Update the UI examples.

examples/ui/png_viewer/png_viewer.cc

+// Copyright 2014 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 <string>
+
+#include "base/bind.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "mojo/application/application_runner_chromium.h"
+#include "mojo/data_pipe_utils/data_pipe_utils.h"
+#include "mojo/public/c/system/main.h"
+#include "mojo/ui/content_viewer_app.h"
+#include "mojo/ui/ganesh_view.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkImage.h"
+#include "third_party/skia/include/core/SkSurface.h"
+#include "ui/gfx/codec/png_codec.h"
+
+namespace examples {
+
+constexpr uint32_t kContentImageResourceId = 1;
+constexpr uint32_t kRootNodeId = mojo::gfx::composition::kSceneRootNodeId;
+
+class PNGView : public mojo::ui::GaneshView {
+ public:
+  PNGView(
+      mojo::ApplicationImpl* app_impl,
+      const skia::RefPtr<SkImage>& image,
+      const mojo::ui::ViewProvider::CreateViewCallback& create_view_callback)
+      : GaneshView(app_impl, "PNGViewer", create_view_callback), image_(image) {
+    DCHECK(image_);
+  }
+
+  ~PNGView() override {}
+
+ private:
+  // |View|:
+  void OnLayout(mojo::ui::ViewLayoutParamsPtr layout_params,
+                mojo::Array<uint32_t> children_needing_layout,
+                const OnLayoutCallback& callback) override {
+    size_.width = layout_params->constraints->max_width;
+    size_.height = layout_params->constraints->max_height;
+
+    auto info = mojo::ui::ViewLayoutResult::New();
+    info->size = size_.Clone();
+    callback.Run(info.Pass());
+
+    UpdateScene();
+  }
+
+  void UpdateScene() {
+    mojo::Rect bounds;
+    bounds.width = size_.width;
+    bounds.height = size_.height;
+
+    auto update = mojo::gfx::composition::SceneUpdate::New();
+    mojo::gfx::composition::ResourcePtr content_resource =
+        ganesh_renderer()->DrawCanvas(
+            size_, base::Bind(&PNGView::DrawContent, base::Unretained(this)));
+    DCHECK(content_resource);
+    update->resources.insert(kContentImageResourceId, content_resource.Pass());
+
+    auto root_node = mojo::gfx::composition::Node::New();
+    root_node->op = mojo::gfx::composition::NodeOp::New();
+    root_node->op->set_image(mojo::gfx::composition::ImageNodeOp::New());
+    root_node->op->get_image()->content_rect = bounds.Clone();
+    root_node->op->get_image()->image_resource_id = kContentImageResourceId;
+    update->nodes.insert(kRootNodeId, root_node.Pass());
+
+    scene()->Update(update.Pass());
+    scene()->Publish(nullptr);
+  }
+
+  void DrawContent(SkCanvas* canvas) {
+    canvas->clear(SK_ColorBLACK);
+
+    int32_t w, h;
+    if (size_.width * image_->height() < size_.height * image_->width()) {
+      w = size_.width;
+      h = image_->height() * size_.width / image_->width();
+    } else {
+      w = image_->width() * size_.height / image_->height();
+      h = size_.height;
+    }
+    canvas->drawImageRect(
+        image_.get(), SkRect::MakeWH(image_->width(), image_->height()),
+        SkRect::MakeXYWH((size_.width - w) / 2, (size_.height - h) / 2, w, h),
+        nullptr);
+
+    canvas->flush();
+  }
+
+  skia::RefPtr<SkImage> image_;
+  mojo::Size size_;
+
+  DISALLOW_COPY_AND_ASSIGN(PNGView);
+};
+
+class PNGContentViewProviderApp : public mojo::ui::ViewProviderApp {
+ public:
+  PNGContentViewProviderApp(skia::RefPtr<SkImage> image) : image_(image) {
+    DCHECK(image_);
+  }
+
+  ~PNGContentViewProviderApp() override {}
+
+  bool CreateView(
+      const std::string& connection_url,
+      mojo::InterfaceRequest<mojo::ServiceProvider> services,
+      mojo::ServiceProviderPtr exposed_services,
+      const mojo::ui::ViewProvider::CreateViewCallback& callback) override {
+    new PNGView(app_impl(), image_, callback);
+    return true;
+  }
+
+ private:
+  skia::RefPtr<SkImage> image_;
+
+  DISALLOW_COPY_AND_ASSIGN(PNGContentViewProviderApp);
+};
+
+class PNGContentViewerApp : public mojo::ui::ContentViewerApp {
+ public:
+  PNGContentViewerApp() {}
+
+  ~PNGContentViewerApp() override {}
+
+  mojo::ui::ViewProviderApp* LoadContent(
+      const std::string& content_handler_url,
+      mojo::URLResponsePtr response) override {
+    std::string data;
+    mojo::common::BlockingCopyToString(response->body.Pass(), &data);
+    SkBitmap bitmap;
+    if (!::gfx::PNGCodec::Decode(
+            reinterpret_cast<const unsigned char*>(data.data()), data.length(),
+            &bitmap) ||
+        bitmap.empty()) {
+      LOG(ERROR) << "Could not decode PNG.";
+      return nullptr;
+    }
+
+    return new PNGContentViewProviderApp(
+        skia::AdoptRef(SkImage::NewFromBitmap(bitmap)));
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(PNGContentViewerApp);
+};
+
+}  // namespace examples
+
+MojoResult MojoMain(MojoHandle application_request) {
+  mojo::ApplicationRunnerChromium runner(new examples::PNGContentViewerApp());
+  return runner.Run(application_request);
+}