Make a clean interface for dialog callbacks.

chrome/browser/ui/app_modal_dialogs/js_modal_dialog.h

 // Copyright (c) 2011 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 CHROME_BROWSER_UI_APP_MODAL_DIALOGS_JS_MODAL_DIALOG_H_
 #define CHROME_BROWSER_UI_APP_MODAL_DIALOGS_JS_MODAL_DIALOG_H_
 #pragma once
 
 #include <string>
 
+#include "base/compiler_specific.h"
 #include "base/time.h"
 #include "build/build_config.h"
 #include "chrome/browser/ui/app_modal_dialogs/app_modal_dialog.h"
 #include "content/browser/javascript_dialogs.h"
-#include "content/common/notification_observer.h"
-#include "content/common/notification_registrar.h"
 
-class ExtensionHost;
-class NativeAppModalDialog;
-class TabContents;
+namespace content {
+class JavaScriptDialogDelegate;
+}
 
 namespace IPC {
 class Message;
 }
 
 // Extra data for JavaScript dialogs to add Chrome-only features.
 class ChromeJavaScriptDialogExtraData {
  public:
   ChromeJavaScriptDialogExtraData();
 
   // The time that the last JavaScript dialog was dismissed.
   base::TimeTicks last_javascript_message_dismissal_;
 
   // True if the user has decided to block future JavaScript dialogs.
   bool suppress_javascript_messages_;
 };
 
 // A controller + model class for JavaScript alert, confirm, prompt, and
 // onbeforeunload dialog boxes.
-class JavaScriptAppModalDialog : public AppModalDialog,
-                                 public NotificationObserver {
+class JavaScriptAppModalDialog : public AppModalDialog {
  public:
   JavaScriptAppModalDialog(content::JavaScriptDialogDelegate* delegate,
                            ChromeJavaScriptDialogExtraData* extra_data,
                            const string16& title,
                            int dialog_flags,
                            const string16& message_text,
                            const string16& default_prompt_text,
                            bool display_suppress_checkbox,
                            bool is_before_unload_dialog,
                            IPC::Message* reply_msg);
   virtual ~JavaScriptAppModalDialog();
 
   // Overridden from AppModalDialog:
-  virtual NativeAppModalDialog* CreateNativeDialog();
-  virtual bool IsJavaScriptModalDialog();
-
-  content::JavaScriptDialogDelegate* delegate() const { return delegate_; }
+  virtual NativeAppModalDialog* CreateNativeDialog() OVERRIDE;
+  virtual bool IsJavaScriptModalDialog() OVERRIDE;
+  virtual void Invalidate() OVERRIDE;
+  virtual content::JavaScriptDialogDelegate* delegate() const OVERRIDE;
 
   // Callbacks from NativeDialog when the user accepts or cancels the dialog.
   void OnCancel(bool suppress_js_messages);
   void OnAccept(const string16& prompt_text, bool suppress_js_messages);
 
   // NOTE: This is only called under Views, and should be removed. Any critical
   // work should be done in OnCancel or OnAccept. See crbug.com/63732 for more.
   void OnClose();
 
   // Used only for testing. The dialog will use the given text when notifying
   // its delegate instead of whatever the UI reports.
   void SetOverridePromptText(const string16& prompt_text);
 
   // Accessors
   int dialog_flags() const { return dialog_flags_; }
   string16 message_text() const { return message_text_; }
   string16 default_prompt_text() const { return default_prompt_text_; }
   bool display_suppress_checkbox() const { return display_suppress_checkbox_; }
   bool is_before_unload_dialog() const { return is_before_unload_dialog_; }
 
  private:
-  // Overridden from NotificationObserver:
-  virtual void Observe(NotificationType type,
-                       const NotificationSource& source,
-                       const NotificationDetails& details);
-
-  // Initializes for notifications to listen.
-  void InitNotifications();
-
   // Notifies the delegate with the result of the dialog.
   void NotifyDelegate(bool success, const string16& prompt_text,
                       bool suppress_js_messages);
 
-  NotificationRegistrar registrar_;
-
   // An implementation of the client interface to provide supporting methods
   // and receive results.
   content::JavaScriptDialogDelegate* delegate_;

[Evan Martin, 2011/06/29 22:01:52]

This is confusing; AppModalDialog already has a protected delegate_ member.

[Avi (use Gerrit), 2011/06/29 22:09:29]

Right, but this as a subclass requires the expanded subclass delegate. I'm not
sure of a better clean way to do it; thoughts?

[Evan Martin, 2011/06/29 22:53:09]

I polled my office and they came up with:

content::JavaScriptDialogDelegate* delegate() const {
  return static_cast<content::JavaScriptDialogDelegate*>(delegate_);
}

[Avi (use Gerrit), 2011/06/29 23:19:48]

You were objecting to the storage rather than the override with the covariant
return type? Oh, I can do that. Done.

 
   // The extra Chrome-only data associated with the delegate_.
   ChromeJavaScriptDialogExtraData* extra_data_;
 
   // The client_ as an ExtensionHost, cached for use during notifications that
   // may arrive after the client has entered its destructor (and is thus
   // treated as a base Delegate). This will be NULL if the |delegate_| is not an
   // ExtensionHost.
   ExtensionHost* extension_host_;
 
   // Information about the message box is held in the following variables.
   int dialog_flags_;
   string16 message_text_;
   string16 default_prompt_text_;
   bool display_suppress_checkbox_;
   bool is_before_unload_dialog_;
   IPC::Message* reply_msg_;
 
   // Used only for testing. Specifies alternative prompt text that should be
   // used when notifying the delegate, if |use_override_prompt_text_| is true.
   string16 override_prompt_text_;
   bool use_override_prompt_text_;
 
   DISALLOW_COPY_AND_ASSIGN(JavaScriptAppModalDialog);
 };
 
 #endif  // CHROME_BROWSER_UI_APP_MODAL_DIALOGS_JS_MODAL_DIALOG_H_