set the TWO_STEPS policy for the image preloader

extensions/cairo_io/cairo-io-jpeg.c

@@ -144,6 +144,7 @@ _cairo_image_surface_create_from_jpeg (GthFileData   *file_data,
 				       GError       **error)
 {
 	GthImage                      *image;
+	gboolean                       load_scaled;
 	GthTransform                   orientation;
 	int                            destination_width;
 	int                            destination_height;
@@ -194,8 +195,9 @@ _cairo_image_surface_create_from_jpeg (GthFileData   *file_data,
 
 	srcinfo.out_color_space = srcinfo.jpeg_color_space; /* make all the color space conversions manually */
 
-	if (requested_size > 0) {
-		for (srcinfo.scale_denom = 16; srcinfo.scale_denom >= 1; srcinfo.scale_denom--) {
+	load_scaled = (requested_size > 0) && (requested_size < srcinfo.image_width) && (requested_size < srcinfo.image_height);
+	if (load_scaled) {
+		for (srcinfo.scale_denom = 1; srcinfo.scale_denom <= 16; srcinfo.scale_denom++) {
 			jpeg_calc_output_dimensions (&srcinfo);
 			if ((srcinfo.output_width < requested_size) || (srcinfo.output_height < requested_size)) {
 				srcinfo.scale_denom += 1;
@@ -205,6 +207,8 @@ _cairo_image_surface_create_from_jpeg (GthFileData   *file_data,
 
 		if (srcinfo.scale_denom == 0)
 			srcinfo.scale_denom = srcinfo.scale_num;
+
+		jpeg_calc_output_dimensions (&srcinfo);
 	}
 
 	jpeg_start_decompress (&srcinfo);
@@ -220,6 +224,15 @@ _cairo_image_surface_create_from_jpeg (GthFileData   *file_data,
 						  &line_step,
 						  &pixel_step);
 
+#if 0
+	g_print ("requested: %d, original [%d, %d] ==> load at [%d, %d]\n",
+			requested_size,
+			srcinfo.image_width,
+			srcinfo.image_height,
+			destination_width,
+			destination_height);
+#endif
+
 	surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, destination_width, destination_height);
 	surface_row = cairo_image_surface_get_data (surface) + line_start;
 
@@ -454,7 +467,7 @@ _cairo_image_surface_create_from_jpeg (GthFileData   *file_data,
 	if (! g_cancellable_is_cancelled (cancellable)) {
 		/* Scale to the requested size */
 
-		if (requested_size > 0) {
+		if (load_scaled) {
 			cairo_surface_t *scaled;
 			int              width;
 			int              height;

extensions/image_viewer/gth-image-viewer-page.c

@@ -322,7 +322,7 @@ image_preloader_requested_ready_cb (GthImagePreloader  *preloader,
 static void
 image_preloader_original_size_ready_cb (GthImagePreloader  *preloader,
 				        GthFileData        *requested,
-				        GdkPixbufAnimation *animation,
+				        GthImage           *image,
 				        int                 original_width,
 				        int                 original_height,
 				        GError             *error,
@@ -335,7 +335,7 @@ image_preloader_original_size_ready_cb (GthImagePreloader  *preloader,
 		return;
 
 	gth_image_viewer_set_better_quality (GTH_IMAGE_VIEWER (self->priv->viewer),
-					     animation,
+					     image,
 					     original_width,
 					     original_height);
 	gth_image_history_clear (self->priv->history);
@@ -819,6 +819,8 @@ gth_image_viewer_page_real_view (GthViewerPage *base,
 	GthFileData        *next_file_data = NULL;
 	GthFileData        *next2_file_data = NULL;
 	GthFileData        *prev_file_data = NULL;
+	int                 window_width;
+	int                 window_height;
 
 	self = (GthImageViewerPage*) base;
 	g_return_if_fail (file_data != NULL);
@@ -858,9 +860,13 @@ gth_image_viewer_page_real_view (GthViewerPage *base,
 			prev_file_data = gth_file_store_get_file (file_store, &iter2);
 	}
 
+	gtk_window_get_size (GTK_WINDOW (self->priv->browser),
+			     &window_width,
+			     &window_height);
+
 	gth_image_preloader_load (self->priv->preloader,
 				  self->priv->file_data,
-				  -1,
+				  (gth_image_prelaoder_get_load_policy (self->priv->preloader) == GTH_LOAD_POLICY_TWO_STEPS) ? MAX (window_width, window_height) : -1,
 				  next_file_data,
 				  next2_file_data,
 				  prev_file_data,

gthumb/gth-browser.c

@@ -4355,7 +4355,7 @@ _gth_browser_construct (GthBrowser *browser)
 
 	/* the image preloader */
 
-	browser->priv->image_preloader = gth_image_preloader_new (GTH_LOAD_POLICY_ONE_STEP, 4);
+	browser->priv->image_preloader = gth_image_preloader_new (GTH_LOAD_POLICY_TWO_STEPS, 4);
 
 	/**/
 

gthumb/gth-image-viewer.c

@@ -1659,13 +1659,49 @@ gth_image_viewer_set_animation (GthImageViewer     *self,
 }
 
 
+static void
+_set_surface (GthImageViewer  *self,
+	      cairo_surface_t *surface,
+	      int              original_width,
+	      int              original_height,
+	      gboolean         better_quality)
+{
+	_cairo_clear_surface (&self->priv->surface);
+	_cairo_clear_surface (&self->priv->iter_surface);
+	_g_clear_object (&self->priv->animation);
+	_g_clear_object (&self->priv->iter);
+
+	self->priv->surface = cairo_surface_reference (surface);
+	self->priv->is_void = (self->priv->surface == NULL);
+	self->priv->is_animation = FALSE;
+	_gth_image_viewer_set_original_size (self, original_width, original_height);
+
+	_gth_image_viewer_content_changed (self, better_quality);
+}
+
+
 void
-gth_image_viewer_set_better_quality (GthImageViewer     *self,
-				     GdkPixbufAnimation *animation,
-				     int                 original_width,
-				     int                 original_height)
+gth_image_viewer_set_better_quality (GthImageViewer *self,
+				     GthImage       *image,
+				     int             original_width,
+				     int             original_height)
 {
-	_set_animation (self, animation, original_width, original_height, TRUE);
+	if (gth_image_is_animation (image)) {
+		GdkPixbufAnimation *animation;
+
+		animation = gth_image_get_pixbuf_animation (image);
+		_set_animation (self, animation, original_width, original_height, TRUE);
+
+		g_object_unref (animation);
+	}
+	else {
+		cairo_surface_t *surface;
+
+		surface = gth_image_get_cairo_surface (image);
+		_set_surface (self, surface, original_width, original_height, TRUE);
+
+		cairo_surface_destroy (surface);
+	}
 }
 
 
@@ -1692,19 +1728,7 @@ gth_image_viewer_set_surface (GthImageViewer  *self,
 			      int              original_width,
 			      int              original_height)
 {
-	g_return_if_fail (self != NULL);
-
-	_cairo_clear_surface (&self->priv->surface);
-	_cairo_clear_surface (&self->priv->iter_surface);
-	_g_clear_object (&self->priv->animation);
-	_g_clear_object (&self->priv->iter);
-
-	self->priv->surface = cairo_surface_reference (surface);
-	self->priv->is_void = (self->priv->surface == NULL);
-	self->priv->is_animation = FALSE;
-	_gth_image_viewer_set_original_size (self, original_width, original_height);
-
-	_gth_image_viewer_content_changed (self, FALSE);
+	_set_surface (self, surface, original_width, original_height, FALSE);
 }
 
 

gthumb/gth-image-viewer.h

@@ -171,7 +171,7 @@ void           gth_image_viewer_set_image                (GthImageViewer     *vi
 							  int                 original_width,
 							  int                 original_height);
 void           gth_image_viewer_set_better_quality       (GthImageViewer     *viewer,
-							  GdkPixbufAnimation *animation,
+						          GthImage           *image,
 							  int                 original_width,
 							  int                 original_height);
 void           gth_image_viewer_set_void                 (GthImageViewer     *viewer);