gtk2/gdk-pixbuf/gdk-pixbuf-io.c
Federico Mena Quintero 567305020d Populated.
1999-11-04  Federico Mena Quintero  <federico@redhat.com>

	* doc/tmpl/gdk-pixbuf.sgml: Populated.

	* doc/tmpl/refcounting.sgml: Populated.

	* doc/tmpl/file-loading.sgml: Populated.

	* src/gdk-pixbuf.c: Added documentation comments.

	* src/gdk-pixbuf-io.c (gdk_pixbuf_new_from_file): Added
	documentation comments.
1999-11-04 08:14:32 +00:00

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/* GdkPixbuf library - Main loading interface.
*
* Copyright (C) 1999 The Free Software Foundation
*
* Authors: Miguel de Icaza <miguel@gnu.org>
* Federico Mena-Quintero <federico@gimp.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library 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 <config.h>
#include <string.h>
#include "gdk-pixbuf-io.h"
static gboolean
pixbuf_check_png (guchar *buffer, int size)
{
if (size < 28)
return FALSE;
if (buffer [0] != 0x89 ||
buffer [1] != 'P' ||
buffer [2] != 'N' ||
buffer [3] != 'G' ||
buffer [4] != 0x0d ||
buffer [5] != 0x0a ||
buffer [6] != 0x1a ||
buffer [7] != 0x0a)
return FALSE;
return TRUE;
}
static gboolean
pixbuf_check_jpeg (guchar *buffer, int size)
{
if (size < 10)
return FALSE;
if (buffer [0] != 0xff || buffer [1] != 0xd8)
return FALSE;
return TRUE;
}
static gboolean
pixbuf_check_tiff (guchar *buffer, int size)
{
if (size < 10)
return FALSE;
if (buffer [0] == 'M' &&
buffer [1] == 'M' &&
buffer [2] == 0 &&
buffer [3] == 0x2a)
return TRUE;
if (buffer [0] == 'I' &&
buffer [1] == 'I' &&
buffer [2] == 0x2a &&
buffer [3] == 0)
return TRUE;
return FALSE;
}
static gboolean
pixbuf_check_gif (guchar *buffer, int size)
{
if (size < 20)
return FALSE;
if (strncmp (buffer, "GIF8", 4) == 0)
return TRUE;
return FALSE;
}
static gboolean
pixbuf_check_xpm (guchar *buffer, int size)
{
if (size < 20)
return FALSE;
if (strncmp (buffer, "/* XPM */", 9) == 0)
return TRUE;
return FALSE;
}
#if 0
static gboolean
pixbuf_check_bmp (guchar *buffer, int size)
{
if (size < 20)
return FALSE;
if (buffer [0] != 'B' || buffer [1] != 'M')
return FALSE;
return TRUE;
}
static gboolean
pixbuf_check_ppm (guchar *buffer, int size)
{
if (size < 20)
return FALSE;
if (buffer [0] == 'P') {
if (buffer [1] == '1' ||
buffer [1] == '2' ||
buffer [1] == '3' ||
buffer [1] == '4' ||
buffer [1] == '5' ||
buffer [1] == '6')
return TRUE;
}
return FALSE;
}
#endif
GdkPixbufModule file_formats [] = {
{ "png", pixbuf_check_png, NULL, NULL, NULL, NULL, NULL, NULL },
{ "jpeg", pixbuf_check_jpeg, NULL, NULL, NULL, NULL, NULL, NULL },
{ "tiff", pixbuf_check_tiff, NULL, NULL, NULL, NULL, NULL, NULL },
{ "gif", pixbuf_check_gif, NULL, NULL, NULL, NULL, NULL, NULL },
#define XPM_FILE_FORMAT_INDEX 4
{ "xpm", pixbuf_check_xpm, NULL, NULL, NULL, NULL, NULL, NULL },
#if 0
{ "bmp", pixbuf_check_bmp, NULL, NULL, NULL, NULL, NULL, NULL },
{ "ppm", pixbuf_check_ppm, NULL, NULL, NULL, NULL, NULL, NULL },
#endif
{ NULL, NULL, NULL, NULL, NULL, NULL, NULL }
};
/* actually load the image handler - gdk_pixbuf_get_module only get a */
/* reference to the module to load, it doesn't actually load it */
/* perhaps these actions should be combined in one function */
void
gdk_pixbuf_load_module (GdkPixbufModule *image_module)
{
char *module_name;
char *path;
GModule *module;
gpointer load_sym;
g_return_if_fail(image_module->module == NULL);
module_name = g_strconcat ("pixbuf-", image_module->module_name, NULL);
path = g_module_build_path (PIXBUF_LIBDIR, module_name);
module = g_module_open (path, G_MODULE_BIND_LAZY);
if (!module) {
/* Debug feature, check in present working directory */
g_free(path);
path = g_module_build_path("", module_name);
module = g_module_open(path, G_MODULE_BIND_LAZY);
if (!module) {
g_warning ("Unable to load module: %s: %s", path, g_module_error());
g_free (module_name);
g_free(path);
return;
} else {
printf("loaded module `%s'\n", module_name);
}
g_free(path);
} else {
printf("loaded module `%s'\n", path);
g_free (path);
}
g_free (module_name);
image_module->module = module;
if (g_module_symbol (module, "image_load", &load_sym))
image_module->load = load_sym;
if (g_module_symbol (module, "image_load_xpm_data", &load_sym))
image_module->load_xpm_data = load_sym;
if (g_module_symbol (module, "image_begin_load", &load_sym))
image_module->begin_load = load_sym;
if (g_module_symbol (module, "image_stop_load", &load_sym))
image_module->stop_load = load_sym;
if (g_module_symbol (module, "image_load_increment", &load_sym))
image_module->load_increment = load_sym;
}
GdkPixbufModule *
gdk_pixbuf_get_module (gchar *buffer, gint size)
{
gint i;
for (i = 0; file_formats [i].module_name; i++) {
if ((* file_formats [i].format_check) (buffer, size))
return &(file_formats[i]);
}
return NULL;
}
/**
* gdk_pixbuf_new_from_file:
* @filename: Name of file to load.
*
* Creates a new pixbuf by loading an image from a file. The file format is
* detected automatically.
*
* Return value: A newly-created pixbuf, or NULL if any of several error
* conditions occurred: the file could not be opened, there was no loader for
* the file's format, there was not enough memory to allocate the image buffer,
* or the image file contained invalid data.
**/
GdkPixbuf *
gdk_pixbuf_new_from_file (const char *filename)
{
GdkPixbuf *pixbuf;
gint size;
FILE *f;
char buffer [128];
GdkPixbufModule *image_module;
f = fopen (filename, "r");
if (!f)
return NULL;
size = fread (&buffer, 1, sizeof (buffer), f);
if (size == 0) {
fclose (f);
return NULL;
}
image_module = gdk_pixbuf_get_module (buffer, size);
if (image_module){
if (image_module->module == NULL)
gdk_pixbuf_load_module (image_module);
if (image_module->load == NULL) {
fclose (f);
return NULL;
}
fseek (f, 0, SEEK_SET);
pixbuf = (* image_module->load) (f);
fclose (f);
if (pixbuf)
g_assert (pixbuf->ref_count != 0);
return pixbuf;
} else {
g_warning ("Unable to find handler for file: %s", filename);
}
fclose (f);
return NULL;
}
GdkPixbuf *
gdk_pixbuf_new_from_xpm_data (const gchar **data)
{
GdkPixbuf *(* load_xpm_data) (const gchar **data);
GdkPixbuf *pixbuf;
if (file_formats[XPM_FILE_FORMAT_INDEX].module == NULL) {
gdk_pixbuf_load_module(&file_formats[XPM_FILE_FORMAT_INDEX]);
}
if (file_formats[XPM_FILE_FORMAT_INDEX].module == NULL) {
g_warning("Can't find gdk-pixbuf module for parsing inline XPM data");
return NULL;
} else if (file_formats[XPM_FILE_FORMAT_INDEX].load_xpm_data == NULL) {
g_warning("gdk-pixbuf XPM module lacks XPM data capability");
return NULL;
} else {
load_xpm_data = file_formats[XPM_FILE_FORMAT_INDEX].load_xpm_data;
}
pixbuf = load_xpm_data(data);
return pixbuf;
}