Add helpers for creating UI components.

mojo/ui/ganesh_renderer.cc

Index: mojo/ui/ganesh_renderer.cc
diff --git a/mojo/ui/ganesh_renderer.cc b/mojo/ui/ganesh_renderer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a1f47b3778053f4920d4ff75c0280ce90bec25a1
--- /dev/null
+++ b/mojo/ui/ganesh_renderer.cc
@@ -0,0 +1,57 @@
+// Copyright 2015 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.
+
+#include "mojo/ui/ganesh_renderer.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "mojo/gpu/gl_texture.h"
+#include "mojo/skia/ganesh_context.h"
+#include "mojo/skia/ganesh_texture_surface.h"
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkSurface.h"
+
+namespace mojo {
+namespace ui {
+
+GaneshRenderer::GaneshRenderer(mojo::skia::GaneshContext* ganesh_context)
+    : ganesh_context_(ganesh_context),
+      gl_renderer_(ganesh_context_->gl_context()) {
+  DCHECK(ganesh_context_);
+}
+
+GaneshRenderer::~GaneshRenderer() {}
+
+mojo::gfx::composition::ResourcePtr GaneshRenderer::DrawSurface(
+    const mojo::Size& size,
+    const DrawSurfaceCallback& callback) {
+  std::unique_ptr<mojo::GLTexture> texture = gl_renderer_.GetTexture(size);
+  DCHECK(texture);
+
+  {
+    mojo::skia::GaneshContext::Scope scope(ganesh_context_);
+    mojo::skia::GaneshTextureSurface texture_surface(scope, std::move(texture));
+
+    callback.Run(texture_surface.surface());
+
+    texture = texture_surface.TakeTexture();
+  }
+
+  return gl_renderer_.BindTextureResource(std::move(texture));
+}
+
+static void RunCanvasCallback(
+    const mojo::ui::GaneshRenderer::DrawCanvasCallback& callback,
+    SkSurface* surface) {
+  callback.Run(surface->getCanvas());
+}
+
+mojo::gfx::composition::ResourcePtr GaneshRenderer::DrawCanvas(
+    const mojo::Size& size,
+    const DrawCanvasCallback& callback) {
+  return DrawSurface(size, base::Bind(&RunCanvasCallback, callback));
+}
+
+}  // namespace ui
+}  // namespace mojo