diff options
Diffstat (limited to 'render/loosen.c')
-rw-r--r-- | render/loosen.c | 415 |
1 files changed, 415 insertions, 0 deletions
diff --git a/render/loosen.c b/render/loosen.c new file mode 100644 index 000000000..91c4056ef --- /dev/null +++ b/render/loosen.c @@ -0,0 +1,415 @@ +/* + * Copyright 2008 Adam Blokus <adamblokus@gmail.com> + * + * 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 <http://www.gnu.org/licenses/>. + */ + +#include <stdbool.h> +#include <assert.h> + +#include "content/content.h" + +#include "render/box.h" +#include "render/font.h" + +#include "utils/log.h" +#include "utils/talloc.h" + +#define AUTO INT_MIN + + +static bool loosen_text(struct box *text, int width, struct content *content); + +static bool loosen_table(struct box *box, int available_width, + struct content *content); + +static bool loosen_position_static(struct box *box, int width, int cx, + struct content *content); + +static bool loosen_shrink_object(struct box *box, int width); + +static bool loosen_all_first_pass(struct box *box, int width, int cx, + struct content *content); +static bool loosen_all_second_pass(struct box *box, int width, int cx, + struct content *content); +static bool loosen_all_third_pass(struct box *box, int width, int cx, + struct content *content); + +/** + * Main loosing procedure + * \param content Reformated content - talloc memory pool for new boxes + * \param layout Root of the loosened box tree + * \param width Width the content is intended to fit + * \param height Height of a single page - to be taken into consideration for \ + * preventing elements for being cropped at top/bottom edges of pages. + * \return true if successful, false otherwise (lack of memory) +*/ +bool loosen_document_layout(struct content *content, struct box *layout, + int width, int height) +{ + /* Optional try - if the current layout is not more than xx% too wide, + * maybe we scale the content to preserve the original layout? + */ + + if (!loosen_all_first_pass(layout, width, 0, content)) + return false; + layout->min_width = 0; + layout->max_width = UNKNOWN_MAX_WIDTH; + content_reformat(content, width, 0); + + /*Check if pass 1 was enough - if re-layouting doesn't give + *us the right width, go on to pass 2. And again - if pass 2 was not + *enough - go on to pass 3 + */ + + if (content->width > width) { + if (!loosen_all_second_pass(layout, width, 0, content)) + return false; + layout->min_width = 0; + layout->max_width = UNKNOWN_MAX_WIDTH; + content_reformat(content, width, 0); + } + + if (content->width > width) { + if (!loosen_all_third_pass(layout, width, 0, content)) + return false; + layout->min_width = 0; + layout->max_width = UNKNOWN_MAX_WIDTH; + content_reformat(content, width, 0); + } + + return true; +} + +/** Primarily - break too wide words into pieces. + * \param text - the box that contains text to be broken + * \param width Width the content is intended to fit + * \param content talloc memory pool for new boxes + * \return true if successful, false otherwise +*/ +bool loosen_text(struct box *text, int width, struct content *content) +{ + unsigned int offset; + int actual_x; + + int *breaks; + int break_count; + + int position, i; + const struct font_functions *font_func; + + if (content->type == CONTENT_HTML) + font_func = content->data.html.font_func; + else + return false; + + if (text->width <= width) { + LOG(("loosen_text called unnecessary?")); + /*Still - not an error for this function*/ + return true; + } + + breaks = malloc( sizeof(int) * text->length); + if (breaks == NULL) + return false; + + break_count = 0; + position = 0; + + while (position < text->length) { + font_func->font_position_in_string(text->style, + text->text + position, + text->length - position, + width, &offset, &actual_x); + + if (offset < text->length - position) { + /*Another break*/ + LOG(("Current text broken at offset %d", + position + offset)); + breaks[break_count++] = position + offset-1; + } + + position += offset; + } + + text->text = talloc_realloc(content, text->text, char, + text->length + break_count); + + i = text->length-1; + text->length = text->length + break_count; + + for (; i>=0; i--) { + text->text[i + break_count] = text->text[i]; + if (i == breaks[break_count - 1]) { + break_count--; + text->text[i + break_count] = ' '; + } + } + + free(breaks); + + return true; +} + +/** + * Changing table layout and structure to fit the contents width. + * In the most extreme case - the table has no influence on the width + * (each row is broken into one-cell rows). + * \param table - the box that contains table to be broken + * \param width Width the content is intended to fit + * \param content talloc memory pool for new boxes + * \return true if successful, false otherwise + */ +bool loosen_table(struct box *table, int width, struct content *content) +{ + + struct box *row_group, *row, *cell, *br, *prev, *inline_container; + unsigned int row_sum; + bool first_cell_in_row; + + if (table->min_width <= width) + return true; + + inline_container = box_create(0, 0, 0, 0, 0, content); + inline_container->type = BOX_INLINE_CONTAINER; + inline_container->parent = table; + inline_container->style = talloc_memdup(content, table->style, + sizeof *table->style); + + prev = NULL; + + 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) { + cell->type = BOX_INLINE_BLOCK; + cell->prev = prev; + cell->parent = inline_container; + cell->max_width = width; + cell->min_width = 0; + + if (prev!=NULL) + prev->next = cell; + else + inline_container->children = cell; + + prev = cell; + } + + br = box_create(0, 0, 0, 0, 0, content); + br->type = BOX_BR; + br->parent = inline_container; + br->prev = prev; + br->style = talloc_memdup(content, table->style, + sizeof *table->style); + br->style->clear = CSS_CLEAR_BOTH; + + if (prev != NULL) + prev->next = br; + else + inline_container->children = br; + + prev = br; + } + } + inline_container->last = prev; + + table->type = BOX_BLOCK; + table->children = table->last = inline_container; + table->col = NULL; + + return true; +} + + +/** + * Change absolute and relative positioned elements into block elements + * in case they are positioned to far to the rigth + * \param box - the box that should be changed + * \param width Width the content is intended to fit + * \param cx current x - not yet in use + * \param content talloc memory pool for new boxes + * \return true if successful, false otherwise + */ +bool loosen_position_static(struct box *box, int width, int cx, + struct content *content) +{ + assert(box->style); + + if (box->style->position == CSS_POSITION_ABSOLUTE) { + box->style->position = CSS_POSITION_NOT_SET; + } + + return true; +} + +/** + * Shrink an object (esp. an image) to fit the page-width + * \note Not sure wheter it won't be better for images to be cropped + * \param box - the box that should be changed + * \param width Width the content is intended to fit + * \return true if successful, false otherwise +*/ +bool loosen_shrink_object(struct box *box, int width) +{ + assert(box->object != NULL); + + box->height = AUTO; + box->width = width; + + if (box->style) { + box->style->width.width = CSS_WIDTH_PERCENT; + box->style->width.value.percent = 100; + box->style->height.height= CSS_HEIGHT_AUTO; + } + + return true; +} + +/** + * Pass 1 of loosening - do such obvious changes as: breaking too long words, + * moving absolute positioned objects into the visibile scope of width. + * \param box - the box that should be changed + * \param width Width the content is intended to fit + * \param cx current x - not yet in use + * \param content talloc memory pool for new boxes + * \return true if successful, false otherwise +*/ +bool loosen_all_first_pass(struct box *box, int width, int cx, + struct content *content) +{ + struct box* c; + int got_width; + int x; + + for (c = box->children; c ; c = c->next) { + x = cx + c->x; + if (c->children != NULL) + if (!loosen_all_first_pass(c, width, x, content)) + return false; + + if (c->style) { + if (c->style->position == CSS_POSITION_RELATIVE || + c->style->position == CSS_POSITION_ABSOLUTE ) + if (!loosen_position_static(c, width, cx, content)) + return false; + if ( c->style->width.width == CSS_WIDTH_LENGTH && + css_len2px(&c->style->width.value.length, c->style) > width) + c->style->width.width = CSS_WIDTH_NOT_SET; + } + + if (c->object && c->width > width) + if (!loosen_shrink_object(c, width)) + return false; + + switch (c->type) { + case BOX_TEXT: + if (!loosen_text(c, width, content)) + return false; + break; + } + + c->min_width = 0; + c->max_width = UNKNOWN_MAX_WIDTH; + + } + + return true; +} + +/** + * Pass 2 of loosening - break tables + * \param box - the box that should be changed + * \param width Width the content is intended to fit + * \param cx current x - not yet in use + * \param content talloc memory pool for new boxes + * \return true if successful, false otherwise + */ +bool loosen_all_second_pass(struct box *box, int width, int cx, + struct content *content) +{ + struct box *c; + int got_width; + int x; + + for (c = box->children; c; c = c->next) { + x = cx + c->x; + if (c->children != NULL) + if (!loosen_all_second_pass(c, width, x, content)) + return false; + + switch (c->type) { + case BOX_TABLE: + if (!loosen_table(c, width, content)) + return false; + break; + } + + c->min_width = 0; + c->max_width = UNKNOWN_MAX_WIDTH; + } + + return true; +} + + +/** + * Pass 3 of loosening -zero all margins and paddings + * \param box - the box that should be changed + * \param width Width the content is intended to fit + * \param cx current x - not yet in use + * \param content talloc memory pool for new boxes + * \return true if successful, false otherwise + */ +bool loosen_all_third_pass(struct box *box, int width, int cx, + struct content *content) +{ + struct box *c; + int got_width; + int x; + + for (c = box->children; c; c = c->next) { + x = cx + c->x; + if (c->children != NULL) + if (!loosen_all_third_pass(c, width, x, content)) + return false; + + c->padding[LEFT] = c->padding[RIGHT] = 0; + c->margin[LEFT] = c->margin[RIGHT] = 0; + + if (c->style) { + c->style->margin[LEFT].margin = CSS_MARGIN_PERCENT; + c->style->margin[LEFT].value.percent = 0; + + c->style->margin[RIGHT].margin = CSS_MARGIN_PERCENT; + c->style->margin[RIGHT].value.percent = 0; + + c->style->padding[LEFT].padding = CSS_PADDING_PERCENT; + c->style->padding[LEFT].value.percent = 0; + + c->style->padding[RIGHT].padding = CSS_PADDING_PERCENT; + c->style->padding[RIGHT].value.percent = 0; + + } + + c->min_width = 0; + c->max_width = UNKNOWN_MAX_WIDTH; + + } + + return true; +} + |