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/*
* Copyright (C) 2006 Apple Computer, Inc. All rights reserved.
* Copyright (C) 2006 Michael Emmel mike.emmel@gmail.com
* Copyright (c) 2007 Hiroyuki Ikezoe
* Copyright (c) 2007 Kouhei Sutou
* Copyright (C) 2007 Alp Toker <alp@atoker.com>
* Copyright (C) 2008 Xan Lopez <xan@gnome.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "Font.h"
#include "GraphicsContext.h"
#include "NotImplemented.h"
#include "SimpleFontData.h"
#include <cairo.h>
#include <pango/pango.h>
#include <pango/pangocairo.h>
namespace WebCore {
#define IS_HIGH_SURROGATE(u) ((UChar)(u) >= (UChar)0xd800 && (UChar)(u) <= (UChar)0xdbff)
#define IS_LOW_SURROGATE(u) ((UChar)(u) >= (UChar)0xdc00 && (UChar)(u) <= (UChar)0xdfff)
static void utf16_to_utf8(const UChar* aText, gint aLength, char* &text, gint &length)
{
gboolean need_copy = FALSE;
int i;
for (i = 0; i < aLength; i++) {
if (!aText[i] || IS_LOW_SURROGATE(aText[i])) {
need_copy = TRUE;
break;
}
else if (IS_HIGH_SURROGATE(aText[i])) {
if (i < aLength - 1 && IS_LOW_SURROGATE(aText[i+1]))
i++;
else {
need_copy = TRUE;
break;
}
}
}
if (need_copy) {
/* Pango doesn't correctly handle nuls. We convert them to 0xff. */
/* Also "validate" UTF-16 text to make sure conversion doesn't fail. */
UChar* p = (UChar*)g_memdup(aText, aLength * sizeof(aText[0]));
/* don't need to reset i */
for (i = 0; i < aLength; i++) {
if (!p[i] || IS_LOW_SURROGATE(p[i]))
p[i] = 0xFFFD;
else if (IS_HIGH_SURROGATE(p[i])) {
if (i < aLength - 1 && IS_LOW_SURROGATE(aText[i+1]))
i++;
else
p[i] = 0xFFFD;
}
}
aText = p;
}
glong items_written;
text = g_utf16_to_utf8(aText, aLength, NULL, &items_written, NULL);
length = items_written;
if (need_copy)
g_free((gpointer)aText);
}
static gchar* convertUniCharToUTF8(const UChar* characters, gint length, int from, int to)
{
gchar* utf8 = 0;
gint new_length = 0;
utf16_to_utf8(characters, length, utf8, new_length);
if (!utf8)
return NULL;
if (from > 0) {
// discard the first 'from' characters
// FIXME: we should do this before the conversion probably
gchar* str_left = g_utf8_offset_to_pointer(utf8, from);
gchar* tmp = g_strdup(str_left);
g_free(utf8);
utf8 = tmp;
}
gchar* pos = utf8;
gint len = strlen(pos);
GString* ret = g_string_new_len(NULL, len);
// replace line break by space
while (len > 0) {
gint index, start;
pango_find_paragraph_boundary(pos, len, &index, &start);
g_string_append_len(ret, pos, index);
if (index == start)
break;
g_string_append_c(ret, ' ');
pos += start;
len -= start;
}
return g_string_free(ret, FALSE);
}
static void setPangoAttributes(const Font* font, const TextRun& run, PangoLayout* layout)
{
PangoAttrList* list = pango_attr_list_new();
PangoAttribute* attr;
attr = pango_attr_size_new_absolute((int)(font->size() * PANGO_SCALE));
attr->end_index = G_MAXUINT;
pango_attr_list_insert_before(list, attr);
if (!run.spacingDisabled()) {
attr = pango_attr_letter_spacing_new(font->letterSpacing() * PANGO_SCALE);
attr->end_index = G_MAXUINT;
pango_attr_list_insert_before(list, attr);
}
// Pango does not yet support synthesising small caps
// See http://bugs.webkit.org/show_bug.cgi?id=15610
pango_layout_set_attributes(layout, list);
pango_attr_list_unref(list);
pango_layout_set_auto_dir(layout, FALSE);
PangoContext* pangoContext = pango_layout_get_context(layout);
PangoDirection direction = run.rtl() ? PANGO_DIRECTION_RTL : PANGO_DIRECTION_LTR;
pango_context_set_base_dir(pangoContext, direction);
}
void Font::drawComplexText(GraphicsContext* context, const TextRun& run, const FloatPoint& point, int from, int to) const
{
cairo_t* cr = context->platformContext();
cairo_save(cr);
PangoLayout* layout = pango_cairo_create_layout(cr);
gchar* utf8 = convertUniCharToUTF8(run.characters(), run.length(), from, to);
pango_layout_set_text(layout, utf8, -1);
g_free(utf8);
setPangoAttributes(this, run, layout);
// Set the text color to use for drawing.
float red, green, blue, alpha;
Color penColor = context->fillColor();
penColor.getRGBA(red, green, blue, alpha);
cairo_set_source_rgba(cr, red, green, blue, alpha);
// Our layouts are single line
cairo_move_to(cr, point.x(), point.y());
PangoLayoutLine* layoutLine = pango_layout_get_line_readonly(layout, 0);
pango_cairo_show_layout_line(cr, layoutLine);
g_object_unref(layout);
cairo_restore(cr);
}
// FIXME: we should create the layout with our actual context, but it seems
// we can't access it from here
static PangoLayout* getDefaultPangoLayout(const TextRun& run)
{
PangoFontMap* map = pango_cairo_font_map_get_default();
PangoContext* pangoContext = pango_cairo_font_map_create_context(PANGO_CAIRO_FONT_MAP(map));
PangoLayout* layout = pango_layout_new(pangoContext);
g_object_unref(pangoContext);
return layout;
}
float Font::floatWidthForComplexText(const TextRun& run) const
{
if (run.length() == 0)
return 0.0f;
PangoLayout* layout = getDefaultPangoLayout(run);
setPangoAttributes(this, run, layout);
gchar* utf8 = convertUniCharToUTF8(run.characters(), run.length(), 0, run.length());
pango_layout_set_text(layout, utf8, -1);
g_free(utf8);
int layoutWidth;
pango_layout_get_size(layout, &layoutWidth, 0);
float width = (float)layoutWidth / (double)PANGO_SCALE;
g_object_unref(layout);
return width;
}
int Font::offsetForPositionForComplexText(const TextRun& run, int x, bool includePartialGlyphs) const
{
PangoLayout* layout = getDefaultPangoLayout(run);
setPangoAttributes(this, run, layout);
gchar* utf8 = convertUniCharToUTF8(run.characters(), run.length(), 0, run.length());
pango_layout_set_text(layout, utf8, -1);
int index, trailing;
pango_layout_xy_to_index(layout, x * PANGO_SCALE, 1, &index, &trailing);
glong offset = g_utf8_pointer_to_offset(utf8, utf8 + index);
g_free(utf8);
g_object_unref(layout);
return offset;
}
FloatRect Font::selectionRectForComplexText(const TextRun& run, const IntPoint& point, int h, int from, int to) const
{
notImplemented();
return FloatRect();
}
}
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