Reverting previous change (optimization of Fl_Group::clear),

because fl_throw_focus and fl_fix_focus would send events
that could access deleted widgets. This must be fixed first.


git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@7039 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

3 files changed, 18 insertions, 35 deletions

diff --git a/CHANGES b/CHANGES
index 40acf40ff..d03f28ff7 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,8 +1,5 @@
 CHANGES IN FLTK 1.3.0
 
-	- Optimized Fl_Group::clear() and Fl_Scroll::clear() as
-	  discussed in fltk.development in "Fl_Group::clear SLOW!"
-	  on Feb. 06/07, 2010 (no STR)
 	- Replaced _WIN32 symbols that had come with UTF-8 and the
 	  new Fl_Table widget with WIN32
 	- Fixed a buffer overflow in fl_utf8from_mb() (STR #2279)
diff --git a/src/Fl_Group.cxx b/src/Fl_Group.cxx
index b84fe7e32..b42f1caf8 100644
--- a/src/Fl_Group.cxx
+++ b/src/Fl_Group.cxx
@@ -382,33 +382,24 @@ Fl_Group::Fl_Group(int X,int Y,int W,int H,const char *l)
   This method differs from the remove() method in that it
   affects all child widgets and deletes them from memory.
 */
-/* Implementation note:
-  This is optimized and does not remove children _during_ the loop.
-  However, deleting one child may also delete other children in the
-  group because a child widget can destroy other children in the same
-  group in its destructor or simply remove them from the parent group.
-  Because of this we must walk forwards through the array of children.
-  The allocated array_ of children is freed after the loop.
-*/
 void Fl_Group::clear() {
   savedfocus_ = 0;
   resizable_ = this;
   init_sizes();
   // okay, now it is safe to destroy the children:
-  int i;
-  for (i=0; i<children_; i++) {	// delete all children
-    Fl_Widget* o = child(i);	// get child widget
-    if (o->parent()==this) {	// should always be true
-      o->parent_ = 0;		// reset child's parent
-      delete o;			// delete it
+  while (children_) {
+    Fl_Widget* o = child(0);	// *first* child widget
+    if (o->parent() == this) {	// should always be true
+      remove(o);		// remove child widget first
+      delete o;			// then delete it
+    } else {			// this should never happen !
+#ifdef DEBUG_CLEAR
+      printf ("Fl_Group::clear() widget:%p, parent: %p != this (%p)\n",
+	      o, o->parent(), this); fflush(stdout);
+#endif // DEBUG_CLEAR
+      remove(o);		// remove it
     }
   }
-  // now free the array_ of children (if any)
-  if (children_ > 1) {
-    free((void*)array_);
-  }
-  array_ = 0;
-  children_ = 0;
 }
 
 /**
@@ -478,8 +469,6 @@ void Fl_Group::add(Fl_Widget &o) {insert(o, children_);}
   This method differs from the clear() method in that it only affects
   a single widget and does not delete it from memory.
 */
-// Note: if you change this, be sure to do similar changes in
-// Fl_Group::clear() as well, if applicable.
 void Fl_Group::remove(Fl_Widget &o) {
   if (!children_) return;
   int i = find(o);
diff --git a/src/Fl_Scroll.cxx b/src/Fl_Scroll.cxx
index 333c4892d..085d47bf0 100644
--- a/src/Fl_Scroll.cxx
+++ b/src/Fl_Scroll.cxx
@@ -32,16 +32,13 @@
 
 /** Clear all but the scrollbars... */
 void Fl_Scroll::clear() {
-  // Note: the scrollbars are removed from the group before
-  // calling Fl_Group::clear() to take advantage of the
-  // optimized widget removal. Finally they are added
-  // to the Fl_Scroll's group again.
-  // This is MUCH faster than removing each widget.
-  remove(scrollbar);
-  remove(hscrollbar);
-  Fl_Group::clear();
-  add(hscrollbar);
-  add(scrollbar);
+  for (int i=children() - 1; i >= 0; i --) {
+    Fl_Widget* o = child(i);
+    if (o != &hscrollbar && o != &scrollbar) {
+      remove(o);
+      delete o;
+    }
+  }
 }
 
 /** Insure the scrollbars are the last children */