"

 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.

"

"{ Package: 'stx:libview' }"

"{ NameSpace: Smalltalk }"

GraphicsContext subclass:#DeviceGraphicsContext

	instanceVariableNames:'drawableId gcId deviceFont foreground background drawableType

		parentId'

	classVariableNames:'CachedScaledForms CachedScales'

	poolDictionaries:''

	category:'Graphics-Support'

!

DeviceHandle subclass:#DevicePixmapGCHandle

	instanceVariableNames:''

	classVariableNames:''

	poolDictionaries:''

	privateIn:DeviceGraphicsContext

!

DeviceHandle subclass:#DeviceWindowGCHandle

	instanceVariableNames:'parentId'

	classVariableNames:''

	poolDictionaries:''

	privateIn:DeviceGraphicsContext

!

!DeviceGraphicsContext 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

"

    I provide the common protocol for a graphicsContext which is associated with a particular

    device (i.e. Bitmaps, Pixmaps, RootWindow and Windows in Xs world, but also postscript

    printer pages or fax pages).

    My instance variables are mainly caching device-related stuff (such as font- and color-Ids)

    to avoid needless message traffic. 

    All real work is done by my device, which is accessed via the device instance variable.

    Most drawing requests are simply forwarded to it, others are simulated by using more basic

    drawing functions (see GraphicsContext drawing vs. basic drawing category).

    The added variables foreground/background are the drawing colors actually

    used; these are the real (i.e. non dithered) colors supported by the device.

    Direct access to fg/bg is discouraged, since in the future, these may be

    totally replaced by paint/bgPaint

    (there are some operations and special cases, for which a direct access to

     fg/bg makes sense)

    [Instance variables:]

        drawableId      <SmallInteger>  my drawableId on the device (a device handle)

        gcId            <SmallInteger>  my gc's ID on the device (a device handle)

        deviceFont      <Font>          the actual font, currently set in the device

        foreground      <Color>         the device foreground color used for drawing

        background      <Color>         the device background color used for drawing

    [see also:]

        DeviceWorkstation

        Color Font Cursor

    [author:]

        Claus Gittinger

"

! !

!DeviceGraphicsContext class methodsFor:'instance creation'!

new

    "create a new drawable - take the current display as

     its device (for now, this may be changed until the view is

     physically created)"

"

    'Warning: DeviceGraphicsContext (' print. self name print. ') should not be created with new' printNL.

"

    |device|

    device := Screen current.

    device isNil ifTrue:[

        device := Display.

        device isNil ifTrue:[

            (self class name,' [warning]: no Display') infoPrintCR.

            Smalltalk lateOpenDisplay.

            device := Screen current ? Display.

            device isNil ifTrue:[ self error:'no screen device' ]

        ].

    ].

    ^ self onDevice:device

!

on:aDevice

    "create a new drawable on aDevice"

    <resource:#obsolete>

    "/ send out a warning: #on: is typically used to create a view

    "/ operating on a model.

    "/ Please use #onDevice: to avoid confusion.

    self obsoleteMethodWarning:'use #onDevice:'.

    ^ self onDevice:aDevice

    "Modified: 5.6.1997 / 21:04:16 / cg"

!

onDevice:aDevice

    "create a new drawable on aDevice"

    |newDrawable|

    newDrawable := self basicNew.

    "

     set display before its initialized

     - so it can do something useful (i.e. get font sizes etc.) in its

     intitialize method(s)

    "

    newDrawable device:aDevice.

    newDrawable initialize.

    ^ newDrawable

    "Modified: 2.4.1997 / 19:19:35 / cg"

! !

!DeviceGraphicsContext class methodsFor:'cleanup'!

lowSpaceCleanup

    CachedScaledForms := CachedScales := nil

! !

!DeviceGraphicsContext methodsFor:'accessing'!

at:aPoint

    "return the pixel at the coordinate given by aPoint"

    ^ self atX:aPoint x y:aPoint y

    "Modified: / 29.1.2000 / 12:17:42 / cg"

!

at:aPoint put:aPixelColor

    "set a pixel"

    ^ self atX:aPoint x y:aPoint y put:aPixelColor

    "

     Display rootView at:(0@0) put:(Color red).

     Display rootView at:(1@1) put:(Color red).

     Display rootView at:(2@2) put:(Color red).

     Display rootView at:(3@3) put:(Color red).

     Display rootView at:(4@4) put:(Color red).

     Display rootView at:(5@5) put:(Color red).

    "

!

atX:x y:y

    "return the pixel at the coordinate given by x/y"

    ^ device getPixelX:x y:y from:drawableId with:gcId

    "Modified: / 22.5.1999 / 01:40:23 / cg"

!

atX:x y:y put:aPixelColor

    "set a pixel"

    |oldFg|

    oldFg := foreground.

    self foreground:aPixelColor.

    self displayPointX:x y:y.

    self foreground:oldFg

!

backgroundPaint:aColor

    "set the background-paint color; this is used in opaque-draw

     operations"

    (aColor ~~ bgPaint) ifTrue:[

	aColor notNil ifTrue:[

	    bgPaint := aColor.

	    gcId notNil ifTrue:[

		bgPaint isColor ifTrue:[

		    bgPaint := aColor onDevice:device.

		    bgPaint colorId notNil ifTrue:[

			background := bgPaint.

			gcId notNil ifTrue:[

			    device setBackground:(bgPaint colorId) in:gcId.

			].

			^ self

		    ]

		].

		self paint:paint on:aColor

	    ]

	]

    ].

!

basicFont:aFont

    "compatibility with GraphicsMedium"

    self font:aFont.

!

capStyle:aSymbol

    "set the style in which the endpoints of lines

     are drawn - aSymbol may be #notLast, #butt, #round, #projecting"

    |s|

    (s := aSymbol) isNil ifTrue:[

	s := #butt.

    ].

    (s ~~ capStyle) ifTrue:[

	capStyle := s.

	gcId notNil ifTrue:[

	    device setLineWidth:lineWidth

			  style:lineStyle

			    cap:s

			   join:joinStyle

			     in:gcId

	]

    ]

    "Modified: 12.5.1996 / 22:23:03 / cg"

!

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 noClipIn:drawableId gc:gcId.

    device setClipByChildren:aBoolean in:drawableId gc:gcId.

    "Created: 17.7.1996 / 13:25:16 / cg"

    "Modified: 29.4.1997 / 15:33:55 / dq"

!

clippingBounds:aRectangleOrNil

    "set the clipping rectangle for drawing (in logical coordinates);

     a nil argument turn off clipping (i.e. whole view is drawable)"

    |x y w h newBounds|

    aRectangleOrNil isNil ifTrue:[

	clipRect isNil ifTrue:[^ self].

	gcId notNil ifTrue:[

	    device noClipIn:drawableId gc:gcId

	].

	clipRect := nil.

	^ self.

    ].

    x := aRectangleOrNil left.

    y := aRectangleOrNil top.

    w := aRectangleOrNil width.

    h := aRectangleOrNil height.

    transformation notNil ifTrue:[

	x := transformation applyToX:x.

	y := transformation applyToY:y.

	w := transformation applyScaleX:w.

	h := transformation applyScaleY:h.

    ].

    (x class == SmallInteger) ifFalse:[

	w := w + (x - x truncated).

	x := x truncated

    ].

    (y class == SmallInteger) ifFalse:[

	h := h + (y - y truncated).

	y := y truncated

    ].

    (w class == SmallInteger) ifFalse:[

	w := w truncated + 1

    ].

    (h class == SmallInteger) ifFalse:[

	h := h truncated + 1

    ].

    w := w max:0.

    h := h max:0.

    newBounds := Rectangle left:x top:y width:w height:h.

    (clipRect notNil and:[clipRect = newBounds]) ifTrue:[

	^ self

    ].

    clipRect := newBounds.

    gcId notNil ifTrue:[

	device setClipX:x y:y width:w height:h in:drawableId gc:gcId.

    ].

    "Created: / 28.5.1996 / 19:40:20 / cg"

    "Modified: / 16.5.1999 / 19:40:37 / cg"

!

colorAt:aPoint

    "return the color of the pixel at the coordinate given by x@y"

    ^ self colorAtX:(aPoint x) y:(aPoint y)

    "Modified: 1.8.1997 / 20:01:58 / cg"

!

colorAtX:x y:y

    "return the color of the pixel at the coordinate given by aPoint"

    |pixel|

    pixel := self atX:x y:y.

    device getScaledRGBFrom:pixel into:[:r :g :b |

	^ Color scaledRed:r scaledGreen:g scaledBlue:b

    ].

    "Created: 1.8.1997 / 20:01:32 / cg"

!

container

    "return my container - for protocol compatibility"

    ^ nil

!

dashStyle:aDashList offset:dashOffset

    "define dashes. Each element of the dashList specifies the length

     of a corresponding dash. For example, setting it to [4 4]

     defines 4on-4off dashing;

     Setting it to [1 2 4 2] defines 1on-2off-4on-2off dashes.

     The dashOffset specifies where in the dashList the dashing starts.

     This may not be supported by all graphics devices."

    gcId notNil ifTrue:[

	device setDashes:(ByteArray withAll:aDashList)

	      dashOffset:dashOffset

		      in:gcId

    ]

    "Modified: 4.6.1996 / 19:03:06 / cg"

!

device

    "return the device, the receiver is associated with"

    ^ device

!

device:aDevice

    "set the device"

    device == aDevice ifTrue:[

        ^ self.

    ].

    device notNil ifTrue:[

        "change of device of an already existing GraphicsContext"

        drawableId notNil ifTrue:[

            device unregisterGraphicsContext:self.

        ].

        device := aDevice.

        self recreate.

        ^ self.

    ].

    "set device of a new GraphicsContext"

    device := aDevice

!

deviceClippingBounds:aRectangleOrNil

    "set the clipping rectangle for drawing (in device coordinates);

     a nil argument turns off clipping (i.e. whole view is drawable - incl. margins)"

    clipRect = aRectangleOrNil ifTrue:[

	^ self

    ].

    clipRect := aRectangleOrNil.

    gcId isNil ifTrue:[

	^ self.

    ].

    aRectangleOrNil isNil ifTrue:[

	device noClipIn:drawableId gc:gcId

    ] ifFalse:[

	device setClipX:aRectangleOrNil left

		    y:aRectangleOrNil top

		    width:aRectangleOrNil width

		    height:aRectangleOrNil height

		    in:drawableId

		    gc:gcId

    ].

    "Modified: / 22.5.1996 / 13:12:07 / cg"

    "Created: / 14.9.1998 / 18:50:31 / cg"

!

deviceClippingBoundsOrNil

    "get the clipping rectangle for drawing (in device coordinates);

     a nil clipping rectangle means: no clipping (i.e. whole view is drawable - incl. margins)"

    ^ clipRect

!

deviceFont

    "return the font for drawing - here, a device font is returned if

     the GC is realized."

    (device notNil and:[font notNil]) ifTrue:[

        font := font onDevice:device

    ].

    ^ font

!

drawableId

    "return the id of the drawable on the device"

    ^ drawableId

!

font

    "return the font for drawing - here, a device font is returned if

     the GC is realized."

    (device notNil and:[font notNil]) ifTrue:[

	font := font onDevice:device

    ].

    ^ font

!

font:aFont

    "set the font for drawing if it has changed.

     This is a low level entry, which is not to be redefined

     (i.e. it must not imply a redraw operation)"

    |id|

    (aFont notNil and:[aFont ~~ font]) ifTrue:[

        font := aFont.

        device notNil ifTrue:[

            font := font onDevice:device.

            gcId notNil ifTrue:[

                id := font fontId.

                id notNil ifTrue:[

                    deviceFont := font.

                    device setFont:id in:gcId

                ]

            ]

        ]

    ]

    "Created: / 23-02-1996 / 17:16:51 / cg"

    "Modified: / 22-10-2006 / 14:11:37 / cg"

!

function:aSymbol

    "set the drawing function if it has changed"

    (aSymbol ~~ function) ifTrue:[

	function := aSymbol.

	gcId notNil ifTrue:[

	    device setFunction:aSymbol in:gcId

	]

    ]

!