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-rw-r--r--frontends/gtk/layout_pango.c309
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diff --git a/frontends/gtk/layout_pango.c b/frontends/gtk/layout_pango.c
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+/*
+ * Copyright 2005 James Bursa <bursa@users.sourceforge.net>
+ *
+ * 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/>.
+ */
+
+/**
+ * \file
+ * GTK implementation of layout handling using pango.
+ *
+ * Pango is used handle and render fonts.
+ */
+
+
+#include <assert.h>
+#include <stdio.h>
+#include <gtk/gtk.h>
+
+#include "utils/log.h"
+#include "utils/nsoption.h"
+#include "desktop/gui_layout.h"
+
+#include "gtk/layout_pango.h"
+#include "gtk/plotters.h"
+
+static PangoContext *nsfont_pango_context = NULL;
+static PangoLayout *nsfont_pango_layout = NULL;
+
+static inline void nsfont_pango_check(void)
+{
+ if (nsfont_pango_context == NULL) {
+ LOG("Creating nsfont_pango_context.");
+ nsfont_pango_context = gdk_pango_context_get();
+ }
+
+ if (nsfont_pango_layout == NULL) {
+ LOG("Creating nsfont_pango_layout.");
+ nsfont_pango_layout = pango_layout_new(nsfont_pango_context);
+ }
+}
+
+/**
+ * Measure the width of a string.
+ *
+ * \param[in] fstyle plot style for this text
+ * \param[in] string UTF-8 string to measure
+ * \param[in] length length of string, in bytes
+ * \param[out] width updated to width of string[0..length)
+ * \return NSERROR_OK and width updated or appropriate error code on faliure
+ */
+static nserror
+nsfont_width(const plot_font_style_t *fstyle,
+ const char *string,
+ size_t length,
+ int *width)
+{
+ PangoFontDescription *desc;
+
+ if (length == 0) {
+ *width = 0;
+ return NSERROR_OK;
+ }
+
+ nsfont_pango_check();
+
+ desc = nsfont_style_to_description(fstyle);
+ pango_layout_set_font_description(nsfont_pango_layout, desc);
+ pango_font_description_free(desc);
+
+ pango_layout_set_text(nsfont_pango_layout, string, length);
+
+ pango_layout_get_pixel_size(nsfont_pango_layout, width, 0);
+
+ /* LOG("fstyle: %p string:\"%.*s\", length: %u, width: %dpx",
+ fstyle, length, string, length, *width);
+ */
+
+ return NSERROR_OK;
+}
+
+
+/**
+ * Find the position in a string where an x coordinate falls.
+ *
+ * \param[in] fstyle style for this text
+ * \param[in] string UTF-8 string to measure
+ * \param[in] length length of string, in bytes
+ * \param[in] x coordinate to search for
+ * \param[out] char_offset updated to offset in string of actual_x, [0..length]
+ * \param[out] actual_x updated to x coordinate of character closest to x
+ * \return NSERROR_OK and char_offset and actual_x updated or appropriate
+ * error code on faliure
+ */
+static nserror
+nsfont_position_in_string(const plot_font_style_t *fstyle,
+ const char *string,
+ size_t length,
+ int x,
+ size_t *char_offset,
+ int *actual_x)
+{
+ int index;
+ PangoFontDescription *desc;
+ PangoRectangle pos;
+
+ nsfont_pango_check();
+
+ desc = nsfont_style_to_description(fstyle);
+ pango_layout_set_font_description(nsfont_pango_layout, desc);
+ pango_font_description_free(desc);
+
+ pango_layout_set_text(nsfont_pango_layout, string, length);
+
+ if (pango_layout_xy_to_index(nsfont_pango_layout,
+ x * PANGO_SCALE,
+ 0, &index, 0) == FALSE) {
+ index = length;
+ }
+
+ pango_layout_index_to_pos(nsfont_pango_layout, index, &pos);
+
+ *char_offset = index;
+ *actual_x = PANGO_PIXELS(pos.x);
+
+ return NSERROR_OK;
+}
+
+
+/**
+ * Find where to split a string to make it fit a width.
+ *
+ * \param[in] fstyle style for this text
+ * \param[in] string UTF-8 string to measure
+ * \param[in] length length of string, in bytes
+ * \param[in] x width available
+ * \param[out] char_offset updated to offset in string of actual_x, [1..length]
+ * \param[out] actual_x updated to x coordinate of character closest to x
+ * \return NSERROR_OK or appropriate error code on faliure
+ *
+ * On exit, char_offset indicates first character after split point.
+ *
+ * \note char_offset of 0 must never be returned.
+ *
+ * Returns:
+ * char_offset giving split point closest to x, where actual_x <= x
+ * else
+ * char_offset giving split point closest to x, where actual_x > x
+ *
+ * Returning char_offset == length means no split possible
+ */
+static nserror
+nsfont_split(const plot_font_style_t *fstyle,
+ const char *string,
+ size_t length,
+ int x,
+ size_t *char_offset,
+ int *actual_x)
+{
+ int index = length;
+ PangoFontDescription *desc;
+ PangoContext *context;
+ PangoLayout *layout;
+ PangoLayoutLine *line;
+
+ context = gdk_pango_context_get();
+ layout = pango_layout_new(context);
+
+ desc = nsfont_style_to_description(fstyle);
+ pango_layout_set_font_description(layout, desc);
+ pango_font_description_free(desc);
+
+ pango_layout_set_text(layout, string, length);
+
+ /* Limit width of layout to the available width */
+ pango_layout_set_width(layout, x * PANGO_SCALE);
+
+ /* Request word wrapping */
+ pango_layout_set_wrap(layout, PANGO_WRAP_WORD);
+
+ /* Prevent pango treating linebreak characters as line breaks */
+ pango_layout_set_single_paragraph_mode(layout, TRUE);
+
+ /* Obtain the second line of the layout (if there is one) */
+ line = pango_layout_get_line(layout, 1);
+ if (line != NULL) {
+ /* Pango split the text. The line's start_index indicates the
+ * start of the character after the line break. */
+ index = line->start_index;
+ }
+
+ g_object_unref(layout);
+ g_object_unref(context);
+
+ *char_offset = index;
+ /* Obtain the pixel offset of the split character */
+ nsfont_width(fstyle, string, index, actual_x);
+
+ return NSERROR_OK;
+}
+
+
+/**
+ * Render a string.
+ *
+ * \param x x coordinate
+ * \param y y coordinate
+ * \param string UTF-8 string to measure
+ * \param length length of string
+ * \param fstyle plot style for this text
+ * \return true on success, false on error and error reported
+ */
+bool nsfont_paint(int x, int y, const char *string, size_t length,
+ const plot_font_style_t *fstyle)
+{
+ PangoFontDescription *desc;
+ PangoLayout *layout;
+ PangoLayoutLine *line;
+
+ if (length == 0)
+ return true;
+
+ layout = pango_cairo_create_layout(current_cr);
+
+ desc = nsfont_style_to_description(fstyle);
+ pango_layout_set_font_description(layout, desc);
+ pango_font_description_free(desc);
+
+ pango_layout_set_text(layout, string, length);
+
+ line = pango_layout_get_line_readonly(layout, 0);
+ cairo_move_to(current_cr, x, y);
+ nsgtk_set_colour(fstyle->foreground);
+ pango_cairo_show_layout_line(current_cr, line);
+
+ g_object_unref(layout);
+
+ return true;
+}
+
+
+/* exported interface documented in gtk/layout_pango.h */
+PangoFontDescription *
+nsfont_style_to_description(const plot_font_style_t *fstyle)
+{
+ unsigned int size;
+ PangoFontDescription *desc;
+ PangoStyle style = PANGO_STYLE_NORMAL;
+
+ switch (fstyle->family) {
+ case PLOT_FONT_FAMILY_SERIF:
+ desc = pango_font_description_from_string(nsoption_charp(font_serif));
+ break;
+ case PLOT_FONT_FAMILY_MONOSPACE:
+ desc = pango_font_description_from_string(nsoption_charp(font_mono));
+ break;
+ case PLOT_FONT_FAMILY_CURSIVE:
+ desc = pango_font_description_from_string(nsoption_charp(font_cursive));
+ break;
+ case PLOT_FONT_FAMILY_FANTASY:
+ desc = pango_font_description_from_string(nsoption_charp(font_fantasy));
+ break;
+ case PLOT_FONT_FAMILY_SANS_SERIF:
+ default:
+ desc = pango_font_description_from_string(nsoption_charp(font_sans));
+ break;
+ }
+
+ size = (fstyle->size * PANGO_SCALE) / FONT_SIZE_SCALE;
+
+ if (fstyle->flags & FONTF_ITALIC)
+ style = PANGO_STYLE_ITALIC;
+ else if (fstyle->flags & FONTF_OBLIQUE)
+ style = PANGO_STYLE_OBLIQUE;
+
+ pango_font_description_set_style(desc, style);
+
+ pango_font_description_set_weight(desc, (PangoWeight) fstyle->weight);
+
+ pango_font_description_set_size(desc, size);
+
+ if (fstyle->flags & FONTF_SMALLCAPS) {
+ pango_font_description_set_variant(desc,
+ PANGO_VARIANT_SMALL_CAPS);
+ } else {
+ pango_font_description_set_variant(desc, PANGO_VARIANT_NORMAL);
+ }
+
+ return desc;
+}
+
+static struct gui_layout_table layout_table = {
+ .width = nsfont_width,
+ .position = nsfont_position_in_string,
+ .split = nsfont_split,
+};
+
+struct gui_layout_table *nsgtk_layout_table = &layout_table;