==== MouSetEventMask ====

**Bindings**: [[setevtmask#C bindings|C]], [[setevtmask#MASM bindings|MASM]]

This call assigns a new event mask to the current mouse device driver. 

//MouSetEventMask// (EventMask, DeviceHandle) 

//EventMask// (**PUSHORT**) - input 
Address of a value in application storage used to indicate what mouse events are to be placed on the event queue (see [[en:ibm:prcp:mou:readevtque|MouReadEventQue]]) and which events are to be ignored. 

The EventMask bit values are described below: 

^Bit ^Description ^
|15-7 |Reserved, set to zero. |
|6 |Set to report button 3 press/release events, without mouse motion |
|5 |Set to report button 3 press/release events, with mouse motion |
|4 |Set to report button 2 press/release events, without mouse motion |
|3 |Set to report button 2 press/release events, with mouse motion |
|2 |Set to report button 1 press/release events, without mouse motion |
|1 |Set to report button 1 press/release events, with mouse motion |
|0 |Set to mouse motion events with no button press/release events |

  
A bit clear setting (set to zero) in an //EventMask// bit position indicates that the associated type of event is not reported to the application. Note also that the mouse buttons are always numbered from left to right. When the mouse is properly positioned for use, the left-hand button is button 1. 

//DeviceHandle// (**HMOU**) - input 
Handle of the mouse device from a previous MouOpen. 

//rc// (**USHORT**) - return 
Return code descriptions are: 

|0 |NO_ERROR |
|385 |ERROR_MOUSE_NO_DEVICE |
|466 |ERROR_MOU_DETACHED |
|501 |ERROR_MOUSE_NO_CONSOLE |
|505 |ERROR_MOU_EXTENDED_SG |

**Remarks** 

Setting a bit in the event mask means that the associated event is reported on the mouse FIFO event queue. See [[en:ibm:prcp:mou:readevtque|MouReadEventQue]] for examples of event mask use. 

=== C bindings ===

<code c>
#define INCL_MOU

USHORT  rc = MouSetEventMask(EventMask, DeviceHandle);

PUSHORT          EventMask;     /* Mouse device event mask ptr */
HMOU             DeviceHandle;  /* Mouse device handle */

USHORT           rc;            /* return code */
</code>

=== MASM bindings ===

<code asm>
EXTRN  MouSetEventMask:FAR
INCL_MOU            EQU 1

PUSH@  WORD    EventMask     ;Mouse device event mask ptr
PUSH   WORD    DeviceHandle  ;Mouse device handle
CALL   MouSetEventMask

Returns WORD
</code>