"
COPYRIGHT (c) 1995 by Claus Gittinger
All Rights Reserved
This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice. This software may not
be provided or otherwise made available to, or used by, any
other person. No title to or ownership of the software is
hereby transferred.
"
Object subclass:#EventListener
instanceVariableNames:''
classVariableNames:''
poolDictionaries:''
category:'Interface-Support'
!
!EventListener class methodsFor:'documentation'!
copyright
"
COPYRIGHT (c) 1995 by Claus Gittinger
All Rights Reserved
This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice. This software may not
be provided or otherwise made available to, or used by, any
other person. No title to or ownership of the software is
hereby transferred.
"
!
documentation
"
abstract class for event listeners. EventListeners can be used to intercept
incoming events (keyboard & mouse) directly from a sensor, or even
for a complete display device.
A concrete application is the bubble help, which tracks entering/leaving
views, and pops up some help message.
See concrete code in ActiveHelp.
For each intercepted event, a corresponding method is called for in instances
of myself - these MUST return true, if the event is to be ignored (i.e.
assumed to be processed and consumed by the reader,
and MUST return false, if the normal event procedure should be performed.
Since this is an abstract class,
all of my intercept methods return false.
They are meant to be redefined in concrete subclasses.
[see also:]
WindowSensor WindowEvent WindowGroup
[author:]
Claus Gittinger
"
! !
!EventListener methodsFor:'events'!
buttonMotion:state x:x y:y view:aView
"not handled here - should be redefined in a concrete subclass"
^ false
"Modified: 23.4.1996 / 21:57:54 / cg"
!
buttonMultiPress:button x:x y:y view:aView
"not handled here - should be redefined in a concrete subclass"
^ false
"Modified: 23.4.1996 / 21:57:58 / cg"
!
buttonPress:button x:x y:y view:aView
"not handled here - should be redefined in a concrete subclass"
^ false
"Modified: 23.4.1996 / 21:58:01 / cg"
!
buttonRelease:button x:x y:y view:aView
"not handled here - should be redefined in a concrete subclass"
^ false
"Modified: 23.4.1996 / 21:58:03 / cg"
!
keyPress:key x:x y:y view:aView
"not handled here - should be redefined in a concrete subclass"
^ false
"Modified: 23.4.1996 / 21:58:08 / cg"
!
keyRelease:key x:x y:y view:aView
"not handled here - should be redefined in a concrete subclass"
^ false
"Modified: 23.4.1996 / 21:58:11 / cg"
!
pointerEnter:state x:x y:y view:view
"not handled here - should be redefined in a concrete subclass"
^ false
"Modified: 23.4.1996 / 21:58:14 / cg"
!
pointerLeave:state view:view
"not handled here - should be redefined in a concrete subclass"
^ false
"Modified: 23.4.1996 / 21:58:17 / cg"
! !
!EventListener methodsFor:'events - window creation'!
preCreateView:aView origin:org
"invoked right before a view is about to be physically created.
May return a new origin."
^ org
!
postCreateView:aView
"invoked right after a view was physically created."
^ self
! !
!EventListener methodsFor:'listen'!
listen
"install myself as listener"
WindowSensor eventListener:self
"
|listener|
listener := EventListener new.
listener listen.
(Delay forSeconds:20) wait.
listener unlisten
"
!
unlisten
"uninstall myself as listener"
WindowSensor eventListener:nil
! !
!EventListener class methodsFor:'documentation'!
version
^ '$Header: /cvs/stx/stx/libview2/EventListener.st,v 1.13 1997-05-07 13:09:22 cg Exp $'
! !