Show only one instance of the keyboard overlay.

chrome/browser/ui/views/keyboard_overlay_dialog_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 "chrome/browser/ui/views/keyboard_overlay_dialog_view.h"
 
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ui/browser_dialogs.h"
 #include "chrome/browser/ui/views/keyboard_overlay_delegate.h"
 #include "grit/generated_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/screen.h"
 #include "ui/views/widget/widget.h"
 #include "ui/web_dialogs/web_dialog_delegate.h"
 
 using ui::WebDialogDelegate;
 
+namespace {
+// Store the pointer to the view currently shown.
+KeyboardOverlayDialogView* g_instance = NULL;
+}
+
 KeyboardOverlayDialogView::KeyboardOverlayDialogView(
     Profile* profile,
     WebDialogDelegate* delegate)
     : WebDialogView(profile, NULL, delegate) {
 }
 
 KeyboardOverlayDialogView::~KeyboardOverlayDialogView() {
 }
 
 void KeyboardOverlayDialogView::ShowDialog() {
+  // Ignore the call if another view is already shown.
+  if (g_instance)
+    return;
 
   KeyboardOverlayDelegate* delegate = new KeyboardOverlayDelegate(
       l10n_util::GetStringUTF16(IDS_KEYBOARD_OVERLAY_TITLE));
   KeyboardOverlayDialogView* view = new KeyboardOverlayDialogView(
       ProfileManager::GetDefaultProfileOrOffTheRecord(), delegate);
   delegate->set_view(view);
 
   views::Widget* widget = new views::Widget;
   views::Widget::InitParams params(
       views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
   params.delegate = view;
   widget->Init(params);
 
   // Show the widget at the bottom of the work area.
   gfx::Size size;
   delegate->GetDialogSize(&size);
   gfx::Rect rect = gfx::Screen::GetMonitorNearestWindow(
       view->GetWidget()->GetNativeView()).work_area();
   gfx::Rect bounds((rect.width() - size.width()) / 2,
                    rect.height() - size.height(),
                    size.width(),
                    size.height());
   view->GetWidget()->SetBounds(bounds);
   view->GetWidget()->Show();
+
+  g_instance = view;
 }
+
+void KeyboardOverlayDialogView::WindowClosing() {
+  g_instance = NULL;
+}