gtk/gdk-pixbuf/gdk-pixbuf-io.c
Federico Mena Quintero 79d6346057 0.6.0 - Federico
2000-02-22 00:29:00 +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 <glib.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;
}
static gboolean
pixbuf_check_pnm (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;
}
static gboolean
pixbuf_check_sunras (guchar *buffer, int size)
{
if (size < 32)
return FALSE;
if (buffer [0] != 0x59 ||
buffer [1] != 0xA6 ||
buffer [2] != 0x6A ||
buffer [3] != 0x95)
return FALSE;
return TRUE;
}
static gboolean
pixbuf_check_ico (guchar *buffer, int size)
{
/* Note that this may cause false positives, but .ico's don't
have a magic number.*/
if (size < 6)
return FALSE;
if (buffer [0] != 0x0 ||
buffer [1] != 0x0 ||
((buffer [2] != 0x1)&&(buffer[2]!=0x2)) ||
buffer [3] != 0x0 ||
buffer [5] != 0x0 )
return FALSE;
return TRUE;
}
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 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 },
{ "pnm", pixbuf_check_pnm, NULL, NULL, NULL, NULL, NULL, NULL },
{ "ras", pixbuf_check_sunras, NULL, NULL, NULL, NULL, NULL, NULL },
{ "ico", pixbuf_check_ico, NULL, NULL, NULL, NULL, NULL, NULL },
{ "bmp", pixbuf_check_bmp, NULL, NULL, NULL, NULL, NULL, NULL },
{ NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL }
};
#ifdef USE_GMODULE
static gboolean
pixbuf_module_symbol (GModule *module, const char *module_name, const char *symbol_name, gpointer *symbol)
{
char *full_symbol_name = g_strconcat ("gdk_pixbuf__", module_name, "_", symbol_name, NULL);
gboolean return_value;
return_value = g_module_symbol (module, full_symbol_name, symbol);
g_free (full_symbol_name);
return return_value;
}
/* 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;
char *name;
g_return_if_fail (image_module->module == NULL);
name = image_module->module_name;
module_name = g_strconcat ("pixbuf-", 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;
}
g_free (path);
} else {
g_free (path);
}
g_free (module_name);
image_module->module = module;
if (pixbuf_module_symbol (module, name, "image_load", &load_sym))
image_module->load = load_sym;
if (pixbuf_module_symbol (module, name, "image_load_xpm_data", &load_sym))
image_module->load_xpm_data = load_sym;
if (pixbuf_module_symbol (module, name, "image_begin_load", &load_sym))
image_module->begin_load = load_sym;
if (pixbuf_module_symbol (module, name, "image_stop_load", &load_sym))
image_module->stop_load = load_sym;
if (pixbuf_module_symbol (module, name, "image_load_increment", &load_sym))
image_module->load_increment = load_sym;
if (pixbuf_module_symbol (module, name, "image_load_animation", &load_sym))
image_module->load_animation = load_sym;
}
#else
#define mname(type,fn) gdk_pixbuf__ ## type ## _image_ ##fn
#define m_load(type) extern GdkPixbuf * mname(type,load) (FILE *f);
#define m_load_xpm_data(type) extern GdkPixbuf * mname(type,load_xpm_data) (const char **data);
#define m_begin_load(type) \
extern gpointer mname(type,begin_load) (ModulePreparedNotifyFunc prepare_func, \
ModuleUpdatedNotifyFunc update_func, \
ModuleFrameDoneNotifyFunc frame_done_func,\
ModuleAnimationDoneNotifyFunc anim_done_func,\
gpointer user_data);
#define m_stop_load(type) extern void mname(type,stop_load) (gpointer context);
#define m_load_increment(type) extern gboolean mname(type,load_increment) (gpointer context, const guchar *buf, guint size);
#define m_load_animation(type) extern GdkPixbufAnimation * mname(type,load_animation) (FILE *f);
m_load (png);
m_begin_load (png);
m_load_increment (png);
m_stop_load (png);
m_load (bmp);
m_begin_load (bmp);
m_load_increment (bmp);
m_stop_load (bmp);
m_load (gif);
m_begin_load (gif);
m_load_increment (gif);
m_stop_load (gif);
m_load_animation (gif);
m_load (ico);
m_begin_load (ico);
m_load_increment (ico);
m_stop_load (ico);
m_load (jpeg);
m_begin_load (jpeg);
m_load_increment (jpeg);
m_stop_load (jpeg);
m_load (pnm);
m_begin_load (pnm);
m_load_increment (pnm);
m_stop_load (pnm);
m_load (ras);
m_begin_load (ras);
m_load_increment (ras);
m_stop_load (ras);
m_load (tiff);
m_begin_load (tiff);
m_load_increment (tiff);
m_stop_load (tiff);
m_load (xpm);
m_load_xpm_data (xpm);
void
gdk_pixbuf_load_module (GdkPixbufModule *image_module)
{
image_module->module = (void *) 1;
if (strcmp (image_module->module_name, "png") == 0){
image_module->load = mname (png,load);
image_module->begin_load = mname (png,begin_load);
image_module->load_increment = mname (png,load_increment);
image_module->stop_load = mname (png,stop_load);
return;
}
if (strcmp (image_module->module_name, "bmp") == 0){
image_module->load = mname (bmp,load);
image_module->begin_load = mname (bmp,begin_load);
image_module->load_increment = mname (bmp,load_increment);
image_module->stop_load = mname (bmp,stop_load);
return;
}
if (strcmp (image_module->module_name, "gif") == 0){
image_module->load = mname (gif,load);
image_module->begin_load = mname (gif,begin_load);
image_module->load_increment = mname (gif,load_increment);
image_module->stop_load = mname (gif,stop_load);
image_module->load_animation = mname (gif,load_animation);
return;
}
if (strcmp (image_module->module_name, "ico") == 0){
image_module->load = mname (ico,load);
image_module->begin_load = mname (ico,begin_load);
image_module->load_increment = mname (ico,load_increment);
image_module->stop_load = mname (ico,stop_load);
return;
}
if (strcmp (image_module->module_name, "jpeg") == 0){
image_module->load = mname (jpeg,load);
image_module->begin_load = mname (jpeg,begin_load);
image_module->load_increment = mname (jpeg,load_increment);
image_module->stop_load = mname (jpeg,stop_load);
return;
}
if (strcmp (image_module->module_name, "pnm") == 0){
image_module->load = mname (pnm,load);
image_module->begin_load = mname (pnm,begin_load);
image_module->load_increment = mname (pnm,load_increment);
image_module->stop_load = mname (pnm,stop_load);
return;
}
if (strcmp (image_module->module_name, "ras") == 0){
image_module->load = mname (ras,load);
image_module->begin_load = mname (ras,begin_load);
image_module->load_increment = mname (ras,load_increment);
image_module->stop_load = mname (ras,stop_load);
return;
}
if (strcmp (image_module->module_name, "tiff") == 0){
image_module->load = mname (tiff,load);
image_module->begin_load = mname (tiff,begin_load);
image_module->load_increment = mname (tiff,load_increment);
image_module->stop_load = mname (tiff,stop_load);
return;
}
if (strcmp (image_module->module_name, "xpm") == 0){
image_module->load = mname (xpm,load);
image_module->load_xpm_data = mname (xpm,load_xpm_data);
return;
}
}
#endif
GdkPixbufModule *
gdk_pixbuf_get_module (guchar *buffer, guint size)
{
int 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 with a reference count of 1, 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;
int size;
FILE *f;
guchar buffer [128];
GdkPixbufModule *image_module;
g_return_val_if_fail (filename != NULL, NULL);
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) {
g_warning ("Unable to find handler for file: %s", filename);
fclose (f);
return NULL;
}
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;
}
/**
* gdk_pixbuf_new_from_xpm_data:
* @data: Pointer to inline XPM data.
*
* Creates a new pixbuf by parsing XPM data in memory. This data is commonly
* the result of including an XPM file into a program's C source.
*
* Return value: A newly-created pixbuf with a reference count of 1.
**/
GdkPixbuf *
gdk_pixbuf_new_from_xpm_data (const char **data)
{
GdkPixbuf *(* load_xpm_data) (const char **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;
}