Implement window.alert() and its cousins for extensions....

chrome/browser/app_modal_dialog.cc

 // Copyright (c) 2009 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 "chrome/browser/app_modal_dialog.h"
 
 #include "chrome/browser/app_modal_dialog_queue.h"
 #include "chrome/browser/tab_contents/tab_contents.h"
 #include "chrome/common/notification_service.h"
 #include "chrome/common/notification_type.h"
 #include "ipc/ipc_message.h"
 
-AppModalDialog::AppModalDialog(TabContents* tab_contents,
+AppModalDialog::AppModalDialog(JavaScriptMessageBoxClient* client,
                                const std::wstring& title,
                                int dialog_flags,
                                const std::wstring& message_text,
                                const std::wstring& default_prompt_text,
                                bool display_suppress_checkbox,
                                bool is_before_unload_dialog,
                                IPC::Message* reply_msg)
     : dialog_(NULL),
-      tab_contents_(tab_contents),
+      client_(client),
+      skip_this_dialog_(false),
       title_(title),
       dialog_flags_(dialog_flags),
       message_text_(message_text),
       default_prompt_text_(default_prompt_text),
       display_suppress_checkbox_(display_suppress_checkbox),
       is_before_unload_dialog_(is_before_unload_dialog),
       reply_msg_(reply_msg) {
   InitNotifications();
 }
 
 void AppModalDialog::Observe(NotificationType type,
                              const NotificationSource& source,
                              const NotificationDetails& details) {
-  if (!tab_contents_)
+  if (skip_this_dialog_)
     return;
 
-  if (type == NotificationType::NAV_ENTRY_COMMITTED &&
-      Source<NavigationController>(source).ptr() ==
-          &tab_contents_->controller())
-    tab_contents_ = NULL;
-
-  if (type == NotificationType::TAB_CONTENTS_DESTROYED &&
-      Source<TabContents>(source).ptr() ==
-      static_cast<TabContents*>(tab_contents_))
-    tab_contents_ = NULL;
-
-  if (!tab_contents_)
-    CloseModalDialog();
+  // We only observe our NavigationController for NAV_ENTRY_COMMITTED and our
+  // TabContents for TAB_CONTENTS_DESTROYED, both of which indicate that we
+  // should ignore this dialog. Also clear the client for good measure, since
+  // it's now invalid.
+  skip_this_dialog_ = true;
+  client_ = NULL;
+  CloseModalDialog();
 }
 
 void AppModalDialog::SendCloseNotification() {
   NotificationService::current()->Notify(
       NotificationType::APP_MODAL_DIALOG_CLOSED,
       Source<AppModalDialog>(this),
       NotificationService::NoDetails());
 }
 
 void AppModalDialog::InitNotifications() {
-  // Make sure we get navigation notifications so we know when our parent
-  // contents will disappear or navigate to a different page.
-  registrar_.Add(this, NotificationType::NAV_ENTRY_COMMITTED,
-                 NotificationService::AllSources());
-  registrar_.Add(this, NotificationType::TAB_CONTENTS_DESTROYED,
-                 NotificationService::AllSources());
+  // Make sure we get relevant navigation notifications so we know when our
+  // parent contents will disappear or navigate to a different page.
+  TabContents* tab_contents = client_->AsTabContents();
+  if (tab_contents) {
+    registrar_.Add(this, NotificationType::NAV_ENTRY_COMMITTED,
+                   Source<NavigationController>(&tab_contents->controller()));
+    registrar_.Add(this, NotificationType::TAB_CONTENTS_DESTROYED,
+                   Source<TabContents>(tab_contents));
+  }
 }
 
 void AppModalDialog::ShowModalDialog() {
   // If the TabContents that created this dialog navigated away before this
   // dialog became visible, simply show the next dialog if any.
-  if (!tab_contents_) {
+  if (skip_this_dialog_) {
     Singleton<AppModalDialogQueue>()->ShowNextDialog();
     delete this;
     return;
   }
+  TabContents* tab_contents = client_->AsTabContents();
+  if (tab_contents)
+    tab_contents->Activate();
 
-  tab_contents_->Activate();
   CreateAndShowDialog();
 
   NotificationService::current()->Notify(
       NotificationType::APP_MODAL_DIALOG_SHOWN,
       Source<AppModalDialog>(this),
       NotificationService::NoDetails());
 }
 
 void AppModalDialog::OnCancel() {
   // We need to do this before WM_DESTROY (WindowClosing()) as any parent frame
-  // will receive it's activation messages before this dialog receives
+  // will receive its activation messages before this dialog receives
   // WM_DESTROY. The parent frame would then try to activate any modal dialogs
   // that were still open in the ModalDialogQueue, which would send activation
   // back to this one. The framework should be improved to handle this, so this
   // is a temporary workaround.
   Singleton<AppModalDialogQueue>()->ShowNextDialog();
 
-  if (tab_contents_) {
-    tab_contents_->OnJavaScriptMessageBoxClosed(reply_msg_, false,
-                                                std::wstring());
+  if (!skip_this_dialog_) {
+    client_->OnMessageBoxClosed(reply_msg_, false, std::wstring());
   }
 
   SendCloseNotification();
 }
 
 void AppModalDialog::OnAccept(const std::wstring& prompt_text,
                               bool suppress_js_messages) {
   Singleton<AppModalDialogQueue>()->ShowNextDialog();
 
-  if (tab_contents_) {
-    tab_contents_->OnJavaScriptMessageBoxClosed(reply_msg_, true,
-                                                prompt_text);
-
+  if (!skip_this_dialog_) {
+    client_->OnMessageBoxClosed(reply_msg_, true, prompt_text);
     if (suppress_js_messages)
-      tab_contents()->set_suppress_javascript_messages(true);
+      client_->SetSuppressMessageBoxes(true);
   }
 
   SendCloseNotification();
 }
 
 void AppModalDialog::OnClose() {
   SendCloseNotification();
 }