Dismiss action in tab modal dialogs.

ui/views/window/dialog_delegate.h

 // 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.
 
 #ifndef UI_VIEWS_WINDOW_DIALOG_DELEGATE_H_
 #define UI_VIEWS_WINDOW_DIALOG_DELEGATE_H_
 
 #include "base/compiler_specific.h"
 #include "base/strings/string16.h"
 #include "ui/base/accessibility/accessibility_types.h"
@@ skipping 36 matching lines @@
   // Override this function to display an extra view in the titlebar.
   // Overrides may construct the view; this will only be called once per dialog.
   // Note: this only works for new style dialogs.
   virtual View* CreateTitlebarExtraView();
 
   // Override this function to display a footnote view below the buttons.
   // Overrides may construct the view; this will only be called once per dialog.
   virtual View* CreateFootnoteView();
 
   // For Dialog boxes, if there is a "Cancel" button or no dialog button at all,
-  // this is called when the user presses the "Cancel" button or the Close
-  // button on the window or in the system menu, or presses the Esc key.
-  // This function should return true if the window can be closed after it
-  // returns, or false if it must remain open.
+  // this is called when the user presses the "Cancel" button or the Esc key.
+  // It can also be called on a dismiss action if |Dismiss| has not been
+  // overridden. This function should return true if the window can be closed
+  // after it returns, or false if it must remain open.
   virtual bool Cancel();
 
   // For Dialog boxes, this is called when the user presses the "OK" button,
-  // or the Enter key.  Can also be called on Esc key or close button
-  // presses if there is no "Cancel" button.  This function should return
-  // true if the window can be closed after it returns, or false if it must
-  // remain open.  If |window_closing| is true, it means that this handler is
+  // or the Enter key. It can also be called on a dismiss action if |Dismiss|
+  // has not been overridden. This function should return true if the window
+  // can be closed after it returns, or false if it must remain open.
+  // If |window_closing| is true, it means that this handler is
   // being called because the window is being closed (e.g.  by Window::Close)
   // and there is no Cancel handler, so Accept is being called instead.
   virtual bool Accept(bool window_closing);
   virtual bool Accept();
 
+  // For Dialog boxes, this is called when the user presses the Close button
+  // on the window or in the system menu. The default behavior is to call
+  // |Cancel| if the dialog has a "Cancel" button or no button at all, or
+  // |Accept| otherwise. This function should return true if the window can be
+  // closed after it returns, or false if it must remain open.
+  virtual bool Dismiss();
+
   // Overridden from ui::DialogModel:
   virtual base::string16 GetDialogLabel() const OVERRIDE;
   virtual base::string16 GetDialogTitle() const OVERRIDE;
   virtual int GetDialogButtons() const OVERRIDE;
   virtual int GetDefaultDialogButton() const OVERRIDE;
   virtual base::string16 GetDialogButtonLabel(
       ui::DialogButton button) const OVERRIDE;
   virtual bool IsDialogButtonEnabled(ui::DialogButton button) const OVERRIDE;
   virtual bool OnDialogButtonActivated(ui::DialogButton button) OVERRIDE;
 
@@ skipping 46 matching lines @@
   virtual const Widget* GetWidget() const OVERRIDE;
   virtual View* GetContentsView() OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DialogDelegateView);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WINDOW_DIALOG_DELEGATE_H_