Why an Event Handler Returns an Event Greater Than 13

ID: Q109153

The information in this article applies to:

• Microsoft FoxPro for Windows, versions 2.5, 2.5a, and 2.5b
• Microsoft FoxPro Library Construction Kit, version 2.5

SUMMARY

Event handlers are functions that trap and process events such as keys being pressed, mouse buttons being clicked, menus being opened, and so on. Even though only 13 events are defined in the PRO_EXT.H file, the event handler can receive an event number greater than 13. However, any event greater than 13 (except 999) is an internal FoxPro event and should be ignored.

MORE INFORMATION

Below is the information from FoxPro's PRO_EXT.H file that describes the events that the event handler can trap for and their value.

   /* EventRec.what value*/

   #define nullEvent        0     /* Null */
   #define mouseDownEvent   1     /* Mouse down */
   #define keyDownEvent     2     /* Key down */
   #define activateEvent    3     /* Activate window*/
   #define deactivateEvent  4     /* Deactivate window*/
   #define updateEvent      5     /* Redraw window*/
   #define menuHitEvent     6     /* Menu hit*/
   #define menuUpdateEvent  7     /* Menu update required*/
   #define closeEvent       8     /* Close window*/
   #define hideEvent        9     /* Hide window*/
   #define showEvent        10    /* Show window*/
   #define hotkeyEvent      11    /* An ON KEY LABEL was pressed*/
   #define sizeEvent        12    /* Size window event*/
   #if defined(__WINDOWS__) || defined(_WINDLL)
   #define rMouseDownEvent  13    /* Right mouse down event*/
   #define zoomEvent        999   /* Not supported in Windows*/
   #else
   #define zoomEvent        13    /* Zoom window event*/
   #endif