#185 OLV.GroupExpandingCollapsing not fired on double click

[Yvonne Pautz]

The GroupExpandingCollapsing Event is not beeing fired when expanding/collapsing group by double click. It only works when using the little arrow button

[Yvonne Pautz]

Had to create a workaround by wrapping the ObjectListView class with my own WndProc:

        public EventHandler<GroupExpandingCollapsingEventArgs> GroupExpandingCollapsing2;

...

            // well.. i dunno if theres a better msg to catch
            if (m.Msg == WM_LBUTTONDBLCLK)
            {

                // this just gives me the listview control
                //Control ctrl = Control.FromHandle(m.HWnd);

                //Point pt = PointToClient(Cursor.Position);
                Point pt = new Point(Native.LOWORD(m.LParam), Native.HIWORD(m.LParam));
                //Console.WriteLine($"------------------ {pt.X} / {pt.Y}");

                // loop through each group
                foreach(OLVGroup grp in this.OLVGroups)
                {

                    // get group header rect
                    RECT rectHeader = new RECT();
                    rectHeader.top = LVGGR_HEADER;
                    SendMessage(m.HWnd, LVM_GETGROUPRECT, grp.GroupId, ref rectHeader);
                    Rectangle rect = new Rectangle(rectHeader.left, rectHeader.top, rectHeader.right - rectHeader.left, rectHeader.bottom - rectHeader.top);

                    // and check if the clicked point is inside rect
                    if (rect.Contains(pt))
                    {   // found the group header!!

                        // the wnd msg is received after collapsing/expanding
                        // so grp.Collapsed is true when the grp has been collapsed

                        // do something...
                        GroupExpandingCollapsingEventArgs args = new GroupExpandingCollapsingEventArgs(grp);
                        GroupExpandingCollapsing2?.Invoke(this, args);
                        if (args.Canceled) return;
                    }
                }
                return;
            }