diff options
| -rw-r--r-- | FL/Enumerations.H | 9 | ||||
| -rw-r--r-- | FL/names.h | 5 | ||||
| -rw-r--r-- | src/Fl_Group.cxx | 16 |
3 files changed, 26 insertions, 4 deletions
diff --git a/FL/Enumerations.H b/FL/Enumerations.H index d944a13a2..339851d81 100644 --- a/FL/Enumerations.H +++ b/FL/Enumerations.H @@ -407,7 +407,14 @@ enum Fl_Event { // events /** A zoom event (ctrl/+/-/0/ or cmd/+/-/0/) was processed. Use Fl::add_handler() to be notified of this event. */ - FL_ZOOM_EVENT = 27 + FL_ZOOM_EVENT = 27, + /** This event is sent if the parent widget is deleted and the parent is about + to delete this widget as well. Returning the default value 0 will give the + parent permission to call the destructor of this widget. Returning 1 will + preserve this widget, but still remove it from the widget hierarchy. + \see Fl_Group::clear() + */ + FL_AUTO_DELETE_EVENT = 28 // DEV NOTE: Keep this list in sync with FL/names.h }; diff --git a/FL/names.h b/FL/names.h index 15a491f84..4f90c3ec1 100644 --- a/FL/names.h +++ b/FL/names.h @@ -73,9 +73,10 @@ const char * const fl_eventnames[] = "FL_FULLSCREEN", "FL_ZOOM_GESTURE", "FL_ZOOM_EVENT", - "FL_EVENT_28", // not yet defined, just in case it /will/ be defined ... + "FL_AUTO_DELETE_EVENT", "FL_EVENT_29", // not yet defined, just in case it /will/ be defined ... - "FL_EVENT_30" // not yet defined, just in case it /will/ be defined ... + "FL_EVENT_30", // not yet defined, just in case it /will/ be defined ... + "FL_EVENT_31" // not yet defined, just in case it /will/ be defined ... }; /** diff --git a/src/Fl_Group.cxx b/src/Fl_Group.cxx index 2576efea7..134b49998 100644 --- a/src/Fl_Group.cxx +++ b/src/Fl_Group.cxx @@ -375,6 +375,19 @@ Fl_Group::Fl_Group(int X,int Y,int W,int H,const char *l) \internal If the Fl_Group widget contains the Fl::focus() or the Fl::pushed() widget these are set to sensible values (other widgets or the Fl_Group widget itself). + + \note FLTK's auto-delete feature efficiently manages widget hierarchies in + C++ applications by automatically cleaning up. However, this feature can + cause issues when FLTK is used with reference-counting languages like Python, + where automatic deletion might interfere with reference counting. To address + this, auto-delete can be disabled for individual widgets. When + \ref Fl_Group::clear() is called, it sends an \ref FL_AUTO_DELETE event to + each widget. If a widget returns 1 in response to this event, it will not + be deleted. In a Python wrapper, this behavior would typically involve + decrementing the widget's reference count instead of deleting it. + + \see Fl_Group::remove(int), Fl_Group::delete_child(int), + Fl_Group::~Fl_Group() */ void Fl_Group::clear() { savedfocus_ = 0; @@ -417,7 +430,8 @@ void Fl_Group::clear() { } else { // slow removal remove(idx); } - delete w; // delete the child + if (w->handle(FL_AUTO_DELETE_EVENT)==0) + delete w; // delete the child } else { // should never happen remove(idx); // remove it anyway } |