Changes the visibility of message view cards.

ui/message_center/message_center_bubble.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 "ui/message_center/message_center_bubble.h"
 
 #include "grit/ui_strings.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/size.h"
@@ skipping 10 matching lines @@
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
 
 namespace message_center {
 
 namespace {
 
 const int kMessageBubbleBaseMinHeight = 80;
 const int kMessageBubbleBaseMaxHeight = 400;
 const int kMarginBetweenItems = 10;
-const SkColor kMessageCenterBackgroundColor = SkColorSetRGB(0xd3, 0xd3, 0xd3);
+const int kItemShadowHeight = 4;
+const SkColor kMessageCenterBackgroundColor = SkColorSetRGB(0xe5, 0xe5, 0xe5);
 const SkColor kBorderDarkColor = SkColorSetRGB(0xaa, 0xaa, 0xaa);
-const SkColor kMessageItemBorderWidth = 1;
-const SkColor kMessageItemBorderColor = SkColorSetRGB(0xaa, 0xaa, 0xaa);
+const SkColor kMessageItemShadowColorBase = SkColorSetARGB(0.3 * 255, 0, 0, 0);
+const SkColor kTransparentColor = SkColorSetARGB(0, 0, 0, 0);
 
 // The view for the buttons at the bottom of the web notification tray.
 class WebNotificationButtonView : public views::View,
                                   public views::ButtonListener {
  public:
   explicit WebNotificationButtonView(NotificationList::Delegate* list_delegate)
       : list_delegate_(list_delegate),
         close_all_button_(NULL) {
     set_background(views::Background::CreateBackgroundPainter(
         true,
@@ skipping 96 matching lines @@
  private:
   gfx::Size fixed_size_;
 
   DISALLOW_COPY_AND_ASSIGN(FixedSizedScrollView);
 };
 
 // Container for the messages.
 class ScrollContentView : public views::View {
  public:
   ScrollContentView() {
+    // Set the margin to 0 for the layout. BoxLayout assumes the same margin
+    // for top and bottom, but the bottom margin here should be smaller
+    // because of the shadow of message view. Use an empty border instead
+    // to provide this margin.
     SetLayoutManager(
         new views::BoxLayout(views::BoxLayout::kVertical,
-                             kMarginBetweenItems,
-                             kMarginBetweenItems,
-                             kMarginBetweenItems));
+                             0,
+                             0,
+                             kMarginBetweenItems - kItemShadowHeight));
     set_background(views::Background::CreateSolidBackground(
         kMessageCenterBackgroundColor));
+    set_border(views::Border::CreateEmptyBorder(
+        kMarginBetweenItems, /* top */
+        kMarginBetweenItems, /* left */
+        kMarginBetweenItems - kItemShadowHeight,  /* bottom */
+        kMarginBetweenItems /* right */ ));
   }
 
   virtual ~ScrollContentView() {
   }
 
   virtual gfx::Size GetPreferredSize() OVERRIDE {
     if (!preferred_size_.IsEmpty())
       return preferred_size_;
     return views::View::GetPreferredSize();
   }
 
   void set_preferred_size(const gfx::Size& size) { preferred_size_ = size; }
 
  private:
   gfx::Size preferred_size_;
   DISALLOW_COPY_AND_ASSIGN(ScrollContentView);
 };
 
+// A view to draw gradient shadow for each MessageView.
+class MessageViewShadow : public views::View {
+ public:
+  MessageViewShadow()
+      : painter_(views::Painter::CreateVerticalGradient(
+            kMessageItemShadowColorBase, kTransparentColor)) {
+  }
+
+ private:
+  // views::View overrides:
+  virtual gfx::Size GetPreferredSize() OVERRIDE {
+    // The preferred size must not be empty. Thus put an arbitrary non-zero
+    // width here. It will be just ignored by the vertical box layout.
+    return gfx::Size(1, kItemShadowHeight);
+  }
+
+  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE {
+    painter_->Paint(canvas, bounds().size());
+  }
+
+  scoped_ptr<views::Painter> painter_;
+  DISALLOW_COPY_AND_ASSIGN(MessageViewShadow);
+};
+
 }  // namespace
 
 // Message Center contents.
 class MessageCenterContentsView : public views::View {
  public:
   explicit MessageCenterContentsView(NotificationList::Delegate* list_delegate)
       : list_delegate_(list_delegate) {
     SetLayoutManager(
         new views::BoxLayout(views::BoxLayout::kVertical, 0, 0, 1));
 
@@ skipping 16 matching lines @@
 
   void Update(const NotificationList::Notifications& notifications)  {
     scroll_content_->RemoveAllChildViews(true);
     scroll_content_->set_preferred_size(gfx::Size());
     size_t num_children = 0;
     for (NotificationList::Notifications::const_iterator iter =
              notifications.begin(); iter != notifications.end(); ++iter) {
       MessageView* view =
           MessageViewFactory::ViewForNotification(*iter, list_delegate_);
       view->set_scroller(scroller_);
-      view->set_border(views::Border::CreateSolidBorder(
-          kMessageItemBorderWidth, kMessageItemBorderColor));
       view->SetUpView();
-      scroll_content_->AddChildView(view);
+
+      views::View* container = new views::View();
+      container->SetLayoutManager(
+          new views::BoxLayout(views::BoxLayout::kVertical, 0, 0, 0));
+      container->AddChildView(view);
+      container->AddChildView(new MessageViewShadow());
+      scroll_content_->AddChildView(container);
       if (++num_children >=
           NotificationList::kMaxVisibleMessageCenterNotifications) {
         break;
       }
     }
     if (num_children == 0) {
       views::Label* label = new views::Label(l10n_util::GetStringUTF16(
           IDS_MESSAGE_CENTER_NO_MESSAGES));
       label->SetFont(label->font().DeriveFont(1));
       label->SetEnabledColor(SK_ColorGRAY);
@@ skipping 82 matching lines @@
 }
 
 void MessageCenterBubble::OnMouseExitedView() {
 }
 
 size_t MessageCenterBubble::NumMessageViewsForTest() const {
   return contents_view_->NumMessageViews();
 }
 
 }  // namespace message_center