processEvent

pub fn processEvent(self: *TreeWidget, e: *dvui.Event) void {
    if (dvui.captured(self.data().id) or (self.init_options.drag_name != null and dvui.dragName(self.init_options.drag_name.?))) {
        switch (e.evt) {
            .mouse => |me| {
                if ((me.action == .press or me.action == .release) and me.button.pointer()) {
                    e.handle(@src(), self.data());
                    self.drag_ending = true;
                    dvui.captureMouse(null, e.num);
                    dvui.dragEnd();
                }
            },
            else => {},
        }
    }
}