gtk/gdk/gdkpango.c
Owen Taylor f9a478644e When drawing underlines, join up adjacent runs where possible, so we don't
Wed Jun  4 19:42:17 2003  Owen Taylor  <otaylor@redhat.com>

        * gdk/gdkpango.c (gdk_draw_layout_line_with_colors):
        When drawing underlines, join up adjacent runs
        where possible, so we don't get changes in
        shaper/font/etc. breaking underlines. (#103662,
        Kang Jeong-Hee)
2003-06-04 23:47:23 +00:00

924 lines
27 KiB
C

/* GDK - The GIMP Drawing Kit
* Copyright (C) 2000 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "gdkcolor.h"
#include "gdkgc.h"
#include "gdkpango.h"
#include "gdkrgb.h"
#include "gdkprivate.h"
#include "gdkscreen.h"
#define GDK_INFO_KEY "gdk-info"
typedef struct _GdkPangoContextInfo GdkPangoContextInfo;
struct _GdkPangoContextInfo
{
GdkColormap *colormap;
};
static PangoAttrType gdk_pango_attr_stipple_type;
static PangoAttrType gdk_pango_attr_embossed_type;
static void gdk_pango_get_item_properties (PangoItem *item,
PangoUnderline *uline,
gboolean *strikethrough,
gint *rise,
PangoColor *fg_color,
gboolean *fg_set,
PangoColor *bg_color,
gboolean *bg_set,
gboolean *embossed,
GdkBitmap **stipple,
gboolean *shape_set,
PangoRectangle *ink_rect,
PangoRectangle *logical_rect);
static void
gdk_pango_context_destroy (GdkPangoContextInfo *info)
{
if (info->colormap)
g_object_unref (info->colormap);
g_free (info);
}
static GdkPangoContextInfo *
gdk_pango_context_get_info (PangoContext *context, gboolean create)
{
GdkPangoContextInfo *info =
g_object_get_qdata (G_OBJECT (context),
g_quark_try_string (GDK_INFO_KEY));
if (!info && create)
{
info = g_new (GdkPangoContextInfo, 1);
info->colormap = NULL;
g_object_set_qdata_full (G_OBJECT (context),
g_quark_from_static_string (GDK_INFO_KEY),
info, (GDestroyNotify)gdk_pango_context_destroy);
}
return info;
}
static GdkGC *
gdk_pango_get_gc (GdkDrawable *drawable,
PangoContext *context,
PangoColor *fg_color,
GdkBitmap *stipple,
GdkGC *base_gc)
{
GdkGC *result;
GdkPangoContextInfo *info;
g_return_val_if_fail (context != NULL, NULL);
info = gdk_pango_context_get_info (context, FALSE);
if (info == NULL || info->colormap == NULL)
{
g_warning ("you must set the colormap on a PangoContext before using it to draw a layout");
return NULL;
}
result = gdk_gc_new (drawable);
gdk_gc_copy (result, base_gc);
if (fg_color)
{
GdkColor color;
color.red = fg_color->red;
color.green = fg_color->green;
color.blue = fg_color->blue;
gdk_rgb_find_color (info->colormap, &color);
gdk_gc_set_foreground (result, &color);
}
if (stipple)
{
gdk_gc_set_fill (result, GDK_STIPPLED);
gdk_gc_set_stipple (result, stipple);
}
return result;
}
static void
gdk_pango_free_gc (PangoContext *context,
GdkGC *gc)
{
g_object_unref (gc);
}
/**
* gdk_pango_context_set_colormap:
* @context: a #PangoContext
* @colormap: a #GdkColormap
*
* Sets the colormap to be used for drawing with @context.
* If you obtained your context from gtk_widget_get_pango_context() or
* gtk_widget_create_pango_context(), the colormap will already be set
* to the colormap for the widget, so you shouldn't need this
* function.
*
**/
void
gdk_pango_context_set_colormap (PangoContext *context,
GdkColormap *colormap)
{
GdkPangoContextInfo *info;
g_return_if_fail (context != NULL);
info = gdk_pango_context_get_info (context, TRUE);
g_return_if_fail (info != NULL);
if (info->colormap != colormap)
{
if (info->colormap)
g_object_unref (info->colormap);
info->colormap = colormap;
if (info->colormap)
g_object_ref (info->colormap);
}
}
static void
draw_underline (GdkDrawable *drawable,
GdkGC *gc,
PangoUnderline uline,
int baseline_y,
int low_y,
int start_x,
int end_x)
{
switch (uline)
{
case PANGO_UNDERLINE_NONE:
break;
case PANGO_UNDERLINE_DOUBLE:
gdk_draw_line (drawable, gc,
start_x, baseline_y + 3,
end_x, baseline_y + 3);
/* Fall through */
case PANGO_UNDERLINE_SINGLE:
gdk_draw_line (drawable, gc,
start_x, baseline_y + 1,
end_x, baseline_y + 1);
break;
case PANGO_UNDERLINE_LOW:
gdk_draw_line (drawable, gc,
start_x, low_y + 1,
end_x, low_y + 1);
break;
}
}
/**
* gdk_draw_layout_line_with_colors:
* @drawable: the drawable on which to draw the line
* @gc: base graphics to use
* @x: the x position of start of string (in pixels)
* @y: the y position of baseline (in pixels)
* @line: a #PangoLayoutLine
* @foreground: foreground override color, or %NULL for none
* @background: background override color, or %NULL for none
*
* Render a #PangoLayoutLine onto a #GdkDrawable, overriding the
* layout's normal colors with @foreground and/or @background.
* @foreground and @background need not be allocated.
*/
void
gdk_draw_layout_line_with_colors (GdkDrawable *drawable,
GdkGC *gc,
gint x,
gint y,
PangoLayoutLine *line,
GdkColor *foreground,
GdkColor *background)
{
GSList *tmp_list = line->runs;
PangoRectangle overall_rect;
PangoRectangle logical_rect;
PangoRectangle ink_rect;
PangoContext *context;
gint x_off = 0;
gint rise = 0;
gboolean embossed;
GdkBitmap *stipple;
PangoUnderline last_uline = PANGO_UNDERLINE_NONE;
gint uline_start_x = 0;
gint uline_end_x = 0;
gint uline_end_x_extended = 0;
gint last_risen_y = 0;
gint low_y = G_MININT;
GdkGC *last_fg_gc = NULL;
gboolean last_fg_set = FALSE;
PangoColor last_fg_color;
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
g_return_if_fail (line != NULL);
context = pango_layout_get_context (line->layout);
pango_layout_line_get_extents (line,NULL, &overall_rect);
while (tmp_list)
{
PangoUnderline this_uline = PANGO_UNDERLINE_NONE;
PangoLayoutRun *run = tmp_list->data;
PangoColor fg_color, bg_color;
gboolean strike, fg_set, bg_set, shape_set;
GdkGC *fg_gc;
gint risen_y;
tmp_list = tmp_list->next;
gdk_pango_get_item_properties (run->item, &this_uline,
&strike,
&rise,
&fg_color, &fg_set,
&bg_color, &bg_set,
&embossed,
&stipple,
&shape_set,
&ink_rect,
&logical_rect);
/* we subtract the rise because X coordinates are upside down */
risen_y = y - rise / PANGO_SCALE;
if (!shape_set)
{
if (this_uline == PANGO_UNDERLINE_NONE)
pango_glyph_string_extents (run->glyphs, run->item->analysis.font,
NULL, &logical_rect);
else
pango_glyph_string_extents (run->glyphs, run->item->analysis.font,
&ink_rect, &logical_rect);
}
if (bg_set || background)
{
GdkGC *bg_gc;
PangoColor tmp = bg_color;
if (background)
{
tmp.red = background->red;
tmp.blue = background->blue;
tmp.green = background->green;
}
bg_gc = gdk_pango_get_gc (drawable, context, &tmp, stipple, gc);
gdk_draw_rectangle (drawable, bg_gc, TRUE,
x + (x_off + logical_rect.x) / PANGO_SCALE,
risen_y + overall_rect.y / PANGO_SCALE,
logical_rect.width / PANGO_SCALE,
overall_rect.height / PANGO_SCALE);
if (stipple)
gdk_gc_set_fill (bg_gc, GDK_SOLID);
gdk_pango_free_gc (context, bg_gc);
}
if (fg_set || stipple || foreground)
{
PangoColor tmp = fg_color;
if (foreground)
{
tmp.red = foreground->red;
tmp.blue = foreground->blue;
tmp.green = foreground->green;
}
fg_gc = gdk_pango_get_gc (drawable, context, (fg_set || foreground) ? &tmp : NULL,
stipple, gc);
}
else
fg_gc = gc;
if (!shape_set)
{
gint gx, gy;
gx = x + x_off / PANGO_SCALE;
gy = risen_y;
if (embossed)
{
PangoColor color = { 65535, 65535, 65535 };
GdkGC *white_gc = gdk_pango_get_gc (drawable, context, &color, stipple, fg_gc);
gdk_draw_glyphs (drawable, white_gc, run->item->analysis.font,
gx + 1,
gy + 1,
run->glyphs);
gdk_pango_free_gc (context, white_gc);
}
gdk_draw_glyphs (drawable, fg_gc, run->item->analysis.font,
gx, gy,
run->glyphs);
}
if (this_uline != last_uline ||
risen_y != last_risen_y ||
fg_set != last_fg_set ||
(fg_set && (last_fg_color.red != fg_color.red ||
last_fg_color.green != fg_color.green ||
last_fg_color.blue != fg_color.blue)))
{
/* If only color changes, the underlines extend to the edge
* of the logical rectangle so they join up; otherwise they
* go 1 pixel beyond the ink rectangle. This doesn't work
* for low underlines (they will be at a different y anyways),
* so they follow the normal path.
*/
gboolean extend_uline = (this_uline == last_uline &&
this_uline != PANGO_UNDERLINE_LOW &&
risen_y == last_risen_y);
/* Starting a new underline run
*/
if (last_uline != PANGO_UNDERLINE_NONE)
{
draw_underline (drawable, last_fg_gc, last_uline,
last_risen_y, low_y,
uline_start_x,
extend_uline ? uline_end_x_extended : uline_end_x);
}
if (this_uline != PANGO_UNDERLINE_NONE)
{
if (extend_uline)
uline_start_x = x + x_off / PANGO_SCALE;
else
uline_start_x = x + (x_off + ink_rect.x) / PANGO_SCALE - 1;
low_y = G_MININT;
}
}
/* Update current underline segment information
*/
if (this_uline != PANGO_UNDERLINE_NONE)
{
uline_end_x = x + (x_off + ink_rect.x + ink_rect.width) / PANGO_SCALE;
uline_end_x_extended = x + (x_off + logical_rect.x + logical_rect.width) / PANGO_SCALE - 1;
}
if (this_uline == PANGO_UNDERLINE_LOW)
low_y = MAX (low_y, risen_y + (ink_rect.y + ink_rect.height) / PANGO_SCALE);
if (strike)
{
int centerline = logical_rect.y + logical_rect.height / 2;
gdk_draw_line (drawable, fg_gc,
x + (x_off + logical_rect.x) / PANGO_SCALE - 1,
risen_y + centerline / PANGO_SCALE,
x + (x_off + logical_rect.x + logical_rect.width) / PANGO_SCALE + 1,
risen_y + centerline / PANGO_SCALE);
}
if (last_fg_gc != gc && last_fg_gc)
gdk_pango_free_gc (context, last_fg_gc);
last_risen_y = risen_y;
last_uline = this_uline;
last_fg_gc = fg_gc;
last_fg_set = fg_set;
if (fg_set)
last_fg_color = fg_color;
x_off += logical_rect.width;
}
/* Finish off any remaining underlines
*/
if (last_uline != PANGO_UNDERLINE_NONE)
draw_underline (drawable, last_fg_gc, last_uline, last_risen_y, low_y,
uline_start_x, uline_end_x);
if (last_fg_gc != gc && last_fg_gc)
gdk_pango_free_gc (context, last_fg_gc);
}
/**
* gdk_draw_layout_with_colors:
* @drawable: the drawable on which to draw string
* @gc: base graphics context to use
* @x: the X position of the left of the layout (in pixels)
* @y: the Y position of the top of the layout (in pixels)
* @layout: a #PangoLayout
* @foreground: foreground override color, or %NULL for none
* @background: background override color, or %NULL for none
*
* Render a #PangoLayout onto a #GdkDrawable, overriding the
* layout's normal colors with @foreground and/or @background.
* @foreground and @background need not be allocated.
*/
void
gdk_draw_layout_with_colors (GdkDrawable *drawable,
GdkGC *gc,
int x,
int y,
PangoLayout *layout,
GdkColor *foreground,
GdkColor *background)
{
PangoLayoutIter *iter;
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
g_return_if_fail (PANGO_IS_LAYOUT (layout));
iter = pango_layout_get_iter (layout);
do
{
PangoRectangle logical_rect;
PangoLayoutLine *line;
int baseline;
line = pango_layout_iter_get_line (iter);
pango_layout_iter_get_line_extents (iter, NULL, &logical_rect);
baseline = pango_layout_iter_get_baseline (iter);
gdk_draw_layout_line_with_colors (drawable, gc,
x + logical_rect.x / PANGO_SCALE,
y + baseline / PANGO_SCALE,
line,
foreground,
background);
}
while (pango_layout_iter_next_line (iter));
pango_layout_iter_free (iter);
}
/**
* gdk_draw_layout_line:
* @drawable: the drawable on which to draw the line
* @gc: base graphics to use
* @x: the x position of start of string (in pixels)
* @y: the y position of baseline (in pixels)
* @line: a #PangoLayoutLine
*
* Render a #PangoLayoutLine onto an GDK drawable
*/
void
gdk_draw_layout_line (GdkDrawable *drawable,
GdkGC *gc,
gint x,
gint y,
PangoLayoutLine *line)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
g_return_if_fail (line != NULL);
gdk_draw_layout_line_with_colors (drawable, gc, x, y, line, NULL, NULL);
}
/**
* gdk_draw_layout:
* @drawable: the drawable on which to draw string
* @gc: base graphics context to use
* @x: the X position of the left of the layout (in pixels)
* @y: the Y position of the top of the layout (in pixels)
* @layout: a #PangoLayout
*
* Render a #PangoLayout onto a GDK drawable
*/
void
gdk_draw_layout (GdkDrawable *drawable,
GdkGC *gc,
int x,
int y,
PangoLayout *layout)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
g_return_if_fail (PANGO_IS_LAYOUT (layout));
gdk_draw_layout_with_colors (drawable, gc, x, y, layout, NULL, NULL);
}
static void
gdk_pango_get_item_properties (PangoItem *item,
PangoUnderline *uline,
gboolean *strikethrough,
gint *rise,
PangoColor *fg_color,
gboolean *fg_set,
PangoColor *bg_color,
gboolean *bg_set,
gboolean *embossed,
GdkBitmap **stipple,
gboolean *shape_set,
PangoRectangle *ink_rect,
PangoRectangle *logical_rect)
{
GSList *tmp_list = item->analysis.extra_attrs;
if (strikethrough)
*strikethrough = FALSE;
if (fg_set)
*fg_set = FALSE;
if (bg_set)
*bg_set = FALSE;
if (shape_set)
*shape_set = FALSE;
if (rise)
*rise = 0;
if (embossed)
*embossed = FALSE;
if (stipple)
*stipple = NULL;
while (tmp_list)
{
PangoAttribute *attr = tmp_list->data;
switch (attr->klass->type)
{
case PANGO_ATTR_UNDERLINE:
if (uline)
*uline = ((PangoAttrInt *)attr)->value;
break;
case PANGO_ATTR_STRIKETHROUGH:
if (strikethrough)
*strikethrough = ((PangoAttrInt *)attr)->value;
break;
case PANGO_ATTR_FOREGROUND:
if (fg_color)
*fg_color = ((PangoAttrColor *)attr)->color;
if (fg_set)
*fg_set = TRUE;
break;
case PANGO_ATTR_BACKGROUND:
if (bg_color)
*bg_color = ((PangoAttrColor *)attr)->color;
if (bg_set)
*bg_set = TRUE;
break;
case PANGO_ATTR_SHAPE:
if (shape_set)
*shape_set = TRUE;
if (logical_rect)
*logical_rect = ((PangoAttrShape *)attr)->logical_rect;
if (ink_rect)
*ink_rect = ((PangoAttrShape *)attr)->ink_rect;
break;
case PANGO_ATTR_RISE:
if (rise)
*rise = ((PangoAttrInt *)attr)->value;
break;
default:
/* stipple_type and embossed_type aren't necessarily
* initialized, but they are 0, which is an
* invalid type so won't occur.
*/
if (stipple && attr->klass->type == gdk_pango_attr_stipple_type)
{
*stipple = ((GdkPangoAttrStipple*)attr)->stipple;
}
else if (embossed && attr->klass->type == gdk_pango_attr_embossed_type)
{
*embossed = ((GdkPangoAttrEmbossed*)attr)->embossed;
}
break;
}
tmp_list = tmp_list->next;
}
}
static PangoAttribute *
gdk_pango_attr_stipple_copy (const PangoAttribute *attr)
{
const GdkPangoAttrStipple *src = (const GdkPangoAttrStipple*) attr;
return gdk_pango_attr_stipple_new (src->stipple);
}
static void
gdk_pango_attr_stipple_destroy (PangoAttribute *attr)
{
GdkPangoAttrStipple *st = (GdkPangoAttrStipple*) attr;
if (st->stipple)
g_object_unref (st->stipple);
g_free (attr);
}
static gboolean
gdk_pango_attr_stipple_compare (const PangoAttribute *attr1,
const PangoAttribute *attr2)
{
const GdkPangoAttrStipple *a = (const GdkPangoAttrStipple*) attr1;
const GdkPangoAttrStipple *b = (const GdkPangoAttrStipple*) attr2;
return a->stipple == b->stipple;
}
/**
* gdk_pango_attr_stipple_new:
* @stipple: a bitmap to be set as stipple
*
* Creates a new attribute containing a stipple bitmap to be used when
* rendering the text.
*
* Return value: new #PangoAttribute
**/
PangoAttribute *
gdk_pango_attr_stipple_new (GdkBitmap *stipple)
{
GdkPangoAttrStipple *result;
static PangoAttrClass klass = {
0,
gdk_pango_attr_stipple_copy,
gdk_pango_attr_stipple_destroy,
gdk_pango_attr_stipple_compare
};
if (!klass.type)
klass.type = gdk_pango_attr_stipple_type =
pango_attr_type_register ("GdkPangoAttrStipple");
result = g_new (GdkPangoAttrStipple, 1);
result->attr.klass = &klass;
if (stipple)
g_object_ref (stipple);
result->stipple = stipple;
return (PangoAttribute *)result;
}
static PangoAttribute *
gdk_pango_attr_embossed_copy (const PangoAttribute *attr)
{
const GdkPangoAttrEmbossed *e = (const GdkPangoAttrEmbossed*) attr;
return gdk_pango_attr_embossed_new (e->embossed);
}
static void
gdk_pango_attr_embossed_destroy (PangoAttribute *attr)
{
g_free (attr);
}
static gboolean
gdk_pango_attr_embossed_compare (const PangoAttribute *attr1,
const PangoAttribute *attr2)
{
const GdkPangoAttrEmbossed *e1 = (const GdkPangoAttrEmbossed*) attr1;
const GdkPangoAttrEmbossed *e2 = (const GdkPangoAttrEmbossed*) attr2;
return e1->embossed == e2->embossed;
}
/**
* gdk_pango_attr_embossed_new:
* @embossed: a bitmap to be set as embossed
*
* Creates a new attribute containing a embossed bitmap to be used when
* rendering the text.
*
* Return value: new #PangoAttribute
**/
PangoAttribute *
gdk_pango_attr_embossed_new (gboolean embossed)
{
GdkPangoAttrEmbossed *result;
static PangoAttrClass klass = {
0,
gdk_pango_attr_embossed_copy,
gdk_pango_attr_embossed_destroy,
gdk_pango_attr_embossed_compare
};
if (!klass.type)
klass.type = gdk_pango_attr_embossed_type =
pango_attr_type_register ("GdkPangoAttrEmbossed");
result = g_new (GdkPangoAttrEmbossed, 1);
result->attr.klass = &klass;
result->embossed = embossed;
return (PangoAttribute *)result;
}
/* Get a clip region to draw only part of a layout. index_ranges
* contains alternating range starts/stops. The region is the
* region which contains the given ranges, i.e. if you draw with the
* region as clip, only the given ranges are drawn.
*/
/**
* gdk_pango_layout_line_get_clip_region:
* @line: a #PangoLayoutLine
* @x_origin: X pixel where you intend to draw the layout line with this clip
* @y_origin: baseline pixel where you intend to draw the layout line with this clip
* @index_ranges: array of byte indexes into the layout, where even members of array are start indexes and odd elements are end indexes
* @n_ranges: number of ranges in @index_ranges, i.e. half the size of @index_ranges
*
* Obtains a clip region which contains the areas where the given
* ranges of text would be drawn. @x_origin and @y_origin are the same
* position you would pass to gdk_draw_layout_line(). @index_ranges
* should contain ranges of bytes in the layout's text. The clip
* region will include space to the left or right of the line (to the
* layout bounding box) if you have indexes above or below the indexes
* contained inside the line. This is to draw the selection all the way
* to the side of the layout. However, the clip region is in line coordinates,
* not layout coordinates.
*
* Return value: a clip region containing the given ranges
**/
GdkRegion*
gdk_pango_layout_line_get_clip_region (PangoLayoutLine *line,
gint x_origin,
gint y_origin,
gint *index_ranges,
gint n_ranges)
{
GdkRegion *clip_region;
gint i;
PangoRectangle logical_rect;
PangoLayoutIter *iter;
gint baseline;
g_return_val_if_fail (line != NULL, NULL);
g_return_val_if_fail (index_ranges != NULL, NULL);
clip_region = gdk_region_new ();
iter = pango_layout_get_iter (line->layout);
while (pango_layout_iter_get_line (iter) != line)
pango_layout_iter_next_line (iter);
pango_layout_iter_get_line_extents (iter, NULL, &logical_rect);
baseline = pango_layout_iter_get_baseline (iter);
pango_layout_iter_free (iter);
i = 0;
while (i < n_ranges)
{
gint *pixel_ranges = NULL;
gint n_pixel_ranges = 0;
gint j;
/* Note that get_x_ranges returns layout coordinates
*/
pango_layout_line_get_x_ranges (line,
index_ranges[i*2],
index_ranges[i*2+1],
&pixel_ranges, &n_pixel_ranges);
for (j=0; j < n_pixel_ranges; j++)
{
GdkRectangle rect;
rect.x = x_origin + pixel_ranges[2*j] / PANGO_SCALE - logical_rect.x / PANGO_SCALE;
rect.y = y_origin - (baseline / PANGO_SCALE - logical_rect.y / PANGO_SCALE);
rect.width = (pixel_ranges[2*j + 1] - pixel_ranges[2*j]) / PANGO_SCALE;
rect.height = logical_rect.height / PANGO_SCALE;
gdk_region_union_with_rect (clip_region, &rect);
}
g_free (pixel_ranges);
++i;
}
return clip_region;
}
/**
* gdk_pango_layout_get_clip_region:
* @layout: a #PangoLayout
* @x_origin: X pixel where you intend to draw the layout with this clip
* @y_origin: Y pixel where you intend to draw the layout with this clip
* @index_ranges: array of byte indexes into the layout, where even members of array are start indexes and odd elements are end indexes
* @n_ranges: number of ranges in @index_ranges, i.e. half the size of @index_ranges
*
* Obtains a clip region which contains the areas where the given ranges
* of text would be drawn. @x_origin and @y_origin are the same position
* you would pass to gdk_draw_layout_line(). @index_ranges should contain
* ranges of bytes in the layout's text.
*
* Return value: a clip region containing the given ranges
**/
GdkRegion*
gdk_pango_layout_get_clip_region (PangoLayout *layout,
gint x_origin,
gint y_origin,
gint *index_ranges,
gint n_ranges)
{
PangoLayoutIter *iter;
GdkRegion *clip_region;
g_return_val_if_fail (PANGO_IS_LAYOUT (layout), NULL);
g_return_val_if_fail (index_ranges != NULL, NULL);
clip_region = gdk_region_new ();
iter = pango_layout_get_iter (layout);
do
{
PangoRectangle logical_rect;
PangoLayoutLine *line;
GdkRegion *line_region;
gint baseline;
line = pango_layout_iter_get_line (iter);
pango_layout_iter_get_line_extents (iter, NULL, &logical_rect);
baseline = pango_layout_iter_get_baseline (iter);
line_region = gdk_pango_layout_line_get_clip_region (line,
x_origin + logical_rect.x / PANGO_SCALE,
y_origin + baseline / PANGO_SCALE,
index_ranges,
n_ranges);
gdk_region_union (clip_region, line_region);
gdk_region_destroy (line_region);
}
while (pango_layout_iter_next_line (iter));
pango_layout_iter_free (iter);
return clip_region;
}
/**
* gdk_pango_context_get:
*
* Creates a #PangoContext for the default GDK screen.
*
* The context must be freed when you're finished with it.
*
* When using GTK+, normally you should use gtk_widget_get_pango_context()
* instead of this function, to get the appropriate context for
* the widget you intend to render text onto.
*
* Return value: a new #PangoContext for the default display
**/
PangoContext *
gdk_pango_context_get (void)
{
return gdk_pango_context_get_for_screen (gdk_screen_get_default ());
}