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/* 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, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "gdkpango.h"
#include <glib/gi18n-lib.h>
#include <math.h>
#include <pango/pangocairo.h>
/* 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.
*/
static cairo_region_t*
layout_iter_get_line_clip_region (PangoLayoutIter *iter,
int x_origin,
int y_origin,
const int *index_ranges,
int n_ranges)
{
PangoLayoutLine *line;
cairo_region_t *clip_region;
PangoRectangle logical_rect;
int baseline;
int i;
line = pango_layout_iter_get_line_readonly (iter);
clip_region = cairo_region_create ();
pango_layout_iter_get_line_extents (iter, NULL, &logical_rect);
baseline = pango_layout_iter_get_baseline (iter);
i = 0;
while (i < n_ranges)
{
int *pixel_ranges = NULL;
int n_pixel_ranges = 0;
int j;
/* Note that get_x_ranges returns layout coordinates
*/
if (index_ranges[i*2+1] >= pango_layout_line_get_start_index (line) &&
index_ranges[i*2] < pango_layout_line_get_start_index (line) + pango_layout_line_get_length (line))
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;
int x_off, y_off;
x_off = PANGO_PIXELS (pixel_ranges[2*j] - logical_rect.x);
y_off = PANGO_PIXELS (baseline - logical_rect.y);
rect.x = x_origin + x_off;
rect.y = y_origin - y_off;
rect.width = PANGO_PIXELS (pixel_ranges[2*j + 1] - logical_rect.x) - x_off;
rect.height = PANGO_PIXELS (baseline - logical_rect.y + logical_rect.height) - y_off;
cairo_region_union_rectangle (clip_region, &rect);
}
g_free (pixel_ranges);
++i;
}
return clip_region;
}
/**
* gdk_pango_layout_line_get_clip_region: (skip)
* @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): 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 top left position of the layout.
* @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.
*
* Note that the regions returned correspond to logical extents of the text
* ranges, not ink extents. So the drawn line may in fact touch areas out of
* the clip region. The clip region is mainly useful for highlightling parts
* of text, such as when text is selected.
*
* Returns: a clip region containing the given ranges
*/
cairo_region_t*
gdk_pango_layout_line_get_clip_region (PangoLayoutLine *line,
int x_origin,
int y_origin,
const int *index_ranges,
int n_ranges)
{
cairo_region_t *clip_region;
PangoLayoutIter *iter;
g_return_val_if_fail (line != NULL, NULL);
g_return_val_if_fail (index_ranges != NULL, NULL);
iter = pango_layout_get_iter (line->layout);
while (pango_layout_iter_get_line_readonly (iter) != line)
pango_layout_iter_next_line (iter);
clip_region = layout_iter_get_line_clip_region(iter, x_origin, y_origin, index_ranges, n_ranges);
pango_layout_iter_free (iter);
return clip_region;
}
/**
* gdk_pango_layout_get_clip_region: (skip)
* @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 top left point to center the layout.
* @index_ranges should contain ranges of bytes in the layout’s text.
*
* Note that the regions returned correspond to logical extents of the text
* ranges, not ink extents. So the drawn layout may in fact touch areas out of
* the clip region. The clip region is mainly useful for highlightling parts
* of text, such as when text is selected.
*
* Returns: a clip region containing the given ranges
*/
cairo_region_t*
gdk_pango_layout_get_clip_region (PangoLayout *layout,
int x_origin,
int y_origin,
const int *index_ranges,
int n_ranges)
{
PangoLayoutIter *iter;
cairo_region_t *clip_region;
g_return_val_if_fail (PANGO_IS_LAYOUT (layout), NULL);
g_return_val_if_fail (index_ranges != NULL, NULL);
clip_region = cairo_region_create ();
iter = pango_layout_get_iter (layout);
do
{
PangoRectangle logical_rect;
cairo_region_t *line_region;
int baseline;
pango_layout_iter_get_line_extents (iter, NULL, &logical_rect);
baseline = pango_layout_iter_get_baseline (iter);
line_region = layout_iter_get_line_clip_region(iter,
x_origin + PANGO_PIXELS (logical_rect.x),
y_origin + PANGO_PIXELS (baseline),
index_ranges,
n_ranges);
cairo_region_union (clip_region, line_region);
cairo_region_destroy (line_region);
}
while (pango_layout_iter_next_line (iter));
pango_layout_iter_free (iter);
return clip_region;
}
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