exo: Recreate Surface resources on context lost.

components/exo/surface.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_EXO_SURFACE_H_
 #define COMPONENTS_EXO_SURFACE_H_
 
 #include <list>
 #include <memory>
 #include <set>
 #include <utility>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "cc/resources/transferable_resource.h"
 #include "cc/surfaces/surface_factory_client.h"
 #include "third_party/skia/include/core/SkRegion.h"
 #include "third_party/skia/include/core/SkXfermode.h"
 #include "ui/aura/window.h"
+#include "ui/compositor/compositor.h"
 #include "ui/compositor/layer_owner_delegate.h"
 #include "ui/gfx/geometry/rect.h"
 
 namespace base {
 namespace trace_event {
 class TracedValue;
 }
 }
 
 namespace cc {
@@ skipping 46 matching lines @@
            std::pair<scoped_refptr<SurfaceFactoryOwner>,
                      std::unique_ptr<cc::SingleReleaseCallback>>>
       release_callbacks_;
   std::unique_ptr<cc::SurfaceIdAllocator> id_allocator_;
   std::unique_ptr<cc::SurfaceFactory> surface_factory_;
   Surface* surface_;
 };
 
 // This class represents a rectangular area that is displayed on the screen.
 // It has a location, size and pixel contents.
-class Surface : public ui::LayerOwnerDelegate {
+class Surface : public ui::LayerOwnerDelegate,
+                public ui::ContextFactoryObserver {
  public:
   typedef void (*PropertyDeallocator)(int64_t value);
 
   Surface();
   ~Surface() override;
 
   // Type-checking downcast routine.
   static Surface* AsSurface(const aura::Window* window);
 
   aura::Window* window() { return window_.get(); }
 
+  cc::SurfaceId surface_id() const { return surface_id_; }
+
   // Set a buffer as the content of this surface. A buffer can only be attached
   // to one surface at a time.
   void Attach(Buffer* buffer);
 
   // Describe the regions where the pending buffer is different from the
   // current surface contents, and where the surface therefore needs to be
   // repainted.
   void Damage(const gfx::Rect& rect);
 
   // Request notification when the next frame is displayed. Useful for
@@ skipping 88 matching lines @@
   // Returns a trace value representing the state of the surface.
   std::unique_ptr<base::trace_event::TracedValue> AsTracedValue() const;
 
   bool HasPendingDamageForTesting(const gfx::Rect& damage) const {
     return pending_damage_.contains(gfx::RectToSkIRect(damage));
   }
 
   // Overridden from ui::LayerOwnerDelegate:
   void OnLayerRecreated(ui::Layer* old_layer, ui::Layer* new_layer) override;
 
+  // Overridden from ui::ContextFactoryObserver.
+  void OnLostResources() override;
+
   void WillDraw(cc::SurfaceId surface_id);
 
   // Check whether this Surface and its children need to create new cc::Surface
   // IDs for their contents next time they get new buffer contents.
   void CheckIfSurfaceHierarchyNeedsCommitToNewSurfaces();
 
   gfx::Size content_size() const { return content_size_; }
 
   // Sets the |value| of the given surface |property|. Setting to the default
   // value (e.g., NULL) removes the property. The caller is responsible for the
@@ skipping 20 matching lines @@
     bool operator!=(const State& other) { return !(*this == other); }
 
     SkRegion opaque_region;
     SkRegion input_region;
     float buffer_scale = 1.f;
     gfx::Size viewport;
     gfx::RectF crop;
     bool only_visible_on_secure_output = false;
     SkXfermode::Mode blend_mode = SkXfermode::kSrcOver_Mode;
     float alpha = 1.0f;
-    ;
+  };
+  class BufferAttachment {
+   public:
+    BufferAttachment();
+    ~BufferAttachment();
+
+    base::WeakPtr<Buffer>& buffer();
+    const base::WeakPtr<Buffer>& buffer() const;
+    void Reset(base::WeakPtr<Buffer> buffer);
+
+   private:
+    base::WeakPtr<Buffer> buffer_;
+    DISALLOW_COPY_AND_ASSIGN(BufferAttachment);

[reveman, 2016/06/23 00:44:39]

nit: blank line before this

   };
 
   friend class subtle::PropertyHelper;
 
   bool needs_commit_surface_hierarchy() const {
     return needs_commit_surface_hierarchy_;
   }
 
   // Returns true if this surface or any child surface needs a commit and has
   // has_pending_layer_changes_ true.
   bool HasLayerHierarchyChanged() const;
 
   // Sets that all children must create new cc::SurfaceIds for their contents.
   void SetSurfaceHierarchyNeedsCommitToNewSurfaces();
 
   // Set SurfaceLayer contents to the current buffer.
   void SetSurfaceLayerContents(ui::Layer* layer);
 
+  // Updates current_resource_ with a new resource id corresponding to the
+  // contents of the attached buffer (or id 0, if no buffer is attached).
+  // UpdateSurface must be called afterwards to ensure the release callback
+  // will be called.
+  void UpdateResource(bool client_usage);
+
+  // Updates the current Surface with a new frame referring to the resource in
+  // current_resource_.
+  void UpdateSurface(bool for_commit);

[reveman, 2016/06/23 00:44:39]

nit: s/for_commit/full_damage/

+
   int64_t SetPropertyInternal(const void* key,
                               const char* name,
                               PropertyDeallocator deallocator,
                               int64_t value,
                               int64_t default_value);
   int64_t GetPropertyInternal(const void* key, int64_t default_value) const;
 
   // This returns true when the surface has some contents assigned to it.
-  bool has_contents() const { return !!current_buffer_; }
+  bool has_contents() const { return !!current_buffer_.buffer(); }
 
   // This window has the layer which contains the Surface contents.
   std::unique_ptr<aura::Window> window_;
 
   // This is true if it's possible that the layer properties (size, opacity,
   // etc.) may have been modified since the last commit. Attaching a new
   // buffer with the same size as the old shouldn't set this to true.
   bool has_pending_layer_changes_ = true;
 
   // This is true if the next commit to this surface should put its contents
   // into a new cc::SurfaceId. This allows for synchronization between Surface
   // and layer changes.
   bool needs_commit_to_new_surface_ = true;
 
   // This is the size of the last committed contents.
   gfx::Size content_size_;
 
   // This is true when Attach() has been called and new contents should take
   // effect next time Commit() is called.
   bool has_pending_contents_;
 
   // The buffer that will become the content of surface when Commit() is called.
-  base::WeakPtr<Buffer> pending_buffer_;
+  BufferAttachment pending_buffer_;
 
   cc::SurfaceManager* surface_manager_;
 
   scoped_refptr<SurfaceFactoryOwner> factory_owner_;
 
   // The Surface Id currently attached to the window.
   cc::SurfaceId surface_id_;
 
   // The next resource id the buffer will be attached to.
   int next_resource_id_ = 1;
@@ skipping 18 matching lines @@
   State state_;
 
   // The stack of sub-surfaces to take effect when Commit() is called.
   // Bottom-most sub-surface at the front of the list and top-most sub-surface
   // at the back.
   using SubSurfaceEntry = std::pair<Surface*, gfx::Point>;
   using SubSurfaceEntryList = std::list<SubSurfaceEntry>;
   SubSurfaceEntryList pending_sub_surfaces_;
 
   // The buffer that is currently set as content of surface.
-  base::WeakPtr<Buffer> current_buffer_;
+  BufferAttachment current_buffer_;
 
   // The last resource that was sent to a surface.
   cc::TransferableResource current_resource_;
 
   // This is true if a call to Commit() as been made but
   // CommitSurfaceHierarchy() has not yet been called.
   bool needs_commit_surface_hierarchy_;
 
   // This is set when the compositing starts and passed to active frame
   // callbacks when compositing successfully ends.
@@ skipping 17 matching lines @@
 
   // Surface observer list. Surface does not own the observers.
   base::ObserverList<SurfaceObserver, true> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(Surface);
 };
 
 }  // namespace exo
 
 #endif  // COMPONENTS_EXO_SURFACE_H_