Adjust behavior of control buttons of notifications.

ui/message_center/views/notification_view.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/views/notification_view.h"
 
 #include <stddef.h>
 
 #include "base/command_line.h"
 #include "base/macros.h"
@@ skipping 327 matching lines @@
   views::View::ScrollRectToVisible(GetLocalBounds());
 }
 
 gfx::NativeCursor NotificationView::GetCursor(const ui::MouseEvent& event) {
   if (!clickable_ || !controller()->HasClickedListener(notification_id()))
     return views::View::GetCursor(event);
 
   return views::GetNativeHandCursor();
 }
 
+void NotificationView::OnMouseEntered(const ui::MouseEvent& event) {
+  MessageView::OnMouseEntered(event);
+  UpdateControlButtonsVisibility();
+}
+
+void NotificationView::OnMouseExited(const ui::MouseEvent& event) {
+  MessageView::OnMouseExited(event);
+  UpdateControlButtonsVisibility();
+}
+
 void NotificationView::UpdateWithNotification(
     const Notification& notification) {
   MessageView::UpdateWithNotification(notification);
 
   CreateOrUpdateViews(notification);
   CreateOrUpdateCloseButtonView(notification);
   Layout();
   SchedulePaint();
 }
 
@@ skipping 160 matching lines @@
       notification.delegate()->ShouldDisplaySettingsButton()) {
     PaddedButton* settings = new PaddedButton(this);
     settings->SetImage(views::Button::STATE_NORMAL, GetSettingsIcon());
     settings->SetAccessibleName(l10n_util::GetStringUTF16(
         IDS_MESSAGE_NOTIFICATION_SETTINGS_BUTTON_ACCESSIBLE_NAME));
     settings->SetTooltipText(l10n_util::GetStringUTF16(
         IDS_MESSAGE_NOTIFICATION_SETTINGS_BUTTON_ACCESSIBLE_NAME));
     settings_button_view_ = settings;
     AddChildView(settings_button_view_);
   }
+  UpdateControlButtonsVisibility();
 }
 
 void NotificationView::CreateOrUpdateProgressBarView(
     const Notification& notification) {
   if (notification.type() != NOTIFICATION_TYPE_PROGRESS) {
     // Deletion will also remove |progress_bar_view_| from its parent.
     delete progress_bar_view_;
     progress_bar_view_ = nullptr;
     return;
   }
@@ skipping 144 matching lines @@
     const Notification& notification) {
   if (!notification.pinned() && !close_button_) {
     close_button_ = base::MakeUnique<PaddedButton>(this);
     close_button_->SetImage(views::Button::STATE_NORMAL, GetCloseIcon());
     close_button_->SetAccessibleName(l10n_util::GetStringUTF16(
         IDS_MESSAGE_CENTER_CLOSE_NOTIFICATION_BUTTON_ACCESSIBLE_NAME));
     close_button_->SetTooltipText(l10n_util::GetStringUTF16(
         IDS_MESSAGE_CENTER_CLOSE_NOTIFICATION_BUTTON_TOOLTIP));
     close_button_->set_owned_by_client();
     AddChildView(close_button_.get());
+    UpdateControlButtonsVisibility();
   } else if (notification.pinned() && close_button_) {
     close_button_.reset();
   }
 }
 
+void NotificationView::UpdateControlButtonsVisibility() {
+  const bool target_visibility =
+      IsMouseHovered() || HasFocus() ||
+      (close_button_ && close_button_->HasFocus()) ||
+      (settings_button_view_ && settings_button_view_->HasFocus());
+
+  if (close_button_) {
+    if (target_visibility != close_button_->visible())
+      close_button_->SetVisible(target_visibility);
+  }
+
+  if (settings_button_view_) {
+    if (target_visibility != settings_button_view_->visible())
+      settings_button_view_->SetVisible(target_visibility);
+  }
+}
+
 int NotificationView::GetMessageLineLimit(int title_lines, int width) const {
   // Image notifications require that the image must be kept flush against
   // their icons, but we can allow more text if no image.
   int effective_title_lines = std::max(0, title_lines - 1);
   int line_reduction_from_title = (image_view_ ? 1 : 2) * effective_title_lines;
   if (!image_view_) {
     // Title lines are counted as twice as big as message lines for the purpose
     // of this calculation.
     // The effect from the title reduction here should be:
     //   * 0 title lines: 5 max lines message.
@@ skipping 22 matching lines @@
 
   return message_line_limit;
 }
 
 int NotificationView::GetMessageHeight(int width, int limit) const {
   return message_view_ ?
          message_view_->GetSizeForWidthAndLines(width, limit).height() : 0;
 }
 
 }  // namespace message_center