XmNexposeCallback
This callback is called when an expose on the window is activated.
XmNinputCallback
This callback is called when an input event is activated (mouse)
XmNresizeCallback
This callback is called during a resize event.
For these callbacks, the returned structure is :
typedef struct {
int reason;
XEvent *event;
Window window;
} XmGPhigsAreaCallbackStruct