[cheese] Track flash opacity explicitly

[David King <davidk src gnome org>]

commit 1c40135ddbd7f99ec8a7f1eafb91889d83b0108a
Author: Benjamin Herr <ben 0x539 de>
Date:   Sun Jul 20 02:30:46 2014 +0200

    Track flash opacity explicitly
    
    Retrieving the opacity of the flash, reducing it by an exponentially
    small step, and setting it again does not always actually decrease the
    widget's opacity, and so the fading does not actually terminate.
    
    Incidentally, also unset the flash timeout tags to avoid calling
    g_source_remove() spuriously.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=733433

 libcheese/cheese-flash.c |   28 ++++++++++++++++++++++++----
 1 files changed, 24 insertions(+), 4 deletions(-)
---
diff --git a/libcheese/cheese-flash.c b/libcheese/cheese-flash.c
index a87602d..cec97a2 100644
--- a/libcheese/cheese-flash.c
+++ b/libcheese/cheese-flash.c
@@ -70,6 +70,7 @@ struct _CheeseFlashPrivate
   GtkWidget *parent;
   guint flash_timeout_tag;
   guint fade_timeout_tag;
+  gdouble opacity;
 };
 
 G_DEFINE_TYPE_WITH_PRIVATE (CheeseFlash, cheese_flash, GTK_TYPE_WINDOW)
@@ -84,6 +85,7 @@ cheese_flash_init (CheeseFlash *self)
 
   priv->flash_timeout_tag = 0;
   priv->fade_timeout_tag  = 0;
+  priv->opacity = 1.0;
 
   /* make it so it doesn't look like a window on the desktop (+fullscreen) */
   gtk_window_set_decorated (window, FALSE);
@@ -186,18 +188,26 @@ cheese_flash_class_init (CheeseFlashClass *klass)
 static gboolean
 cheese_flash_opacity_fade (gpointer data)
 {
-  GtkWidget *flash_window = GTK_WIDGET (data);
-  gdouble opacity = gtk_widget_get_opacity (flash_window);
+  CheeseFlashPrivate *priv;
+  GtkWidget *flash_window;
+
+  flash_window = GTK_WIDGET (data);
+  priv = cheese_flash_get_instance_private (CHEESE_FLASH (data));
 
   /* exponentially decrease */
-  gtk_widget_set_opacity (flash_window, opacity * FLASH_FADE_FACTOR);
+  priv->opacity *= FLASH_FADE_FACTOR;
 
-  if (opacity <= FLASH_LOW_THRESHOLD)
+  if (priv->opacity <= FLASH_LOW_THRESHOLD)
   {
     /* the flasher has finished when we reach the quit value */
     gtk_widget_hide (flash_window);
+    priv->fade_timeout_tag = 0;
     return G_SOURCE_REMOVE;
   }
+  else
+  {
+    gtk_widget_set_opacity (flash_window, priv->opacity);
+  }
 
   return G_SOURCE_CONTINUE;
 }
@@ -225,6 +235,7 @@ cheese_flash_start_fade (gpointer data)
   }
 
   flash_priv->fade_timeout_tag = g_timeout_add (1000.0 / FLASH_ANIMATION_RATE, cheese_flash_opacity_fade, 
data);
+  flash_priv->flash_timeout_tag = 0;
   return G_SOURCE_REMOVE;
 }
 
@@ -253,9 +264,18 @@ cheese_flash_fire (CheeseFlash *flash)
   flash_window = GTK_WINDOW (flash);
 
   if (flash_priv->flash_timeout_tag > 0)
+  {
     g_source_remove (flash_priv->flash_timeout_tag);
+    flash_priv->flash_timeout_tag = 0;
+  }
+
   if (flash_priv->fade_timeout_tag > 0)
+  {
     g_source_remove (flash_priv->fade_timeout_tag);
+    flash_priv->fade_timeout_tag = 0;
+  }
+
+  flash_priv->opacity = 1.0;
 
   parent  = gtk_widget_get_toplevel (flash_priv->parent);
   screen  = gtk_widget_get_screen (parent);