrinsic_width != 0)) { /* Update height */ *height = (*width * intrinsic_height) / intrinsic_width; } scaled = false; /* Deal with min/max-height */ if (min_height > 0 && min_height > *height) { *height = min_height; scaled = true; } if (max_height >= 0 && max_height < *height) { *height = max_height; scaled = true; } if (scaled && (intrinsic_height != 0)) { /* Update width */ *width = (*height * intrinsic_width) / intrinsic_height; } } else if (*width == AUTO) { /* Have given height; width is calculated from the given height * and ratio of intrinsic dimensions */ int intrinsic_width = content_get_width(box->object); int intrinsic_height = content_get_height(box->object); if (intrinsic_height != 0) *width = (*height * intrinsic_width) / intrinsic_height; else *width = intrinsic_width; if (min_width > 0 && min_width > *width) *width = min_width; if (max_width >= 0 && max_width < *width) *width = max_width; } else if (*height == AUTO) { /* Have given width; height is calculated from the given width * and ratio of intrinsic dimensions */ int intrinsic_width = content_get_width(box->object); int intrinsic_height = content_get_height(box->object); if (min_width > 0 && min_width > *width) *width = min_width; if (max_width >= 0 && max_width < *width) *width = max_width; if (intrinsic_width != 0) *height = (*width * intrinsic_height) / intrinsic_width; else *height = intrinsic_height; } } /** * Calculate the text-indent length. * * \param style style of block * \param width width of containing block * \return length of indent */ static int layout_text_indent( const nscss_len_ctx *len_ctx, const css_computed_style *style, int width) { css_fixed value = 0; css_unit unit = CSS_UNIT_PX; css_computed_text_indent(style, &value, &unit); if (unit == CSS_UNIT_PCT) { return FPCT_OF_INT_TOINT(value, width); } else { return FIXTOINT(nscss_len2px(len_ctx, value, unit, style)); } } /** * Determine width of margin, borders, and padding on one side of a box. * * \param len_ctx CSS length conversion context for document * \param style style to measure * \param side side of box to measure * \param margin whether margin width is required * \param border whether border width is required * \param padding whether padding width is required * \param fixed increased by sum of fixed margin, border, and padding * \param frac increased by sum of fractional margin and padding */ static void calculate_mbp_width(const nscss_len_ctx *len_ctx, const css_computed_style *style, unsigned int side, bool margin, bool border, bool padding, int *fixed, float *frac) { css_fixed value = 0; css_unit unit = CSS_UNIT_PX; assert(style); /* margin */ if (margin) { enum css_margin_e type; type = margin_funcs[side](style, &value, &unit); if (type == CSS_MARGIN_SET) { if (unit == CSS_UNIT_PCT) { *frac += FIXTOINT(FDIV(value, F_100)); } else { *fixed += FIXTOINT(nscss_len2px(len_ctx, value, unit, style)); } } } /* border */ if (border) { if (border_style_funcs[side](style) != CSS_BORDER_STYLE_NONE) { border_width_funcs[side](style, &value, &unit); *fixed += FIXTOINT(nscss_len2px(len_ctx, value, unit, style)); } } /* padding */ if (padding) { padding_funcs[side](style, &value, &unit); if (unit == CSS_UNIT_PCT) { *frac += FIXTOINT(FDIV(value, F_100)); } else { *fixed += FIXTOINT(nscss_len2px(len_ctx, value, unit, style)); } } } /** * Calculate minimum and maximum width of a table. * * \param table box of type TABLE * \param font_func Font functions * \param content The HTML content we are laying out. * \post table->min_width and table->max_width filled in, * 0 <= table->min_width <= table->max_width */ static void layout_minmax_table(struct box *table, const struct gui_layout_table *font_func, const html_content *content) { unsigned int i, j; int border_spacing_h = 0; int table_min = 0, table_max = 0; int extra_fixed = 0; float extra_frac = 0; struct column *col; struct box *row_group, *row, *cell; enum css_width_e wtype; css_fixed value = 0; css_unit unit = CSS_UNIT_PX; /* check if the widths have already been calculated */ if (table->max_width != UNKNOWN_MAX_WIDTH) return; if (table_calculate_column_types(&content->len_ctx, table) == false) { NSLOG(netsurf, WARNING, "Could not establish table column types."); return; } col = table->col; /* start with 0 except for fixed-width columns */ for (i = 0; i != table->columns; i++) { if (col[i].type == COLUMN_WIDTH_FIXED) col[i].min = col[i].max = col[i].width; else col[i].min = col[i].max = 0; } /* border-spacing is used in the separated borders model */ if (css_computed_border_collapse(table->style) == CSS_BORDER_COLLAPSE_SEPARATE) { css_fixed h = 0, v = 0; css_unit hu = CSS_UNIT_PX, vu = CSS_UNIT_PX; css_computed_border_spacing(table->style, &h, &hu, &v, &vu); border_spacing_h = FIXTOINT(nscss_len2px(&content->len_ctx, h, hu, table->style)); } /* 1st pass: consider cells with colspan 1 only */ for (row_group = table->children; row_group; row_group =row_group->next) for (row = row_group->children; row; row = row->next) for (cell = row->children; cell; cell = cell->next) { assert(cell->type == BOX_TABLE_CELL); assert(cell->style); /** TODO: Handle colspan="0" correctly. * It's currently converted to 1 in box normaisation */ assert(cell->columns != 0); if (cell->columns != 1) continue; layout_minmax_block(cell, font_func, content); i = cell->start_column; if (col[i].positioned) continue; /* update column min, max widths using cell widths */ if (col[i].min < cell->min_width) col[i].min = cell->min_width; if (col[i].max < cell->max_width) col[i].max = cell->max_width; } /* 2nd pass: cells which span multiple columns */ for (row_group = table->children; row_group; row_group =row_group->next) for (row = row_group->children; row; row = row->next) for (cell = row->children; cell; cell = cell->next) { unsigned int flexible_columns = 0; int min = 0, max = 0, fixed_width = 0, extra; if (cell->columns == 1) continue; layout_minmax_block(cell, font_func, content); i = cell->start_column; /* find min width so far of spanned columns, and count * number of non-fixed spanned columns and total fixed width */ for (j = 0; j != cell->columns; j++) { min += col[i + j].min; if (col[i + j].type == COLUMN_WIDTH_FIXED) fixed_width += col[i + j].width; else flexible_columns++; } min += (cell->columns - 1) * border_spacing_h; /* distribute extra min to spanned columns */ if (min < cell->min_width) { if (flexible_columns == 0) { extra = 1 + (cell->min_width - min) / cell->columns; for (j = 0; j != cell->columns; j++) { col[i + j].min += extra; if (col[i + j].max < col[i + j].min) col[i + j].max = col[i + j].min; } } else { extra = 1 + (cell->min_width - min) / flexible_columns; for (j = 0; j != cell->columns; j++) { if (col[i + j].type != COLUMN_WIDTH_FIXED) { col[i + j].min += extra; if (col[i + j].max < col[i + j].min) col[i + j].max = col[i + j].min; } } } } /* find max width so far of spanned columns */ for (j = 0; j != cell->columns; j++) max += col[i + j].max; max += (cell->columns - 1) * border_spacing_h; /* distribute extra max to spanned columns */ if (max < cell->max_width && flexible_columns) { extra = 1 + (cell->max_width - max) / flexible_columns; for (j = 0; j != cell->columns; j++) if (col[i + j].type != COLUMN_WIDTH_FIXED) col[i + j].max += extra; } } for (i = 0; i != table->columns; i++) { if (col[i].max < col[i].min) { box_dump(stderr, table, 0, true); assert(0); } table_min += col[i].min; table_max += col[i].max; } /* fixed width takes priority, unless it is too narrow */ wtype = css_computed_width(table->style, &value, &unit); if (wtype == CSS_WIDTH_SET && unit != CSS_UNIT_PCT) { int width = FIXTOINT(nscss_len2px(&content->len_ctx, value, unit, table->style)); if (table_min < width) table_min = width; if (table_max < width) table_max = width; } /* add margins, border, padding to min, max widths */ calculate_mbp_width(&content->len_ctx, table->style, LEFT, true, true, true, &extra_fixed, &extra_frac); calculate_mbp_width(&content->len_ctx, table->style, RIGHT, true, true, true, &extra_fixed, &extra_frac); if (extra_fixed < 0) extra_fixed = 0; if (extra_frac < 0) extra_frac = 0; if (1.0 <= extra_frac) extra_frac = 0.9; table->min_width = (table_min + extra_fixed) / (1.0 - extra_frac); table->max_width = (table_max + extra_fixed) / (1.0 - extra_frac); table->min_width += (table->columns + 1) * border_spacing_h; table->max_width += (table->columns + 1) * border_spacing_h; assert(0 <= table->min_width && table->min_width <= table->max_width); } /** * Helper to check if a box has percentage max width. * * \param[in] b Box to check. * \return true iff box has percnetage max width. */ static inline bool box_has_percentage_max_width(struct box *b) { css_unit unit = CSS_UNIT_PX; enum css_max_width_e type; css_fixed value = 0; assert(b != NULL); type = css_computed_max_width(b->style, &value, &unit); return ((type == CSS_MAX_WIDTH_SET) && (unit == CSS_UNIT_PCT)); } /** * Calculate minimum and maximum width of a line. * * \param first a box in an inline container * \param line_min updated to minimum width of line starting at first * \param line_max updated to maximum width of line starting at first * \param first_line true iff this is the first line in the inline container * \param line_has_height updated to true or false, depending on line * \param font_func Font functions. * \return first box in next line, or 0 if no more lines * \post 0 <= *line_min <= *line_max */ static struct box * layout_minmax_line(struct box *first, int *line_min, int *line_max, bool first_line, bool *line_has_height, const struct gui_layout_table *font_func, const html_content *content) { int min = 0, max = 0, width, height, fixed; float frac; size_t i, j; struct box *b; struct box *block; plot_font_style_t fstyle; bool no_wrap; assert(first->parent); assert(first->parent->parent); assert(first->parent->parent->style); block = first->parent->parent; no_wrap = (css_computed_white_space(block->style) == CSS_WHITE_SPACE_NOWRAP || css_computed_white_space(block->style) == CSS_WHITE_SPACE_PRE); *line_has_height = false; /* corresponds to the pass 1 loop in layout_line() */ for (b = first; b; b = b->next) { enum css_width_e wtype; enum css_height_e htype; enum css_box_sizing_e bs; css_fixed value = 0; css_unit unit = CSS_UNIT_PX; assert(b->type == BOX_INLINE || b->type == BOX_INLINE_BLOCK || b->type == BOX_FLOAT_LEFT || b->type == BOX_FLOAT_RIGHT || b->type == BOX_BR || b->type == BOX_TEXT || b->type == BOX_INLINE_END); NSLOG(layout, DEBUG, "%p: min %i, max %i", b, min, max); if (b->type == BOX_BR) { b = b->next; break; } if (b->type == BOX_FLOAT_LEFT || b->type == BOX_FLOAT_RIGHT) { assert(b->children); if (b->children->type == BOX_BLOCK) layout_minmax_block(b->children, font_func, content); else layout_minmax_table(b->children, font_func, content); b->min_width = b->children->min_width; b->max_width = b->children->max_width; if (min < b->min_width) min = b->min_width; max += b->max_width; continue; } if (b->type == BOX_INLINE_BLOCK) { layout_minmax_block(b, font_func, content); if (min < b->min_width) min = b->min_width; max += b->max_width; if (b->flags & HAS_HEIGHT) *line_has_height = true; continue; } assert(b->style); font_plot_style_from_css(&content->len_ctx, b->style, &fstyle); if (b->type == BOX_INLINE && !b->object && !(b->flags & REPLACE_DIM) && !(b->flags & IFRAME)) { fixed = frac = 0; calculate_mbp_width(&content->len_ctx, b->style, LEFT, true, true, true, &fixed, &frac); if (!b->inline_end) calculate_mbp_width(&content->len_ctx, b->style, RIGHT, true, true, true, &fixed, &frac); if (0 < fixed) max += fixed; *line_has_height = true; /* \todo update min width, consider fractional extra */ } else if (b->type == BOX_INLINE_END) { fixed = frac = 0; calculate_mbp_width(&content->len_ctx, b->inline_end->style, RIGHT, true, true, true, &fixed, &frac); if (0 < fixed) max += fixed; if (b->next) { if (b->space == UNKNOWN_WIDTH) { font_func->width(&fstyle, " ", 1, &b->space); } max += b->space; } *line_has_height = true; continue; } if (!b->object && !(b->flags & IFRAME) && !b->gadget && !(b->flags & REPLACE_DIM)) { /* inline non-replaced, 10.3.1 and 10.6.1 */ bool no_wrap_box; if (!b->text) continue; no_wrap_box = (css_computed_white_space(b->style) == CSS_WHITE_SPACE_NOWRAP || css_computed_white_space(b->style) == CSS_WHITE_SPACE_PRE); if (b->width == UNKNOWN_WIDTH) { /** \todo handle errors */ /* If it's a select element, we must use the * width of the widest option text */ if (b->parent->parent->gadget && b->parent->parent->gadget->type == GADGET_SELECT) { int opt_maxwidth = 0; struct form_option *o; for (o = b->parent->parent->gadget-> data.select.items; o; o = o->next) { int opt_width; font_func->width(&fstyle, o->text, strlen(o->text), &opt_width); if (opt_maxwidth < opt_width) opt_maxwidth =opt_width; } b->width = opt_maxwidth; if (nsoption_bool(core_select_menu)) b->width += SCROLLBAR_WIDTH; } else { font_func->width(&fstyle, b->text, b->length, &b->width); b->flags |= MEASURED; } } max += b->width; if (b->next) { if (b->space == UNKNOWN_WIDTH) { font_func->width(&fstyle, " ", 1, &b->space); } max += b->space; } if (no_wrap) { /* Don't wrap due to block style, * so min is the same as max */ min = max; } else if (no_wrap_box) { /* This inline box can't be wrapped, * for min, consider box's width */ if (min < b->width) min = b->width; } else if (b->parent->flags & NEED_MIN) { /* If we care what the minimum width is, * calculate it. (It's only needed if we're * shrinking-to-fit.) */ /* min = widest single word */ i = 0; do { for (j = i; j != b->length && b->text[j] != ' '; j++) ; font_func->width(&fstyle, b->text + i, j - i, &width); if (min < width) min = width; i = j + 1; } while (j != b->length); } *line_has_height = true; continue; } /* inline replaced, 10.3.2 and 10.6.2 */ assert(b->style); /* calculate box width */ wtype = css_computed_width(b->style, &value, &unit); bs = css_computed_box_sizing(block->style); if (wtype == CSS_WIDTH_SET) { if (unit == CSS_UNIT_PCT) { width = AUTO; } else { width = FIXTOINT(nscss_len2px(&content->len_ctx, value, unit, b->style)); if (bs == CSS_BOX_SIZING_BORDER_BOX) { fixed = frac = 0; calculate_mbp_width(&content->len_ctx, block->style, LEFT, false, true, true, &fixed, &frac); calculate_mbp_width(&content->len_ctx, block->style, RIGHT, false, true, true, &fixed, &frac); if (width < fixed) { width = fixed; } } if (width < 0) width = 0; } } else { width = AUTO; } /* height */ htype = css_computed_height(b->style, &value, &unit); if (htype == CSS_HEIGHT_SET) { height = FIXTOINT(nscss_len2px(&content->len_ctx, value, unit, b->style)); } else { height = AUTO; } if (b->object || (b->flags & REPLACE_DIM)) { if (b->object) { int temp_height = height; layout_get_object_dimensions(b, &width, &temp_height, INT_MIN, INT_MAX, INT_MIN, INT_MAX); } fixed = frac = 0; if (bs == CSS_BOX_SIZING_BORDER_BOX) { calculate_mbp_width(&content->len_ctx, b->style, LEFT, true, false, false, &fixed, &frac); calculate_mbp_width(&content->len_ctx, b->style, RIGHT, true, false, false, &fixed, &frac); } else { calculate_mbp_width(&content->len_ctx, b->style, LEFT, true, true, true, &fixed, &frac); calculate_mbp_width(&content->len_ctx, b->style, RIGHT, true, true, true, &fixed, &frac); } if (0 < width + fixed) width += fixed; } else if (b->flags & IFRAME) { /* TODO: handle percentage widths properly */ if (width == AUTO) width = 400; fixed = frac = 0; if (bs == CSS_BOX_SIZING_BORDER_BOX) { calculate_mbp_width(&content->len_ctx, b->style, LEFT, true, false, false, &fixed, &frac); calculate_mbp_width(&content->len_ctx, b->style, RIGHT, true, false, false, &fixed, &frac); } else { calculate_mbp_width(&content->len_ctx, b->style, LEFT, true, true, true, &fixed, &frac); calculate_mbp_width(&content->len_ctx, b->style, RIGHT, true, true, true, &fixed, &frac); } if (0 < width + fixed) width += fixed; } else { /* form control with no object */ if (width == AUTO) width = FIXTOINT(nscss_len2px( &content->len_ctx, INTTOFIX(1), CSS_UNIT_EM, b->style)); } if (min < width && !box_has_percentage_max_width(b)) min = width; if (width > 0) max += width; *line_has_height = true; } if (first_line) { /* todo: handle percentage values properly */ /* todo: handle text-indent interaction with floats */ int text_indent = layout_text_indent(&content->len_ctx, first->parent->parent->style, 100); min = (min + text_indent < 0) ? 0 : min + text_indent; max = (max + text_indent < 0) ? 0 : max + text_indent; } *line_min = min; *line_max = max; NSLOG(layout, DEBUG, "line_min %i, line_max %i", min, max); assert(b != first); assert(0 <= *line_min); assert(*line_min <= *line_max); return b; } /** * Calculate minimum and maximum width of an inline container. * * \param inline_container box of type INLINE_CONTAINER * \param[out] has_height set to true if container has height * \param font_func Font functions. * \post inline_container->min_width and inline_container->max_width filled in, * 0 <= inline_container->min_width <= inline_container->max_width */ static void layout_minmax_inline_container(struct box *inline_container, bool *has_height, const struct gui_layout_table *font_func, const html_content *content) { struct box *child; int line_min = 0, line_max = 0; int min = 0, max = 0; bool first_line = true; bool line_has_height; assert(inline_container->type == BOX_INLINE_CONTAINER); /* check if the widths have already been calculated */ if (inline_container->max_width != UNKNOWN_MAX_WIDTH) return; *has_height = false; for (child = inline_container->children; child; ) { child = layout_minmax_line(child, &line_min, &line_max, first_line, &line_has_height, font_func, content); if (min < line_min) min = line_min; if (max < line_max) max = line_max; first_line = false; *has_height |= line_has_height; } inline_container->min_width = min; inline_container->max_width = max; assert(0 <= inline_container->min_width && inline_container->min_width <= inline_container->max_width); } /** * Calculate minimum and maximum width of a block. * * \param block box of type BLOCK, INLINE_BLOCK, or TABLE_CELL * \param font_func font functions * \param content The HTML content being layed out. * \post block->min_width and block->max_width filled in, * 0 <= block->min_width <= block->max_width */ static void layout_minmax_block( struct box *block, const struct gui_layout_table *font_func, const html_content *content) { struct box *child; int min = 0, max = 0; int extra_fixed = 0; float extra_frac = 0; enum css_width_e wtype = CSS_WIDTH_AUTO; css_fixed width = 0; css_unit wunit = CSS_UNIT_PX; enum css_height_e htype = CSS_HEIGHT_AUTO; css_fixed height = 0; css_unit hunit = CSS_UNIT_PX; enum css_box_sizing_e bs = CSS_BOX_SIZING_CONTENT_BOX; bool child_has_height = false; assert(block->type == BOX_BLOCK || block->type == BOX_INLINE_BLOCK || block->type == BOX_TABLE_CELL); /* check if the widths have already been calculated */ if (block->max_width != UNKNOWN_MAX_WIDTH) return; if (block->style != NULL) { wtype = css_computed_width(block->style, &width, &wunit); htype = css_computed_height(block->style, &height, &hunit); bs = css_computed_box_sizing(block->style); } /* set whether the minimum width is of any interest for this box */ if (((block->parent && (block->parent->type == BOX_FLOAT_LEFT || block->parent->type == BOX_FLOAT_RIGHT)) || block->type == BOX_INLINE_BLOCK) && wtype != CSS_WIDTH_SET) { /* box shrinks to fit; need minimum width */ block->flags |= NEED_MIN; } else if (block->type == BOX_TABLE_CELL) { /* box shrinks to fit; need minimum width */ block->flags |= NEED_MIN; } else if (block->parent && (block->parent->flags & NEED_MIN) && wtype != CSS_WIDTH_SET) { /* box inside shrink-to-fit context; need minimum width */ block->flags |= NEED_MIN; } if (block->gadget && (block->gadget->type == GADGET_TEXTBOX || block->gadget->type == GADGET_PASSWORD || block->gadget->type == GADGET_FILE || block->gadget->type == GADGET_TEXTAREA) && block->style && wtype == CSS_WIDTH_AUTO) { css_fixed size = INTTOFIX(10); css_unit unit = CSS_UNIT_EM; min = max = FIXTOINT(nscss_len2px(&content->len_ctx, size, unit, block->style)); block->flags |= HAS_HEIGHT; } if (block->gadget && (block->gadget->type == GADGET_RADIO || block->gadget->type == GADGET_CHECKBOX) && block->style && wtype == CSS_WIDTH_AUTO) { css_fixed size = INTTOFIX(1); css_unit unit = CSS_UNIT_EM; /* form checkbox or radio button * if width is AUTO, set it to 1em */ min = max = FIXTOINT(nscss_len2px(&content->len_ctx, size, unit, block->style)); block->flags |= HAS_HEIGHT; } if (block->object) { if (content_get_type(block->object) == CONTENT_HTML) { layout_minmax_block(html_get_box_tree(block->object), font_func, content); min = html_get_box_tree(block->object)->min_width; max = html_get_box_tree(block->object)->max_width; } else { min = max = content_get_width(block->object); } block->flags |= HAS_HEIGHT; } else if (block->flags & IFRAME) { /** \todo do we need to know the min/max width of the iframe's * content? */ block->flags |= HAS_HEIGHT; } else { /* recurse through children */ for (child = block->children; child; child = child->next) { switch (child->type) { case BOX_BLOCK: layout_minmax_block(child, font_func, content); if (child->flags & HAS_HEIGHT) child_has_height = true; break; case BOX_INLINE_CONTAINER: if (block->flags & NEED_MIN) child->flags |= NEED_MIN; layout_minmax_inline_container(child, &child_has_height, font_func, content); if (child_has_height && child == child->parent->children) { block->flags |= MAKE_HEIGHT; } break; case BOX_TABLE: layout_minmax_table(child, font_func, content); /* todo: fix for zero height tables */ child_has_height = true; child->flags |= MAKE_HEIGHT; break; default: assert(0); } assert(child->max_width != UNKNOWN_MAX_WIDTH); if (child->style && (css_computed_position(child->style) == CSS_POSITION_ABSOLUTE || css_computed_position(child->style) == CSS_POSITION_FIXED)) { /* This child is positioned out of normal flow, * so it will have no affect on width */ continue; } if (min < child->min_width) min = child->min_width; if (max < child->max_width) max = child->max_width; if (child_has_height) block->flags |= HAS_HEIGHT; } } if (max < min) { box_dump(stderr, block, 0, true); assert(0); } /* fixed width takes priority */ if (block->type != BOX_TABLE_CELL && wtype == CSS_WIDTH_SET && wunit != CSS_UNIT_PCT) { min = max = FIXTOINT(nscss_len2px(&content->len_ctx, width, wunit, block->style)); if (bs == CSS_BOX_SIZING_BORDER_BOX) { int border_box_fixed = 0; float border_box_frac = 0; calculate_mbp_width(&content->len_ctx, block->style, LEFT, false, true, true, &border_box_fixed, &border_box_frac); calculate_mbp_width(&content->len_ctx, block->style, RIGHT, false, true, true, &border_box_fixed, &border_box_frac); if (min < border_box_fixed) { min = max = border_box_fixed; } } } if (htype == CSS_HEIGHT_SET && hunit != CSS_UNIT_PCT && height > INTTOFIX(0)) { block->flags |= MAKE_HEIGHT; block->flags |= HAS_HEIGHT; } /* add margins, border, padding to min, max widths */ /* Note: we don't know available width here so percentage margin * and paddings are wrong. */ if (bs == CSS_BOX_SIZING_BORDER_BOX && wtype == CSS_WIDTH_SET) { /* Border and padding included in width, so just get margin */ calculate_mbp_width(&content->len_ctx, block->style, LEFT, true, false, false, &extra_fixed, &extra_frac); calculate_mbp_width(&content->len_ctx, block->style, RIGHT, true, false, false, &extra_fixed, &extra_frac); } else { calculate_mbp_width(&content->len_ctx, block->style, LEFT, true, true, true, &extra_fixed, &extra_frac); calculate_mbp_width(&content->len_ctx, block->style, RIGHT, true, true, true, &extra_fixed, &extra_frac); } if (extra_fixed < 0) extra_fixed = 0; if (extra_frac < 0) extra_frac = 0; if (1.0 <= extra_frac) extra_frac = 0.9; if (block->style != NULL && (css_computed_float(block->style) == CSS_FLOAT_LEFT || css_computed_float(block->style) == CSS_FLOAT_RIGHT)) { /* floated boxs */ block->min_width = min + extra_fixed; block->max_width = max + extra_fixed; } else { /* not floated */ block->min_width = (min + extra_fixed) / (1.0 - extra_frac); block->max_width = (max + extra_fixed) / (1.0 - extra_frac); } assert(0 <= block->min_width && block->min_width <= block->max_width); } /** * Adjust a specified width or height for the box-sizing property. * * This turns the specified dimension into a content-box dimension. * * \param len_ctx Length conversion context * \param box gadget to adjust dimensions of * \param available_width width of containing block * \param setwidth set true if the dimension to be tweaked is a width, * else set false for a height * \param dimension current value for given width/height dimension. * updated to new value after consideration of * gadget properties. */ static void layout_handle_box_sizing( const nscss_len_ctx *len_ctx, struct box *box, int available_width, bool setwidth, int *dimension) { enum css_box_sizing_e bs; assert(box && box->style); bs = css_computed_box_sizing(box->style); if (bs == CSS_BOX_SIZING_BORDER_BOX) { int orig = *dimension; int fixed = 0; float frac = 0; calculate_mbp_width(len_ctx, box->style, setwidth ? LEFT : TOP, false, true, true, &fixed, &frac); calculate_mbp_width(len_ctx, box->style, setwidth ? RIGHT : BOTTOM, false, true, true, &fixed, &frac); orig -= frac * available_width + fixed; *dimension = orig > 0 ? orig : 0; } } /** * Calculate width, height, and thickness of margins, paddings, and borders. * * \param len_ctx Length conversion context * \param available_width width of containing block * \param viewport_height height of viewport in pixels or -ve if unknown * \param box current box * \param style style giving width, height, margins, paddings, * and borders * \param width updated to width, may be NULL * \param height updated to height, may be NULL * \param max_width updated to max-width, may be NULL * \param min_width updated to min-width, may be NULL * \param max_height updated to max-height, may be NULL * \param min_height updated to min-height, may be NULL * \param margin filled with margins, may be NULL * \param padding filled with paddings, may be NULL * \param border filled with border widths, may be NULL */ static void layout_find_dimensions(const nscss_len_ctx *len_ctx, int available_width, int viewport_height, struct box *box, const css_computed_style *style, int *width, int *height, int *max_width, int *min_width, int *max_height, int *min_height, int margin[4], int padding[4], struct box_border border[4]) { struct box *containing_block = NULL; unsigned int i; if (width) { enum css_width_e wtype; css_fixed value = 0; css_unit unit = CSS_UNIT_PX; wtype = css_computed_width(style, &value, &unit); if (wtype == CSS_WIDTH_SET) { if (unit == CSS_UNIT_PCT) { *width = FPCT_OF_INT_TOINT( value, available_width); } else { *width = FIXTOINT(nscss_len2px(len_ctx, value, unit, style)); } } else { *width = AUTO; } if (*width != AUTO) { layout_handle_box_sizing(len_ctx, box, available_width, true, width); } } if (height) { enum css_height_e htype; css_fixed value = 0; css_unit unit = CSS_UNIT_PX; htype = css_computed_height(style, &value, &unit); if (htype == CSS_HEIGHT_SET) { if (unit == CSS_UNIT_PCT) { enum css_height_e cbhtype; if (css_computed_position(box->style) == CSS_POSITION_ABSOLUTE && box->parent) { /* Box is absolutely positioned */ assert(box->float_container); containing_block = box->float_container; } else if (box->float_container && css_computed_position(box->style) != CSS_POSITION_ABSOLUTE && (css_computed_float(box->style) == CSS_FLOAT_LEFT || css_computed_float(box->style) == CSS_FLOAT_RIGHT)) { /* Box is a float */ assert(box->parent && box->parent->parent && box->parent->parent->parent); containing_block = box->parent->parent->parent; } else if (box->parent && box->parent->type != BOX_INLINE_CONTAINER) { /* Box is a block level element */ containing_block = box->parent; } else if (box->parent && box->parent->type == BOX_INLINE_CONTAINER) { /* Box is an inline block */ assert(box->parent->parent); containing_block = box->parent->parent; } if (containing_block) { css_fixed f = 0; css_unit u = CSS_UNIT_PX; cbhtype = css_computed_height( containing_block->style, &f, &u); } if (containing_block && containing_block->height != AUTO && (css_computed_position(box->style) == CSS_POSITION_ABSOLUTE || cbhtype == CSS_HEIGHT_SET)) { /* Box is absolutely positioned or its * containing block has a valid * specified height. * (CSS 2.1 Section 10.5) */ *height = FPCT_OF_INT_TOINT(value, containing_block->height); } else if ((!box->parent || !box->parent->parent) && viewport_height >= 0) { /* If root element or it's child * (HTML or BODY) */ *height = FPCT_OF_INT_TOINT(value, viewport_height); } else { /* precentage height not permissible * treat height as auto */ *height = AUTO; } } else { *height = FIXTOINT(nscss_len2px(len_ctx, value, unit, style)); } } else { *height = AUTO; } if (*height != AUTO) { layout_handle_box_sizing(len_ctx, box, available_width, false, height); } } if (max_width) { enum css_max_width_e type; css_fixed value = 0; css_unit unit = CSS_UNIT_PX; type = css_computed_max_width(style, &value, &unit); if (type == CSS_MAX_WIDTH_SET) { if (unit == CSS_UNIT_PCT) { *max_width = FPCT_OF_INT_TOINT(value, available_width); } else { *max_width = FIXTOINT(nscss_len2px(len_ctx, value, unit, style)); } } else { /* Inadmissible */ *max_width = -1; } if (*max_width != -1) { layout_handle_box_sizing(len_ctx, box, available_width, true, max_width); } } if (min_width) { enum css_min_width_e type; css_fixed value = 0; css_unit unit = CSS_UNIT_PX; type = ns_computed_min_width(style, &value, &unit); if (type == CSS_MIN_WIDTH_SET) { if (unit == CSS_UNIT_PCT) { *min_width = FPCT_OF_INT_TOINT(value, available_width); } else { *min_width = FIXTOINT(nscss_len2px(len_ctx, value, unit, style)); } } else { /* Inadmissible */ *min_width = 0; } if (*min_width != 0) { layout_handle_box_sizing(len_ctx, box, available_width, true, min_width); } } if (max_height) { enum css_max_height_e type; css_fixed value = 0; css_unit unit = CSS_UNIT_PX; type = css_computed_max_height(style, &value, &unit); if (type == CSS_MAX_HEIGHT_SET) { if (unit == CSS_UNIT_PCT) { /* TODO: handle percentage */ *max_height = -1; } else { *max_height = FIXTOINT(nscss_len2px(len_ctx, value, unit, style)); } } else { /* Inadmissible */ *max_height = -1; } } if (min_height) { enum css_min_height_e type; css_fixed value = 0; css_unit unit = CSS_UNIT_PX; type = ns_computed_min_height(style, &value, &unit); if (type == CSS_MIN_HEIGHT_SET) { if (unit == CSS_UNIT_PCT) { /* TODO: handle percentage */ *min_height = 0; } else { *min_height = FIXTOINT(nscss_len2px(len_ctx, value, unit, style)); } } else { /* Inadmissible */ *min_height = 0; } } for (i = 0; i != 4; i++) { if (margin) { enum css_margin_e type = CSS_MARGIN_AUTO; css_fixed value = 0; css_unit unit = CSS_UNIT_PX; type = margin_funcs[i](style, &value, &unit); if (type == CSS_MARGIN_SET) { if (unit == CSS_UNIT_PCT) { margin[i] = FPCT_OF_INT_TOINT(value, available_width); } else { margin[i] = FIXTOINT(nscss_len2px( len_ctx, value, unit, style)); } } else { margin[i] = AUTO; } } if (padding) { css_fixed value = 0; css_unit unit = CSS_UNIT_PX; padding_funcs[i](style, &value, &unit); if (unit == CSS_UNIT_PCT) { padding[i] = FPCT_OF_INT_TOINT(value, available_width); } else { padding[i] = FIXTOINT(nscss_len2px(len_ctx, value, unit, style)); } } /* Table cell borders are populated in table.c */ if (border && box->type != BOX_TABLE_CELL) { enum css_border_style_e bstyle = CSS_BORDER_STYLE_NONE; css_color color = 0; css_fixed value = 0; css_unit unit = CSS_UNIT_PX; border_width_funcs[i](style, &value, &unit); bstyle = border_style_funcs[i](style); border_color_funcs[i](style, &color); border[i].style = bstyle; border[i].c = color; if (bstyle == CSS_BORDER_STYLE_HIDDEN || bstyle == CSS_BORDER_STYLE_NONE) /* spec unclear: following Mozilla */ border[i].width = 0; else border[i].width = FIXTOINT(nscss_len2px(len_ctx, value, unit, style)); /* Special case for border-collapse: make all borders * on table/table-row-group/table-row zero width. */ if (css_computed_border_collapse(style) == CSS_BORDER_COLLAPSE_COLLAPSE && (box->type == BOX_TABLE || box->type == BOX_TABLE_ROW_GROUP || box->type == BOX_TABLE_ROW)) border[i].width = 0; } } } /** * Find next block that current margin collapses to. * * \param len_ctx Length conversion context * \param box box to start tree-order search from (top margin is included) * \param block box responsible for current block fromatting context * \param viewport_height height of viewport in px * \param max_pos_margin updated to to maximum positive margin encountered * \param max_neg_margin updated to to maximum negative margin encountered * \return next box that current margin collapses to, or NULL if none. */ static struct box* layout_next_margin_block(const nscss_len_ctx *len_ctx, struct box *box, struct box *block, int viewport_height, int *max_pos_margin, int *max_neg_margin) { assert(block != NULL); while (box != NULL) { if (box->type == BOX_INLINE_CONTAINER || (box->style && (css_computed_position(box->style) != CSS_POSITION_ABSOLUTE && css_computed_position(box->style) != CSS_POSITION_FIXED))) { /* Not positioned */ /* Get margins */ if (box->style) { layout_find_dimensions(len_ctx, box->parent->width, viewport_height, box, box->style, NULL, NULL, NULL, NULL, NULL, NULL, box->margin, box->padding, box->border); /* Apply top margin */ if (*max_pos_margin < box->margin[TOP]) *max_pos_margin = box->margin[TOP]; else if (*max_neg_margin < -box->margin[TOP]) *max_neg_margin = -box->margin[TOP]; } /* Check whether box is the box current margin collapses * to */ if (box->flags & MAKE_HEIGHT || box->border[TOP].width || box->padding[TOP] || (box->style && css_computed_overflow_y(box->style) != CSS_OVERFLOW_VISIBLE) || (box->type == BOX_INLINE_CONTAINER && !box_is_first_child(box))) { /* Collapse to this box; return it */ return box; } } /* Find next box */ if (box->type == BOX_BLOCK && !box->object && box->children && box->style && css_computed_overflow_y(box->style) == CSS_OVERFLOW_VISIBLE) { /* Down into children. */ box = box->children; } else { if (!box->next) { /* No more siblings: * Go up to first ancestor with a sibling. */ do { /* Apply bottom margin */ if (*max_pos_margin < box->margin[BOTTOM]) *max_pos_margin = box->margin[BOTTOM]; else if (*max_neg_margin < -box->margin[BOTTOM]) *max_neg_margin = -box->margin[BOTTOM]; box = box->parent; } while (box != block && !box->next); if (box == block) { /* Margins don't collapse with stuff * outside the block formatting context */ return block; } } /* Apply bottom margin */ if (*max_pos_margin < box->margin[BOTTOM]) *max_pos_margin = box->margin[BOTTOM]; else if (*max_neg_margin < -box->margin[BOTTOM]) *max_neg_margin = -box->margin[BOTTOM]; /* To next sibling. */ box = box->next; /* Get margins */ if (box->style) { layout_find_dimensions(len_ctx, box->parent->width, viewport_height, box, box->style, NULL, NULL, NULL, NULL, NULL, NULL, box->margin, box->padding, box->border); } } } return NULL; } /** * Find y coordinate which clears all floats on left and/or right. * * \param fl first float in float list * \param clear type of clear * \return y coordinate relative to ancestor box for floats */ static int layout_clear(struct box *fl, enum css_clear_e clear) { int y = 0; for (; fl; fl = fl->next_float) { if ((clear == CSS_CLEAR_LEFT || clear == CSS_CLEAR_BOTH) && fl->type == BOX_FLOAT_LEFT) if (y < fl->y + fl->height) y = fl->y + fl->height; if ((clear == CSS_CLEAR_RIGHT || clear == CSS_CLEAR_BOTH) && fl->type == BOX_FLOAT_RIGHT) if (y < fl->y + fl->height) y = fl->y + fl->height; } return y; } /** * Find left and right edges in a vertical range. * * \param fl first float in float list * \param y0 start of y range to search * \param y1 end of y range to search * \param x0 start left edge, updated to available left edge * \param x1 start right edge, updated to available right edge * \param left returns float on left if present * \param right returns float on right if present */ static void find_sides(struct box *fl, int y0, int y1, int *x0, int *x1, struct box **left, struct box **right) { int fy0, fy1, fx0, fx1; NSLOG(layout, DEBUG, "y0 %i, y1 %i, x0 %i, x1 %i", y0, y1, *x0, *x1); *left = *right = 0; for (; fl; fl = fl->next_float) { fy1 = fl->y + fl->height; if (fy1 < y0) { /* Floats are sorted in order of decreasing bottom pos. * Past here, all floats will be too high to concern us. */ return; } fy0 = fl->y; if (y0 < fy1 && fy0 <= y1) { if (fl->type == BOX_FLOAT_LEFT) { fx1 = fl->x + fl->width; if (*x0 < fx1) { *x0 = fx1; *left = fl; } } else { fx0 = fl->x; if (fx0 < *x1) { *x1 = fx0; *right = fl; } } } } NSLOG(layout, DEBUG, "x0 %i, x1 %i, left %p, right %p", *x0, *x1, *left, *right); } /** * Solve the width constraint as given in CSS 2.1 section 10.3.3. * * \param box Box to solve constraint for * \param available_width Max width available in pixels * \param width Current box width * \param lm Min left margin required to avoid floats in px. * zero if not applicable * \param rm Min right margin required to avoid floats in px. * zero if not applicable * \param max_width Box max-width ( -ve means no max-width to apply) * \param min_width Box min-width ( <=0 means no min-width to apply) * \return New box width * * \post \a box's left/right margins will be updated. */ static int layout_solve_width(struct box *box, int available_width, int width, int lm, int rm, int max_width, int min_width) { bool auto_width = false; /* Increase specified left/right margins */ if (box->margin[LEFT] != AUTO && box->margin[LEFT] < lm && box->margin[LEFT] >= 0) box->margin[LEFT] = lm; if (box->margin[RIGHT] != AUTO && box->margin[RIGHT] < rm && box->margin[RIGHT] >= 0) box->margin[RIGHT] = rm; /* Find width */ if (width == AUTO) { int margin_left = box->margin[LEFT]; int margin_right = box->margin[RIGHT]; if (margin_left == AUTO) { margin_left = lm; } if (margin_right == AUTO) { margin_right = rm; } width = available_width - (margin_left + box->border[LEFT].width + box->padding[LEFT] + box->padding[RIGHT] + box->border[RIGHT].width + margin_right); width = width < 0 ? 0 : width; auto_width = true; } if (max_width >= 0 && width > max_width) { /* max-width is admissable and width exceeds max-width */ width = max_width; auto_width = false; } if (min_width > 0 && width < min_width) { /* min-width is admissable and width is less than max-width */ width = min_width; auto_width = false; } /* Width was auto, and unconstrained by min/max width, so we're done */ if (auto_width) { /* any other 'auto' become 0 or the minimum required values */ if (box->margin[LEFT] == AUTO) { box->margin[LEFT] = lm; } if (box->margin[RIGHT] == AUTO) { box->margin[RIGHT] = rm; } return width; } /* Width was not auto, or was constrained by min/max width * Need to compute left/right margins */ /* HTML alignment (only applies to over-constrained boxes) */ if (box->margin[LEFT] != AUTO && box->margin[RIGHT] != AUTO && box->parent != NULL && box->parent->style != NULL) { switch (css_computed_text_align(box->parent->style)) { case CSS_TEXT_ALIGN_LIBCSS_RIGHT: box->margin[LEFT] = AUTO; box->margin[RIGHT] = 0; break; case CSS_TEXT_ALIGN_LIBCSS_CENTER: box->margin[LEFT] = box->margin[RIGHT] = AUTO; break; case CSS_TEXT_ALIGN_LIBCSS_LEFT: box->margin[LEFT] = 0; box->margin[RIGHT] = AUTO; break; default: /* Leave it alone; no HTML alignment */ break; } } if (box->margin[LEFT] == AUTO && box->margin[RIGHT] == AUTO) { /* make the margins equal, centering the element */ box->margin[LEFT] = box->margin[RIGHT] = (available_width - lm - rm - (box->border[LEFT].width + box->padding[LEFT] + width + box->padding[RIGHT] + box->border[RIGHT].width)) / 2; if (box->margin[LEFT] < 0) { box->margin[RIGHT] += box->margin[LEFT]; box->margin[LEFT] = 0; } box->margin[LEFT] += lm; } else if (box->margin[LEFT] == AUTO) { box->margin[LEFT] = available_width - lm - (box->border[LEFT].width + box->padding[LEFT] + width + box->padding[RIGHT] + box->border[RIGHT].width + box->margin[RIGHT]); box->margin[LEFT] = box->margin[LEFT] < lm ? lm : box->margin[LEFT]; } else { /* margin-right auto or "over-constrained" */ box->margin[RIGHT] = available_width - rm - (box->margin[LEFT] + box->border[LEFT].width + box->padding[LEFT] + width + box->padding[RIGHT] + box->border[RIGHT].width); } return width; } /** * Compute dimensions of box, margins, paddings, and borders for a block-level * element. * * \param len_ctx Length conversion context * \param available_width Max width available in pixels * \param viewport_height Height of viewport in pixels or -ve if unknown * \param lm min left margin required to avoid floats in px. * zero if not applicable * \param rm min right margin required to avoid floats in px. * zero if not applicable * \param box box to find dimensions of. updated with new width, * height, margins, borders and paddings * * See CSS 2.1 10.3.3, 10.3.4, 10.6.2, and 10.6.3. */ static void layout_block_find_dimensions(const nscss_len_ctx *len_ctx, int available_width, int viewport_height, int lm, int rm, struct box *box) { int width, max_width, min_width; int height, max_height, min_height; int *margin = box->margin; int *padding = box->padding; struct box_border *border = box->border; const css_computed_style *style = box->style; layout_find_dimensions(len_ctx, available_width, viewport_height, box, style, &width, &height, &max_width, &min_width, &max_height, &min_height, margin, padding, border); if (box->object && !(box->flags & REPLACE_DIM) && content_get_type(box->object) != CONTENT_HTML) { /* block-level replaced element, see 10.3.4 and 10.6.2 */ layout_get_object_dimensions(box, &width, &height, min_width, max_width, min_height, max_height); } box->width = layout_solve_width(box, available_width, width, lm, rm, max_width, min_width); box->height = height; if (margin[TOP] == AUTO) margin[TOP] = 0; if (margin[BOTTOM] == AUTO) margin[BOTTOM] = 0; } /** * Manipulate a block's [RB]padding/height/width to accommodate scrollbars * * \param box Box to apply scrollbar space too. Must be BOX_BLOCK. * \param which Which scrollbar to make space for. Must be RIGHT or BOTTOM. */ static void layout_block_add_scrollbar(struct box *box, int which) { enum css_overflow_e overflow_x, overflow_y; assert(box->type == BOX_BLOCK && (which == RIGHT || which == BOTTOM)); if (box->style == NULL) return; overflow_x = css_computed_overflow_x(box->style); overflow_y = css_computed_overflow_y(box->style); if (which == BOTTOM && (overflow_x == CSS_OVERFLOW_SCROLL || overflow_x == CSS_OVERFLOW_AUTO || (box->object && content_get_type(box->object) == CONTENT_HTML))) { /* make space for scrollbar, unless height is AUTO */ if (box->height != AUTO && (overflow_x == CSS_OVERFLOW_SCROLL || box_hscrollbar_present(box))) { box->padding[BOTTOM] += SCROLLBAR_WIDTH; } } else if (which == RIGHT && (overflow_y == CSS_OVERFLOW_SCROLL || overflow_y == CSS_OVERFLOW_AUTO || (box->object && content_get_type(box->object) == CONTENT_HTML))) { /* make space for scrollbars, unless width is AUTO */ enum css_height_e htype; css_fixed height = 0; css_unit hunit = CSS_UNIT_PX; htype = css_computed_height(box->style, &height, &hunit); if (which == RIGHT && box->width != AUTO && htype == CSS_HEIGHT_SET && (overflow_y == CSS_OVERFLOW_SCROLL || box_vscrollbar_present(box))) { box->width -= SCROLLBAR_WIDTH; box->padding[RIGHT] += SCROLLBAR_WIDTH; } } } /** * Moves the children of a box by a specified amount * * \param box top of tree of boxes * \param x the amount to move children by horizontally * \param y the amount to move children by vertically */ static void layout_move_children(struct box *box, int x, int y) { assert(box); for (box = box->children; box; box = box->next) { box->x += x; box->y += y; } } /** * Layout a table. * * \param table table to layout * \param available_width width of containing block * \param content memory pool for any new boxes * \return true on success, false on memory exhaustion */ static bool layout_table(struct box *table, int available_width, html_content *content) { unsigned int columns = table->columns; /* total columns */ unsigned int i; unsigned int *row_span; int *excess_y; int table_width, min_width = 0, max_width = 0; int required_width = 0; int x, remainder = 0, count = 0; int table_height = 0; int min_height = 0; int *xs; /* array of column x positions */ int auto_width; int spare_width; int relative_sum = 0; int border_spacing_h = 0, border_spacing_v = 0; int spare_height; int positioned_columns = 0; struct box *containing_block = NULL; struct box *c; struct box *row; struct box *row_group; struct box **row_span_cell; struct column *col; const css_computed_style *style = table->style; enum css_width_e wtype; enum css_height_e htype; css_fixed value = 0; css_unit unit = CSS_UNIT_PX; assert(table->type == BOX_TABLE); assert(style); assert(table->children && table->children->children); assert(columns); /* allocate working buffers */ col = malloc(columns * sizeof col[0]); excess_y = malloc(columns * sizeof excess_y[0]); row_span = malloc(columns * sizeof row_span[0]); row_span_cell = malloc(columns * sizeof row_span_cell[0]); xs = malloc((columns + 1) * sizeof xs[0]); if (!col || !xs || !row_span || !excess_y || !row_span_cell) { free(col); free(excess_y); free(row_span); free(row_span_cell); free(xs); return false; } memcpy(col, table->col, sizeof(col[0]) * columns); /* find margins, paddings, and borders for table and cells */ layout_find_dimensions(&content->len_ctx, available_width, -1, table, style, 0, 0, 0, 0, 0, 0, table->margin, table->padding, table->border); for (row_group = table->children; row_group; row_group = row_group->next) { for (row = row_group->children; row; row = row->next) { for (c = row->children; c; c = c->next) { enum css_overflow_e overflow_x; enum css_overflow_e overflow_y; assert(c->style); table_used_border_for_cell( &content->len_ctx, c); layout_find_dimensions(&content->len_ctx, available_width, -1, c, c->style, 0, 0, 0, 0, 0, 0, 0, c->padding, c->border); overflow_x = css_computed_overflow_x(c->style); overflow_y = css_computed_overflow_y(c->style); if (overflow_x == CSS_OVERFLOW_SCROLL || overflow_x == CSS_OVERFLOW_AUTO) { c->padding[BOTTOM] += SCROLLBAR_WIDTH; } if (overflow_y == CSS_OVERFLOW_SCROLL || overflow_y == CSS_OVERFLOW_AUTO) { c->padding[RIGHT] += SCROLLBAR_WIDTH; } } } } /* border-spacing is used in the separated borders model */ if (css_computed_border_collapse(style) == CSS_BORDER_COLLAPSE_SEPARATE) { css_fixed h = 0, v = 0; css_unit hu = CSS_UNIT_PX, vu = CSS_UNIT_PX; css_computed_border_spacing(style, &h, &hu, &v, &vu); border_spacing_h = FIXTOINT(nscss_len2px(&content->len_ctx, h, hu, style)); border_spacing_v = FIXTOINT(nscss_len2px(&content->len_ctx, v, vu, style)); } /* find specified table width, or available width if auto-width */ wtype = css_computed_width(style, &value, &unit); if (wtype == CSS_WIDTH_SET) { if (unit == CSS_UNIT_PCT) { table_width = FPCT_OF_INT_TOINT(value, available_width); } else { table_width = FIXTOINT(nscss_len2px(&content->len_ctx, value, unit, style)); } /* specified width includes border */ table_width -= table->border[LEFT].width + table->border[RIGHT].width; table_width = table_width < 0 ? 0 : table_width; auto_width = table_width; } else { table_width = AUTO; auto_width = available_width - ((table->margin[LEFT] == AUTO ? 0 : table->margin[LEFT]) + table->border[LEFT].width + table->padding[LEFT] + table->padding[RIGHT] + table->border[RIGHT].width + (table->margin[RIGHT] == AUTO ? 0 : table->margin[RIGHT])); } /* Find any table height specified within CSS/HTML */ htype = css_computed_height(style, &value, &unit); if (htype == CSS_HEIGHT_SET) { if (unit == CSS_UNIT_PCT) { /* This is the minimum height for the table * (see 17.5.3) */ if (css_computed_position(table->style) == CSS_POSITION_ABSOLUTE) { /* Table is absolutely positioned */ assert(table->float_container); containing_block = table->float_container; } else if (table->float_container && css_computed_position(table->style) != CSS_POSITION_ABSOLUTE && (css_computed_float(table->style) == CSS_FLOAT_LEFT || css_computed_float(table->style) == CSS_FLOAT_RIGHT)) { /* Table is a float */ assert(table->parent && table->parent->parent && table->parent->parent->parent); containing_block = table->parent->parent->parent; } else if (table->parent && table->parent->type != BOX_INLINE_CONTAINER) { /* Table is a block level element */ containing_block = table->parent; } else if (table->parent && table->parent->type == BOX_INLINE_CONTAINER) { /* Table is an inline block */ assert(table->parent->parent); containing_block = table->parent->parent; } if (containing_block) { css_fixed ignored = 0; htype = css_computed_height( containing_block->style, &ignored, &unit); } if (containing_block && containing_block->height != AUTO && (css_computed_position(table->style) == CSS_POSITION_ABSOLUTE || htype == CSS_HEIGHT_SET)) { /* Table is absolutely positioned or its * containing block has a valid specified * height. (CSS 2.1 Section 10.5) */ min_height = FPCT_OF_INT_TOINT(value, containing_block->height); } } else { /* This is the minimum height for the table * (see 17.5.3) */ min_height = FIXTOINT(nscss_len2px(&content->len_ctx, value, unit, style)); } } /* calculate width required by cells */ for (i = 0; i != columns; i++) { NSLOG(layout, DEBUG, "table %p, column %u: type %s, width %i, min %i, max %i", table, i, ((const char *[]){ "UNKNOWN", "FIXED", "AUTO", "PERCENT", "RELATIVE", })[col[i].type], col[i].width, col[i].min, col[i].max); if (col[i].positioned) { positioned_columns++; continue; } else if (col[i].type == COLUMN_WIDTH_FIXED) { if (col[i].width < col[i].min) col[i].width = col[i].max = col[i].min; else col[i].min = col[i].max = col[i].width; required_width += col[i].width; } else if (col[i].type == COLUMN_WIDTH_PERCENT) { int width = col[i].width * auto_width / 100; required_width += col[i].min < width ? width : col[i].min; } else required_width += col[i].min; NSLOG(layout, DEBUG, "required_width %i", required_width); } required_width += (columns + 1 - positioned_columns) * border_spacing_h; NSLOG(layout, DEBUG, "width %i, min %i, max %i, auto %i, required %i", table_width, table->min_width, table->max_width, auto_width, required_width); if (auto_width < required_width) { /* table narrower than required width for columns: * treat percentage widths as maximums */ for (i = 0; i != columns; i++) { if (col[i].type == COLUMN_WIDTH_RELATIVE) continue; if (col[i].type == COLUMN_WIDTH_PERCENT) { col[i].max = auto_width * col[i].width / 100; if (col[i].max < col[i].min) col[i].max = col[i].min; } min_width += col[i].min; max_width += col[i].max; } } else { /* take percentages exactly */ for (i = 0; i != columns; i++) { if (col[i].type == COLUMN_WIDTH_RELATIVE) continue; if (col[i].type == COLUMN_WIDTH_PERCENT) { int width = auto_width * col[i].width / 100; if (width < col[i].min) width = col[i].min; col[i].min = col[i].width = col[i].max = width; col[i].type = COLUMN_WIDTH_FIXED; } min_width += col[i].min; max_width += col[i].max; } } /* allocate relative widths */ spare_width = auto_width; for (i = 0; i != columns; i++) { if (col[i].type == COLUMN_WIDTH_RELATIVE) relative_sum += col[i].width; else if (col[i].type == COLUMN_WIDTH_FIXED) spare_width -= col[i].width; else spare_width -= col[i].min; } spare_width -= (columns + 1) * border_spacing_h; if (relative_sum != 0) { if (spare_width < 0) spare_width = 0; for (i = 0; i != columns; i++) { if (col[i].type == COLUMN_WIDTH_RELATIVE) { col[i].min = ceil(col[i].max = (float) spare_width * (float) col[i].width / relative_sum); min_width += col[i].min; max_width += col[i].max; } } } min_width += (columns + 1) * border_spacing_h; max_width += (columns + 1) * border_spacing_h; if (auto_width <= min_width) { /* not enough space: minimise column widths */ for (i = 0; i < columns; i++) { col[i].width = col[i].min; } table_width = min_width; } else if (max_width <= auto_width) { /* more space than maximum width */ if (table_width == AUTO) { /* for auto-width tables, make columns max width */ for (i = 0; i < columns; i++) { col[i].width = col[i].max; } table_width = max_width; } else { /* for fixed-width tables, distribute the extra space * too */ unsigned int flexible_columns = 0; for (i = 0; i != columns; i++) if (col[i].type != COLUMN_WIDTH_FIXED) flexible_columns++; if (flexible_columns == 0) { int extra = (table_width - max_width) / columns; remainder = (table_width - max_width) - (extra * columns); for (i = 0; i != columns; i++) { col[i].width = col[i].max + extra; count -= remainder; if (count < 0) { col[i].width++; count += columns; } } } else { int extra = (table_width - max_width) / flexible_columns; remainder = (table_width - max_width) - (extra * flexible_columns); for (i = 0; i != columns; i++) if (col[i].type != COLUMN_WIDTH_FIXED) { col[i].width = col[i].max + extra; count -= remainder; if (count < 0) { col[i].width++; count += flexible_columns; } } } } } else { /* space between min and max: fill it exactly */ float scale = (float) (auto_width - min_width) / (float) (max_width - min_width); /* fprintf(stderr, "filling, scale %f\n", scale); */ for (i = 0; i < columns; i++) { col[i].width = col[i].min + (int) (0.5 + (col[i].max - col[i].min) * scale); } table_width = auto_width; } xs[0] = x = border_spacing_h; for (i = 0; i != columns; i++) { if (!col[i].positioned) x += col[i].width + border_spacing_h; xs[i + 1] = x; row_span[i] = 0; excess_y[i] = 0; row_span_cell[i] = 0; } /* position cells */ table_height = border_spacing_v; for (row_group = table->children; row_group; row_group = row_group->next) { int row_group_height = 0; for (row = row_group->children; row; row = row->next) { int row_height = 0; htype = css_computed_height(row->style, &value, &unit); if (htype == CSS_HEIGHT_SET && unit != CSS_UNIT_PCT) { row_height = FIXTOINT(nscss_len2px( &content->len_ctx, value, unit, row->style)); } for (c = row->children; c; c = c->next) { assert(c->style); c->width = xs[c->start_column + c->columns] - xs[c->start_column] - border_spacing_h - c->border[LEFT].width - c->padding[LEFT] - c->padding[RIGHT] - c->border[RIGHT].width; c->float_children = 0; c->cached_place_below_level = 0; c->height = AUTO; if (!layout_block_context(c, -1, content)) { free(col); free(excess_y); free(row_span); free(row_span_cell); free(xs); return false; } /* warning: c->descendant_y0 and * c->descendant_y1 used as temporary storage * until after vertical alignment is complete */ c->descendant_y0 = c->height; c->descendant_y1 = c->padding[BOTTOM]; htype = css_computed_height(c->style, &value, &unit); if (htype == CSS_HEIGHT_SET && unit != CSS_UNIT_PCT) { /* some sites use height="1" or similar * to attempt to make cells as small as * possible, so treat it as a minimum */ int h = FIXTOINT(nscss_len2px( &content->len_ctx, value, unit, c->style)); if (c->height < h) c->height = h; } /* specified row height is treated as a minimum */ if (c->height < row_height) c->height = row_height; c->x = xs[c->start_column] + c->border[LEFT].width; c->y = c->border[TOP].width; for (i = 0; i != c->columns; i++) { row_span[c->start_column + i] = c->rows; excess_y[c->start_column + i] = c->border[TOP].width + c->padding[TOP] + c->height + c->padding[BOTTOM] + c->border[BOTTOM].width; row_span_cell[c->start_column + i] = 0; } row_span_cell[c->start_column] = c; c->padding[BOTTOM] = -border_spacing_v - c->border[TOP].width - c->padding[TOP] - c->height - c->border[BOTTOM].width; } for (i = 0; i != columns; i++) if (row_span[i] != 0) row_span[i]--; else row_span_cell[i] = 0; if (row->next || row_group->next) { /* row height is greatest excess of a cell * which ends in this row */ for (i = 0; i != columns; i++) if (row_span[i] == 0 && row_height < excess_y[i]) row_height = excess_y[i]; } else { /* except in the last row */ for (i = 0; i != columns; i++) if (row_height < excess_y[i]) row_height = excess_y[i]; } for (i = 0; i != columns; i++) { if (row_height < excess_y[i]) excess_y[i] -= row_height; else excess_y[i] = 0; if (row_span_cell[i] != 0) row_span_cell[i]->padding[BOTTOM] += row_height + border_spacing_v; } row->x = 0; row->y = row_group_height; row->width = table_width; row->height = row_height; row_group_height += row_height + border_spacing_v; } row_group->x = 0; row_group->y = table_height; row_group->width = table_width; row_group->height = row_group_height; table_height += row_group_height; } /* Table height is either the height of the contents, or specified * height if greater */ table_height = max(table_height, min_height); /** \todo distribute spare height over the row groups / rows / cells */ /* perform vertical alignment */ for (row_group = table->children; row_group; row_group = row_group->next) { for (row = row_group->children; row; row = row->next) { for (c = row->children; c; c = c->next) { enum css_vertical_align_e vertical_align; /* unextended bottom padding is in * c->descendant_y1, and unextended * cell height is in c->descendant_y0 */ spare_height = (c->padding[BOTTOM] - c->descendant_y1) + (c->height - c->descendant_y0); vertical_align = css_computed_vertical_align( c->style, &value, &unit); switch (vertical_align) { case CSS_VERTICAL_ALIGN_SUB: case CSS_VERTICAL_ALIGN_SUPER: case CSS_VERTICAL_ALIGN_TEXT_TOP: case CSS_VERTICAL_ALIGN_TEXT_BOTTOM: case CSS_VERTICAL_ALIGN_SET: case CSS_VERTICAL_ALIGN_BASELINE: /* todo: baseline alignment, for now * just use ALIGN_TOP */ case CSS_VERTICAL_ALIGN_TOP: break; case CSS_VERTICAL_ALIGN_MIDDLE: c->padding[TOP] += spare_height / 2; c->padding[BOTTOM] -= spare_height / 2; layout_move_children(c, 0, spare_height / 2); break; case CSS_VERTICAL_ALIGN_BOTTOM: c->padding[TOP] += spare_height; c->padding[BOTTOM] -= spare_height; layout_move_children(c, 0, spare_height); break; case CSS_VERTICAL_ALIGN_INHERIT: assert(0); break; } } } } /* Top and bottom margins of 'auto' are set to 0. CSS2.1 10.6.3 */ if (table->margin[TOP] == AUTO) table->margin[TOP] = 0; if (table->margin[BOTTOM] == AUTO) table->margin[BOTTOM] = 0; free(col); free(excess_y); free(row_span); free(row_span_cell); free(xs); table->width = table_width; table->height = table_height; return true; } /** * Manimpulate box height according to CSS min-height and max-height properties * * \param len_ctx CSS length conversion context for document. * \param box block to modify with any min-height or max-height * \param container containing block for absolutely positioned elements, or * NULL for non absolutely positioned elements. * \return whether the height has been changed */ static bool layout_apply_minmax_height( const nscss_len_ctx *len_ctx, struct box *box, struct box *container) { int h; struct box *containing_block = NULL; bool updated = false; /* Find containing block for percentage heights */ if (box->style != NULL && css_computed_position(box->style) == CSS_POSITION_ABSOLUTE) { /* Box is absolutely positioned */ assert(container); containing_block = container; } else if (box->float_container && box->style != NULL && (css_computed_float(box->style) == CSS_FLOAT_LEFT || css_computed_float(box->style) == CSS_FLOAT_RIGHT)) { /* Box is a float */ assert(box->parent && box->parent->parent && box->parent->parent->parent); containing_block = box->parent->parent->parent; } else if (box->parent && box->parent->type != BOX_INLINE_CONTAINER) { /* Box is a block level element */ containing_block = box->parent; } else if (box->parent && box->parent->type == BOX_INLINE_CONTAINER) { /* Box is an inline block */ assert(box->parent->parent); containing_block = box->parent->parent; } if (box->style) { enum css_height_e htype = CSS_HEIGHT_AUTO; css_fixed value = 0; css_unit unit = CSS_UNIT_PX; if (containing_block) { htype = css_computed_height(containing_block->style, &value, &unit); } /* max-height */ if (css_computed_max_height(box->style, &value, &unit) == CSS_MAX_HEIGHT_SET) { if (unit == CSS_UNIT_PCT) { if (containing_block && containing_block->height != AUTO && (css_computed_position(box->style) == CSS_POSITION_ABSOLUTE || htype == CSS_HEIGHT_SET)) { /* Box is absolutely positioned or its * containing block has a valid * specified height. (CSS 2.1 * Section 10.5) */ h = FPCT_OF_INT_TOINT(value, containing_block->height); if (h < box->height) { box->height = h; updated = true; } } } else { h = FIXTOINT(nscss_len2px(len_ctx, value, unit, box->style)); if (h < box->height) { box->height = h; updated = true; } } } /* min-height */ if (ns_computed_min_height(box->style, &value, &unit) == CSS_MIN_HEIGHT_SET) { if (unit == CSS_UNIT_PCT) { if (containing_block && containing_block->height != AUTO && (css_computed_position(box->style) == CSS_POSITION_ABSOLUTE || htype == CSS_HEIGHT_SET)) { /* Box is absolutely positioned or its * containing block has a valid * specified height. (CSS 2.1 * Section 10.5) */ h = FPCT_OF_INT_TOINT(value, containing_block->height); if (h > box->height) { box->height = h; updated = true; } } } else { h = FIXTOINT(nscss_len2px(len_ctx, value, unit, box->style)); if (h > box->height) { box->height = h; updated = true; } } } } return updated; } /** * Layout a block which contains an object. * * \param block box of type BLOCK, INLINE_BLOCK, TABLE, or TABLE_CELL * \return true on success, false on memory exhaustion */ static bool layout_block_object(struct box *block) { assert(block); assert(block->type == BOX_BLOCK || block->type == BOX_INLINE_BLOCK || block->type == BOX_TABLE || block->type == BOX_TABLE_CELL); assert(block->object); NSLOG(layout, DEBUG, "block %p, object %p, width %i", block, hlcache_handle_get_url(block->object), block->width); if (content_get_type(block->object) == CONTENT_HTML) { content_reformat(block->object, false, block->width, 1); } else { /* Non-HTML objects */ /* this case handled already in * layout_block_find_dimensions() */ } return true; } /** * Insert a float into a container. * * \param cont block formatting context block, used to contain float * \param b box to add to float * * This sorts floats in order of descending bottom edges. */ static void add_float_to_container(struct box *cont, struct box *b) { struct box *box = cont->float_children; int b_bottom = b->y + b->height; assert(b->type == BOX_FLOAT_LEFT || b->type == BOX_FLOAT_RIGHT); if (box == NULL) { /* No other float children */ b->next_float = NULL; cont->float_children = b; return; } else if (b_bottom >= box->y + box->height) { /* Goes at start of list */ b->next_float = cont->float_children; cont->float_children = b; } else { struct box *prev = NULL; while (box != NULL && b_bottom < box->y + box->height) { prev = box; box = box->next_float; } if (prev != NULL) { b->next_float = prev->next_float; prev->next_float = b; } } } /** * Split a text box. * * \param content memory pool for any new boxes * \param fstyle style for text in text box * \param split_box box with text to split * \param new_length new length for text in split_box, after splitting * \param new_width new width for text in split_box, after splitting * \return true on success, false on memory exhaustion * * A new box is created and inserted into the box tree after split_box, * containing the text after new_length excluding the initial space character. */ static bool layout_text_box_split(html_content *content, plot_font_style_t *fstyle, struct box *split_box, size_t new_length, int new_width) { int space_width = split_box->space; struct box *c2; const struct gui_layout_table *font_func = content->font_func; bool space = (split_box->text[new_length] == ' '); int used_length = new_length + (space ? 1 : 0); if ((space && space_width == 0) || space_width == UNKNOWN_WIDTH) { /* We're need to add a space, and we don't know how big * it's to be, OR we have a space of unknown width anyway; * Calculate space width */ font_func->width(fstyle, " ", 1, &space_width); } if (split_box->space == UNKNOWN_WIDTH) split_box->space = space_width; if (!space) space_width = 0; /* Create clone of split_box, c2 */ c2 = talloc_memdup(content->bctx, split_box, sizeof *c2); if (!c2) return false; c2->flags |= CLONE; /* Set remaining text in c2 */ c2->text += used_length; /* Set c2 according to the remaining text */ c2->width -= new_width + space_width; c2->flags &= ~MEASURED; /* width has been estimated */ c2->length = split_box->length - used_length; /* Update split_box for its reduced text */ split_box->width = new_width; split_box->flags |= MEASURED; split_box->length = new_length; split_box->space = space_width; /* Insert c2 into box list */ c2->next = split_box->next; split_box->next = c2; c2->prev = split_box; if (c2->next) c2->next->prev = c2; else c2->parent->last = c2; NSLOG(layout, DEBUG, "split_box %p len: %" PRIsizet " \"%.*s\"", split_box, split_box->length, (int)split_box->length, split_box->text); NSLOG(layout, DEBUG, " new_box %p len: %" PRIsizet " \"%.*s\"", c2, c2->length, (int)c2->length, c2->text); return true; } /** * Compute dimensions of box, margins, paddings, and borders for a floating * element using shrink-to-fit. Also used for inline-blocks. * * \param len_ctx CSS length conversion context for document. * \param available_width Max width available in pixels * \param style Box's style * \param box Box for which to find dimensions * Box margins, borders, paddings, width and * height are updated. */ static void layout_float_find_dimensions( const nscss_len_ctx *len_ctx, int available_width, const css_computed_style *style, struct box *box) { int width, height, max_width, min_width, max_height, min_height; int *margin = box->margin; int *padding = box->padding; struct box_border *border = box->border; enum css_overflow_e overflow_x = css_computed_overflow_x(style); enum css_overflow_e overflow_y = css_computed_overflow_y(style); int scrollbar_width_x = (overflow_x == CSS_OVERFLOW_SCROLL || overflow_x == CSS_OVERFLOW_AUTO) ? SCROLLBAR_WIDTH : 0; int scrollbar_width_y = (overflow_y == CSS_OVERFLOW_SCROLL || overflow_y == CSS_OVERFLOW_AUTO) ? SCROLLBAR_WIDTH : 0; layout_find_dimensions(len_ctx, available_width, -1, box, style, &width, &height, &max_width, &min_width, &max_height, &min_height, margin, padding, border); if (margin[LEFT] == AUTO) margin[LEFT] = 0; if (margin[RIGHT] == AUTO) margin[RIGHT] = 0; if (box->gadget == NULL) { padding[RIGHT] += scrollbar_width_y; padding[BOTTOM] += scrollbar_width_x; } if (box->object && !(box->flags & REPLACE_DIM) && content_get_type(box->object) != CONTENT_HTML) { /* Floating replaced element, with intrinsic width or height. * See 10.3.6 and 10.6.2 */ layout_get_object_dimensions(box, &width, &height, min_width, max_width, min_height, max_height); } else if (box->gadget && (box->gadget->type == GADGET_TEXTBOX || box->gadget->type == GADGET_PASSWORD || box->gadget->type == GADGET_FILE || box->gadget->type == GADGET_TEXTAREA)) { css_fixed size = 0; css_unit unit = CSS_UNIT_EM; /* Give sensible dimensions to gadgets, with auto width/height, * that don't shrink to fit contained text. */ assert(box->style); if (box->gadget->type == GADGET_TEXTBOX || box->gadget->type == GADGET_PASSWORD || box->gadget->type == GADGET_FILE) { if (width == AUTO) { size = INTTOFIX(10); width = FIXTOINT(nscss_len2px(len_ctx, size, unit, box->style)); } if (box->gadget->type == GADGET_FILE && height == AUTO) { size = FLTTOFIX(1.5); height = FIXTOINT(nscss_len2px(len_ctx, size, unit, box->style)); } } if (box->gadget->type == GADGET_TEXTAREA) { if (width == AUTO) { size = INTTOFIX(10); width = FIXTOINT(nscss_len2px(len_ctx, size, unit, box->style)); } if (height == AUTO) { size = INTTOFIX(4); height = FIXTOINT(nscss_len2px(len_ctx, size, unit, box->style)); } } } else if (width == AUTO) { /* CSS 2.1 section 10.3.5 */ width = min(max(box->min_width, available_width), box->max_width); /* width includes margin, borders and padding */ if (width == available_width) { width -= box->margin[LEFT] + box->border[LEFT].width + box->padding[LEFT] + box->padding[RIGHT] + box->border[RIGHT].width + box->margin[RIGHT]; } else { /* width was obtained from a min_width or max_width * value, so need to use the same method for calculating * mbp as was used in layout_minmax_block() */ int fixed = 0; float frac = 0; calculate_mbp_width(len_ctx, box->style, LEFT, true, true, true, &fixed, &frac); calculate_mbp_width(len_ctx, box->style, RIGHT, true, true, true, &fixed, &frac); if (fixed < 0) fixed = 0; width -= fixed; } if (max_width >= 0 && width > max_width) width = max_width; if (min_width > 0 && width < min_width) width = min_width; } else { if (max_width >= 0 && width > max_width) width = max_width; if (min_width > 0 && width < min_width) width = min_width; width -= scrollbar_width_y; } box->width = width; box->height = height; if (margin[TOP] == AUTO) margin[TOP] = 0; if (margin[BOTTOM] == AUTO) margin[BOTTOM] = 0; } /** * Layout the contents of a float or inline block. * * \param b float or inline block box * \param width available width * \param content memory pool for any new boxes * \return true on success, false on memory exhaustion */ static bool layout_float(struct box *b, int width, html_content *content) { assert(b->type == BOX_TABLE || b->type == BOX_BLOCK || b->type == BOX_INLINE_BLOCK); layout_float_find_dimensions(&content->len_ctx, width, b->style, b); if (b->type == BOX_TABLE) { if (!layout_table(b, width, content)) return false; if (b->margin[LEFT] == AUTO) b->margin[LEFT] = 0; if (b->margin[RIGHT] == AUTO) b->margin[RIGHT] = 0; if (b->margin[TOP] == AUTO) b->margin[TOP] = 0; if (b->margin[BOTTOM] == AUTO) b->margin[BOTTOM] = 0; } else return layout_block_context(b, -1, content); return true; } /** * Position a float in the first available space. * * \param c float box to position * \param width available width * \param cx x coordinate relative to cont to place float right of * \param y y coordinate relative to cont to place float below * \param cont ancestor box which defines horizontal space, for floats */ static void place_float_below(struct box *c, int width, int cx, int y, struct box *cont) { int x0, x1, yy; struct box *left; struct box *right; yy = y > cont->cached_place_below_level ? y : cont->cached_place_below_level; NSLOG(layout, DEBUG, "c %p, width %i, cx %i, y %i, cont %p", c, width, cx, y, cont); do { y = yy; x0 = cx; x1 = cx + width; find_sides(cont->float_children, y, y + c->height, &x0, &x1, &left, &right); if (left != 0 && right != 0) { yy = (left->y + left->height < right->y + right->height ? left->y + left->height : right->y + right->height); } else if (left == 0 && right != 0) { yy = right->y + right->height; } else if (left != 0 && right == 0) { yy = left->y + left->height; } } while ((left != 0 || right != 0) && (c->width > x1 - x0)); if (c->type == BOX_FLOAT_LEFT) { c->x = x0; } else { c->x = x1 - c->width; } c->y = y; cont->cached_place_below_level = y; } /** * Calculate line height from a style. */ static int line_height( const nscss_len_ctx *len_ctx, const css_computed_style *style) { enum css_line_height_e lhtype; css_fixed lhvalue = 0; css_unit lhunit = CSS_UNIT_PX; css_fixed line_height; assert(style); lhtype = css_computed_line_height(style, &lhvalue, &lhunit); if (lhtype == CSS_LINE_HEIGHT_NORMAL) { /* Normal => use a constant of 1.3 * font-size */ lhvalue = FLTTOFIX(1.3); lhtype = CSS_LINE_HEIGHT_NUMBER; } if (lhtype == CSS_LINE_HEIGHT_NUMBER || lhunit == CSS_UNIT_PCT) { line_height = nscss_len2px(len_ctx, lhvalue, CSS_UNIT_EM, style); if (lhtype != CSS_LINE_HEIGHT_NUMBER) line_height = FDIV(line_height, F_100); } else { assert(lhunit != CSS_UNIT_PCT); line_height = nscss_len2px(len_ctx, lhvalue, lhunit, style); } return FIXTOINT(line_height); } /** * Position a line of boxes in inline formatting context. * * \param first box at start of line * \param width available width on input, updated with actual width on output * (may be incorrect if the line gets split?) * \param y coordinate of top of line, updated on exit to bottom * \param cx coordinate of left of line relative to cont * \param cy coordinate of top of line relative to cont * \param cont ancestor box which defines horizontal space, for floats * \param indent apply any first-line indent * \param has_text_children at least one TEXT in the inline_container * \param next_box updated to first box for next line, or 0 at end * \param content memory pool for any new boxes * \return true on success, false on memory exhaustion */ static bool layout_line(struct box *first, int *width, int *y, int cx, int cy, struct box *cont, bool indent, bool has_text_children, html_content *content, struct box **next_box) { int height, used_height; int x0 = 0; int x1 = *width; int x, h, x_previous; int fy = cy; struct box *left; struct box *right; struct box *b; struct box *split_box = 0; struct box *d; struct box *br_box = 0; bool move_y = false; bool place_below = false; int space_before = 0, space_after = 0; unsigned int inline_count = 0; unsigned int i; const struct gui_layout_table *font_func = content->font_func; plot_font_style_t fstyle; NSLOG(layout, DEBUG, "first %p, first->text '%.*s', width %i, y %i, cx %i, cy %i", first, (int)first->length, first->text, *width, *y, cx, cy); /* find sides at top of line */ x0 += cx; x1 += cx; find_sides(cont->float_children, cy, cy, &x0, &x1, &left, &right); x0 -= cx; x1 -= cx; if (indent) x0 += layout_text_indent(&content->len_ctx, first->parent->parent->style, *width); if (x1 < x0) x1 = x0; /* get minimum line height from containing block. * this is the line-height if there are text children and also in the * case of an initially empty text input */ if (has_text_children || first->parent->parent->gadget) used_height = height = line_height(&content->len_ctx, first->parent->parent->style); else /* inline containers with no text are usually for layout and * look better with no minimum line-height */ used_height = height = 0; /* pass 1: find height of line assuming sides at top of line: loop * body executed at least once * keep in sync with the loop in layout_minmax_line() */ NSLOG(layout, DEBUG, "x0 %i, x1 %i, x1 - x0 %i", x0, x1, x1 - x0); for (x = 0, b = first; x <= x1 - x0 && b != 0; b = b->next) { int min_width, max_width, min_height, max_height; assert(b->type == BOX_INLINE || b->type == BOX_INLINE_BLOCK || b->type == BOX_FLOAT_LEFT || b->type == BOX_FLOAT_RIGHT || b->type == BOX_BR || b->type == BOX_TEXT || b->type == BOX_INLINE_END); NSLOG(layout, DEBUG, "pass 1: b %p, x %i", b, x); if (b->type == BOX_BR) break; if (b->type == BOX_FLOAT_LEFT || b->type == BOX_FLOAT_RIGHT) continue; if (b->type == BOX_INLINE_BLOCK && (css_computed_position(b->style) == CSS_POSITION_ABSOLUTE || css_computed_position(b->style) == CSS_POSITION_FIXED)) continue; assert(b->style != NULL); font_plot_style_from_css(&content->len_ctx, b->style, &fstyle); x += space_after; if (b->type == BOX_INLINE_BLOCK) { if (b->max_width != UNKNOWN_WIDTH) if (!layout_float(b, *width, content)) return false; h = b->border[TOP].width + b->padding[TOP] + b->height + b->padding[BOTTOM] + b->border[BOTTOM].width; if (height < h) height = h; x += b->margin[LEFT] + b->border[LEFT].width + b->padding[LEFT] + b->width + b->padding[RIGHT] + b->border[RIGHT].width + b->margin[RIGHT]; space_after = 0; continue; } if (b->type == BOX_INLINE) { /* calculate borders, margins, and padding */ layout_find_dimensions(&content->len_ctx, *width, -1, b, b->style, 0, 0, 0, 0, 0, 0, b->margin, b->padding, b->border); for (i = 0; i != 4; i++) if (b->margin[i] == AUTO) b->margin[i] = 0; x += b->margin[LEFT] + b->border[LEFT].width + b->padding[LEFT]; if (b->inline_end) { b->inline_end->margin[RIGHT] = b->margin[RIGHT]; b->inline_end->padding[RIGHT] = b->padding[RIGHT]; b->inline_end->border[RIGHT] = b->border[RIGHT]; } else { x += b->padding[RIGHT] + b->border[RIGHT].width + b->margin[RIGHT]; } } else if (b->type == BOX_INLINE_END) { b->width = 0; if (b->space == UNKNOWN_WIDTH) { font_func->width(&fstyle, " ", 1, &b->space); /** \todo handle errors */ } space_after = b->space; x += b->padding[RIGHT] + b->border[RIGHT].width + b->margin[RIGHT]; continue; } if (!b->object && !(b->flags & IFRAME) && !b->gadget && !(b->flags & REPLACE_DIM)) { /* inline non-replaced, 10.3.1 and 10.6.1 */ b->height = line_height(&content->len_ctx, b->style ? b->style : b->parent->parent->style); if (height < b->height) height = b->height; if (!b->text) { b->width = 0; space_after = 0; continue; } if (b->width == UNKNOWN_WIDTH) { /** \todo handle errors */ /* If it's a select element, we must use the * width of the widest option text */ if (b->parent->parent->gadget && b->parent->parent->gadget->type == GADGET_SELECT) { int opt_maxwidth = 0; struct form_option *o; for (o = b->parent->parent->gadget-> data.select.items; o; o = o->next) { int opt_width; font_func->width(&fstyle, o->text, strlen(o->text), &opt_width); if (opt_maxwidth < opt_width) opt_maxwidth =opt_width; } b->width = opt_maxwidth; if (nsoption_bool(core_select_menu)) b->width += SCROLLBAR_WIDTH; } else { font_func->width(&fstyle, b->text, b->length, &b->width); b->flags |= MEASURED; } } /* If the current text has not been measured (i.e. its * width was estimated after splitting), and it fits on * the line, measure it properly, so next box is placed * correctly. */ if (b->text && (x + b->width < x1 - x0) && !(b->flags & MEASURED) && b->next) { font_func->width(&fstyle, b->text, b->length, &b->width); b->flags |= MEASURED; } x += b->width; if (b->space == UNKNOWN_WIDTH) { font_func->width(&fstyle, " ", 1, &b->space); /** \todo handle errors */ } space_after = b->space; continue; } space_after = 0; /* inline replaced, 10.3.2 and 10.6.2 */ assert(b->style); layout_find_dimensions(&content->len_ctx, *width, -1, b, b->style, &b->width, &b->height, &max_width, &min_width, &max_height, &min_height, NULL, NULL, NULL); if (b->object && !(b->flags & REPLACE_DIM)) { layout_get_object_dimensions(b, &b->width, &b->height, min_width, max_width, min_height, max_height); } else if (b->flags & IFRAME) { /* TODO: should we look at the content dimensions? */ if (b->width == AUTO) b->width = 400; if (b->height == AUTO) b->height = 300; /* We reformat the iframe browser window to new * dimensions in pass 2 */ } else { /* form control with no object */ if (b->width == AUTO) b->width = FIXTOINT(nscss_len2px( &content->len_ctx, INTTOFIX(1), CSS_UNIT_EM, b->style)); if (b->height == AUTO) b->height = FIXTOINT(nscss_len2px( &content->len_ctx, INTTOFIX(1), CSS_UNIT_EM, b->style)); } /* Reformat object to new box size */ if (b->object && content_get_type(b->object) == CONTENT_HTML && b->width != content_get_available_width(b->object)) { css_fixed value = 0; css_unit unit = CSS_UNIT_PX; enum css_height_e htype = css_computed_height(b->style, &value, &unit); content_reformat(b->object, false, b->width, b->height); if (htype == CSS_HEIGHT_AUTO) b->height = content_get_height(b->object); } if (height < b->height) height = b->height; x += b->width; } /* find new sides using this height */ x0 = cx; x1 = cx + *width; find_sides(cont->float_children, cy, cy + height, &x0, &x1, &left, &right); x0 -= cx; x1 -= cx; if (indent) x0 += layout_text_indent(&content->len_ctx, first->parent->parent->style, *width); if (x1 < x0) x1 = x0; space_after = space_before = 0; /* pass 2: place boxes in line: loop body executed at least once */ NSLOG(layout, DEBUG, "x0 %i, x1 %i, x1 - x0 %i", x0, x1, x1 - x0); for (x = x_previous = 0, b = first; x <= x1 - x0 && b; b = b->next) { NSLOG(layout, DEBUG, "pass 2: b %p, x %i", b, x); if (b->type == BOX_INLINE_BLOCK && (css_computed_position(b->style) == CSS_POSITION_ABSOLUTE || css_computed_position(b->style) == CSS_POSITION_FIXED)) { b->x = x + space_after; } else if (b->type == BOX_INLINE || b->type == BOX_INLINE_BLOCK || b->type == BOX_TEXT || b->type == BOX_INLINE_END) { assert(b->width != UNKNOWN_WIDTH); x_previous = x; x += space_after; b->x = x; if ((b->type == BOX_INLINE && !b->inline_end) || b->type == BOX_INLINE_BLOCK) { b->x += b->margin[LEFT] + b->border[LEFT].width; x = b->x + b->padding[LEFT] + b->width + b->padding[RIGHT] + b->border[RIGHT].width + b->margin[RIGHT]; } else if (b->type == BOX_INLINE) { b->x += b->margin[LEFT] + b->border[LEFT].width; x = b->x + b->padding[LEFT] + b->width; } else if (b->type == BOX_INLINE_END) { b->height = b->inline_end->height; x += b->padding[RIGHT] + b->border[RIGHT].width + b->margin[RIGHT]; } else { x += b->width; } space_before = space_after; if (b->object || b->flags & REPLACE_DIM || b->flags & IFRAME) space_after = 0; else if (b->text || b->type == BOX_INLINE_END) { if (b->space == UNKNOWN_WIDTH) { font_plot_style_from_css( &content->len_ctx, b->style, &fstyle); /** \todo handle errors */ font_func->width(&fstyle, " ", 1, &b->space); } space_after = b->space; } else { space_after = 0; } split_box = b; move_y = true; inline_count++; } else if (b->type == BOX_BR) { b->x = x; b->width = 0; br_box = b; b = b->next; split_box = 0; move_y = true; break; } else { /* float */ NSLOG(layout, DEBUG, "float %p", b); d = b->children; d->float_children = 0; d->cached_place_below_level = 0; b->float_container = d->float_container = cont; if (!layout_float(d, *width, content)) return false; NSLOG(layout, DEBUG, "%p : %d %d", d, d->margin[TOP], d->border[TOP].width); d->x = d->margin[LEFT] + d->border[LEFT].width; d->y = d->margin[TOP] + d->border[TOP].width; b->width = d->margin[LEFT] + d->border[LEFT].width + d->padding[LEFT] + d->width + d->padding[RIGHT] + d->border[RIGHT].width + d->margin[RIGHT]; b->height = d->margin[TOP] + d->border[TOP].width + d->padding[TOP] + d->height + d->padding[BOTTOM] + d->border[BOTTOM].width + d->margin[BOTTOM]; if (b->width > (x1 - x0) - x) place_below = true; if (d->style && (css_computed_clear(d->style) == CSS_CLEAR_NONE || (css_computed_clear(d->style) == CSS_CLEAR_LEFT && left == 0) || (css_computed_clear(d->style) == CSS_CLEAR_RIGHT && right == 0) || (css_computed_clear(d->style) == CSS_CLEAR_BOTH && left == 0 && right == 0)) && (!place_below || (left == 0 && right == 0 && x == 0)) && cy >= cont->clear_level && cy >= cont->cached_place_below_level) { /* + not cleared or, * cleared and there are no floats to clear * + fits without needing to be placed below or, * this line is empty with no floats * + current y, cy, is below the clear level * * Float affects current line */ if (b->type == BOX_FLOAT_LEFT) { b->x = cx + x0; if (b->width > 0) x0 += b->width; left = b; } else { b->x = cx + x1 - b->width; if (b->width > 0) x1 -= b->width; right = b; } b->y = cy; } else { /* cleared or doesn't fit on line */ /* place below into next available space */ int fcy = (cy > cont->clear_level) ? cy : cont->clear_level; fcy = (fcy > cont->cached_place_below_level) ? fcy : cont->cached_place_below_level; fy = (fy > fcy) ? fy : fcy; fy = (fy == cy) ? fy + height : fy; place_float_below(b, *width, cx, fy, cont); fy = b->y; if (d->style && ( (css_computed_clear(d->style) == CSS_CLEAR_LEFT && left != 0) || (css_computed_clear(d->style) == CSS_CLEAR_RIGHT && right != 0) || (css_computed_clear(d->style) == CSS_CLEAR_BOTH && (left != 0 || right != 0)))) { /* to be cleared below existing * floats */ if (b->type == BOX_FLOAT_LEFT) b->x = cx; else b->x = cx + *width - b->width; fcy = layout_clear(cont->float_children, css_computed_clear(d->style)); if (fcy > cont->clear_level) cont->clear_level = fcy; if (b->y < fcy) b->y = fcy; } if (b->type == BOX_FLOAT_LEFT) left = b; else right = b; } add_float_to_container(cont, b); split_box = 0; } } if (x1 - x0 < x && split_box) { /* the last box went over the end */ size_t split = 0; int w; bool no_wrap = css_computed_white_space( split_box->style) == CSS_WHITE_SPACE_NOWRAP || css_computed_white_space( split_box->style) == CSS_WHITE_SPACE_PRE; x = x_previous; if (!no_wrap && (split_box->type == BOX_INLINE || split_box->type == BOX_TEXT) && !split_box->object && !(split_box->flags & REPLACE_DIM) && !(split_box->flags & IFRAME) && !split_box->gadget && split_box->text) { font_plot_style_from_css(&content->len_ctx, split_box->style, &fstyle); /** \todo handle errors */ font_func->split(&fstyle, split_box->text, split_box->length, x1 - x0 - x - space_before, &split, &w); } /* split == 0 implies that text can't be split */ if (split == 0) w = split_box->width; NSLOG(layout, DEBUG, "splitting: split_box %p \"%.*s\", spilt %"PRIsizet ", w %i, left %p, right %p, inline_count %u", split_box, (int)split_box->length, split_box->text, split, w, left, right, inline_count); if ((split == 0 || x1 - x0 <= x + space_before + w) && !left && !right && inline_count == 1) { /* first word of box doesn't fit, but no floats and * first box on line so force in */ if (split == 0 || split == split_box->length) { /* only one word in this box, or not text * or white-space:nowrap */ b = split_box->next; } else { /* cut off first word for this line */ if (!layout_text_box_split(content, &fstyle, split_box, split, w)) return false; b = split_box->next; } x += space_before + w; NSLOG(layout, DEBUG, "forcing"); } else if ((split == 0 || x1 - x0 <= x + space_before + w) && inline_count == 1) { /* first word of first box doesn't fit, but a float is * taking some of the width so move below it */ assert(left || right); used_height = 0; if (left) { NSLOG(layout, DEBUG, "cy %i, left->y %i, left->height %i", cy, left->y, left->height); used_height = left->y + left->height - cy + 1; NSLOG(layout, DEBUG, "used_height %i", used_height); } if (right && used_height < right->y + right->height - cy + 1) used_height = right->y + right->height - cy + 1; if (used_height < 0) used_height = 0; b = split_box; NSLOG(layout, DEBUG, "moving below float"); } else if (split == 0 || x1 - x0 <= x + space_before + w) { /* first word of box doesn't fit so leave box for next * line */ b = split_box; NSLOG(layout, DEBUG, "leaving for next line"); } else { /* fit as many words as possible */ assert(split != 0); NSLOG(layout, DEBUG, "'%.*s' %i %"PRIsizet" %i", (int)split_box->length, split_box->text, x1 - x0, split, w); if (split != split_box->length) { if (!layout_text_box_split(content, &fstyle, split_box, split, w)) return false; b = split_box->next; } x += space_before + w; NSLOG(layout, DEBUG, "fitting words"); } move_y = true; } /* set positions */ switch (css_computed_text_align(first->parent->parent->style)) { case CSS_TEXT_ALIGN_RIGHT: case CSS_TEXT_ALIGN_LIBCSS_RIGHT: x0 = x1 - x; break; case CSS_TEXT_ALIGN_CENTER: case CSS_TEXT_ALIGN_LIBCSS_CENTER: x0 = (x0 + (x1 - x)) / 2; break; case CSS_TEXT_ALIGN_LEFT: case CSS_TEXT_ALIGN_LIBCSS_LEFT: case CSS_TEXT_ALIGN_JUSTIFY: /* leave on left */ break; case CSS_TEXT_ALIGN_DEFAULT: /* None; consider text direction */ switch (css_computed_direction(first->parent->parent->style)) { case CSS_DIRECTION_LTR: /* leave on left */ break; case CSS_DIRECTION_RTL: x0 = x1 - x; break; } break; } for (d = first; d != b; d = d->next) { d->flags &= ~NEW_LINE; if (d->type == BOX_INLINE_BLOCK && (css_computed_position(d->style) == CSS_POSITION_ABSOLUTE || css_computed_position(d->style) == CSS_POSITION_FIXED)) { /* positioned inline-blocks: * set static position (x,y) only, rest of positioning * is handled later */ d->x += x0; d->y = *y; continue; } else if ((d->type == BOX_INLINE && ((d->object || d->gadget) == false) && !(d->flags & IFRAME) && !(d->flags & REPLACE_DIM)) || d->type == BOX_BR || d->type == BOX_TEXT || d->type == BOX_INLINE_END) { /* regular (non-replaced) inlines */ d->x += x0; d->y = *y - d->padding[TOP]; if (d->type == BOX_TEXT && d->height > used_height) { /* text */ used_height = d->height; } } else if ((d->type == BOX_INLINE) || d->type == BOX_INLINE_BLOCK) { /* replaced inlines and inline-blocks */ d->x += x0; d->y = *y + d->border[TOP].width + d->margin[TOP]; h = d->margin[TOP] + d->border[TOP].width + d->padding[TOP] + d->height + d->padding[BOTTOM] + d->border[BOTTOM].width + d->margin[BOTTOM]; if (used_height < h) used_height = h; } } first->flags |= NEW_LINE; assert(b != first || (move_y && 0 < used_height && (left || right))); /* handle vertical-align by adjusting box y values */ /** \todo proper vertical alignment handling */ for (d = first; d != b; d = d->next) { if ((d->type == BOX_INLINE && d->inline_end) || d->type == BOX_BR || d->type == BOX_TEXT || d->type == BOX_INLINE_END) { css_fixed value = 0; css_unit unit = CSS_UNIT_PX; switch (css_computed_vertical_align(d->style, &value, &unit)) { case CSS_VERTICAL_ALIGN_SUPER: case CSS_VERTICAL_ALIGN_TOP: case CSS_VERTICAL_ALIGN_TEXT_TOP: /* already at top */ break; case CSS_VERTICAL_ALIGN_SUB: case CSS_VERTICAL_ALIGN_BOTTOM: case CSS_VERTICAL_ALIGN_TEXT_BOTTOM: d->y += used_height - d->height; break; default: case CSS_VERTICAL_ALIGN_BASELINE: d->y += 0.75 * (used_height - d->height); break; } } } /* handle clearance for br */ if (br_box && css_computed_clear(br_box->style) != CSS_CLEAR_NONE) { int clear_y = layout_clear(cont->float_children, css_computed_clear(br_box->style)); if (used_height < clear_y - cy) used_height = clear_y - cy; } if (move_y) *y += used_height; *next_box = b; *width = x; /* return actual width */ return true; } /** * Layout lines of text or inline boxes with floats. * * \param box inline container box * \param width horizontal space available * \param cont ancestor box which defines horizontal space, for floats * \param cx box position relative to cont * \param cy box position relative to cont * \param content memory pool for any new boxes * \return true on success, false on memory exhaustion */ static bool layout_inline_container(struct box *inline_container, int width, struct box *cont, int cx, int cy, html_content *content) { bool first_line = true; bool has_text_children; struct box *c, *next; int y = 0; int curwidth,maxwidth = width; assert(inline_container->type == BOX_INLINE_CONTAINER); NSLOG(layout, DEBUG, "inline_container %p, width %i, cont %p, cx %i, cy %i", inline_container, width, cont, cx, cy); has_text_children = false; for (c = inline_container->children; c; c = c->next) { bool is_pre = false; if (c->style) { enum css_white_space_e whitespace; whitespace = css_computed_white_space(c->style); is_pre = (whitespace == CSS_WHITE_SPACE_PRE || whitespace == CSS_WHITE_SPACE_PRE_LINE || whitespace == CSS_WHITE_SPACE_PRE_WRAP); } if ((!c->object && !(c->flags & REPLACE_DIM) && !(c->flags & IFRAME) && c->text && (c->length || is_pre)) || c->type == BOX_BR) has_text_children = true; } /** \todo fix wrapping so that a box with horizontal scrollbar will * shrink back to 'width' if no word is wider than 'width' (Or just set * curwidth = width and have the multiword lines wrap to the min width) */ for (c = inline_container->children; c; ) { NSLOG(layout, DEBUG, "c %p", c); curwidth = inline_container->width; if (!layout_line(c, &curwidth, &y, cx, cy + y, cont, first_line, has_text_children, content, &next)) return false; maxwidth = max(maxwidth,curwidth); c = next; first_line = false; } inline_container->width = maxwidth; inline_container->height = y; return true; } /** * Layout a block formatting context. * * \param block BLOCK, INLINE_BLOCK, or TABLE_CELL to layout * \param viewport_height Height of viewport in pixels or -ve if unknown * \param content Memory pool for any new boxes * \return true on success, false on memory exhaustion * * This function carries out layout of a block and its children, as described * in CSS 2.1 9.4.1. */ static bool layout_block_context(struct box *block, int viewport_height, html_content *content) { struct box *box; int cx, cy; /**< current coordinates */ int max_pos_margin = 0; int max_neg_margin = 0; int y = 0; int lm, rm; struct box *margin_collapse = NULL; bool in_margin = false; css_fixed gadget_size; css_unit gadget_unit; /* Checkbox / radio buttons */ assert(block->type == BOX_BLOCK || block->type == BOX_INLINE_BLOCK || block->type == BOX_TABLE_CELL); assert(block->width != UNKNOWN_WIDTH); assert(block->width != AUTO); block->float_children = NULL; block->cached_place_below_level = 0; block->clear_level = 0; /* special case if the block contains an object */ if (block->object) { int temp_width = block->width; if (!layout_block_object(block)) return false; layout_get_object_dimensions(block, &temp_width, &block->height, INT_MIN, INT_MAX, INT_MIN, INT_MAX); return true; } else if (block->flags & REPLACE_DIM) { return true; } /* special case if the block contains an radio button or checkbox */ if (block->gadget && (block->gadget->type == GADGET_RADIO || block->gadget->type == GADGET_CHECKBOX)) { /* form checkbox or radio button * if width or height is AUTO, set it to 1em */ gadget_unit = CSS_UNIT_EM; gadget_size = INTTOFIX(1); if (block->height == AUTO) block->height = FIXTOINT(nscss_len2px( &content->len_ctx, gadget_size, gadget_unit, block->style)); } box = block->children; /* set current coordinates to top-left of the block */ cx = 0; y = cy = block->padding[TOP]; if (box) box->y = block->padding[TOP]; /* Step through the descendants of the block in depth-first order, but * not into the children of boxes which aren't blocks. For example, if * the tree passed to this function looks like this (box->type shown): * * block -> BOX_BLOCK * BOX_BLOCK * (1) * BOX_INLINE_CONTAINER * (2) * BOX_INLINE * BOX_TEXT * ... * BOX_BLOCK * (3) * BOX_TABLE * (4) * BOX_TABLE_ROW * BOX_TABLE_CELL * ... * BOX_TABLE_CELL * ... * BOX_BLOCK * (5) * BOX_INLINE_CONTAINER * (6) * BOX_TEXT * ... * then the while loop will visit each box marked with *, setting box * to each in the order shown. */ while (box) { enum css_overflow_e overflow_x = CSS_OVERFLOW_VISIBLE; enum css_overflow_e overflow_y = CSS_OVERFLOW_VISIBLE; assert(box->type == BOX_BLOCK || box->type == BOX_TABLE || box->type == BOX_INLINE_CONTAINER); /* Tables are laid out before being positioned, because the * position depends on the width which is calculated in * table layout. Blocks and inline containers are positioned * before being laid out, because width is not dependent on * content, and the position is required during layout for * correct handling of floats. */ if (box->style && (css_computed_position(box->style) == CSS_POSITION_ABSOLUTE || css_computed_position(box->style) == CSS_POSITION_FIXED)) { box->x = box->parent->padding[LEFT]; /* absolute positioned; this element will establish * its own block context when it gets laid out later, * so no need to look at its children now. */ goto advance_to_next_box; } /* If we don't know which box the current margin collapses * through to, find out. Update the pos/neg margin values. */ if (margin_collapse == NULL) { margin_collapse = layout_next_margin_block( &content->len_ctx, box, block, viewport_height, &max_pos_margin, &max_neg_margin); /* We have a margin that has not yet been applied. */ in_margin = true; } /* Clearance. */ y = 0; if (box->style && css_computed_clear(box->style) != CSS_CLEAR_NONE) y = layout_clear(block->float_children, css_computed_clear(box->style)); /* Find box's overflow properties */ if (box->style) { overflow_x = css_computed_overflow_x(box->style); overflow_y = css_computed_overflow_y(box->style); } /* Blocks establishing a block formatting context get minimum * left and right margins to avoid any floats. */ lm = rm = 0; if (box->type == BOX_BLOCK || box->flags & IFRAME) { if (!box->object && !(box->flags & IFRAME) && !(box->flags & REPLACE_DIM) && box->style && (overflow_x != CSS_OVERFLOW_VISIBLE || overflow_y != CSS_OVERFLOW_VISIBLE)) { /* box establishes new block formatting context * so available width may be diminished due to * floats. */ int x0, x1, top; struct box *left, *right; top = cy + max_pos_margin - max_neg_margin; top = (top > y) ? top : y; x0 = cx; x1 = cx + box->parent->width - box->parent->padding[LEFT] - box->parent->padding[RIGHT]; find_sides(block->float_children, top, top, &x0, &x1, &left, &right); /* calculate min required left & right margins * needed to avoid floats */ lm = x0 - cx; rm = cx + box->parent->width - box->parent->padding[LEFT] - box->parent->padding[RIGHT] - x1; } layout_block_find_dimensions(&content->len_ctx, box->parent->width, viewport_height, lm, rm, box); if (box->type == BOX_BLOCK && !(box->flags & IFRAME)) { layout_block_add_scrollbar(box, RIGHT); layout_block_add_scrollbar(box, BOTTOM); } } else if (box->type == BOX_TABLE) { if (box->style != NULL) { enum css_width_e wtype; css_fixed width = 0; css_unit unit = CSS_UNIT_PX; wtype = css_computed_width(box->style, &width, &unit); if (wtype == CSS_WIDTH_AUTO) { /* max available width may be * diminished due to floats. */ int x0, x1, top; struct box *left, *right; top = cy + max_pos_margin - max_neg_margin; top = (top > y) ? top : y; x0 = cx; x1 = cx + box->parent->width - box->parent->padding[LEFT] - box->parent->padding[RIGHT]; find_sides(block->float_children, top, top, &x0, &x1, &left, &right); /* calculate min required left & right * margins needed to avoid floats */ lm = x0 - cx; rm = cx + box->parent->width - box->parent->padding[LEFT] - box->parent->padding[RIGHT] - x1; } } if (!layout_table(box, box->parent->width - lm - rm, content)) return false; layout_solve_width(box, box->parent->width, box->width, lm, rm, -1, -1); } /* Position box: horizontal. */ box->x = box->parent->padding[LEFT] + box->margin[LEFT] + box->border[LEFT].width; cx += box->x; /* Position box: vertical. */ if (box->border[TOP].width) { box->y += box->border[TOP].width; cy += box->border[TOP].width; } /* Vertical margin */ if (((box->type == BOX_BLOCK && (box->flags & HAS_HEIGHT)) || box->type == BOX_TABLE || (box->type == BOX_INLINE_CONTAINER && !box_is_first_child(box)) || margin_collapse == box) && in_margin == true) { /* Margin goes above this box. */ cy += max_pos_margin - max_neg_margin; box->y += max_pos_margin - max_neg_margin; /* Current margin has been applied. */ in_margin = false; max_pos_margin = max_neg_margin = 0; } /* Handle clearance */ if (box->type != BOX_INLINE_CONTAINER && (y > 0) && (cy < y)) { /* box clears something*/ box->y += y - cy; cy = y; } /* Unless the box has an overflow style of visible, the box * establishes a new block context. */ if (box->type == BOX_BLOCK && box->style && (overflow_x != CSS_OVERFLOW_VISIBLE || overflow_y != CSS_OVERFLOW_VISIBLE)) { layout_block_context(box, viewport_height, content); cy += box->padding[TOP]; if (box->height == AUTO) { box->height = 0; layout_block_add_scrollbar(box, BOTTOM); } cx -= box->x; cy += box->height + box->padding[BOTTOM] + box->border[BOTTOM].width; y = box->y + box->padding[TOP] + box->height + box->padding[BOTTOM] + box->border[BOTTOM].width; /* Skip children, because they are done in the new * block context */ goto advance_to_next_box; } NSLOG(layout, DEBUG, "box %p, cx %i, cy %i", box, cx, cy); /* Layout (except tables). */ if (box->object) { if (!layout_block_object(box)) return false; } else if (box->type == BOX_INLINE_CONTAINER) { box->width = box->parent->width; if (!layout_inline_container(box, box->width, block, cx, cy, content)) return false; } else if (box->type == BOX_TABLE) { /* Move down to avoid floats if necessary. */ int x0, x1; struct box *left, *right; y = cy; while (1) { enum css_width_e wtype; css_fixed width = 0; css_unit unit = CSS_UNIT_PX; wtype = css_computed_width(box->style, &width, &unit); x0 = cx; x1 = cx + box->parent->width; find_sides(block->float_children, y, y + box->height, &x0, &x1, &left, &right); if (wtype == CSS_WIDTH_AUTO) break; if (box->width <= x1 - x0) break; if (!left && !right) break; else if (!left) y = right->y + right->height + 1; else if (!right) y = left->y + left->height + 1; else if (left->y + left->height < right->y + right->height) y = left->y + left->height + 1; else y = right->y + right->height + 1; } box->x += x0 - cx; cx = x0; box->y += y - cy; cy = y; } /* Advance to next box. */ if (box->type == BOX_BLOCK && !box->object && !(box->iframe) && box->children) { /* Down into children. */ if (box == margin_collapse) { /* Current margin collapsed though to this box. * Unset margin_collapse. */ margin_collapse = NULL; } y = box->padding[TOP]; box = box->children; box->y = y; cy += y; continue; } else if (box->type == BOX_BLOCK || box->object || box->flags & IFRAME) cy += box->padding[TOP]; if (box->type == BOX_BLOCK && box->height == AUTO) { box->height = 0; layout_block_add_scrollbar(box, BOTTOM); } cy += box->height + box->padding[BOTTOM] + box->border[BOTTOM].width; cx -= box->x; y = box->y + box->padding[TOP] + box->height + box->padding[BOTTOM] + box->border[BOTTOM].width; advance_to_next_box: if (!box->next) { /* No more siblings: * up to first ancestor with a sibling. */ do { if (box == margin_collapse) { /* Current margin collapsed though to * this box. Unset margin_collapse. */ margin_collapse = NULL; } /* Apply bottom margin */ if (max_pos_margin < box->margin[BOTTOM]) max_pos_margin = box->margin[BOTTOM]; else if (max_neg_margin < -box->margin[BOTTOM]) max_neg_margin = -box->margin[BOTTOM]; box = box->parent; if (box == block) break; /* Margin is invalidated if this is a box * margins can't collapse through. */ if (box->type == BOX_BLOCK && box->flags & MAKE_HEIGHT) { margin_collapse = NULL; in_margin = false; max_pos_margin = max_neg_margin = 0; } if (box->height == AUTO) { box->height = y - box->padding[TOP]; if (box->type == BOX_BLOCK) layout_block_add_scrollbar(box, BOTTOM); } else cy += box->height - (y - box->padding[TOP]); /* Apply any min-height and max-height to * boxes in normal flow */ if (box->style && css_computed_position(box->style) != CSS_POSITION_ABSOLUTE && layout_apply_minmax_height( &content->len_ctx, box, NULL)) { /* Height altered */ /* Set current cy */ cy += box->height - (y - box->padding[TOP]); } cy += box->padding[BOTTOM] + box->border[BOTTOM].width; cx -= box->x; y = box->y + box->padding[TOP] + box->height + box->padding[BOTTOM] + box->border[BOTTOM].width; } while (box->next == NULL); if (box == block) break; } /* To next sibling. */ if (box == margin_collapse) { /* Current margin collapsed though to this box. * Unset margin_collapse. */ margin_collapse = NULL; } if (max_pos_margin < box->margin[BOTTOM]) max_pos_margin = box->margin[BOTTOM]; else if (max_neg_margin < -box->margin[BOTTOM]) max_neg_margin = -box->margin[BOTTOM]; box = box->next; box->y = y; } /* Account for bottom margin of last contained block */ cy += max_pos_margin - max_neg_margin; /* Increase height to contain any floats inside (CSS 2.1 10.6.7). */ for (box = block->float_children; box; box = box->next_float) { y = box->y + box->height + box->padding[BOTTOM] + box->border[BOTTOM].width + box->margin[BOTTOM]; if (cy < y) cy = y; } if (block->height == AUTO) { block->height = cy - block->padding[TOP]; if (block->type == BOX_BLOCK) layout_block_add_scrollbar(block, BOTTOM); } if (block->style && css_computed_position(block->style) != CSS_POSITION_ABSOLUTE) { /* Block is in normal flow */ layout_apply_minmax_height(&content->len_ctx, block, NULL); } if (block->gadget && (block->gadget->type == GADGET_TEXTAREA || block->gadget->type == GADGET_PASSWORD || block->gadget->type == GADGET_TEXTBOX)) { plot_font_style_t fstyle; int ta_width = block->padding[LEFT] + block->width + block->padding[RIGHT]; int ta_height = block->padding[TOP] + block->height + block->padding[BOTTOM]; font_plot_style_from_css(&content->len_ctx, block->style, &fstyle); fstyle.background = NS_TRANSPARENT; textarea_set_layout(block->gadget->data.text.ta, &fstyle, ta_width, ta_height, block->padding[TOP], block->padding[RIGHT], block->padding[BOTTOM], block->padding[LEFT]); } return true; } /** * Layout list markers. */ static void layout_lists(struct box *box, const struct gui_layout_table *font_func, const nscss_len_ctx *len_ctx) { struct box *child; struct box *marker; plot_font_style_t fstyle; for (child = box->children; child; child = child->next) { if (child->list_marker) { marker = child->list_marker; if (marker->object) { marker->width = content_get_width(marker->object); marker->x = -marker->width; marker->height = content_get_height(marker->object); marker->y = (line_height(len_ctx, marker->style) - marker->height) / 2; } else if (marker->text) { if (marker->width == UNKNOWN_WIDTH) { font_plot_style_from_css(len_ctx, marker->style, &fstyle); font_func->width(&fstyle, marker->text, marker->length, &marker->width); marker->flags |= MEASURED; } marker->x = -marker->width; marker->y = 0; marker->height = line_height(len_ctx, marker->style); } else { marker->x = 0; marker->y = 0; marker->width = 0; marker->height = 0; } /* Gap between marker and content */ marker->x -= 4; } layout_lists(child, font_func, len_ctx); } } /** * Compute box offsets for a relatively or absolutely positioned box with * respect to a box. * * \param len_ctx Length conversion context * \param box box to compute offsets for * \param containing_block box to compute percentages with respect to * \param top updated to top offset, or AUTO * \param right updated to right offset, or AUTO * \param bottom updated to bottom offset, or AUTO * \param left updated to left offset, or AUTO * * See CSS 2.1 9.3.2. containing_block must have width and height. */ static void layout_compute_offsets(const nscss_len_ctx *len_ctx, struct box *box, struct box *containing_block, int *top, int *right, int *bottom, int *left) { uint32_t type; css_fixed value = 0; css_unit unit = CSS_UNIT_PX; assert(containing_block->width != UNKNOWN_WIDTH && containing_block->width != AUTO && containing_block->height != AUTO); /* left */ type = css_computed_left(box->style, &value, &unit); if (type == CSS_LEFT_SET) { if (unit == CSS_UNIT_PCT) { *left = FPCT_OF_INT_TOINT(value, containing_block->width); } else { *left = FIXTOINT(nscss_len2px(len_ctx, value, unit, box->style)); } } else { *left = AUTO; } /* right */ type = css_computed_right(box->style, &value, &unit); if (type == CSS_RIGHT_SET) { if (unit == CSS_UNIT_PCT) { *right = FPCT_OF_INT_TOINT(value, containing_block->width); } else { *right = FIXTOINT(nscss_len2px(len_ctx, value, unit, box->style)); } } else { *right = AUTO; } /* top */ type = css_computed_top(box->style, &value, &unit); if (type == CSS_TOP_SET) { if (unit == CSS_UNIT_PCT) { *top = FPCT_OF_INT_TOINT(value, containing_block->height); } else { *top = FIXTOINT(nscss_len2px(len_ctx, value, unit, box->style)); } } else { *top = AUTO; } /* bottom */ type = css_computed_bottom(box->style, &value, &unit); if (type == CSS_BOTTOM_SET) { if (unit == CSS_UNIT_PCT) { *bottom = FPCT_OF_INT_TOINT(value, containing_block->height); } else { *bottom = FIXTOINT(nscss_len2px(len_ctx, value, unit, box->style)); } } else { *bottom = AUTO; } } /** * Layout and position an absolutely positioned box. * * \param box absolute box to layout and position * \param containing_block containing block * \param cx position of box relative to containing_block * \param cy position of box relative to containing_block * \param content memory pool for any new boxes * \return true on success, false on memory exhaustion */ static bool layout_absolute(struct box *box, struct box *containing_block, int cx, int cy, html_content *content) { int static_left, static_top; /* static position */ int top, right, bottom, left; int width, height, max_width, min_width; int *margin = box->margin; int *padding = box->padding; struct box_border *border = box->border; int available_width = containing_block->width; int space; assert(box->type == BOX_BLOCK || box->type == BOX_TABLE || box->type == BOX_INLINE_BLOCK); /* The static position is where the box would be if it was not * absolutely positioned. The x and y are filled in by * layout_block_context(). */ static_left = cx + box->x; static_top = cy + box->y; if (containing_block->type == BOX_BLOCK || containing_block->type == BOX_INLINE_BLOCK || containing_block->type == BOX_TABLE_CELL) { /* Block level container => temporarily increase containing * block dimensions to include padding (we restore this * again at the end) */ containing_block->width += containing_block->padding[LEFT] + containing_block->padding[RIGHT]; containing_block->height += containing_block->padding[TOP] + containing_block->padding[BOTTOM]; } else { /** \todo inline containers */ } layout_compute_offsets(&content->len_ctx, box, containing_block, &top, &right, &bottom, &left); /* Pass containing block into layout_find_dimensions via the float * containing block box member. This is unused for absolutely positioned * boxes because a box can't be floated and absolutely positioned. */ box->float_container = containing_block; layout_find_dimensions(&content->len_ctx, available_width, -1, box, box->style, &width, &height, &max_width, &min_width, 0, 0, margin, padding, border); box->float_container = NULL; /* 10.3.7 */ NSLOG(layout, DEBUG, "%i + %i + %i + %i + %i + %i + %i + %i + %i = %i", left, margin[LEFT], border[LEFT].width, padding[LEFT], width, padding[RIGHT], border[RIGHT].width, margin[RIGHT], right, containing_block->width); if (left == AUTO && width == AUTO && right == AUTO) { if (margin[LEFT] == AUTO) margin[LEFT] = 0; if (margin[RIGHT] == AUTO) margin[RIGHT] = 0; left = static_left; width = min(max(box->min_width, available_width), box->max_width); width -= box->margin[LEFT] + box->border[LEFT].width + box->padding[LEFT] + box->padding[RIGHT] + box->border[RIGHT].width + box->margin[RIGHT]; /* Adjust for {min|max}-width */ if (max_width >= 0 && width > max_width) width = max_width; if (width < min_width) width = min_width; right = containing_block->width - left - margin[LEFT] - border[LEFT].width - padding[LEFT] - width - padding[RIGHT] - border[RIGHT].width - margin[RIGHT]; } else if (left != AUTO && width != AUTO && right != AUTO) { /* Adjust for {min|max}-width */ if (max_width >= 0 && width > max_width) width = max_width; if (min_width > 0 && width < min_width) width = min_width; if (margin[LEFT] == AUTO && margin[RIGHT] == AUTO) { space = containing_block->width - left - border[LEFT].width - padding[LEFT] - width - padding[RIGHT] - border[RIGHT].width - right; if (space < 0) { margin[LEFT] = 0; margin[RIGHT] = space; } else { margin[LEFT] = margin[RIGHT] = space / 2; } } else if (margin[LEFT] == AUTO) { margin[LEFT] = containing_block->width - left - border[LEFT].width - padding[LEFT] - width - padding[RIGHT] - border[RIGHT].width - margin[RIGHT] - right; } else if (margin[RIGHT] == AUTO) { margin[RIGHT] = containing_block->width - left - margin[LEFT] - border[LEFT].width - padding[LEFT] - width - padding[RIGHT] - border[RIGHT].width - right; } else { right = containing_block->width - left - margin[LEFT] - border[LEFT].width - padding[LEFT] - width - padding[RIGHT] - border[RIGHT].width - margin[RIGHT]; } } else { if (margin[LEFT] == AUTO) margin[LEFT] = 0; if (margin[RIGHT] == AUTO) margin[RIGHT] = 0; if (left == AUTO && width == AUTO && right != AUTO) { available_width -= right; width = min(max(box->min_width, available_width), box->max_width); width -= box->margin[LEFT] + box->border[LEFT].width + box->padding[LEFT] + box->padding[RIGHT] + box->border[RIGHT].width + box->margin[RIGHT]; /* Adjust for {min|max}-width */ if (max_width >= 0 && width > max_width) width = max_width; if (width < min_width) width = min_width; left = containing_block->width - margin[LEFT] - border[LEFT].width - padding[LEFT] - width - padding[RIGHT] - border[RIGHT].width - margin[RIGHT] - right; } else if (left == AUTO && width != AUTO && right == AUTO) { /* Adjust for {min|max}-width */ if (max_width >= 0 && width > max_width) width = max_width; if (min_width > 0 && width < min_width) width = min_width; left = static_left; right = containing_block->width - left - margin[LEFT] - border[LEFT].width - padding[LEFT] - width - padding[RIGHT] - border[RIGHT].width - margin[RIGHT]; } else if (left != AUTO && width == AUTO && right == AUTO) { available_width -= left; width = min(max(box->min_width, available_width), box->max_width); width -= box->margin[LEFT] + box->border[LEFT].width + box->padding[LEFT] + box->padding[RIGHT] + box->border[RIGHT].width + box->margin[RIGHT]; /* Adjust for {min|max}-width */ if (max_width >= 0 && width > max_width) width = max_width; if (width < min_width) width = min_width; right = containing_block->width - left - margin[LEFT] - border[LEFT].width - padding[LEFT] - width - padding[RIGHT] - border[RIGHT].width - margin[RIGHT]; } else if (left == AUTO && width != AUTO && right != AUTO) { /* Adjust for {min|max}-width */ if (max_width >= 0 && width > max_width) width = max_width; if (width < min_width) width = min_width; left = containing_block->width - margin[LEFT] - border[LEFT].width - padding[LEFT] - width - padding[RIGHT] - border[RIGHT].width - margin[RIGHT] - right; } else if (left != AUTO && width == AUTO && right != AUTO) { width = containing_block->width - left - margin[LEFT] - border[LEFT].width - padding[LEFT] - padding[RIGHT] - border[RIGHT].width - margin[RIGHT] - right; /* Adjust for {min|max}-width */ if (max_width >= 0 && width > max_width) width = max_width; if (width < min_width) width = min_width; } else if (left != AUTO && width != AUTO && right == AUTO) { /* Adjust for {min|max}-width */ if (max_width >= 0 && width > max_width) width = max_width; if (width < min_width) width = min_width; right = containing_block->width - left - margin[LEFT] - border[LEFT].width - padding[LEFT] - width - padding[RIGHT] - border[RIGHT].width - margin[RIGHT]; } } NSLOG(layout, DEBUG, "%i + %i + %i + %i + %i + %i + %i + %i + %i = %i", left, margin[LEFT], border[LEFT].width, padding[LEFT], width, padding[RIGHT], border[RIGHT].width, margin[RIGHT], right, containing_block->width); box->x = left + margin[LEFT] + border[LEFT].width - cx; if (containing_block->type == BOX_BLOCK || containing_block->type == BOX_INLINE_BLOCK || containing_block->type == BOX_TABLE_CELL) { /* Block-level ancestor => reset container's width */ containing_block->width -= containing_block->padding[LEFT] + containing_block->padding[RIGHT]; } else { /** \todo inline ancestors */ } box->width = width; box->height = height; if (box->type == BOX_BLOCK || box->type == BOX_INLINE_BLOCK || box->object || box->flags & IFRAME) { if (!layout_block_context(box, -1, content)) return false; } else if (box->type == BOX_TABLE) { /* layout_table also expects the containing block to be * stored in the float_container field */ box->float_container = containing_block; /* \todo layout_table considers margins etc. again */ if (!layout_table(box, width, content)) return false; box->float_container = NULL; layout_solve_width(box, box->parent->width, box->width, 0, 0, -1, -1); } /* 10.6.4 */ NSLOG(layout, DEBUG, "%i + %i + %i + %i + %i + %i + %i + %i + %i = %i", top, margin[TOP], border[TOP].width, padding[TOP], height, padding[BOTTOM], border[BOTTOM].width, margin[BOTTOM], bottom, containing_block->height); if (top == AUTO && height == AUTO && bottom == AUTO) { top = static_top; height = box->height; if (margin[TOP] == AUTO) margin[TOP] = 0; if (margin[BOTTOM] == AUTO) margin[BOTTOM] = 0; bottom = containing_block->height - top - margin[TOP] - border[TOP].width - padding[TOP] - height - padding[BOTTOM] - border[BOTTOM].width - margin[BOTTOM]; } else if (top != AUTO && height != AUTO && bottom != AUTO) { if (margin[TOP] == AUTO && margin[BOTTOM] == AUTO) { space = containing_block->height - top - border[TOP].width - padding[TOP] - height - padding[BOTTOM] - border[BOTTOM].width - bottom; margin[TOP] = margin[BOTTOM] = space / 2; } else if (margin[TOP] == AUTO) { margin[TOP] = containing_block->height - top - border[TOP].width - padding[TOP] - height - padding[BOTTOM] - border[BOTTOM].width - margin[BOTTOM] - bottom; } else if (margin[BOTTOM] == AUTO) { margin[BOTTOM] = containing_block->height - top - margin[TOP] - border[TOP].width - padding[TOP] - height - padding[BOTTOM] - border[BOTTOM].width - bottom; } else { bottom = containing_block->height - top - margin[TOP] - border[TOP].width - padding[TOP] - height - padding[BOTTOM] - border[BOTTOM].width - margin[BOTTOM]; } } else { if (margin[TOP] == AUTO) margin[TOP] = 0; if (margin[BOTTOM] == AUTO) margin[BOTTOM] = 0; if (top == AUTO && height == AUTO && bottom != AUTO) { height = box->height; top = containing_block->height - margin[TOP] - border[TOP].width - padding[TOP] - height - padding[BOTTOM] - border[BOTTOM].width - margin[BOTTOM] - bottom; } else if (top == AUTO && height != AUTO && bottom == AUTO) { top = static_top; bottom = containing_block->height - top - margin[TOP] - border[TOP].width - padding[TOP] - height - padding[BOTTOM] - border[BOTTOM].width - margin[BOTTOM]; } else if (top != AUTO && height == AUTO && bottom == AUTO) { height = box->height; bottom = containing_block->height - top - margin[TOP] - border[TOP].width - padding[TOP] - height - padding[BOTTOM] - border[BOTTOM].width - margin[BOTTOM]; } else if (top == AUTO && height != AUTO && bottom != AUTO) { top = containing_block->height - margin[TOP] - border[TOP].width - padding[TOP] - height - padding[BOTTOM] - border[BOTTOM].width - margin[BOTTOM] - bottom; } else if (top != AUTO && height == AUTO && bottom != AUTO) { height = containing_block->height - top - margin[TOP] - border[TOP].width - padding[TOP] - padding[BOTTOM] - border[BOTTOM].width - margin[BOTTOM] - bottom; } else if (top != AUTO && height != AUTO && bottom == AUTO) { bottom = containing_block->height - top - margin[TOP] - border[TOP].width - padding[TOP] - height - padding[BOTTOM] - border[BOTTOM].width - margin[BOTTOM]; } } NSLOG(layout, DEBUG, "%i + %i + %i + %i + %i + %i + %i + %i + %i = %i", top, margin[TOP], border[TOP].width, padding[TOP], height, padding[BOTTOM], border[BOTTOM].width, margin[BOTTOM], bottom, containing_block->height); box->y = top + margin[TOP] + border[TOP].width - cy; if (containing_block->type == BOX_BLOCK || containing_block->type == BOX_INLINE_BLOCK || containing_block->type == BOX_TABLE_CELL) { /* Block-level ancestor => reset container's height */ containing_block->height -= containing_block->padding[TOP] + containing_block->padding[BOTTOM]; } else { /** \todo Inline ancestors */ } box->height = height; layout_apply_minmax_height(&content->len_ctx, box, containing_block); return true; } /** * Recursively layout and position absolutely positioned boxes. * * \param box tree of boxes to layout * \param containing_block current containing block * \param cx position of box relative to containing_block * \param cy position of box relative to containing_block * \param content memory pool for any new boxes * \return true on success, false on memory exhaustion */ static bool layout_position_absolute(struct box *box, struct box *containing_block, int cx, int cy, html_content *content) { struct box *c; for (c = box->children; c; c = c->next) { if ((c->type == BOX_BLOCK || c->type == BOX_TABLE || c->type == BOX_INLINE_BLOCK) && (css_computed_position(c->style) == CSS_POSITION_ABSOLUTE || css_computed_position(c->style) == CSS_POSITION_FIXED)) { if (!layout_absolute(c, containing_block, cx, cy, content)) return false; if (!layout_position_absolute(c, c, 0, 0, content)) return false; } else if (c->style && css_computed_position(c->style) == CSS_POSITION_RELATIVE) { if (!layout_position_absolute(c, c, 0, 0, content)) return false; } else { int px, py; if (c->style && (css_computed_float(c->style) == CSS_FLOAT_LEFT || css_computed_float(c->style) == CSS_FLOAT_RIGHT)) { /* Float x/y coords are relative to nearest * ansestor with float_children, rather than * relative to parent. Need to get x/y relative * to parent */ struct box *p; px = c->x; py = c->y; for (p = box->parent; p && !p->float_children; p = p->parent) { px -= p->x; py -= p->y; } } else { /* Not a float, so box x/y coords are relative * to parent */ px = c->x; py = c->y; } if (!layout_position_absolute(c, containing_block, cx + px, cy + py, content)) return false; } } return true; } /** * Compute a box's relative offset as per CSS 2.1 9.4.3 * * \param len_ctx Length conversion context * \param box Box to compute relative offsets for. * \param x Receives relative offset in x. * \param y Receives relative offset in y. */ static void layout_compute_relative_offset( const nscss_len_ctx *len_ctx, struct box *box, int *x, int *y) { int left, right, top, bottom; struct box *containing_block; assert(box && box->parent && box->style && css_computed_position(box->style) == CSS_POSITION_RELATIVE); if (box->float_container && (css_computed_float(box->style) == CSS_FLOAT_LEFT || css_computed_float(box->style) == CSS_FLOAT_RIGHT)) { containing_block = box->float_container; } else { containing_block = box->parent; } layout_compute_offsets(len_ctx, box, containing_block, &top, &right, &bottom, &left); if (left == AUTO && right == AUTO) left = right = 0; else if (left == AUTO) /* left is auto => computed = -right */ left = -right; else if (right == AUTO) /* right is auto => computed = -left */ right = -left; else { /* over constrained => examine direction property * of containing block */ if (containing_block->style && css_computed_direction( containing_block->style) == CSS_DIRECTION_RTL) { /* right wins */ left = -right; } else { /* assume LTR in all other cases */ right = -left; } } assert(left == -right); if (top == AUTO && bottom == AUTO) { top = bottom = 0; } else if (top == AUTO) { top = -bottom; } else { /* bottom is AUTO, or neither are AUTO */ bottom = -top; } NSLOG(layout, DEBUG, "left %i, right %i, top %i, bottom %i", left, right, top, bottom); *x = left; *y = top; } /** * Adjust positions of relatively positioned boxes. * * \param len_ctx Length conversion context * \param root box to adjust the position of * \param fp box which forms the block formatting context for children of * "root" which are floats * \param fx x offset due to intervening relatively positioned boxes * between current box, "root", and the block formatting context * box, "fp", for float children of "root" * \param fy y offset due to intervening relatively positioned boxes * between current box, "root", and the block formatting context * box, "fp", for float children of "root" */ static void layout_position_relative( const nscss_len_ctx *len_ctx, struct box *root, struct box *fp, int fx, int fy) { struct box *box; /* for children of "root" */ struct box *fn; /* for block formatting context box for children of * "box" */ struct box *fc; /* for float children of the block formatting context, * "fp" */ int x, y; /* for the offsets resulting from any relative * positioning on the current block */ int fnx, fny; /* for affsets which apply to flat children of "box" */ /**\todo ensure containing box is large enough after moving boxes */ assert(root); /* Normal children */ for (box = root->children; box; box = box->next) { if (box->type == BOX_TEXT) continue; /* If relatively positioned, get offsets */ if (box->style && css_computed_position(box->style) == CSS_POSITION_RELATIVE) layout_compute_relative_offset( len_ctx, box, &x, &y); else x = y = 0; /* Adjust float coordinates. * (note float x and y are relative to their block formatting * context box and not their parent) */ if (box->style && (css_computed_float(box->style) == CSS_FLOAT_LEFT || css_computed_float(box->style) == CSS_FLOAT_RIGHT) && (fx != 0 || fy != 0)) { /* box is a float and there is a float offset to * apply */ for (fc = fp->float_children; fc; fc = fc->next_float) { if (box == fc->children) { /* Box is floated in the block * formatting context block, fp. * Apply float offsets. */ box->x += fx; box->y += fy; fx = fy = 0; } } } if (box->float_children) { fn = box; fnx = fny = 0; } else { fn = fp; fnx = fx + x; fny = fy + y; } /* recurse first */ layout_position_relative(len_ctx, box, fn, fnx, fny); /* Ignore things we're not interested in. */ if (!box->style || (box->style && css_computed_position(box->style) != CSS_POSITION_RELATIVE)) continue; box->x += x; box->y += y; /* Handle INLINEs - their "children" are in fact * the sibling boxes between the INLINE and * INLINE_END boxes */ if (box->type == BOX_INLINE && box->inline_end) { struct box *b; for (b = box->next; b && b != box->inline_end; b = b->next) { b->x += x; b->y += y; } } } } /** * Find a box's bounding box relative to itself, i.e. the box's border edge box * * \param len_ctx Length conversion context * \param box box find bounding box of * \param desc_x0 updated to left of box's bbox * \param desc_y0 updated to top of box's bbox * \param desc_x1 updated to right of box's bbox * \param desc_y1 updated to bottom of box's bbox */ static void layout_get_box_bbox( const nscss_len_ctx *len_ctx, struct box *box, int *desc_x0, int *desc_y0, int *desc_x1, int *desc_y1) { *desc_x0 = -box->border[LEFT].width; *desc_y0 = -box->border[TOP].width; *desc_x1 = box->padding[LEFT] + box->width + box->padding[RIGHT] + box->border[RIGHT].width; *desc_y1 = box->padding[TOP] + box->height + box->padding[BOTTOM] + box->border[BOTTOM].width; /* To stop the top of text getting clipped when css line-height is * reduced, we increase the top of the descendant bbox. */ if (box->type == BOX_BLOCK && box->style != NULL && css_computed_overflow_y(box->style) == CSS_OVERFLOW_VISIBLE && box->object == NULL) { css_fixed font_size = 0; css_unit font_unit = CSS_UNIT_PT; int text_height; css_computed_font_size(box->style, &font_size, &font_unit); text_height = nscss_len2px(len_ctx, font_size, font_unit, box->style); text_height = FIXTOINT(text_height * 3 / 4); *desc_y0 = (*desc_y0 < -text_height) ? *desc_y0 : -text_height; } } /** * Apply changes to box descendant_[xy][01] values due to given child. * * \param len_ctx Length conversion context * \param box box to update * \param child a box, which may affect box's descendant bbox * \param off_x offset to apply to child->x coord to treat as child of box * \param off_y offset to apply to child->y coord to treat as child of box */ static void layout_update_descendant_bbox( const nscss_len_ctx *len_ctx, struct box *box, struct box *child, int off_x, int off_y) { int child_desc_x0, child_desc_y0, child_desc_x1, child_desc_y1; /* get coordinates of child relative to box */ int child_x = child->x - off_x; int child_y = child->y - off_y; bool html_object = (child->object && content_get_type(child->object) == CONTENT_HTML); enum css_overflow_e overflow_x = CSS_OVERFLOW_VISIBLE; enum css_overflow_e overflow_y = CSS_OVERFLOW_VISIBLE; if (child->style != NULL) { overflow_x = css_computed_overflow_x(child->style); overflow_y = css_computed_overflow_y(child->style); } /* Get child's border edge */ layout_get_box_bbox(len_ctx, child, &child_desc_x0, &child_desc_y0, &child_desc_x1, &child_desc_y1); if (overflow_x == CSS_OVERFLOW_VISIBLE && html_object == false) { /* get child's descendant bbox relative to box */ child_desc_x0 = child->descendant_x0; child_desc_x1 = child->descendant_x1; } if (overflow_y == CSS_OVERFLOW_VISIBLE && html_object == false) { /* get child's descendant bbox relative to box */ child_desc_y0 = child->descendant_y0; child_desc_y1 = child->descendant_y1; } child_desc_x0 += child_x; child_desc_y0 += child_y; child_desc_x1 += child_x; child_desc_y1 += child_y; /* increase box's descendant bbox to contain descendants */ if (child_desc_x0 < box->descendant_x0) box->descendant_x0 = child_desc_x0; if (child_desc_y0 < box->descendant_y0) box->descendant_y0 = child_desc_y0; if (box->descendant_x1 < child_desc_x1) box->descendant_x1 = child_desc_x1; if (box->descendant_y1 < child_desc_y1) box->descendant_y1 = child_desc_y1; } /** * Recursively calculate the descendant_[xy][01] values for a laid-out box tree * and inform iframe browser windows of their size and position. * * \param len_ctx Length conversion context * \param box tree of boxes to update */ static void layout_calculate_descendant_bboxes( const nscss_len_ctx *len_ctx, struct box *box) { struct box *child; assert(box->width != UNKNOWN_WIDTH); assert(box->height != AUTO); /* assert((box->width >= 0) && (box->height >= 0)); */ /* Initialise box's descendant box to border edge box */ layout_get_box_bbox(len_ctx, box, &box->descendant_x0, &box->descendant_y0, &box->descendant_x1, &box->descendant_y1); /* Extend it to contain HTML contents if box is replaced */ if (box->object && content_get_type(box->object) == CONTENT_HTML) { if (box->descendant_x1 < content_get_width(box->object)) box->descendant_x1 = content_get_width(box->object); if (box->descendant_y1 < content_get_height(box->object)) box->descendant_y1 = content_get_height(box->object); } if (box->iframe != NULL) { int x, y; box_coords(box, &x, &y); browser_window_set_position(box->iframe, x, y); browser_window_set_dimensions(box->iframe, box->width, box->height); browser_window_reformat(box->iframe, true, box->width, box->height); } if (box->type == BOX_INLINE || box->type == BOX_TEXT) return; if (box->type == BOX_INLINE_END) { box = box->inline_end; for (child = box->next; child; child = child->next) { if (child->type == BOX_FLOAT_LEFT || child->type == BOX_FLOAT_RIGHT) continue; layout_update_descendant_bbox(len_ctx, box, child, box->x, box->y); if (child == box->inline_end) break; } return; } if (box->flags & REPLACE_DIM) /* Box's children aren't displayed if the box is replaced */ return; for (child = box->children; child; child = child->next) { if (child->type == BOX_FLOAT_LEFT || child->type == BOX_FLOAT_RIGHT) continue; layout_calculate_descendant_bboxes(len_ctx, child); if (box->style && css_computed_overflow_x(box->style) == CSS_OVERFLOW_HIDDEN && css_computed_overflow_y(box->style) == CSS_OVERFLOW_HIDDEN) continue; layout_update_descendant_bbox(len_ctx, box, child, 0, 0); } for (child = box->float_children; child; child = child->next_float) { assert(child->type == BOX_FLOAT_LEFT || child->type == BOX_FLOAT_RIGHT); layout_calculate_descendant_bboxes(len_ctx, child); layout_update_descendant_bbox(len_ctx, box, child, 0, 0); } if (box->list_marker) { child = box->list_marker; layout_calculate_descendant_bboxes(len_ctx, child); layout_update_descendant_bbox(len_ctx, box, child, 0, 0); } } /* exported function documented in html/layout.h */ bool layout_document(html_content *content, int width, int height) { bool ret; struct box *doc = content->layout; const struct gui_layout_table *font_func = content->font_func; NSLOG(layout, DEBUG, "Doing layout to %ix%i of %s", width, height, nsurl_access(content_get_url( &content->base))); layout_minmax_block(doc, font_func, content); layout_block_find_dimensions(&content->len_ctx, width, height, 0, 0, doc); doc->x = doc->margin[LEFT] + doc->border[LEFT].width; doc->y = doc->margin[TOP] + doc->border[TOP].width; width -= doc->margin[LEFT] + doc->border[LEFT].width + doc->padding[LEFT] + doc->padding[RIGHT] + doc->border[RIGHT].width + doc->margin[RIGHT]; if (width < 0) { width = 0; } doc->width = width; ret = layout_block_context(doc, height, content); /* make and fill available height */ if (doc->y + doc->padding[TOP] + doc->height + doc->padding[BOTTOM] + doc->border[BOTTOM].width + doc->margin[BOTTOM] < height) { doc->height = height - (doc->y + doc->padding[TOP] + doc->padding[BOTTOM] + doc->border[BOTTOM].width + doc->margin[BOTTOM]); if (doc->children) doc->children->height = doc->height - (doc->children->margin[TOP] + doc->children->border[TOP].width + doc->children->padding[TOP] + doc->children->padding[BOTTOM] + doc->children->border[BOTTOM].width + doc->children->margin[BOTTOM]); } layout_lists(doc, font_func, &content->len_ctx); layout_position_absolute(doc, doc, 0, 0, content); layout_position_relative(&content->len_ctx, doc, doc, 0, 0); layout_calculate_descendant_bboxes(&content->len_ctx, doc); return ret; }