1 files changed, 78 insertions, 0 deletions
diff --git a/widget/CompositorWidget.cpp b/widget/CompositorWidget.cpp
new file mode 100644
index 0000000000..6eddecff4a
--- /dev/null
+++ b/widget/CompositorWidget.cpp
@@ -0,0 +1,78 @@
+/* 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(const layers::CompositorOptions& aOptions)
+    : mOptions(aOptions) {}
+
+CompositorWidget::~CompositorWidget() = default;
+
+already_AddRefed<gfx::DrawTarget> CompositorWidget::StartRemoteDrawing() {
+  return nullptr;
+}
+
+void CompositorWidget::CleanupRemoteDrawing() { mLastBackBuffer = nullptr; }
+
+already_AddRefed<gfx::DrawTarget> CompositorWidget::GetBackBufferDrawTarget(
+    gfx::DrawTarget* aScreenTarget, const gfx::IntRect& aRect,
+    bool* aOutIsCleared) {
+  MOZ_ASSERT(aScreenTarget);
+  gfx::SurfaceFormat format =
+      aScreenTarget->GetFormat() == gfx::SurfaceFormat::B8G8R8X8
+          ? gfx::SurfaceFormat::B8G8R8X8
+          : gfx::SurfaceFormat::B8G8R8A8;
+  gfx::IntSize size = aRect.Size();
+  gfx::IntSize clientSize = Max(size, GetClientSize().ToUnknownSize());
+
+  *aOutIsCleared = false;
+  // Re-use back buffer if possible
+  if (!mLastBackBuffer ||
+      mLastBackBuffer->GetBackendType() != aScreenTarget->GetBackendType() ||
+      mLastBackBuffer->GetFormat() != format ||
+      mLastBackBuffer->GetSize() != clientSize) {
+    mLastBackBuffer =
+        aScreenTarget->CreateSimilarDrawTarget(clientSize, format);
+    *aOutIsCleared = true;
+  }
+  return do_AddRef(mLastBackBuffer);
+}
+
+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;
+}
+
+LayoutDeviceIntRegion CompositorWidget::GetTransparentRegion() {
+  // By default, we check the transparency mode to determine if the widget is
+  // transparent, and if so, designate the entire widget drawing area as
+  // transparent. Widgets wanting more complex transparency region determination
+  // should override this method.
+  auto* widget = RealWidget();
+  if (!widget || widget->GetTransparencyMode() != TransparencyMode::Opaque ||
+      widget->WidgetPaintsBackground()) {
+    return LayoutDeviceIntRect(LayoutDeviceIntPoint(0, 0), GetClientSize());
+  }
+  return LayoutDeviceIntRegion();
+}
+
+}  // namespace widget
+}  // namespace mozilla