Make the visual feedback for taking screenshot, with fix.

This is almost identical with http://codereview.chromium.org/9430041
but contains the fix for the compilation failure on linux-clang
http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20%28Clang%20dbg%29/builds/8613/steps/compile/logs/stdio

BUG=113467
TEST=manually


Review URL: http://codereview.chromium.org/9545014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@124929 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/views/ash/screenshot_taker.cc

@@ -6,6 +6,8 @@
 
 #include <string>
 
+#include "ash/shell.h"
+#include "ash/shell_window_ids.h"
 #include "base/bind.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
@@ -64,11 +66,21 @@ void SaveScreenshot(bool is_logged_in,
   }
 }
 
+// How opaque should the layer that we flash onscreen to provide visual
+// feedback after the screenshot is taken be?
+const float kVisualFeedbackLayerOpacity = 0.25f;
+
+// How long should the visual feedback layer be displayed?
+const int64 kVisualFeedbackLayerDisplayTimeMs = 100;
+
 }  // namespace
 
 ScreenshotTaker::ScreenshotTaker() {
 }
 
+ScreenshotTaker::~ScreenshotTaker() {
+}
+
 void ScreenshotTaker::HandleTakePartialScreenshot(
     aura::Window* window, const gfx::Rect& rect) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
@@ -81,6 +93,7 @@ void ScreenshotTaker::HandleTakePartialScreenshot(
 #endif
 
   if (browser::GrabWindowSnapshot(window, &png_data->data(), rect)) {
+    DisplayVisualFeedback(rect);
     content::BrowserThread::PostTask(
         content::BrowserThread::FILE, FROM_HERE,
         base::Bind(&SaveScreenshot, is_logged_in, png_data));
@@ -92,3 +105,25 @@ void ScreenshotTaker::HandleTakePartialScreenshot(
 void ScreenshotTaker::HandleTakeScreenshot(aura::Window* window) {
   HandleTakePartialScreenshot(window, window->bounds());
 }
+
+void ScreenshotTaker::CloseVisualFeedbackLayer() {
+  visual_feedback_layer_.reset();
+}
+
+void ScreenshotTaker::DisplayVisualFeedback(const gfx::Rect& rect) {
+  visual_feedback_layer_.reset(new ui::Layer(ui::Layer::LAYER_SOLID_COLOR));
+  visual_feedback_layer_->SetColor(SK_ColorWHITE);
+  visual_feedback_layer_->SetOpacity(kVisualFeedbackLayerOpacity);
+  visual_feedback_layer_->SetBounds(rect);
+
+  ui::Layer* parent = ash::Shell::GetInstance()->GetContainer(
+      ash::internal::kShellWindowId_OverlayContainer)->layer();
+  parent->Add(visual_feedback_layer_.get());
+  visual_feedback_layer_->SetVisible(true);
+
+  MessageLoopForUI::current()->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&ScreenshotTaker::CloseVisualFeedbackLayer,
+                 base::Unretained(this)),
+      base::TimeDelta::FromMilliseconds(kVisualFeedbackLayerDisplayTimeMs));
+}

chrome/browser/ui/views/ash/screenshot_taker.h

@@ -9,6 +9,7 @@
 #include "ash/screenshot_delegate.h"
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
+#include "ui/gfx/compositor/layer.h"
 
 namespace aura {
 class Window;
@@ -17,6 +18,7 @@ class Window;
 class ScreenshotTaker : public ash::ScreenshotDelegate {
  public:
   ScreenshotTaker();
+  virtual ~ScreenshotTaker();
 
   // Overridden from ash::ScreenshotDelegate:
   virtual void HandleTakeScreenshot(aura::Window* window) OVERRIDE;
@@ -24,6 +26,15 @@ class ScreenshotTaker : public ash::ScreenshotDelegate {
       aura::Window* window, const gfx::Rect& rect) OVERRIDE;
 
  private:
+  // Flashes the screen to provide visual feedback that a screenshot has
+  // been taken.
+  void DisplayVisualFeedback(const gfx::Rect& rect);
+
+  // Closes the visual feedback layer.
+  void CloseVisualFeedbackLayer();
+
+  scoped_ptr<ui::Layer> visual_feedback_layer_;
+
   DISALLOW_COPY_AND_ASSIGN(ScreenshotTaker);
 };