Preliminary interactive layout of window manager's demo_launcher

mojo/examples/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 <algorithm>
 
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_tokenizer.h"
 #include "mojo/examples/media_viewer/media_viewer.mojom.h"
 #include "mojo/public/cpp/application/application_connection.h"
 #include "mojo/public/cpp/application/application_delegate.h"
 #include "mojo/services/public/cpp/view_manager/node.h"
+#include "mojo/services/public/cpp/view_manager/node_observer.h"
 #include "mojo/services/public/cpp/view_manager/types.h"
 #include "mojo/services/public/cpp/view_manager/view.h"
 #include "mojo/services/public/cpp/view_manager/view_manager.h"
 #include "mojo/services/public/cpp/view_manager/view_manager_delegate.h"
 #include "mojo/services/public/interfaces/navigation/navigation.mojom.h"
 #include "skia/ext/platform_canvas.h"
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkPaint.h"
@@ skipping 81 matching lines @@
     }
     return 0;
   }
 
   PNGViewer* viewer_;
 
   DISALLOW_COPY_AND_ASSIGN(NavigatorImpl);
 };
 
 class PNGViewer : public ApplicationDelegate,
-                  public view_manager::ViewManagerDelegate {
+                  public view_manager::ViewManagerDelegate,
+                  public view_manager::NodeObserver {
  public:
-  PNGViewer() : content_view_(NULL), zoom_percentage_(kDefaultZoomPercentage) {}
-  virtual ~PNGViewer() {}
+  PNGViewer()
+      : content_view_(NULL),
+        root_(NULL),
+        zoom_percentage_(kDefaultZoomPercentage) {}
+  virtual ~PNGViewer() {
+    if (root_)
+      root_->RemoveObserver(this);
+  }
 
   void UpdateView(view_manager::Id node_id, const SkBitmap& bitmap) {
     bitmap_ = bitmap;
     zoom_percentage_ = kDefaultZoomPercentage;
     DrawBitmap();
   }
 
   void ZoomIn() {
     if (zoom_percentage_ >= kMaxZoomPercentage)
       return;
@@ skipping 26 matching lines @@
       MOJO_OVERRIDE {
     connection->AddService<NavigatorImpl>(this);
     connection->AddService<ZoomableMediaImpl>(this);
     view_manager::ViewManager::ConfigureIncomingConnection(connection, this);
     return true;
   }
 
   // Overridden from view_manager::ViewManagerDelegate:
   virtual void OnRootAdded(view_manager::ViewManager* view_manager,
                            view_manager::Node* root) OVERRIDE {
+    root_ = root;
+    root_->AddObserver(this);
     content_view_ = view_manager::View::Create(view_manager);
-    root->SetActiveView(content_view_);
+    root_->SetActiveView(content_view_);
     content_view_->SetColor(SK_ColorGRAY);
     if (!bitmap_.isNull())
       DrawBitmap();
   }
   virtual void OnViewManagerDisconnected(
       view_manager::ViewManager* view_manager) OVERRIDE {
     base::MessageLoop::current()->Quit();
   }
 
   void DrawBitmap() {
     if (!content_view_)
       return;
 
     skia::RefPtr<SkCanvas> canvas(skia::AdoptRef(skia::CreatePlatformCanvas(
         content_view_->node()->bounds().width(),
         content_view_->node()->bounds().height(),
         true)));
     canvas->drawColor(SK_ColorGRAY);
     SkPaint paint;
     SkScalar scale =
         SkFloatToScalar(zoom_percentage_ * 1.0f / kDefaultZoomPercentage);
     canvas->scale(scale, scale);
     canvas->drawBitmap(bitmap_, 0, 0, &paint);
     content_view_->SetContents(skia::GetTopDevice(*canvas)->accessBitmap(true));
   }
 
+  // NodeObserver:
+  virtual void OnNodeBoundsChanged(view_manager::Node* node,
+                                   const gfx::Rect& old_bounds,
+                                   const gfx::Rect& new_bounds) OVERRIDE {
+    DCHECK_EQ(node, root_);
+    DrawBitmap();
+  }
+  virtual void OnNodeDestroyed(view_manager::Node* node) OVERRIDE {
+    DCHECK_EQ(node, root_);
+    node->RemoveObserver(this);
+    root_ = NULL;
+  }
+
   view_manager::View* content_view_;
+  view_manager::Node* root_;
   SkBitmap bitmap_;
   uint16_t zoom_percentage_;
 
   DISALLOW_COPY_AND_ASSIGN(PNGViewer);
 };
 
 void ZoomableMediaImpl::ZoomIn() {
   viewer_->ZoomIn();
 }
 
@@ skipping 11 matching lines @@
 }
 
 }  // namespace examples
 
 // static
 ApplicationDelegate* ApplicationDelegate::Create() {
   return new examples::PNGViewer;
 }
 
 }  // namespace mojo