egl/x11: Created a child window to control resizes and prevent flashes

ui/gl/gl_surface_egl.h

 // Copyright (c) 2012 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 UI_GL_GL_SURFACE_EGL_H_
 #define UI_GL_GL_SURFACE_EGL_H_
 
 #if defined(OS_WIN)
 #include <windows.h>
 #endif
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/time/time.h"
+#include "ui/events/platform/platform_event_dispatcher.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/vsync_provider.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_surface.h"
 
 namespace gfx {
 
 // Get default EGL display for GLSurfaceEGL (differs by platform).
 EGLNativeDisplayType GetPlatformDefaultEGLNativeDisplay();
 
@@ skipping 37 matching lines @@
   static bool IsEGLSurfacelessContextSupported();
 
  protected:
   ~GLSurfaceEGL() override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(GLSurfaceEGL);
 };
 
 // Encapsulates an EGL surface bound to a view.
-class GL_EXPORT NativeViewGLSurfaceEGL : public GLSurfaceEGL {
+class GL_EXPORT NativeViewGLSurfaceEGL : public GLSurfaceEGL,
+                                         public ui::PlatformEventDispatcher {
  public:
   explicit NativeViewGLSurfaceEGL(EGLNativeWindowType window);
 
   // Implement GLSurface.
   EGLConfig GetConfig() override;
   bool Initialize() override;
   void Destroy() override;
   bool Resize(const gfx::Size& size, float scale_factor) override;
   bool Recreate() override;
   bool IsOffscreen() override;
@@ skipping 11 matching lines @@
 
   // Create a NativeViewGLSurfaceEGL with an externally provided VSyncProvider.
   // Takes ownership of the VSyncProvider.
   virtual bool Initialize(scoped_ptr<VSyncProvider> sync_provider);
 
  protected:
   ~NativeViewGLSurfaceEGL() override;
 
   EGLNativeWindowType window_;
 
+#if defined(USE_X11)
+  EGLNativeWindowType parent_window_;
+#endif
+
   void OnSetSwapInterval(int interval) override;
 
  private:
   EGLSurface surface_;
   bool supports_post_sub_buffer_;
   EGLConfig config_;
   gfx::Size size_;
 
   scoped_ptr<VSyncProvider> vsync_provider_;
 
   int swap_interval_;
 
 #if defined(OS_WIN)
   bool vsync_override_;
 
   unsigned int swap_generation_;
   static unsigned int current_swap_generation_;
   static unsigned int swaps_this_generation_;
   static unsigned int last_multiswap_generation_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(NativeViewGLSurfaceEGL);
+
+ private:
+  // PlatformEventDispatcher implementation.
+  bool CanDispatchEvent(const ui::PlatformEvent& event) override;
+  uint32_t DispatchEvent(const ui::PlatformEvent& event) override;

[piman, 2015/11/30 22:07:44]

nit: keep these in the existing private: section.
DISALLOW_COPY_AND_ASSIGN should be the last thing there, and otherwise within a
section the order should be:
- Types
- Methods
- Fields

 };
 
 // Encapsulates a pbuffer EGL surface.
 class GL_EXPORT PbufferGLSurfaceEGL : public GLSurfaceEGL {
  public:
   explicit PbufferGLSurfaceEGL(const gfx::Size& size);
 
   // Implement GLSurface.
   EGLConfig GetConfig() override;
   bool Initialize() override;
@@ skipping 35 matching lines @@
   void* GetShareHandle() override;
 
  protected:
   ~SurfacelessEGL() override;
 
  private:
   gfx::Size size_;
   DISALLOW_COPY_AND_ASSIGN(SurfacelessEGL);
 };
 
+#if !defined(USE_X11)
+// PlatformEventDispatcher implementation.
+bool NativeViewGLSurfaceEGL::CanDispatchEvent(const ui::PlatformEvent&) {
+  return false;
+}
+uint32_t NativeViewGLSurfaceEGL::DispatchEvent(const ui::PlatformEvent&) {
+  return ui::POST_DISPATCH_NONE;
+}
+#endif

[piman, 2015/11/30 22:07:44]

nit: move these to the .cc file.

Another option is to create a subclass NativeViewGLSurfaceEGLX11 and have the
X11-specific logic (including the ui::PlatformEventDispatcher) there.

+
 }  // namespace gfx
 
 #endif  // UI_GL_GL_SURFACE_EGL_H_