From fc93216036e3bc4c980358fd8c6686714faa1e20 Mon Sep 17 00:00:00 2001
From: Bas Schouten <bschouten@mozilla.com>
Date: Tue, 30 Mar 2010 20:58:37 +0200
Subject: [PATCH] Bug 556029: Add the ability to detect which layers backend is
 used. r=roc

---
 gfx/layers/Layers.h                 | 12 ++++++++++++
 gfx/layers/basic/BasicLayers.h      |  1 +
 gfx/layers/opengl/LayerManagerOGL.h |  2 ++
 3 files changed, 15 insertions(+)

diff --git a/gfx/layers/Layers.h b/gfx/layers/Layers.h
index f0494369be4..a3759ceeebd 100644
--- a/gfx/layers/Layers.h
+++ b/gfx/layers/Layers.h
@@ -109,6 +109,11 @@ class THEBES_API LayerManager {
   THEBES_INLINE_DECL_REFCOUNTING(LayerManager)  
 
 public:
+  enum LayersBackend {
+    LAYERS_BASIC = 0,
+    LAYERS_OPENGL
+  };
+
   virtual ~LayerManager() {}
 
   /**
@@ -162,6 +167,13 @@ public:
    * Can be called anytime
    */
   virtual already_AddRefed<ImageContainer> CreateImageContainer() = 0;
+
+  /**
+   * Type of layer manager his is. This is to be used sparsely in order to
+   * avoid a lot of Layers backend specific code. It should be used only when
+   * Layers backend specific functionality is necessary.
+   */
+  virtual LayersBackend GetBackendType() = 0;
 };
 
 /**
diff --git a/gfx/layers/basic/BasicLayers.h b/gfx/layers/basic/BasicLayers.h
index 668b71a6104..332587e97e6 100644
--- a/gfx/layers/basic/BasicLayers.h
+++ b/gfx/layers/basic/BasicLayers.h
@@ -87,6 +87,7 @@ public:
   virtual already_AddRefed<ContainerLayer> CreateContainerLayer();
   virtual already_AddRefed<ImageLayer> CreateImageLayer();
   virtual already_AddRefed<ImageContainer> CreateImageContainer();
+  virtual LayersBackend GetBackendType() { return LAYERS_BASIC; }
 
 #ifdef DEBUG
   PRBool InConstruction() { return mPhase == PHASE_CONSTRUCTION; }
diff --git a/gfx/layers/opengl/LayerManagerOGL.h b/gfx/layers/opengl/LayerManagerOGL.h
index 31f8290d55d..a2db6b4b078 100644
--- a/gfx/layers/opengl/LayerManagerOGL.h
+++ b/gfx/layers/opengl/LayerManagerOGL.h
@@ -203,6 +203,8 @@ public:
 
   virtual already_AddRefed<ImageContainer> CreateImageContainer();
 
+  virtual LayersBackend GetBackendType() { return LAYERS_OPENGL; }
+
   /**
    * Helper methods.
    */