netsurf/gtk/thumbnail.c
Michael Drake 8813181cea Use core's thumbnail_redraw().
svn path=/trunk/netsurf/; revision=11717
2011-02-19 22:24:36 +00:00

143 lines
4.2 KiB
C

/*
* Copyright 2006 Rob Kendrick <rjek@rjek.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/>.
*/
/** \file
* Page thumbnail creation (implementation).
*
* Thumbnails are created by setting the current drawing contexts to the
* bitmap (a gdk pixbuf) we are passed, and plotting the page at a small
* scale.
*/
#include <assert.h>
#include <gtk/gtk.h>
#include "content/content.h"
#include "content/hlcache.h"
#include "content/urldb.h"
#include "desktop/plotters.h"
#include "desktop/browser.h"
#include "desktop/thumbnail.h"
#include "gtk/scaffolding.h"
#include "gtk/plotters.h"
#include "gtk/bitmap.h"
#include "image/bitmap.h"
#include "render/font.h"
#include "utils/log.h"
#include "utils/utils.h"
/**
* Create a thumbnail of a page.
*
* \param content content structure to thumbnail
* \param bitmap the bitmap to draw to
* \param url the URL the thumnail belongs to, or NULL
*/
bool thumbnail_create(hlcache_handle *content, struct bitmap *bitmap,
const char *url)
{
GdkPixbuf *pixbuf;
int cwidth, cheight;
gint width;
gint height;
gint depth;
GdkPixmap *pixmap;
GdkPixbuf *big;
float plot_scale;
double scale;
assert(content);
assert(bitmap);
/* Get details of required final thumbnail image */
pixbuf = gtk_bitmap_get_primary(bitmap);
width = gdk_pixbuf_get_width(pixbuf);
height = gdk_pixbuf_get_height(pixbuf);
depth = (gdk_screen_get_system_visual(gdk_screen_get_default()))->depth;
/* Calculate size of buffer to render the content into */
/* We get the width from the content width, unless it exceeds 1024,
* in which case we use 1024. This means we never create excessively
* large render buffers for huge contents, which would eat memory and
* cripple performance. */
cwidth = min(content_get_width(content), 1024);
/* The height is set in proportion with the width, according to the
* aspect ratio of the required thumbnail. */
cheight = ((cwidth * height) + (width / 2)) / width;
/* Create buffer to render into */
pixmap = gdk_pixmap_new(NULL, cwidth, cheight, depth);
if (pixmap == NULL) {
/* the creation failed for some reason: most likely because
* we've been asked to create with with at least one dimention
* as zero. The RISC OS thumbnail generator returns false
* from here when it can't create a bitmap, so we assume it's
* safe to do so here too.
*/
return false;
}
gdk_drawable_set_colormap(pixmap, gdk_colormap_get_system());
/* set the plotting functions up */
plot = nsgtk_plotters;
/* Plotters need to know thumbnail scale */
plot_scale = thumbnail_get_redraw_scale(content, cwidth);
nsgtk_plot_set_scale(plot_scale);
/* set to plot to pixmap */
current_drawable = pixmap;
current_gc = gdk_gc_new(current_drawable);
#ifdef CAIRO_VERSION
current_cr = gdk_cairo_create(current_drawable);
#endif
/* render the content */
thumbnail_redraw(content, cwidth, cheight);
/* get the pixbuf we rendered the content into */
big = gdk_pixbuf_get_from_drawable(NULL, pixmap, NULL, 0, 0, 0, 0,
cwidth, cheight);
/* resample the large plot down to the size of our thumbnail */
scale = (double)width / (double)cwidth;
gdk_pixbuf_scale(big, pixbuf, 0, 0, width, height, 0, 0,
scale, scale, GDK_INTERP_TILES);
/* As a debugging aid, try this to dump out a copy of the thumbnail as
* a PNG: gdk_pixbuf_save(pixbuf, "thumbnail.png", "png", NULL, NULL);
*/
/* register the thumbnail with the URL */
if (url)
urldb_set_thumbnail(url, bitmap);
bitmap_modified(bitmap);
g_object_unref(current_gc);
#ifdef CAIRO_VERSION
cairo_destroy(current_cr);
#endif
g_object_unref(pixmap);
g_object_unref(big);
return true;
}