glx: forward Expose event from child window to parent

r272290 added a child window to GLSurfaceGLX, but it needs to forward
Expose events to the parent.

BUG=326995
R=ccameron@chromium.org, sadrul@chromium.org

Review URL: https://codereview.chromium.org/299143002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@272648 0039d316-1c4b-4281-b951-d872f2087c98

content/gpu/gpu_main.cc

@@ -32,6 +32,7 @@
 #include "gpu/command_buffer/service/gpu_switches.h"
 #include "gpu/config/gpu_info_collector.h"
 #include "gpu/config/gpu_util.h"
+#include "ui/events/platform/platform_event_source.h"
 #include "ui/gl/gl_implementation.h"
 #include "ui/gl/gl_surface.h"
 #include "ui/gl/gl_switches.h"
@@ -144,6 +145,12 @@ int GpuMain(const MainFunctionParams& parameters) {
     message_loop_type = base::MessageLoop::TYPE_UI;
   }
   base::MessageLoop main_message_loop(message_loop_type);
+#elif defined(OS_LINUX) && defined(USE_X11)
+  // We need a UI loop so that we can grab the Expose events. See GLSurfaceGLX
+  // and https://crbug.com/326995.
+  base::MessageLoop main_message_loop(base::MessageLoop::TYPE_UI);
+  scoped_ptr<ui::PlatformEventSource> event_source =
+      ui::PlatformEventSource::CreateDefault();
 #elif defined(OS_LINUX)
   base::MessageLoop main_message_loop(base::MessageLoop::TYPE_DEFAULT);
 #elif defined(OS_MACOSX)

ui/gl/DEPS

@@ -2,6 +2,7 @@ include_rules = [
   "+third_party/khronos",
   "+third_party/mesa/src/include",
   "+third_party/skia",
+  "+ui/events",
   "+ui/gfx",
   "+ui/ozone",
 ]

ui/gl/gl.gyp

@@ -222,6 +222,7 @@
             '<(DEPTH)/build/linux/system.gyp:x11',
             '<(DEPTH)/build/linux/system.gyp:xcomposite',
             '<(DEPTH)/build/linux/system.gyp:xext',
+            '<(DEPTH)/ui/events/platform/events_platform.gyp:events_platform',
             '<(DEPTH)/ui/gfx/x/gfx_x11.gyp:gfx_x11',
           ],
         }],

ui/gl/gl_surface_glx.cc

@@ -21,6 +21,7 @@ extern "C" {
 #include "base/threading/thread.h"
 #include "base/time/time.h"
 #include "third_party/mesa/src/include/GL/osmesa.h"
+#include "ui/events/platform/platform_event_source.h"
 #include "ui/gfx/x/x11_connection.h"
 #include "ui/gfx/x/x11_types.h"
 #include "ui/gl/gl_bindings.h"
@@ -425,6 +426,15 @@ bool NativeViewGLSurfaceGLX::Initialize() {
                           NULL);
   XMapWindow(g_display, window_);
 
+  ui::PlatformEventSource* event_source =
+      ui::PlatformEventSource::GetInstance();
+  // Can be NULL in tests, when we don't care about Exposes.
+  if (event_source) {
+    XSelectInput(g_display, window_, ExposureMask);
+    ui::PlatformEventSource::GetInstance()->AddPlatformEventDispatcher(this);
+  }
+  XFlush(g_display);
+
   gfx::AcceleratedWidget window_for_vsync = window_;
 
   if (g_glx_oml_sync_control_supported)
@@ -437,11 +447,28 @@ bool NativeViewGLSurfaceGLX::Initialize() {
 
 void NativeViewGLSurfaceGLX::Destroy() {
   if (window_) {
+    ui::PlatformEventSource* event_source =
+        ui::PlatformEventSource::GetInstance();
+    if (event_source)
+      event_source->RemovePlatformEventDispatcher(this);
     XDestroyWindow(g_display, window_);
     XFlush(g_display);
   }
 }
 
+bool NativeViewGLSurfaceGLX::CanDispatchEvent(const ui::PlatformEvent& event) {
+  return event->type == Expose && event->xexpose.window == window_;
+}
+
+uint32_t NativeViewGLSurfaceGLX::DispatchEvent(const ui::PlatformEvent& event) {
+  XEvent forwarded_event = *event;
+  forwarded_event.xexpose.window = parent_window_;
+  XSendEvent(g_display, parent_window_, False, ExposureMask,
+             &forwarded_event);
+  XFlush(g_display);
+  return ui::POST_DISPATCH_STOP_PROPAGATION;
+}
+
 bool NativeViewGLSurfaceGLX::Resize(const gfx::Size& size) {
   size_ = size;
   glXWaitGL();
@@ -547,12 +574,6 @@ VSyncProvider* NativeViewGLSurfaceGLX::GetVSyncProvider() {
   return vsync_provider_.get();
 }
 
-NativeViewGLSurfaceGLX::NativeViewGLSurfaceGLX()
-  : parent_window_(0),
-    window_(0),
-    config_(NULL) {
-}
-
 NativeViewGLSurfaceGLX::~NativeViewGLSurfaceGLX() {
   Destroy();
 }

ui/gl/gl_surface_glx.h

@@ -8,6 +8,7 @@
 #include <string>
 
 #include "base/compiler_specific.h"
+#include "ui/events/platform/platform_event_dispatcher.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/size.h"
 #include "ui/gfx/vsync_provider.h"
@@ -48,7 +49,8 @@ class GL_EXPORT GLSurfaceGLX : public GLSurface {
 };
 
 // A surface used to render to a view.
-class GL_EXPORT NativeViewGLSurfaceGLX : public GLSurfaceGLX {
+class GL_EXPORT NativeViewGLSurfaceGLX : public GLSurfaceGLX,
+                                         public ui::PlatformEventDispatcher {
  public:
   explicit NativeViewGLSurfaceGLX(gfx::AcceleratedWidget window);
 
@@ -66,13 +68,16 @@ class GL_EXPORT NativeViewGLSurfaceGLX : public GLSurfaceGLX {
   virtual VSyncProvider* GetVSyncProvider() OVERRIDE;
 
  protected:
-  NativeViewGLSurfaceGLX();
   virtual ~NativeViewGLSurfaceGLX();
 
  private:
   // The handle for the drawable to make current or swap.
   gfx::AcceleratedWidget GetDrawableHandle() const;
 
+  // PlatformEventDispatcher implementation
+  virtual bool CanDispatchEvent(const ui::PlatformEvent& event) OVERRIDE;
+  virtual uint32_t DispatchEvent(const ui::PlatformEvent& event) OVERRIDE;
+
   // Window passed in at creation. Always valid.
   gfx::AcceleratedWidget parent_window_;