Re #142: Load all images from Tweet

Rather than wait until we display each one, start async
loading all images when the media dialog gets created
so that they're ready when the user clicks "Next"

src/CbMediaImageWidget.c

@@ -103,7 +103,10 @@ cb_media_image_widget_init (CbMediaImageWidget *self)
 }
 
 void
-hires_complete (GObject *source_object, GAsyncResult *res, gpointer user_data) {
+hires_progress (CbMedia *_media, gpointer user_data) {
+  if (!_media->loaded_hires) {
+    return;
+  }
   LoadingData *data = user_data;
   CbMediaImageWidget *self = CB_MEDIA_IMAGE_WIDGET(data->widget);
   CbMedia *media = data->media;
@@ -138,17 +141,21 @@ cb_media_image_widget_new (CbMedia *media, GdkRectangle *max_dimensions)
     double scale_height = media->height * 1.0 / media->thumb_height;
 
     if (scale_width != 1 || scale_height != 1) {
+      data = g_new0 (LoadingData, 1);
+      data->widget = g_object_ref (self);
+      data->media = g_object_ref (media);
+      g_signal_connect(media, "hires-progress", G_CALLBACK(hires_progress), data);
       self->image_surface = cairo_image_surface_create(cairo_image_surface_get_format(media->surface), media->width, media->height);
       cairo_t *ct = cairo_create(self->image_surface);
       cairo_scale(ct, scale_width, scale_height);
       cairo_set_source_surface (ct, media->surface, 0, 0);
       cairo_paint(ct);
       cairo_destroy(ct);
       gtk_image_set_from_surface (GTK_IMAGE (self->image), self->image_surface);
-      data = g_new0 (LoadingData, 1);
-      data->widget = g_object_ref (self);
-      data->media = g_object_ref (media);
-      cb_media_downloader_load_hires_async (cb_media_downloader_get_default(), media, hires_complete, data);
+      if (!media->loading) {
+        // NULL callback because we should pick it up from the earlier g_signal_connect
+        cb_media_downloader_load_hires_async (cb_media_downloader_get_default(), media, NULL, NULL);
+      }
     }
     else {
       gtk_image_set_from_surface (GTK_IMAGE (self->image), media->surface);

src/window/MediaDialog.vala

@@ -32,6 +32,12 @@ class MediaDialog : Gtk.Window {
                       int      start_media_index,
                       Gdk.Rectangle max_dimensions) {
     this.media = media;
+    var downloader = Cb.MediaDownloader.get_default();
+    foreach (Cb.Media m in media){
+      if (!m.loaded_hires && !m.loading_hires) {
+        downloader.load_hires_async.begin (m);
+      }
+    }
     Cb.Media cur_media = media[start_media_index];
     this.cur_index = start_media_index;
     this.max_dimensions = max_dimensions;

vapi/cawbird-internal.vapi

@@ -96,6 +96,7 @@ namespace Cb {
   public class MediaDownloader : GLib.Object {
     public static unowned MediaDownloader get_default ();
     public async void load_async (Media media);
+    public async void load_hires_async (Media media);
     public void disable ();
     public void shutdown ();
   }