aura: Fix crash when the aura window hosting a tooltip is destroyed. We fix

ash/tooltips/tooltip_controller.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 "ash/tooltips/tooltip_controller.h"
 
 #include <vector>
 
 #include "ash/ash_switches.h"
 #include "ash/shell.h"
@@ skipping 10 matching lines @@
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/text/text_elider.h"
 #include "ui/gfx/font.h"
 #include "ui/gfx/point.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/screen.h"
 #include "ui/views/background.h"
 #include "ui/views/border.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/widget/widget.h"
+#include "ui/views/widget/widget_observer.h"
 
 namespace {
 
 const SkColor kTooltipBackground = 0xFFFFFFCC;
 const SkColor kTooltipBorder = 0xFF646450;
 const int kTooltipBorderWidth = 1;
 const int kTooltipHorizontalPadding = 3;
 
 // Max visual tooltip width. If a tooltip is greater than this width, it will
 // be wrapped.
@@ skipping 33 matching lines @@
 
 // Creates a widget of type TYPE_TOOLTIP
 views::Widget* CreateTooltip() {
   views::Widget* widget = new views::Widget;
   views::Widget::InitParams params;
   // For aura, since we set the type to TOOLTIP_TYPE, the widget will get
   // auto-parented to the MenuAndTooltipsContainer.
   params.type = views::Widget::InitParams::TYPE_TOOLTIP;
   params.keep_on_top = true;
   params.accept_events = false;
-  params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
   widget->Init(params);
   return widget;
 }
 
 }  // namespace
 
 namespace ash {
 namespace internal {
 
 // Displays a widget with tooltip using a views::Label.
-class TooltipController::Tooltip {
+class TooltipController::Tooltip : public views::WidgetObserver {
  public:
-  Tooltip() {
+  Tooltip() : widget_(NULL) {
     label_.set_background(
         views::Background::CreateSolidBackground(kTooltipBackground));
     if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kAuraNoShadows)) {
       label_.set_border(
           views::Border::CreateSolidBorder(kTooltipBorderWidth,
                                            kTooltipBorder));
     }
     label_.set_owned_by_client();
-    widget_.reset(CreateTooltip());
-    widget_->SetContentsView(&label_);
   }
 
   ~Tooltip() {
-    widget_->Close();
+    if (widget_) {
+      widget_->RemoveObserver(this);
+      widget_->Close();
+    }
   }
 
   // Updates the text on the tooltip and resizes to fit.
   void SetText(string16 tooltip_text, gfx::Point location) {
     int max_width, line_count;
     TrimTooltipToFit(&tooltip_text, &max_width, &line_count,
                      location.x(), location.y());
     label_.SetText(tooltip_text);
 
     int width = max_width + 2 * kTooltipHorizontalPadding;
     int height = label_.GetPreferredSize().height() +
         2 * kTooltipVerticalPadding;
     if (CommandLine::ForCurrentProcess()->HasSwitch(
             switches::kAuraNoShadows)) {
       width += 2 * kTooltipBorderWidth;
       height += 2 * kTooltipBorderWidth;
     }
     SetTooltipBounds(location, width, height);
   }
 
   // Shows the tooltip.
   void Show() {
-    widget_->Show();
+    GetWidget()->Show();
   }
 
   // Hides the tooltip.
   void Hide() {
-    widget_->Hide();
+    if (widget_)
+      widget_->Hide();
   }
 
   bool IsVisible() {
-    return widget_->IsVisible();
+    return widget_? widget_->IsVisible() : false;
+  }
+
+  // Overriden from views::WidgetObserver.
+  virtual void OnWidgetClosing(views::Widget* widget) OVERRIDE {
+    DCHECK_EQ(widget_, widget);
+    widget_ = NULL;
   }
 
  private:
   views::Label label_;
-  scoped_ptr<views::Widget> widget_;
+  views::Widget* widget_;
 
   // Adjusts the bounds given by the arguments to fit inside the desktop
   // and applies the adjusted bounds to the label_.
   void SetTooltipBounds(gfx::Point mouse_pos,
                         int tooltip_width,
                         int tooltip_height) {
     gfx::Rect tooltip_rect(mouse_pos.x(), mouse_pos.y(), tooltip_width,
                            tooltip_height);
 
     tooltip_rect.Offset(kCursorOffsetX, kCursorOffsetY);
     gfx::Rect display_bounds =
         gfx::Screen::GetDisplayNearestPoint(tooltip_rect.origin()).bounds();
 
     // If tooltip is out of bounds on the x axis, we simply shift it
     // horizontally by the offset.
     if (tooltip_rect.right() > display_bounds.right()) {
       int h_offset = tooltip_rect.right() - display_bounds.right();
       tooltip_rect.Offset(-h_offset, 0);
     }
 
     // If tooltip is out of bounds on the y axis, we flip it to appear above the
     // mouse cursor instead of below.
     if (tooltip_rect.bottom() > display_bounds.bottom())
       tooltip_rect.set_y(mouse_pos.y() - tooltip_height);
 
-    widget_->SetBounds(tooltip_rect.AdjustToFit(display_bounds));
+    GetWidget()->SetBounds(tooltip_rect.AdjustToFit(display_bounds));
   }
 
+  views::Widget* GetWidget() {
+    if (!widget_) {
+      widget_ = CreateTooltip();
+      widget_->SetContentsView(&label_);
+      widget_->AddObserver(this);
+    }
+    return widget_;
+  }
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 // TooltipController public:
 
 TooltipController::TooltipController(
     aura::client::DragDropClient* drag_drop_client)
     : drag_drop_client_(drag_drop_client),
       tooltip_window_(NULL),
       tooltip_window_at_mouse_press_(NULL),
@@ skipping 269 matching lines @@
 }
 
 TooltipController::Tooltip* TooltipController::GetTooltip() {
   if (!tooltip_.get())
     tooltip_.reset(new Tooltip);
   return tooltip_.get();
 }
 
 }  // namespace internal
 }  // namespace ash