gtk: Disable the "Import" button on Import Bookmarks dialog if there is no checkbox checked.

chrome/browser/gtk/import_dialog_gtk.h

 // Copyright (c) 2010 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_GTK_IMPORT_DIALOG_GTK_H_
 #define CHROME_BROWSER_GTK_IMPORT_DIALOG_GTK_H_
 
+#include "app/gtk_signal.h"
 #include "chrome/browser/importer/importer.h"
 
 class AccessibleWidgetHelper;
 class Profile;
 
 class ImportDialogGtk : public ImportObserver {
  public:
   // Displays the import box to import data from another browser into |profile|
   // |initial_state| is a bitmask of ImportItems. Each checkbox for the bits in
   // is checked.
   static void Show(GtkWindow* parent, Profile* profile, int initial_state);
 
   // Overridden from ImportObserver:
   virtual void ImportCanceled();
   virtual void ImportComplete();
 
  private:
   ImportDialogGtk(GtkWindow* parent, Profile* profile, int initial_state);
   ~ImportDialogGtk();
 
-  static void HandleOnResponseDialog(GtkWidget* widget,
-                                     int response,
-                                     ImportDialogGtk* user_data) {
-    user_data->OnDialogResponse(widget, response);
-  }
-  void OnDialogResponse(GtkWidget* widget, int response);
+  // Handler to respond to OK or Cancel responses from the dialog.
+  CHROMEGTK_CALLBACK_1(ImportDialogGtk, void, OnDialogResponse, int);
+
+  // Handler to respond to widget clicked actions from the dialog.
+  CHROMEGTK_CALLBACK_0(ImportDialogGtk, void, OnDialogWidgetClicked);
+
+  // Enable or disable the dialog buttons depending on the state of the
+  // checkboxes.
+  void UpdateDialogButtons();
+
+  // Create a bitmask from the checkboxes of the dialog.
+  uint16 GetCheckedItems();
 
   // Parent window
   GtkWindow* parent_;
 
   // Import Dialog
   GtkWidget* dialog_;
 
   // Combo box that displays list of profiles from which we can import.
   GtkWidget* combo_;
 
@@ skipping 17 matching lines @@
 
   int initial_state_;
 
   // Helper object to manage accessibility metadata.
   scoped_ptr<AccessibleWidgetHelper> accessible_widget_helper_;
 
   DISALLOW_COPY_AND_ASSIGN(ImportDialogGtk);
 };
 
 #endif  // CHROME_BROWSER_GTK_IMPORT_DIALOG_GTK_H_