1 files changed, 82 insertions, 0 deletions
diff --git a/gfx/layers/UpdateImageHelper.h b/gfx/layers/UpdateImageHelper.h
new file mode 100644
index 0000000000..b0d07c85fc
--- /dev/null
+++ b/gfx/layers/UpdateImageHelper.h
@@ -0,0 +1,82 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#ifndef GFX_UPDATEIMAGEHELPER_H
+#define GFX_UPDATEIMAGEHELPER_H
+
+#include "mozilla/layers/CompositorTypes.h"
+#include "mozilla/layers/ImageClient.h"
+#include "mozilla/layers/TextureClient.h"
+#include "mozilla/layers/TextureClientRecycleAllocator.h"
+#include "mozilla/layers/TextureWrapperImage.h"
+#include "mozilla/gfx/Types.h"
+
+namespace mozilla {
+namespace layers {
+
+class UpdateImageHelper {
+ public:
+  UpdateImageHelper(ImageContainer* aImageContainer, ImageClient* aImageClient,
+                    gfx::IntSize aImageSize, gfx::SurfaceFormat aFormat)
+      : mImageContainer(aImageContainer),
+        mImageClient(aImageClient),
+        mImageSize(aImageSize),
+        mIsLocked(false) {
+    mTexture = mImageClient->GetTextureClientRecycler()->CreateOrRecycle(
+        aFormat, mImageSize, BackendSelector::Content, TextureFlags::DEFAULT);
+    if (!mTexture) {
+      return;
+    }
+
+    mIsLocked = mTexture->Lock(OpenMode::OPEN_WRITE_ONLY);
+    if (!mIsLocked) {
+      return;
+    }
+  }
+
+  ~UpdateImageHelper() {
+    if (mIsLocked) {
+      mTexture->Unlock();
+      mIsLocked = false;
+    }
+  }
+
+  already_AddRefed<gfx::DrawTarget> GetDrawTarget() {
+    RefPtr<gfx::DrawTarget> target;
+    if (mTexture) {
+      target = mTexture->BorrowDrawTarget();
+    }
+    return target.forget();
+  }
+
+  bool UpdateImage() {
+    if (!mTexture) {
+      return false;
+    }
+
+    if (mIsLocked) {
+      mTexture->Unlock();
+      mIsLocked = false;
+    }
+
+    RefPtr<TextureWrapperImage> image = new TextureWrapperImage(
+        mTexture, gfx::IntRect(gfx::IntPoint(0, 0), mImageSize));
+    mImageContainer->SetCurrentImageInTransaction(image);
+    return mImageClient->UpdateImage(mImageContainer, /* unused */ 0);
+  }
+
+ private:
+  RefPtr<ImageContainer> mImageContainer;
+  RefPtr<ImageClient> mImageClient;
+  gfx::IntSize mImageSize;
+  RefPtr<TextureClient> mTexture;
+  bool mIsLocked;
+};
+
+}  // namespace layers
+}  // namespace mozilla
+
+#endif  // GFX_UPDATEIMAGEHELPER_H