Add an empty message to the notification center.

This will now match the UI on Windows and ChromeOS.

BUG=284556

Review URL: https://codereview.chromium.org/142413005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247981 0039d316-1c4b-4281-b951-d872f2087c98

ui/message_center/cocoa/tray_view_controller.h

@@ -46,6 +46,12 @@ MESSAGE_CENTER_EXPORT
   // The "Notifications" label at the top.
   base::scoped_nsobject<NSTextField> title_;
 
+  // The 1px horizontal divider between the scroll view and the title bar.
+  base::scoped_nsobject<NSBox> divider_;
+
+  // The "Nothing to see here" label in an empty message center.
+  base::scoped_nsobject<NSTextField> emptyDescription_;
+
   // The scroll view that contains all the notifications in its documentView.
   base::scoped_nsobject<NSScrollView> scrollView_;
 
@@ -157,6 +163,8 @@ MESSAGE_CENTER_EXPORT
 // Testing API /////////////////////////////////////////////////////////////////
 
 @interface MCTrayViewController (TestingAPI)
+- (NSBox*)divider;
+- (NSTextField*)emptyDescription;
 - (NSScrollView*)scrollView;
 - (HoverImageButton*)pauseButton;
 - (HoverImageButton*)clearAllButton;

ui/message_center/cocoa/tray_view_controller.mm

@@ -359,6 +359,14 @@ const CGFloat kTrayBottomMargin = 75;
 
 // Testing API /////////////////////////////////////////////////////////////////
 
+- (NSBox*)divider {
+  return divider_.get();
+}
+
+- (NSTextField*)emptyDescription {
+  return emptyDescription_.get();
+}
+
 - (NSScrollView*)scrollView {
   return scrollView_.get();
 }
@@ -390,16 +398,21 @@ const CGFloat kTrayBottomMargin = 75;
   ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
   NSView* view = [self view];
 
+  auto configureLabel = ^(NSTextField* textField) {
+      [textField setAutoresizingMask:NSViewMinYMargin];
+      [textField setBezeled:NO];
+      [textField setBordered:NO];
+      [textField setDrawsBackground:NO];
+      [textField setEditable:NO];
+      [textField setSelectable:NO];
+  };
+
   // Create the "Notifications" label at the top of the tray.
   NSFont* font = [NSFont labelFontOfSize:message_center::kTitleFontSize];
   title_.reset([[NSTextField alloc] initWithFrame:NSZeroRect]);
-  [title_ setAutoresizingMask:NSViewMinYMargin];
-  [title_ setBezeled:NO];
-  [title_ setBordered:NO];
-  [title_ setDrawsBackground:NO];
-  [title_ setEditable:NO];
+  configureLabel(title_);
+
   [title_ setFont:font];
-  [title_ setSelectable:NO];
   [title_ setStringValue:
       l10n_util::GetNSString(IDS_MESSAGE_CENTER_FOOTER_TITLE)];
   [title_ setTextColor:gfx::SkColorToCalibratedNSColor(
@@ -445,16 +458,17 @@ const CGFloat kTrayBottomMargin = 75;
   [[self view] addSubview:backButton_];
 
   // Create the divider line between the control area and the notifications.
-  base::scoped_nsobject<NSBox> divider(
+  divider_.reset(
       [[NSBox alloc] initWithFrame:NSMakeRect(0, 0, NSWidth([view frame]), 1)]);
-  [divider setAutoresizingMask:NSViewMinYMargin];
-  [divider setBorderType:NSNoBorder];
-  [divider setBoxType:NSBoxCustom];
-  [divider setContentViewMargins:NSZeroSize];
-  [divider setFillColor:gfx::SkColorToCalibratedNSColor(
+  [divider_ setAutoresizingMask:NSViewMinYMargin];
+  [divider_ setBorderType:NSNoBorder];
+  [divider_ setBoxType:NSBoxCustom];
+  [divider_ setContentViewMargins:NSZeroSize];
+  [divider_ setFillColor:gfx::SkColorToCalibratedNSColor(
       message_center::kFooterDelimiterColor)];
-  [divider setTitlePosition:NSNoTitle];
-  [view addSubview:divider];
+  [divider_ setTitlePosition:NSNoTitle];
+  [view addSubview:divider_];
+
 
   auto getButtonFrame = ^NSRect(CGFloat maxX, NSImage* image) {
       NSSize size = [image size];
@@ -524,13 +538,45 @@ const CGFloat kTrayBottomMargin = 75;
   [pauseButton_ setAction:@selector(toggleQuietMode:)];
   configureButton(pauseButton_);
   [view addSubview:pauseButton_];
+
+  // Create the description field for the empty message center.  Initially it is
+  // invisible.
+  emptyDescription_.reset([[NSTextField alloc] initWithFrame:NSZeroRect]);
+  configureLabel(emptyDescription_);
+
+  NSFont* smallFont =
+      [NSFont labelFontOfSize:message_center::kEmptyCenterFontSize];
+  [emptyDescription_ setFont:smallFont];
+  [emptyDescription_ setStringValue:
+      l10n_util::GetNSString(IDS_MESSAGE_CENTER_NO_MESSAGES)];
+  [emptyDescription_ setTextColor:gfx::SkColorToCalibratedNSColor(
+      message_center::kDimTextColor)];
+  [emptyDescription_ sizeToFit];
+  [emptyDescription_ setHidden:YES];
+
+  [view addSubview:emptyDescription_];
 }
 
 - (void)updateTrayViewAndWindow {
-  CGFloat scrollContentHeight = 0;
+  CGFloat scrollContentHeight = message_center::kMinScrollViewHeight;
   if ([notifications_ count]) {
+    [emptyDescription_ setHidden:YES];
+    [scrollView_ setHidden:NO];
+    [divider_ setHidden:NO];
     scrollContentHeight = NSMaxY([[[notifications_ lastObject] view] frame]) +
         message_center::kMarginBetweenItems;;
+  } else {
+    [emptyDescription_ setHidden:NO];
+    [scrollView_ setHidden:YES];
+    [divider_ setHidden:YES];
+
+    NSRect centeredFrame = [emptyDescription_ frame];
+    NSPoint centeredOrigin = NSMakePoint(
+      floor((NSWidth([[self view] frame]) - NSWidth(centeredFrame))/2 + 0.5),
+      floor((scrollContentHeight - NSHeight(centeredFrame))/2 + 0.5));
+
+    centeredFrame.origin = centeredOrigin;
+    [emptyDescription_ setFrame:centeredFrame];
   }
 
   // Resize the scroll view's content.

ui/message_center/cocoa/tray_view_controller_unittest.mm

@@ -98,7 +98,10 @@ TEST_F(TrayViewControllerTest, AddRemoveOne) {
   center_->RemoveNotification("1", true);
   [tray_ onMessageCenterTrayChanged];
   EXPECT_EQ(0u, [[view subviews] count]);
-  EXPECT_CGFLOAT_EQ(0, NSHeight([view frame]));
+  // The empty tray is now 100px tall to accommodate
+  // the empty message.
+  EXPECT_CGFLOAT_EQ(message_center::kMinScrollViewHeight,
+                    NSHeight([view frame]));
 }
 
 TEST_F(TrayViewControllerTest, AddThreeClearAll) {
@@ -146,7 +149,10 @@ TEST_F(TrayViewControllerTest, AddThreeClearAll) {
   [tray_ onMessageCenterTrayChanged];
 
   EXPECT_EQ(0u, [[view subviews] count]);
-  EXPECT_CGFLOAT_EQ(0, NSHeight([view frame]));
+  // The empty tray is now 100px tall to accommodate
+  // the empty message.
+  EXPECT_CGFLOAT_EQ(message_center::kMinScrollViewHeight,
+                    NSHeight([view frame]));
 }
 
 TEST_F(TrayViewControllerTest, NoClearAllWhenNoNotifications) {
@@ -244,4 +250,30 @@ TEST_F(TrayViewControllerTest, Settings) {
   EXPECT_EQ(trayHeight, NSHeight([[tray_ view] frame]));
 }
 
+TEST_F(TrayViewControllerTest, EmptyCenter) {
+  EXPECT_FALSE([[tray_ emptyDescription] isHidden]);
+
+  // With no notifications, the divider should be hidden.
+  EXPECT_TRUE([[tray_ divider] isHidden]);
+  EXPECT_TRUE([[tray_ scrollView] isHidden]);
+
+  scoped_ptr<message_center::Notification> notification;
+  notification.reset(new message_center::Notification(
+      message_center::NOTIFICATION_TYPE_SIMPLE,
+      "1",
+      ASCIIToUTF16("First notification"),
+      ASCIIToUTF16("This is a simple test."),
+      gfx::Image(),
+      base::string16(),
+      DummyNotifierId(),
+      message_center::RichNotificationData(),
+      NULL));
+  center_->AddNotification(notification.Pass());
+  [tray_ onMessageCenterTrayChanged];
+
+  EXPECT_FALSE([[tray_ divider] isHidden]);
+  EXPECT_FALSE([[tray_ scrollView] isHidden]);
+  EXPECT_TRUE([[tray_ emptyDescription] isHidden]);
+}
+
 }  // namespace message_center

ui/message_center/message_center_style.h

@@ -31,6 +31,7 @@ const size_t kMaxVisiblePopupNotifications = 3;
 
 // DIP dimension; H size of the whole card.
 const int kNotificationWidth = 360;
+const int kMinScrollViewHeight = 100;
 
 // Colors.
 MESSAGE_CENTER_EXPORT extern const SkColor kMessageCenterBorderColor;
@@ -64,6 +65,7 @@ const int kIconBottomPadding = 16;  // Minimum non-zero V space between icon
 
 // Text sizes.
 const int kTitleFontSize = 14;             // For title only.
+const int kEmptyCenterFontSize = 13;       // For empty message only.
 const int kTitleLineHeight = 20;           // In DIPs.
 const int kMessageFontSize = 12;           // For everything but title.
 const int kMessageLineHeight = 18;         // In DIPs.

ui/message_center/views/message_center_view.cc

@@ -51,7 +51,6 @@ const SkColor kNoNotificationsTextColor = SkColorSetRGB(0xb4, 0xb4, 0xb4);
 const SkColor kTransparentColor = SkColorSetARGB(0, 0, 0, 0);
 #endif
 const int kAnimateClearingNextNotificationDelayMS = 40;
-const int kMinScrollViewHeight = 100;
 
 const int kDefaultAnimationDurationMs = 120;
 const int kDefaultFrameRateHz = 60;