"

 COPYRIGHT (c) 1992 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.

"

GraphicsMedium subclass:#DisplaySurface

	instanceVariableNames:'viewBackground cursor eventMask middleButtonMenu keyCommands

		gotExpose exposePending backed saveUnder delegate'

	classVariableNames:''

	poolDictionaries:''

	category:'Graphics-Support'

!

!DisplaySurface  class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1992 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 abstract class describes stuff common to any Window on a display 

    device. i.e. RootWindow, TopWindows, PopUps and Subwindows.

    That is, they have a viewBackground, cursor etc. and especially events.

    A special feature is the delegate field, which allows key- and button 

    events to be stolen from a view. 

    If the delegate is non-nil, these events will be sent to it instead.

    So you can change a views behavior even if it was not initially designed 

    for it. Also, controller functionality could be simulated using delegates.

    [instance variables:]

        viewBackground  <Color|Form|Image>      the views background

        cursor          <Cursor>                the cursor

        eventMask                               mask specifying the enabled

                                                events.

        middleButtonMenu                        a popup menu for the middle

                                                button.

        keyCommands                             not yet supported

        gotExpose                               for exposure handling after

        exposePending                           after a scroll

        backed                                  true if backing store for that

                                                view is enabled

        saveUnder                               true if saveunder store for 

                                                that view is enabled

        delegate                                for event delegation

    [see also:]

        DeviceWorkstation

        WindowGroup

        StandardSYstemView SimpleView View

    [author:]

        Claus Gittinger

"

! !

!DisplaySurface methodsFor:'accessing'!

depth

    "return the depth in pixels of the view.

     Notice, that this is currently the devices depth, 

     but support for mixed depth views is being prepared.

     (especially useful on SGI, with 24bit view)"

    ^ device depth

!

insideColor:aColor

    "set the views background color - ST-80 compatibility"

    self viewBackground:aColor.

    self background:aColor

!

setViewBackground

    "install the viewBackground for the receiver on the device"

    |id devBgPixmap bgPixmap w h colors|

    drawableId notNil ifTrue:[

	viewBackground isColor ifTrue:[

	    viewBackground := viewBackground on:device.

	    id := viewBackground colorId.

	    "

	     a real color (i.e. one supported by the device) ?

	    "

	    id notNil ifTrue:[

		device setWindowBackground:id in:drawableId.

		^ self

	    ].

	    "

	     no, a dithered one - must have a dither-pattern

	     (which is ready for the device, since viewBackground

	      is already assigned to the device)

	    "

	    bgPixmap := viewBackground ditherForm.

	] ifFalse:[

	    "

	     assume, it can convert itself to a form

	    "

	    bgPixmap := viewBackground asFormOn:device

	].

	"

	 must now have:

	 a dithered color or bitmap or pixmap

	"

	bgPixmap isNil ifTrue:[

	    'PSEUDOVIEW: background not convertable - ignored' errorPrintNL.

	    ^ self

	].

	w := bgPixmap width.

	h := bgPixmap height.

	(bgPixmap depth ~~ device depth) ifTrue:[

	    (bgPixmap depth ~~ 1) ifTrue:[

		self error:'bad dither depth'.

		^ self

	    ].

	    "

	     convert it into a deep form

	    "

	    colors := bgPixmap colorMap.

	    devBgPixmap := Form width:w height:h depth:(device depth) on:device.

	    devBgPixmap paint:(colors at:1).

	    devBgPixmap fillRectangleX:0 y:0 width:w height:h.

	    devBgPixmap foreground:(colors at:2) background:(colors at:1).

	    devBgPixmap copyPlaneFrom:bgPixmap x:0 y:0 toX:0 y:0 width:w height:h.

	    bgPixmap := devBgPixmap.

	] ifFalse:[

	    (bgPixmap depth == 1) ifTrue:[

		"

		 although depth matches,

		 values in the dither are to be interpreted via the ditherForms

		 colormap, which is not always the same as blackpixel/whitepixel ...

		"

		(bgPixmap colorMap at:1) colorId == device whitepixel ifTrue:[

		    (bgPixmap colorMap at:2) colorId == device blackpixel ifTrue:[

			"

			 ok, can use it

			"

			device setWindowBackgroundPixmap:(bgPixmap id) in:drawableId.

			^ self

		    ]

		].

		"

		 no, must invert it

		"

		devBgPixmap := Form width:w height:h depth:(device depth) on:device.

		devBgPixmap paint:(bgPixmap colorMap at:2) on:(bgPixmap colorMap at:1).

		devBgPixmap copyPlaneFrom:bgPixmap x:0 y:0 toX:0 y:0 width:w height:h.

		bgPixmap := devBgPixmap.

	    ]

	].

	device setWindowBackgroundPixmap:(bgPixmap id) in:drawableId.

    ]

!

viewBackground

    "return the viewBackground"

    ^ viewBackground

!

viewBackground:something

    "set the viewBackground to something, a color, image or form.

     The viewBackground is the color or pattern with which exposed

     regions are filled - do not confuse this with the drawing background

     color, which is used with opaque drawing."

    viewBackground ~~ something ifTrue:[

	viewBackground := something.

	drawableId notNil ifTrue:[

	    self setViewBackground

	]

    ]

!

viewBackgroundAndClear:something

    "set the viewBackground to something, a color, image or form.

     and clear the View.

     The viewBackground is the color or pattern with which exposed

     regions are filled - do not confuse this with the drawing background

     color, which is used with opaque drawing."

    self viewBackground:something.

    self clear.

    "Created: 27.4.1996 / 14:09:08 / cg"

!

viewGravity

    "return the views gravity"

    ^ #NorthWest

!

viewOrigin

    "0@0 here, since by default we cannot be scrolled"

    ^ 0 @ 0

!

widget

    "ST-80 compatibility"

    ^ self

! !

!DisplaySurface methodsFor:'accessing-cursor'!

cursor

    "return the views cursor"

    ^ cursor

!

cursor:aCursor

    "set the views cursor. This cursor will be automatically displayed whenever 

     the mouse-pointer enters the receiver. 

     Cursors are typically set at view creation time and left as installed."

    self cursor:aCursor now:true

    "

     |v|

     v := View new.

     v cursor:(Cursor wait).

     v open.

     [v shown] whileFalse:[Processor yield].

     [v shown] whileTrue:[   

	(Delay forSeconds:1) wait.

	v cursor:(Cursor normal).

	(Delay forSeconds:1) wait.

	v cursor:(Cursor wait).

     ]

    "

    "Modified: 14.12.1995 / 21:28:14 / cg"

!

cursor:aCursor now:showImmediately

    "set the views cursor. This cursor will be automatically displayed whenever 

     the mouse-pointer enters the receiver. 

     Cursors are typically set at view creation time and left as installed."

    |id|

    aCursor notNil ifTrue:[

	(aCursor ~~ cursor) ifTrue:[

	    cursor := aCursor.

	    drawableId notNil ifTrue:[

		cursor := cursor on:device.

		cursor isNil ifTrue:[ ^ self].

		id := cursor id.

		id isNil ifTrue:[

		    'PSEUDOVIEW: nil cursorId ignored; shape=' errorPrint. cursor shape errorPrintNL.

		    ^ self

		].

		device setCursor:id in:drawableId.

		(showImmediately and:[realized]) ifTrue:[

		    "flush, to make cursor immediately visible"

		    device flush

		]

	    ]

	]

    ]

    "

     |v|

     v := View new.

     v cursor:(Cursor wait).

     v open.

     [v shown] whileFalse:[Processor yield].

     [v shown] whileTrue:[   

	(Delay forSeconds:1) wait.

	v cursor:(Cursor normal).

	(Delay forSeconds:1) wait.

	v cursor:(Cursor wait).

     ]

    "

    "Created: 14.12.1995 / 21:28:00 / cg"

!

withCursor:aCursor do:aBlock

    "evaluate aBlock showing aCursor until ready; then restore the old cursor

     and return the value as returned by aBlock.

     Notice, that this method only changes the cursor for a SINGLE (sub-)view.

     Most applications want to have the cursor changed in all views of its

     application. Use 'aView windowGroup withCursor:do:' to acomplish this."

    |savedCursor|

    savedCursor := cursor.

    self cursor:aCursor.

    ^ aBlock valueNowOrOnUnwindDo:[self cursor:savedCursor]

!

withExecuteCursorDo:aBlock

    "evaluate aBlock while showing an execute cursor in all my views.

     Return the value as returned by aBlock."

    ^ self withCursor:(Cursor execute) do:aBlock

    "Created: 10.1.1996 / 13:53:03 / cg"

!

withReadCursorDo:aBlock

    "evaluate aBlock while showing a readCursor in all my views.

     Return the value as returned by aBlock."

    ^ self withCursor:(Cursor read) do:aBlock

    "Modified: 14.12.1995 / 20:57:40 / cg"

    "Created: 10.1.1996 / 13:52:52 / cg"

!

withWaitCursorDo:aBlock

    "evaluate aBlock while showing a waitCursor in all my views.

     Return the value as returned by aBlock."

    ^ self withCursor:(Cursor wait) do:aBlock

    "Created: 10.1.1996 / 13:51:08 / cg"

! !

!DisplaySurface methodsFor:'accessing-hierarchy'!

delegate

    "return the delegate - thats the one getting keyboard and button events"

    ^ delegate

!

delegate:someOne

    "set the delegate - keyboard- and button events will be forwarded to

     that object if it is interested in them.

     See the sendEvent... method in WindowEvent."

    delegate := someOne

!

superView

    "return the superView - nil here"

    ^ nil

!

topComponent

    "return the topView - that the one with no superview"

    ^ self

    "Created: 9.5.1996 / 01:39:43 / cg"

!

topView

    "return the topView - that the one with no superview"

    ^ self

! !

!DisplaySurface methodsFor:'accessing-limits'!

maxExtent

    "return the views maximum extent - this is nil here.

     Only standardSystemViews support this."

    ^ nil

!

maxExtent:extent

    "set the views maximum extent - ignored here.

     Only standardSystemViews support this."

    ^ self

!

minExtent

    "return the views minimum extent - this is nil here.

     Only standardSystemViews support this."

    ^ nil

!

minExtent:extent

    "set the views minimum extent - ignored here.

     Only standardSystemViews support this."

    ^ self

! !

!DisplaySurface methodsFor:'accessing-misc'!

backingStore:how

    "turn on/off backingStore (saving my pixels)

     how may true/false, but also #always, #whenMapped or #never."

    how ~~ backed ifTrue:[

	backed := how.

	drawableId notNil ifTrue:[

	    device setBackingStore:how in:drawableId

	]

    ]

!

clipByChildren

    "drawing shall be done into my view only (default)"

    ^ self clippedByChildren:true

!

clippedByChildren:aBoolean

    "turn on/off drawing over children.

     If on, a superview may draw 'over' its children.

     If off (the default), drawing is 'under' its children.

     Only useful for the rootView, to draw over any visible views.

     (for example, when dragging a rubber-line)"

    gcId isNil ifTrue:[

	self initGC

    ].

    device setClipByChildren:aBoolean in:gcId

!

eventMask

    "return a (numeric) mask of allowed events -

     this is X-specific and will be removed / replaced by symbolic values)"

    ^ eventMask

!

eventMask:aMask

    "set a (numeric) mask of allowed events -

     this is X-specific and will be removed / replaced by symbolic values)"

    eventMask := aMask

!

getKeyboardFocus

    "tell the Display to assign keyboard focus to the receiver"

    drawableId notNil ifTrue:[

	self shown ifTrue:[

	    device setInputFocusTo:drawableId

	]

    ].

!

isInputOnly

    "return true, if the receiver is an input only view - that is: 

     the view will realize as a transparent view, into which you cannot

     draw, but get events as usual. Thich can be used to catch events away from 

     others, which where never meant to work in such a setup.

     (for example, if you want to manipulate views in some DrawTool-like manner).

     This uses a special X feature, which might not be supported in the near future

     or on other plattforms."

    ^ false

    "Created: 1.6.1996 / 13:21:51 / cg"

!

noClipByChildren

    "drawing shall also be done into subviews"

    ^ self clippedByChildren:false 

!

preferredDepth

    "return a non nil integer, if a specific depth is wanted in this view.

     Return nil if we do not care (i.e. the displays default is wanted).

     This is experimental and may change/vanish - do not use it."

    ^ nil

!

preferredVisual

    "return a non nil id, if a specific visual is wanted in this view.

     Return nil if we do not care (i.e. the displays default is wanted). 

     This is experimental and may change/vanish - do not use it."

    ^ nil

!

saveUnder:aBoolean

    "turn on/off saveUnder (saving pixels under myself)

     - used for temporary views (i.e. PopUps and ModalBoxes)"

    saveUnder := aBoolean.

    drawableId notNil ifTrue:[

	device setSaveUnder:aBoolean in:drawableId

    ]

! !