I have written a Grid widget that is a subclass of XmDrawingArea. An instance of this widget is a child of an XrtTabManager (I have also used an XmNotebook, with same results). When this child is not the visible page, the app does some processing that causes the Grid widget to resize. However, the Grid's Resize method is not invoked.
If I register an event handler on the widget using StructureNotifyMask; the event handler proc does get called with event type ConfigureNotify and the widget's size has changed.
Why am I getting a ConfigureNotify event but not a Resize when the size has changed?
XmNotebook makes unmanaged
XmNotebook makes unmanaged widgets on invisible page in order to hide them. Resize is not invoked because your widget is unmanaged when it is on invisible page.
No, the widget *is* managed,
No, the widget *is* managed, but just not the active page. Notebook configures these children such that they are just outside the notebook's window and are therefore not visible.
Even when the page then becomes the active page, at a different size than it was before, its Resize method is still not called.