Makes the visual feedback for taking screenshot.

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

 // Copyright (c) 2012 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 "chrome/browser/ui/views/aura/screenshot_taker.h"
 
 #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"
 #include "base/logging.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/stringprintf.h"
 #include "base/time.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/compositor/layer.h"
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/login/user_manager.h"
 #endif
 
 namespace {
 std::string GetScreenshotFileName() {
   base::Time::Exploded now;
   base::Time::Now().LocalExplode(&now);
 
@@ skipping 27 matching lines @@
           screenshot_filename);
       if (!file_util::ReplaceFile(screenshot_path, real_path)) {
         LOG(ERROR) << "Failed to rename the file to " << real_path.value();
       }
     }
   } else {
     LOG(ERROR) << "Failed to save to " << screenshot_path.value();
   }
 }
 
+// How opaque should the layer that we flash onscreen to provide visual
+// feedback after the screenshot is taken be?
+const unsigned char kVisualFeedbackWindowOpacity = 64;

[Daniel Erat, 2012/02/24 00:48:46]

nit: s/Window/Layer/ in variable name

[Jun Mukai, 2012/02/24 02:24:55]

Done.

+
+// How long should the visual feedback window be displayed?
+const uint64_t kVisualFeedbackWindowDisplayTimeMs = 100;

[Daniel Erat, 2012/02/24 00:48:46]

s/Window/Layer/

[Jun Mukai, 2012/02/24 02:24:55]

Done.

+
+void CloseFeedbackLayer(ui::Layer* layer) {
+  DCHECK(layer);
+  layer->SetVisible(false);

[Daniel Erat, 2012/02/24 00:48:46]

nit: unneeded; deleting it makes it invisible :-)

[Jun Mukai, 2012/02/24 02:24:55]

Done.

+  delete layer;
+}
+
+// Flashes the screen to provide visual feedback that a screenshot has
+// been taken.
+void DisplayVisualFeedback(const gfx::Rect& rect) {
+  scoped_ptr<ui::Layer> layer(new ui::Layer(ui::Layer::LAYER_SOLID_COLOR));
+  layer->SetColor(SkColorSetA(SK_ColorWHITE, kVisualFeedbackWindowOpacity));
+  layer->SetBounds(rect);
+
+  ui::Layer* parent = ash::Shell::GetInstance()->GetContainer(
+      ash::internal::kShellWindowId_OverlayContainer)->layer();
+  parent->Add(layer.get());
+  layer->SetVisible(true);
+
+  MessageLoopForUI::current()->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&CloseFeedbackLayer, base::Unretained(layer.release())),

[Daniel Erat, 2012/02/24 00:48:46]

i meant that you could make these functions instead be private methods of
ScreenshotTaker.  create a scoped_ptr<ui::Layer> named something like
ScreenshotTaker::visual_feedback_layer_ and make CloseFeedbackLayer() take no
parameters and just call visual_feedback_layer_.reset();

[Jun Mukai, 2012/02/24 02:24:55]

Ah, thank you for the explanation.  Done.

+      kVisualFeedbackWindowDisplayTimeMs);
+}
+
 }  // namespace
 
 ScreenshotTaker::ScreenshotTaker() {
 }
 
 void ScreenshotTaker::HandleTakePartialScreenshot(
     aura::Window* window, const gfx::Rect& rect) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 
   scoped_refptr<RefCountedBytes> png_data(new RefCountedBytes);
 
   bool is_logged_in = true;
 #if defined(OS_CHROMEOS)
   is_logged_in = chromeos::UserManager::Get()->user_is_logged_in();
 #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));
   } else {
     LOG(ERROR) << "Failed to grab the window screenshot";
   }
 }
 
 void ScreenshotTaker::HandleTakeScreenshot(aura::Window* window) {
   HandleTakePartialScreenshot(window, window->bounds());
 }