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, 15 insertions, 0 deletions

diff --git a/src/Fl_Widget.cxx b/src/Fl_Widget.cxx
index 550f1eb1c..740dad6fd 100644
--- a/src/Fl_Widget.cxx
+++ b/src/Fl_Widget.cxx
@@ -293,6 +293,21 @@ Fl_Widget::copy_label(const char *a) {
   redraw_label();
 }
 
+/** Calls the widget callback.
+
+  Causes a widget to invoke its callback function with arbitrary arguments.
+  \param[in] o call the callback with \a o as the widget argument
+  \param[in] arg call the callback with \a arg as the user data argument
+  \see callback()
+*/
+void
+Fl_Widget::do_callback(Fl_Widget* o,void* arg) {
+  Fl_Watch wp(o);
+  callback_(o,arg); 
+  if (wp.deleted()) return;
+  if (callback_ != default_callback) 
+    clear_changed();
+}
 
 //
 // End of "$Id$".