Added the helper class Fl_Watch to simplify safe handling of widget deletion

in callbacks. This is used e.g. in Fl_Widget::do_callback() to prevent 
accessing widgets after deletion in the callback.

Documentation adjusted, Fl_Menu_Button.cxx changed to use Fl_Watch instead
of Fl::watch_widget_pointer.

Fl::watch_widget_pointer() and Fl::release_widget_pointer() have been
modified to use an array without "holes" (NULL pointers) for storing the
widget pointers for faster access: Fl::release_widget_pointer() now shifts
pointers to close gaps of freed pointers.


git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@6651 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

1 files changed, 2 insertions, 4 deletions

diff --git a/src/Fl_Menu_Button.cxx b/src/Fl_Menu_Button.cxx
index 988a6e727..9389ca49f 100644
--- a/src/Fl_Menu_Button.cxx
+++ b/src/Fl_Menu_Button.cxx
@@ -58,8 +58,7 @@ const Fl_Menu_Item* Fl_Menu_Button::popup() {
   const Fl_Menu_Item* m;
   pressed_menu_button_ = this;
   redraw();
-  Fl_Widget *mb = this;
-  Fl::watch_widget_pointer(mb);
+  Fl_Watch mb(this);
   if (!box() || type()) {
     m = menu()->popup(Fl::event_x(), Fl::event_y(), label(), mvalue(), this);
   } else {
@@ -67,8 +66,7 @@ const Fl_Menu_Item* Fl_Menu_Button::popup() {
   }
   picked(m);
   pressed_menu_button_ = 0;
-  if (mb) mb->redraw();
-  Fl::release_widget_pointer(mb);
+  if (mb.exists()) redraw();
   return m;
 }