"

 COPYRIGHT (c) 1988 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.

"

DisplaySurface subclass:#DisplayRootView

	instanceVariableNames:''

	classVariableNames:''

	poolDictionaries:''

	category:'Views-Special'

!

!DisplayRootView class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1988 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

"

    this class describes Xs rootWindow (which is the background window and

    can be used for drawing outside of Views i.e. for dragging between Views).

    For historic and compatibility reasons, there is a global variable 

    called 'RootView', which is bound to the default displays ('Display')

    rootview. We recommend, not to access this variable, instead, get a

    displays rootView via the #rootView message (sent to the device).

    Otherwise, your application will not work in a multiScreen environment.

    Instances of myself (i.e. these rootViews) are light-weight views; 

    they do not support events, models etc.

    They are pure drawing canvases and should be only used for special

    applications (i.e. dragging). 

    There may be display systems in which rootViews are not

    supported/allowed implemented. So be VERY careful when using them.

    Be aware, that the rootView is not always visible - some

    windowManagers install another (pseudoRoot), into which icons and

    windowManager menus are drawn. If that is the case, your paining

    into the rootView may not be visible, unless you set the #noClipByChildren

    option (see below).

    In general, you should never use the rootView for normal applications.

    To draw in the (Displays) root window:

        |rootView|

        rootView := Screen current rootView.

        rootView paint:(Color red).

        rootView fillRectangleX:10 y:10 width:100 height:100.

    of course, all stuff from View and its superclasses can be used:

        |rootView|

        rootView := Screen current rootView.

        rootView paint:(Color red).

        rootView noClipByChildren.

        rootView fillRectangleX:10 y:10 width:100 height:100.

    [author:]

        Claus Gittinger

"

! !

!DisplayRootView class methodsFor:'initialization'!

initialize

    Display isNil ifTrue:[

	Workstation initialize

    ].

    super initialize

! !

!DisplayRootView class methodsFor:'instance creation'!

    "since there is only one RootView - catch new and return

     the one and only rootView."

    aDisplay == Display ifTrue:[

    ].

! !

!DisplayRootView methodsFor:'accessing'!

controller

    "I have no controller"

    ^ nil

!

name

    ^ 'RootWindow'

!

sensor

    "I have no sensor"

    ^ nil

!

windowGroup

    "I have no windowGroup"

    ^ nil

! !

!DisplayRootView methodsFor:'destroying'!

destroy

    "catch destroy - some windowmanagers get confused if

     we destroy the rootWindow if its a virtual root window"

    ^ self

! !

!DisplayRootView methodsFor:'initialization'!

initialize

    super initialize.

    width := device width.

    height := device height.

    drawableId := device rootWindowFor:self.

    realized := true.

!

reinitialize

    "reinit after snapin"

    width := device width.

    height := device height.

    drawableId := device rootWindowFor:self.

    realized := true.

    gcId := nil.

! !

!DisplayRootView methodsFor:'queries'!

canDrop:anObjectOrCollection

    "return true, if anObjectOrCollection can be

     dropped in the receiver. This method should be

     redefined in views which can take objects"

    ^ false

!

isRootView

    "yes, I am a rootview"

    ^ true

    "Created: 5.7.1996 / 13:48:24 / cg"

    "Modified: 5.7.1996 / 14:57:44 / cg"

!

isWindowManagerRunning

    "answer true, if a window manager is currently running.

     This is done by performing an action (enabling button events of

     root window), which will fail if a window manager is running."

    |errorOccured|

    errorOccured := false.

    device class deviceErrorSignal handle:[:ex |

	errorOccured := true.

	ex return

    ] do:[

	self enableButtonEvents.

	device flush.

    ].

    ^ errorOccured

    "

     DisplayRootView new

     RootView isWindowManagerRunning

    "

!

shown

    "a rootview is always assumed to be visible"

    ^ true

    "Created: 5.7.1996 / 13:48:05 / cg"

    "Modified: 5.7.1996 / 14:57:34 / cg"

! !

!DisplayRootView class methodsFor:'documentation'!

version

! !

DisplayRootView initialize!