Scilab Function

seteventhandler - set an event handler for the current graphic window

### Calling Sequence

  `seteventhandler(sfun_name)`
  `seteventhandler('')`

### Parameters

- `sfun_name` : a character string. The name of the Scilab function which is intended to handle the events

### Description

The function allows the user to set a particular event handler for the current graphic window. `seteventhandler('')` removes the handler.

The event handler is defined by a Scilab function whose calling sequence must be `function sfun_name(win,x,y,ibut)` , where

  `win` represents the number of the window where the event had occured.

  `x,y` are the coordinates of the pointer (in pixels), when the event has occured

  `ibut` is the event type:

  - ibut==0 : Left mouse button has been pressed
  - ibut==-5 : Left mouse button has been released
  - ibut==1 : Middle mouse button has been pressed
  - ibut==-4 : Middle mouse button has been released
  - ibut==2 : Right mouse button has been pressed
  - ibut==-3 : Right mouse button has been released
  - ibut==-1 : pointer has moved
  - ibut > =32 : key with ascii code ascii(ibut) has been pressed
  - ibut < =-32 : key with ascii code ascii(-ibut) has been released
  - ibut==-1000 : graphic window has been closed

### Examples

       function my_eventhandler(win,x,y,ibut)
           if ibut==-1 then
             [x,y]=xchange(x,y,'i2f')
             xinfo('Mouse position is ('+string(x)+','+string(y)+')')
           end
       endfunction
       plot2d()
       seteventhandler('my_eventhandler')
       //now move the mouse over the graphic window/
       seteventhandler('') //suppress the event handler

### See Also

`addmenu` , `xgetmouse` , `xclick` , `xchange` ,