1 files changed, 84 insertions, 0 deletions
diff --git a/widget/CompositorWidget.cpp b/widget/CompositorWidget.cpp
new file mode 100644
index 0000000000..2cdf8010ad
--- /dev/null
+++ b/widget/CompositorWidget.cpp
@@ -0,0 +1,84 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CompositorWidget.h"
+#include "GLConsts.h"
+#include "nsBaseWidget.h"
+#include "VsyncDispatcher.h"
+
+namespace mozilla {
+namespace widget {
+
+CompositorWidget::~CompositorWidget()
+{
+}
+
+already_AddRefed<gfx::DrawTarget>
+CompositorWidget::StartRemoteDrawing()
+{
+  return nullptr;
+}
+
+void
+CompositorWidget::CleanupRemoteDrawing()
+{
+  mLastBackBuffer = nullptr;
+}
+
+already_AddRefed<gfx::DrawTarget>
+CompositorWidget::GetBackBufferDrawTarget(gfx::DrawTarget* aScreenTarget,
+                                          const LayoutDeviceIntRect& aRect,
+                                          const LayoutDeviceIntRect& aClearRect)
+{
+  MOZ_ASSERT(aScreenTarget);
+  gfx::SurfaceFormat format =
+    aScreenTarget->GetFormat() == gfx::SurfaceFormat::B8G8R8X8 ? gfx::SurfaceFormat::B8G8R8X8 : gfx::SurfaceFormat::B8G8R8A8;
+  gfx::IntSize size = aRect.ToUnknownRect().Size();
+  gfx::IntSize clientSize(GetClientSize().ToUnknownSize());
+
+  RefPtr<gfx::DrawTarget> target;
+  // Re-use back buffer if possible
+  if (mLastBackBuffer &&
+      mLastBackBuffer->GetBackendType() == aScreenTarget->GetBackendType() &&
+      mLastBackBuffer->GetFormat() == format &&
+      size <= mLastBackBuffer->GetSize() &&
+      mLastBackBuffer->GetSize() <= clientSize) {
+    target = mLastBackBuffer;
+    target->SetTransform(gfx::Matrix());
+    if (!aClearRect.IsEmpty()) {
+      gfx::IntRect clearRect = aClearRect.ToUnknownRect() - aRect.ToUnknownRect().TopLeft();
+      target->ClearRect(gfx::Rect(clearRect.x, clearRect.y, clearRect.width, clearRect.height));
+    }
+  } else {
+    target = aScreenTarget->CreateSimilarDrawTarget(size, format);
+    mLastBackBuffer = target;
+  }
+  return target.forget();
+}
+
+already_AddRefed<gfx::SourceSurface>
+CompositorWidget::EndBackBufferDrawing()
+{
+  RefPtr<gfx::SourceSurface> surface = mLastBackBuffer ? mLastBackBuffer->Snapshot() : nullptr;
+  return surface.forget();
+}
+
+uint32_t
+CompositorWidget::GetGLFrameBufferFormat()
+{
+  return LOCAL_GL_RGBA;
+}
+
+RefPtr<VsyncObserver>
+CompositorWidget::GetVsyncObserver() const
+{
+  // This should only used when the widget is in the GPU process, and should be
+  // implemented by IPDL-enabled CompositorWidgets.
+  // GPU process does not have a CompositorVsyncDispatcher.
+  MOZ_ASSERT_UNREACHABLE("Must be implemented by derived class");
+  return nullptr;
+}
+
+} // namespace widget
+} // namespace mozilla