Add stream i/o functions for gdk-pixbuf

svn path=/trunk/; revision=19373

4 files changed, 329 insertions, 61 deletions

diff --git a/gdk-pixbuf/ChangeLog b/gdk-pixbuf/ChangeLog
index 560eeff38..620a8bf84 100644
--- a/gdk-pixbuf/ChangeLog
+++ b/gdk-pixbuf/ChangeLog
@@ -1,3 +1,11 @@
+2008-01-15  Matthias Clasen  <mclasne@redhat.com>
+
+	* gdk-pixbuf.symbols:
+	* gdk-pixbuf-core.h:
+	* gdk-pixbuf-io.c (gdk_pixbuf_new_from_stream):
+	(gdk_pixbuf_new_from_stream_at_scale):
+	(gdk_pixbuf_save_to_stream): New stream i/o functions.
+
 2008-01-14  Michael Natterer  <mitch@imendio.com>
 
 	* gdk-pixbuf-loader.c (gdk_pixbuf_loader_prepare): cast the return
diff --git a/gdk-pixbuf/gdk-pixbuf-core.h b/gdk-pixbuf/gdk-pixbuf-core.h
index 4ae589526..04f89b000 100644
--- a/gdk-pixbuf/gdk-pixbuf-core.h
+++ b/gdk-pixbuf/gdk-pixbuf-core.h
@@ -28,6 +28,7 @@
 
 #include <glib.h>
 #include <glib-object.h>
+#include <gio/gio.h>
 
 G_BEGIN_DECLS
 
@@ -214,6 +215,24 @@ gboolean gdk_pixbuf_save_to_bufferv     (GdkPixbuf  *pixbuf,
 					 char      **option_values,
 					 GError    **error);
 
+GdkPixbuf *gdk_pixbuf_new_from_stream   (GInputStream   *stream,
+					 GCancellable   *cancellable,
+                                         GError        **error);
+
+GdkPixbuf *gdk_pixbuf_new_from_stream_at_scale   (GInputStream   *stream,
+                                                  gint            width,
+                                                  gint            height,
+                                                  gboolean        preserve_aspect_ratio,
+						  GCancellable   *cancellable,
+                                                  GError        **error);
+
+gboolean   gdk_pixbuf_save_to_stream    (GdkPixbuf      *pixbuf,
+                                         GOutputStream  *stream,
+                                         const char     *type,
+					 GCancellable   *cancellable,
+                                         GError        **error,
+                                         ...);
+
 /* Adding an alpha channel */
 GdkPixbuf *gdk_pixbuf_add_alpha (const GdkPixbuf *pixbuf, gboolean substitute_color,
 				 guchar r, guchar g, guchar b);
diff --git a/gdk-pixbuf/gdk-pixbuf-io.c b/gdk-pixbuf/gdk-pixbuf-io.c
index 1dbbd26cf..61b7991db 100644
--- a/gdk-pixbuf/gdk-pixbuf-io.c
+++ b/gdk-pixbuf/gdk-pixbuf-io.c
@@ -27,14 +27,17 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
-#include <glib.h>
 #include <errno.h>
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif
 
+#include <glib.h>
+#include <gio/gio.h>
+
 #include "gdk-pixbuf-private.h"
 #include "gdk-pixbuf-io.h"
+#include "gdk-pixbuf-loader.h"
 #include "gdk-pixbuf-alias.h"
 
 #include <glib/gstdio.h>
@@ -45,6 +48,9 @@
 #undef STRICT
 #endif
 
+#define SNIFF_BUFFER_SIZE 4096
+#define LOAD_BUFFER_SIZE 65536
+
 static gint 
 format_check (GdkPixbufModule *module, guchar *buffer, int size)
 {
@@ -755,7 +761,7 @@ _gdk_pixbuf_generic_image_load (GdkPixbufModule *module,
 				FILE *f,
 				GError **error)
 {
-	guchar buffer[4096];
+	guchar buffer[LOAD_BUFFER_SIZE];
 	size_t length;
 	GdkPixbuf *pixbuf = NULL;
 	GdkPixbufAnimation *animation = NULL;
@@ -829,7 +835,7 @@ gdk_pixbuf_new_from_file (const char *filename,
 	GdkPixbuf *pixbuf;
 	int size;
 	FILE *f;
-	guchar buffer[1024];
+	guchar buffer[SNIFF_BUFFER_SIZE];
 	GdkPixbufModule *image_module;
 	gchar *display_name;
 
@@ -934,49 +940,6 @@ gdk_pixbuf_new_from_file (const char *filename,
 }
 #endif
 
-static void
-size_prepared_cb (GdkPixbufLoader *loader, 
-		  int              width,
-		  int              height,
-		  gpointer         data)
-{
-	struct {
-		gint width;
-		gint height;
-		gboolean preserve_aspect_ratio;
-	} *info = data;
-
-	g_return_if_fail (width > 0 && height > 0);
-
-	if (info->preserve_aspect_ratio && 
-	    (info->width > 0 || info->height > 0)) {
-		if (info->width < 0)
-		{
-			width = width * (double)info->height/(double)height;
-			height = info->height;
-		}
-		else if (info->height < 0)
-		{
-			height = height * (double)info->width/(double)width;
-			width = info->width;
-		}
-		else if ((double)height * (double)info->width >
-			 (double)width * (double)info->height) {
-			width = 0.5 + (double)width * (double)info->height / (double)height;
-			height = info->height;
-		} else {
-			height = 0.5 + (double)height * (double)info->width / (double)width;
-			width = info->width;
-		}
-	} else {
-		if (info->width > 0)
-			width = info->width;
-		if (info->height > 0)
-			height = info->height;
-	}
-	
-	gdk_pixbuf_loader_set_size (loader, width, height);
-}
 
 /**
  * gdk_pixbuf_new_from_file_at_size:
@@ -1037,6 +1000,52 @@ gdk_pixbuf_new_from_file_at_size (const char *filename,
 }
 #endif
 
+typedef	struct {
+	gint width;
+	gint height;
+	gboolean preserve_aspect_ratio;
+} AtScaleData; 
+
+static void
+at_scale_size_prepared_cb (GdkPixbufLoader *loader, 
+	 		   int              width,
+		  	   int              height,
+		  	   gpointer         data)
+{
+	AtScaleData *info = data;
+
+	g_return_if_fail (width > 0 && height > 0);
+
+	if (info->preserve_aspect_ratio && 
+	    (info->width > 0 || info->height > 0)) {
+		if (info->width < 0)
+		{
+			width = width * (double)info->height/(double)height;
+			height = info->height;
+		}
+		else if (info->height < 0)
+		{
+			height = height * (double)info->width/(double)width;
+			width = info->width;
+		}
+		else if ((double)height * (double)info->width >
+			 (double)width * (double)info->height) {
+			width = 0.5 + (double)width * (double)info->height / (double)height;
+			height = info->height;
+		} else {
+			height = 0.5 + (double)height * (double)info->width / (double)width;
+			width = info->width;
+		}
+	} else {
+		if (info->width > 0)
+			width = info->width;
+		if (info->height > 0)
+			height = info->height;
+	}
+	
+	gdk_pixbuf_loader_set_size (loader, width, height);
+}
+
 /**
  * gdk_pixbuf_new_from_file_at_scale:
  * @filename: Name of file to load, in the GLib file name encoding
@@ -1075,15 +1084,10 @@ gdk_pixbuf_new_from_file_at_scale (const char *filename,
 
 	GdkPixbufLoader *loader;
 	GdkPixbuf       *pixbuf;
-
-	guchar buffer [4096];
+	guchar buffer[LOAD_BUFFER_SIZE];
 	int length;
 	FILE *f;
-	struct {
-		gint width;
-		gint height;
-		gboolean preserve_aspect_ratio;
-	} info;
+	AtScaleData info;
 	GdkPixbufAnimation *animation;
 	GdkPixbufAnimationIter *iter;
 	gboolean has_frame;
@@ -1112,7 +1116,8 @@ gdk_pixbuf_new_from_file_at_scale (const char *filename,
 	info.height = height;
         info.preserve_aspect_ratio = preserve_aspect_ratio;
 
-	g_signal_connect (loader, "size-prepared", G_CALLBACK (size_prepared_cb), &info);
+	g_signal_connect (loader, "size-prepared", 
+			  G_CALLBACK (at_scale_size_prepared_cb), &info);
 
 	has_frame = FALSE;
 	while (!has_frame && !feof (f) && !ferror (f)) {
@@ -1193,6 +1198,157 @@ gdk_pixbuf_new_from_file_at_scale (const char *filename,
 #endif
 
 
+static GdkPixbuf *
+load_from_stream (GdkPixbufLoader  *loader,
+		  GInputStream     *stream,
+		  GCancellable     *cancellable,
+		  GError          **error)
+{
+	GdkPixbuf *pixbuf;
+	gssize n_read;
+	guchar buffer[LOAD_BUFFER_SIZE];
+	gboolean res;
+
+  	res = TRUE;
+	while (1) { 
+		n_read = g_input_stream_read (stream, 
+					      buffer, 
+					      sizeof (buffer), 
+					      cancellable, 
+					      error);
+		if (n_read < 0) {
+			res = FALSE;
+			error = NULL; /* Ignore further errors */
+			break;
+		}
+
+		if (n_read == 0)
+			break;
+
+		if (!gdk_pixbuf_loader_write (loader, 
+					      buffer, 
+					      n_read, 
+					      error)) {
+			res = FALSE;
+			error = NULL;
+			break;
+		}
+	}
+
+	if (!gdk_pixbuf_loader_close (loader, error)) {
+		res = FALSE;
+		error = NULL;
+	}
+
+	pixbuf = NULL;
+	if (res) {
+		pixbuf = gdk_pixbuf_loader_get_pixbuf (loader);
+		if (pixbuf)
+			g_object_ref (pixbuf);
+	}
+
+	return pixbuf;
+}
+
+
+/**
+ * gdk_pixbuf_new_from_stream_at_scale:
+ * @stream:  a #GInputStream to load the pixbuf from
+ * @width: The width the image should have or -1 to not constrain the width
+ * @height: The height the image should have or -1 to not constrain the height
+ * @preserve_aspect_ratio: %TRUE to preserve the image's aspect ratio
+ * @cancellable: optional #GCancellable object, %NULL to ignore
+ * @error: Return location for an error
+ *
+ * Creates a new pixbuf by loading an image from an input stream.  
+ *
+ * The file format is detected automatically. If %NULL is returned, then 
+ * @error will be set. The @cancellable can be used to abort the operation
+ * from another thread. If the operation was cancelled, the error 
+ * %GIO_ERROR_CANCELLED will be returned. Other possible errors are in 
+ * the #GDK_PIXBUF_ERROR and %G_IO_ERROR domains. 
+ *
+ * The image will be scaled to fit in the requested size, optionally 
+ * preserving the image's aspect ratio. When preserving the aspect ratio, 
+ * a @width of -1 will cause the image to be scaled to the exact given 
+ * height, and a @height of -1 will cause the image to be scaled to the 
+ * exact given width. When not preserving aspect ratio, a @width or 
+ * @height of -1 means to not scale the image at all in that dimension.
+ *
+ * The stream is not closed.
+ *
+ * Return value: A newly-created pixbuf, or %NULL if any of several error 
+ * conditions occurred: the file could not be opened, the image format is 
+ * not supported, there was not enough memory to allocate the image buffer, 
+ * the stream contained invalid data, or the operation was cancelled.
+ *
+ * Since: 2.16
+ */
+GdkPixbuf *
+gdk_pixbuf_new_from_stream_at_scale (GInputStream  *stream,
+				     gint	    width,
+				     gint 	    height,
+				     gboolean       preserve_aspect_ratio,
+				     GCancellable  *cancellable,
+		  	    	     GError       **error)
+{
+	GdkPixbufLoader *loader;
+	GdkPixbuf *pixbuf;
+	AtScaleData info;
+
+	loader = gdk_pixbuf_loader_new ();
+
+	info.width = width;
+	info.height = height;
+        info.preserve_aspect_ratio = preserve_aspect_ratio;
+
+	g_signal_connect (loader, "size-prepared", 
+			  G_CALLBACK (at_scale_size_prepared_cb), &info);
+
+	pixbuf = load_from_stream (loader, stream, cancellable, error);
+	g_object_unref (loader);
+
+	return pixbuf;
+}
+
+/**
+ * gdk_pixbuf_new_from_stream:
+ * @stream:  a #GInputStream to load the pixbuf from
+ * @cancellable: optional #GCancellable object, %NULL to ignore
+ * @error: Return location for an error
+ *
+ * Creates a new pixbuf by loading an image from an input stream.  
+ *
+ * The file format is detected automatically. If %NULL is returned, then 
+ * @error will be set. The @cancellable can be used to abort the operation
+ * from another thread. If the operation was cancelled, the error 
+ * %GIO_ERROR_CANCELLED will be returned. Other possible errors are in 
+ * the #GDK_PIXBUF_ERROR and %G_IO_ERROR domains. 
+ *
+ * The stream is not closed.
+ *
+ * Return value: A newly-created pixbuf, or %NULL if any of several error 
+ * conditions occurred: the file could not be opened, the image format is 
+ * not supported, there was not enough memory to allocate the image buffer, 
+ * the stream contained invalid data, or the operation was cancelled.
+ *
+ * Since: 2.16
+ **/
+GdkPixbuf *
+gdk_pixbuf_new_from_stream (GInputStream  *stream,
+			    GCancellable  *cancellable,
+		  	    GError       **error)
+{
+	GdkPixbuf *pixbuf;
+	GdkPixbufLoader *loader;
+
+	loader = gdk_pixbuf_loader_new ();
+	pixbuf = load_from_stream (loader, stream, cancellable, error);
+	g_object_unref (loader);
+
+	return pixbuf;
+}
+
 static void
 info_cb (GdkPixbufLoader *loader, 
 	 int              width,
@@ -1234,7 +1390,7 @@ gdk_pixbuf_get_file_info (const gchar  *filename,
 			  gint         *height)
 {
 	GdkPixbufLoader *loader;
-	guchar buffer [4096];
+	guchar buffer[SNIFF_BUFFER_SIZE];
 	int length;
 	FILE *f;
 	struct {
@@ -1579,18 +1735,18 @@ gdk_pixbuf_real_save_to_callback (GdkPixbuf         *pixbuf,
  * installed. The list of all writable formats can be determined in the 
  * following way:
  *
- * <informalexample><programlisting>
+ * |[
  * void add_if_writable (GdkPixbufFormat *data, GSList **list)
  * {
  *   if (gdk_pixbuf_format_is_writable (data))
  *     *list = g_slist_prepend (*list, data);
  * }
- * <!-- -->
- * GSList *formats = gdk_pixbuf_get_formats (<!-- -->);
+ * 
+ * GSList *formats = gdk_pixbuf_get_formats ();
  * GSList *writable_formats = NULL;
- * g_slist_foreach (formats, add_if_writable, &amp;writable_formats);
+ * g_slist_foreach (formats, add_if_writable, &writable_formats);
  * g_slist_free (formats);
- * </programlisting></informalexample>
+ * ]|
  *
  * If @error is set, %FALSE will be returned. Possible errors include 
  * those in the #GDK_PIXBUF_ERROR domain and those in the #G_FILE_ERROR domain.
@@ -1999,7 +2155,8 @@ save_to_buffer_callback (const gchar *data,
  * @error: return location for error, or %NULL
  *
  * Saves pixbuf to a new buffer in format @type, which is currently "jpeg",
- * "tiff", "png", "ico" or "bmp".  See gdk_pixbuf_save_to_buffer() for more details.
+ * "tiff", "png", "ico" or "bmp".  See gdk_pixbuf_save_to_buffer() 
+ * for more details.
  *
  * Return value: whether an error was set
  *
@@ -2044,6 +2201,87 @@ gdk_pixbuf_save_to_bufferv     (GdkPixbuf  *pixbuf,
 	return TRUE;
 }
 
+typedef struct {
+	GOutputStream *stream;
+	GCancellable  *cancellable;
+} SaveToStreamData;
+
+static gboolean
+save_to_stream (const gchar  *buffer,
+		gsize         count,
+		GCancellable *cancellable,
+		GError      **error,
+		gpointer      data)
+{
+	SaveToStreamData *sdata = (SaveToStreamData *)data;
+
+	g_output_stream_write (sdata->stream, 
+			       buffer, count, 
+			       sdata->cancellable, 
+			       error);
+}
+
+/** 
+ * gdk_pixbuf_save_to_stream:
+ * @pixbuf: a #GdkPixbuf
+ * @stream: a #GOutputStream to save the pixbuf to
+ * @type: name of file format
+ * @cancellable: optional #GCancellable object, %NULL to ignore
+ * @error: return location for error, or %NULL
+ * @Varargs: list of key-value save options
+ *
+ * Saves @pixbuf to an output stream.
+ *
+ * Supported file formats are currently "jpeg", "tiff", "png", "ico" or 
+ * "bmp". See gdk_pixbuf_save_to_buffer() for more details.
+ *
+ * The @cancellable can be used to abort the operation from another 
+ * thread. If the operation was cancelled, the error %GIO_ERROR_CANCELLED 
+ * will be returned. Other possible errors are in the #GDK_PIXBUF_ERROR 
+ * and %G_IO_ERROR domains. 
+ *
+ * The stream is not closed.
+ *
+ * Returns: %TRUE if the pixbuf was saved successfully, %FALSE if an
+ *     error was set.
+ *
+ * Since: 2.16
+ */
+gboolean
+gdk_pixbuf_save_to_stream (GdkPixbuf      *pixbuf,
+		  	   GOutputStream  *stream,
+			   const char     *type,
+			   GCancellable   *cancellable,
+			   GError        **error,
+			   ...)
+{
+	gboolean res;
+	gchar **keys = NULL;
+	gchar **values = NULL;
+	va_list args;
+	SaveToStreamData data;
+
+	va_start (args, error);
+	collect_save_options (args, &keys, &values);
+	va_end (args);
+
+	data.stream = stream;
+	data.cancellable = cancellable;
+
+	if (!gdk_pixbuf_save_to_callbackv (pixbuf, save_to_stream, 
+					   &data, type, 
+					   keys, values, 
+					   error)) {
+		error = NULL; /* Ignore further errors */
+		res = FALSE;
+	}
+
+	g_strfreev (keys);
+	g_strfreev (values);
+
+	return res;
+}
+
 /**
  * gdk_pixbuf_format_get_name:
  * @format: a #GdkPixbufFormat
diff --git a/gdk-pixbuf/gdk-pixbuf.symbols b/gdk-pixbuf/gdk-pixbuf.symbols
index fa9e906d7..37b6a9b8b 100644
--- a/gdk-pixbuf/gdk-pixbuf.symbols
+++ b/gdk-pixbuf/gdk-pixbuf.symbols
@@ -56,6 +56,8 @@ gdk_pixbuf_new_from_file_at_scale PRIVATE
 gdk_pixbuf_new_from_file_at_scale_utf8
 #endif
 gdk_pixbuf_new_from_xpm_data
+gdk_pixbuf_new_from_stream
+gdk_pixbuf_new_from_stream_at_scale
 gdk_pixbuf_save PRIVATE G_GNUC_NULL_TERMINATED
 #ifdef G_OS_WIN32
 gdk_pixbuf_save_utf8
@@ -68,6 +70,7 @@ gdk_pixbuf_savev PRIVATE
 #ifdef G_OS_WIN32
 gdk_pixbuf_savev_utf8
 #endif
+gdk_pixbuf_save_to_stream
 #endif
 #endif