Makes the visual feedback for taking screenshot.

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

Index: chrome/browser/ui/views/aura/screenshot_taker.cc
diff --git a/chrome/browser/ui/views/aura/screenshot_taker.cc b/chrome/browser/ui/views/aura/screenshot_taker.cc
index c004e9c736fb66c4022d03da8cd7c0549332872e..ba44b9b3a9553a04a2cd5f919c97564f0952bfd4 100644
--- a/chrome/browser/ui/views/aura/screenshot_taker.cc
+++ b/chrome/browser/ui/views/aura/screenshot_taker.cc
@@ -13,10 +13,15 @@
 #include "base/memory/ref_counted_memory.h"
 #include "base/stringprintf.h"
 #include "base/time.h"
+#include "ash/shell.h"

[Daniel Erat, 2012/02/22 17:22:06]

alphabetize these

[Jun Mukai, 2012/02/23 03:28:58]

Done.

+#include "ash/shell_window_ids.h"
 #include "chrome/browser/download/download_util.h"
 #include "chrome/browser/ui/window_snapshot/window_snapshot.h"
 #include "content/public/browser/browser_thread.h"
 #include "ui/aura/window.h"
+#include "ui/gfx/canvas.h"
+#include "ui/views/widget/widget.h"
+#include "ui/views/widget/widget_delegate.h"
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/login/user_manager.h"
@@ -64,6 +69,68 @@ void SaveScreenshot(bool is_logged_in,
   }
 }
 
+// How opaque should the window that we flash onscreen to provide visual
+// feedback after the screenshot is taken be?
+const unsigned char kVisualFeedbackWindowOpacity = 64;
+
+// How long should the visual feedback window be displayed?
+const uint64_t kVisualFeedbackWindowDisplayTimeMs = 100;
+
+// The view of making visual feedback for screenshot, i.e.: flashing the screen.

[Daniel Erat, 2012/02/22 17:22:06]

// Flashes the screen to provide visual feedback that a screenshot has been
taken.

[Jun Mukai, 2012/02/23 03:28:58]

Done.

+class VisualFeedbackView : public views::WidgetDelegateView {

[Daniel Erat, 2012/02/22 17:22:06]

not sure how much to care about this, but it'd be more efficient to just create
a ui::Layer of type LAYER_SOLID_COLOR

[Jun Mukai, 2012/02/23 03:28:58]

Done.

+ public:
+  VisualFeedbackView();
+
+ private:
+  // Overridden from View:
+  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
+
+  DISALLOW_COPY_AND_ASSIGN(VisualFeedbackView);
+};
+
+VisualFeedbackView::VisualFeedbackView() {

[Daniel Erat, 2012/02/22 17:22:06]

define this inline in the class declaration?

[Jun Mukai, 2012/02/23 03:28:58]

removed the class itself and use ui::Layer instead.

+}
+
+void VisualFeedbackView::OnPaint(gfx::Canvas* canvas) {
+  // All white.

[Daniel Erat, 2012/02/22 17:22:06]

delete unnecessary comment

[Jun Mukai, 2012/02/23 03:28:58]

removed the class itself.

+  canvas->FillRect(bounds(), SK_ColorWHITE);
+}
+
+void CleanupFeedbackView(aura::Window* window) {
+  DCHECK(window);
+  window->Hide();
+  MessageLoopForUI::current()->DeleteSoon(FROM_HERE, window);
+}
+
+// Makes the actual visual feedback, i.e.: flashing the screen.  It's
+// achieved by creating a transparent white window and removing it
+// 100msec later.
+void MakeVisualFeedback(const gfx::Rect& rect) {

[Daniel Erat, 2012/02/22 17:22:06]

nit: s/MakeVisualFeedback/DisplayVisualFeedback/

[Jun Mukai, 2012/02/23 03:28:58]

Done.

+  views::Widget* widget = new views::Widget;
+  VisualFeedbackView* view = new VisualFeedbackView();
+
+  views::Widget::InitParams params(
+      views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
+  params.transparent = true;
+  params.delegate = view;
+  params.parent = ash::Shell::GetInstance()->GetContainer(
+      ash::internal::kShellWindowId_OverlayContainer);
+
+  widget->Init(params);
+  widget->SetContentsView(view);
+  widget->SetBounds(rect);
+  widget->GetNativeView()->SetName("ScreenshotVisualFeedback");
+  widget->SetOpacity(kVisualFeedbackWindowOpacity);
+  widget->StackAtTop();
+  widget->Show();
+
+  MessageLoopForUI::current()->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&CleanupFeedbackView,
+                 base::Unretained(widget->GetNativeView())),
+      kVisualFeedbackWindowDisplayTimeMs);
+}
+
 }  // namespace
 
 ScreenshotTaker::ScreenshotTaker() {
@@ -81,6 +148,7 @@ void ScreenshotTaker::HandleTakePartialScreenshot(
 #endif
 
   if (browser::GrabWindowSnapshot(window, &png_data->data(), rect)) {
+    MakeVisualFeedback(rect);
     content::BrowserThread::PostTask(
         content::BrowserThread::FILE, FROM_HERE,
         base::Bind(&SaveScreenshot, is_logged_in, png_data));