rsvg.c

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/*
 * Copyright 2007 Rob Kendrick <rjek@netsurf-browser.org>
 *
 * 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
 * implementation of content handler for image/svg using librsvg.
 *
 * SVG files are rendered to a NetSurf bitmap by creating a Cairo rendering
 * surface (content_rsvg_data.cs) over the bitmap's data, creating a Cairo
 * drawing context using that surface, and then passing that drawing context
 * to librsvg which then uses Cairo calls to plot the graphic to the bitmap.
 * We store this in content->bitmap, and then use the usual bitmap plotter
 * function to render it for redraw requests.
 */
 
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>
#include <string.h>
#include <sys/types.h>
 
#include <librsvg/rsvg.h>
#ifndef RSVG_CAIRO_H
#include <librsvg/rsvg-cairo.h>
#endif
 
#include <nsutils/endian.h>
 
#include "utils/log.h"
#include "utils/utils.h"
#include "utils/messages.h"
#include "netsurf/plotters.h"
#include "netsurf/bitmap.h"
#include "netsurf/content.h"
#include "content/llcache.h"
#include "content/content_protected.h"
#include "content/content_factory.h"
#include "desktop/gui_internal.h"
#include "desktop/bitmap.h"
 
#include "image/rsvg.h"
 
typedef struct rsvg_content {
        struct content base;
 
        RsvgHandle *rsvgh;      /**< Context handle for RSVG renderer */
        cairo_surface_t *cs;    /**< The surface built inside a nsbitmap */
        cairo_t *ct;            /**< Cairo drawing context */
        struct bitmap *bitmap;  /**< Created NetSurf bitmap */
} rsvg_content;
 
static nserror rsvg_create_svg_data(rsvg_content *c)
{
        c->rsvgh = NULL;
        c->cs = NULL;
        c->ct = NULL;
        c->bitmap = NULL;
 
        if ((c->rsvgh = rsvg_handle_new()) == NULL) {
                NSLOG(netsurf, INFO, "rsvg_handle_new() returned NULL.");
                content_broadcast_error(&c->base, NSERROR_NOMEM, NULL);
                return NSERROR_NOMEM;
        }
 
        return NSERROR_OK;
}
 
 
static nserror rsvg_create(const content_handler *handler,
                lwc_string *imime_type, const struct http_parameter *params,
                llcache_handle *llcache, const char *fallback_charset,
                bool quirks, struct content **c)
{
        rsvg_content *svg;
        nserror error;
 
        svg = calloc(1, sizeof(rsvg_content));
        if (svg == NULL)
                return NSERROR_NOMEM;
 
        error = content__init(&svg->base, handler, imime_type, params,
                        llcache, fallback_charset, quirks);
        if (error != NSERROR_OK) {
                free(svg);
                return error;
        }
 
        error = rsvg_create_svg_data(svg);
        if (error != NSERROR_OK) {
                free(svg);
                return error;
        }
 
        *c = (struct content *) svg;
 
        return NSERROR_OK;
}
 
 
static bool rsvg_process_data(struct content *c, const char *data,
                        unsigned int size)
{
        rsvg_content *d = (rsvg_content *) c;
        GError *err = NULL;
 
        if (rsvg_handle_write(d->rsvgh, (const guchar *)data, (gsize)size,
                                &err) == FALSE) {
                NSLOG(netsurf, INFO,
                      "rsvg_handle_write returned an error: %s", err->message);
                content_broadcast_error(c, NSERROR_SVG_ERROR, NULL);
                return false;
        }
 
        return true;
}
 
static bool rsvg_convert(struct content *c)
{
        rsvg_content *d = (rsvg_content *) c;
        RsvgDimensionData rsvgsize;
        GError *err = NULL;
 
        if (rsvg_handle_close(d->rsvgh, &err) == FALSE) {
                NSLOG(netsurf, INFO,
                      "rsvg_handle_close returned an error: %s", err->message);
                content_broadcast_error(c, NSERROR_SVG_ERROR, NULL);
                return false;
        }
 
        assert(err == NULL);
 
        /* we should now be able to query librsvg for the natural size of the
         * graphic, so we can create our bitmap.
         */
 
        rsvg_handle_get_dimensions(d->rsvgh, &rsvgsize);
        c->width = rsvgsize.width;
        c->height = rsvgsize.height;
 
        if ((d->bitmap = guit->bitmap->create(c->width, c->height,
                        BITMAP_NONE)) == NULL) {
                NSLOG(netsurf, INFO,
                      "Failed to create bitmap for rsvg render.");
                content_broadcast_error(c, NSERROR_NOMEM, NULL);
                return false;
        }
 
        if ((d->cs = cairo_image_surface_create_for_data(
                        (unsigned char *)guit->bitmap->get_buffer(d->bitmap),
                        CAIRO_FORMAT_ARGB32,
                        c->width, c->height,
                        guit->bitmap->get_rowstride(d->bitmap))) == NULL) {
                NSLOG(netsurf, INFO,
                      "Failed to create Cairo image surface for rsvg render.");
                content_broadcast_error(c, NSERROR_NOMEM, NULL);
                return false;
        }
 
        if ((d->ct = cairo_create(d->cs)) == NULL) {
                NSLOG(netsurf, INFO,
                      "Failed to create Cairo drawing context for rsvg render.");
                content_broadcast_error(c, NSERROR_NOMEM, NULL);
                return false;
        }
 
        rsvg_handle_render_cairo(d->rsvgh, d->ct);
 
        bitmap_format_to_client(d->bitmap, &(bitmap_fmt_t) {
                .layout = BITMAP_LAYOUT_ARGB8888,
        });
        guit->bitmap->modified(d->bitmap);
        content_set_ready(c);
        content_set_done(c);
        /* Done: update status bar */
        content_set_status(c, "");
 
        return true;
}
 
static bool rsvg_redraw(struct content *c, struct content_redraw_data *data,
                const struct rect *clip, const struct redraw_context *ctx)
{
        rsvg_content *rsvgcontent = (rsvg_content *) c;
        bitmap_flags_t flags = BITMAPF_NONE;
 
        assert(rsvgcontent->bitmap != NULL);
 
        if (data->repeat_x)
                flags |= BITMAPF_REPEAT_X;
        if (data->repeat_y)
                flags |= BITMAPF_REPEAT_Y;
 
        return (ctx->plot->bitmap(ctx,
                                  rsvgcontent->bitmap,
                                  data->x, data->y,
                                  data->width, data->height,
                                  data->background_colour,
                                  flags) == NSERROR_OK);
}
 
static void rsvg_destroy(struct content *c)
{
        rsvg_content *d = (rsvg_content *) c;
 
        if (d->bitmap != NULL) guit->bitmap->destroy(d->bitmap);
        if (d->rsvgh != NULL) g_object_unref(d->rsvgh);
        if (d->ct != NULL) cairo_destroy(d->ct);
        if (d->cs != NULL) cairo_surface_destroy(d->cs);
 
        return;
}
 
static nserror rsvg_clone(const struct content *old, struct content **newc)
{
        rsvg_content *svg;
        nserror error;
        const uint8_t *data;
        size_t size;
 
        svg = calloc(1, sizeof(rsvg_content));
        if (svg == NULL)
                return NSERROR_NOMEM;
 
        error = content__clone(old, &svg->base);
        if (error != NSERROR_OK) {
                content_destroy(&svg->base);
                return error;
        }
 
        /* Simply replay create/process/convert */
        error = rsvg_create_svg_data(svg);
        if (error != NSERROR_OK) {
                content_destroy(&svg->base);
                return error;
        }
 
        data = content__get_source_data(&svg->base, &size);
        if (size > 0) {
                if (rsvg_process_data(&svg->base, (const char *)data, size) == false) {
                        content_destroy(&svg->base);
                        return NSERROR_NOMEM;
                }
        }
 
        if (old->status == CONTENT_STATUS_READY ||
                        old->status == CONTENT_STATUS_DONE) {
                if (rsvg_convert(&svg->base) == false) {
                        content_destroy(&svg->base);
                        return NSERROR_CLONE_FAILED;
                }
        }
 
        *newc = (struct content *) svg;
 
        return NSERROR_OK;
}
 
static void *rsvg_get_internal(const struct content *c, void *context)
{
        rsvg_content *d = (rsvg_content *) c;
 
        return d->bitmap;
}
 
static content_type rsvg_content_type(void)
{
        return CONTENT_IMAGE;
}
 
 
static bool rsvg_content_is_opaque(struct content *c)
{
        rsvg_content *d = (rsvg_content *) c;
 
        if (d->bitmap != NULL) {
                return guit->bitmap->get_opaque(d->bitmap);
        }
 
        return false;
}
 
 
static const content_handler rsvg_content_handler = {
        .create = rsvg_create,
        .process_data = rsvg_process_data,
        .data_complete = rsvg_convert,
        .destroy = rsvg_destroy,
        .redraw = rsvg_redraw,
        .clone = rsvg_clone,
        .get_internal = rsvg_get_internal,
        .type = rsvg_content_type,
        .is_opaque = rsvg_content_is_opaque,
        .no_share = false,
};
 
static const char *rsvg_types[] = {
        "image/svg",
        "image/svg+xml"
};
 
CONTENT_FACTORY_REGISTER_TYPES(nsrsvg, rsvg_types, rsvg_content_handler);