netsurf/gtk/thumbnail.c
2012-10-11 11:20:02 +01:00

129 lines
3.7 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 <gdk/gdk.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,
nsurl *url)
{
cairo_surface_t *dsurface = bitmap->surface;
cairo_surface_t *surface;
cairo_t *old_cr;
gint dwidth, dheight;
int cwidth, cheight;
struct redraw_context ctx = {
.interactive = false,
.background_images = true,
.plot = &nsgtk_plotters
};
assert(content);
assert(bitmap);
dwidth = cairo_image_surface_get_width(dsurface);
dheight = cairo_image_surface_get_height(dsurface);
/* 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 * dheight) + (dwidth / 2)) / dwidth;
/* Create surface to render into */
surface = cairo_surface_create_similar(dsurface, CAIRO_CONTENT_COLOR_ALPHA, cwidth, cheight);
if (cairo_surface_status(surface) != CAIRO_STATUS_SUCCESS) {
cairo_surface_destroy(surface);
return false;
}
old_cr = current_cr;
current_cr = cairo_create(surface);
/* render the content */
thumbnail_redraw(content, cwidth, cheight, &ctx);
cairo_destroy(current_cr);
current_cr = old_cr;
cairo_t *cr = cairo_create(dsurface);
/* Scale *before* setting the source surface (1) */
cairo_scale (cr, (double)dwidth / cwidth, (double)dheight / cheight);
cairo_set_source_surface (cr, surface, 0, 0);
/* To avoid getting the edge pixels blended with 0 alpha,
* which would occur with the default EXTEND_NONE. Use
* EXTEND_PAD for 1.2 or newer (2)
*/
cairo_pattern_set_extend (cairo_get_source(cr), CAIRO_EXTEND_REFLECT);
/* Replace the destination with the source instead of overlaying */
cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
/* Do the actual drawing */
cairo_paint(cr);
cairo_destroy(cr);
cairo_surface_destroy(surface);
/* register the thumbnail with the URL */
if (url)
urldb_set_thumbnail(url, bitmap);
return true;
}