diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/Fl_Group.cxx | 33 | ||||
| -rw-r--r-- | src/Fl_Scroll.cxx | 17 |
2 files changed, 32 insertions, 18 deletions
diff --git a/src/Fl_Group.cxx b/src/Fl_Group.cxx index b42f1caf8..b84fe7e32 100644 --- a/src/Fl_Group.cxx +++ b/src/Fl_Group.cxx @@ -382,24 +382,33 @@ 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: - 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 + 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 } } + // now free the array_ of children (if any) + if (children_ > 1) { + free((void*)array_); + } + array_ = 0; + children_ = 0; } /** @@ -469,6 +478,8 @@ 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 085d47bf0..333c4892d 100644 --- a/src/Fl_Scroll.cxx +++ b/src/Fl_Scroll.cxx @@ -32,13 +32,16 @@ /** Clear all but the scrollbars... */ void Fl_Scroll::clear() { - for (int i=children() - 1; i >= 0; i --) { - Fl_Widget* o = child(i); - if (o != &hscrollbar && o != &scrollbar) { - remove(o); - delete o; - } - } + // 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); } /** Insure the scrollbars are the last children */ |