chrome/browser/ui/libgtk2ui/gtk2_signal_registrar.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_UI_LIBGTK2UI_GTK2_SIGNAL_REGISTRAR_H_
   6 #define CHROME_BROWSER_UI_LIBGTK2UI_GTK2_SIGNAL_REGISTRAR_H_
   7
   8 #include <glib.h>
   9 #include <map>
  10 #include <vector>
  11
  12 #include "base/basictypes.h"
  13
  14 typedef void (*GCallback) (void);
  15 typedef struct _GObject GObject;
  16 typedef struct _GtkWidget GtkWidget;
  17
  18 namespace libgtk2ui {
  19
  20 // A class that ensures that callbacks don't run on stale owner objects. Similar
  21 // in spirit to NotificationRegistrar. Use as follows:
  22 //
  23 //   class ChromeObject {
  24 //    public:
  25 //     ChromeObject() {
  26 //       ...
  27 //
  28 //       signals_.Connect(widget, "event", CallbackThunk, this);
  29 //     }
  30 //
  31 //     ...
  32 //
  33 //    private:
  34 //     Gtk2SignalRegistrar signals_;
  35 //   };
  36 //
  37 // When |signals_| goes down, it will disconnect the handlers connected via
  38 // Connect.
  39 class Gtk2SignalRegistrar {
  40  public:
  41   Gtk2SignalRegistrar();
  42   ~Gtk2SignalRegistrar();
  43
  44   // Connect before the default handler. Returns the handler id.
  45   glong Connect(gpointer instance, const gchar* detailed_signal,
  46                 GCallback signal_handler, gpointer data);
  47   // Connect after the default handler. Returns the handler id.
  48   glong ConnectAfter(gpointer instance, const gchar* detailed_signal,
  49                      GCallback signal_handler, gpointer data);
  50
  51   // Disconnects all signal handlers connected to |instance|.
  52   void DisconnectAll(gpointer instance);
  53
  54  private:
  55   typedef std::vector<glong> HandlerList;
  56   typedef std::map<GObject*, HandlerList> HandlerMap;
  57
  58   static void WeakNotifyThunk(gpointer data, GObject* where_the_object_was) {
  59     reinterpret_cast<Gtk2SignalRegistrar*>(data)->WeakNotify(
  60         where_the_object_was);
  61   }
  62   void WeakNotify(GObject* where_the_object_was);
  63
  64   glong ConnectInternal(gpointer instance, const gchar* detailed_signal,
  65                         GCallback signal_handler, gpointer data, bool after);
  66
  67   HandlerMap handler_lists_;
  68
  69   DISALLOW_COPY_AND_ASSIGN(Gtk2SignalRegistrar);
  70 };
  71
  72 }  // namespace libgtk2ui
  73
  74 #endif  // CHROME_BROWSER_UI_LIBGTK2UI_GTK2_SIGNAL_REGISTRAR_H_