"

 COPYRIGHT (c) 1989 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.

"

SimpleView subclass:#ScrollBar

	instanceVariableNames:'thumb button1 button2 buttonLayout elementSpacing'

	classVariableNames:'DefaultButtonPositions DefaultLevel DefaultElementSpacing

		DefaultScrollerBordered'

	poolDictionaries:''

	category:'Views-Interactors'

!

!ScrollBar class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1989 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 implements vertical scrollbars with scroller and

    2 step-scroll buttons. when moved or stepped, it performs a

    predefined action.

    The action is specified by:                 the block to be evaluated for step-up

        aScrollBar scrollUpAction:aBlock 

        (scrollLeftAction for hor-Scrollbars)

        aScrollBar scrollDownAction:aBlock      the block to be evaluated for step-down

        (scrollRightAction for hor-Scrollbars)

        aScrollbar scrollAction:aBlock          the block to be evaluated for scroll

                                                passing percentage as argument.

    Scrollbars can scroll syncronous (i.e. every movement is notified immediately via the

    scrollAction) or asynchronous (i.e. only one notification takes place at the end of the movement).

    The choice is up to the user of the scrollbar (typically, views which are complicated to redraw,

    will set it to asynchronous.)

    Most often scrollbars are used hidden with ScrollableView or HVScrollableView (i.e. you

    dont have to care for all the details).

    The scrollBars and scrollers protocols have been made similar enough to

    allow transparent use of either a scroller or a scrollBar in applications.

    [author:]

        Claus Gittinger

    [see also:]

        Scroller Slider

        ScrollableView

"

! !

!ScrollBar class methodsFor:'style changes'!

updateStyleCache

    "extract values from the styleSheet and cache them in class variables"

    <resource: #style (#scrollBarButtonPositions #scrollBarLevel

		       #scrollBarScrollerBordered #scrollBarElementSpacing)>

    DefaultButtonPositions := StyleSheet at:'scrollBarButtonPositions' default:#bottom.

    DefaultLevel := StyleSheet at:'scrollBarLevel'.

    DefaultScrollerBordered := StyleSheet at:'scrollBarScrollerBordered' default:false.

    DefaultElementSpacing := StyleSheet at:'scrollBarElementSpacing' 

					default:(StyleSheet is3D ifTrue:[1] ifFalse:[0]).

    "Modified: 1.3.1996 / 13:46:29 / cg"

! !

!ScrollBar methodsFor:'accessing'!

thumbHeight

    "return height of thumb in percent"

    ^ thumb thumbHeight

!

thumbHeight:newHeight

    "set height of thumb in percent"

    thumb thumbHeight:newHeight.

    self enableDisableButtons

!

thumbOrigin

    "return position of (top of) thumb in percent"

    ^ thumb thumbOrigin

!

thumbOrigin:newOrigin

    "set position of (top of) thumb in percent"

    thumb thumbOrigin:newOrigin.

    self enableDisableButtons

!

thumbOrigin:newOrigin thumbHeight:newHeight

    "set origin and height of thumb (both in percent)"

    thumb thumbOrigin:newOrigin thumbHeight:newHeight.

    self enableDisableButtons

! !

!ScrollBar methodsFor:'accessing-behavior'!

asynchronousOperation

    "set asynchronous-mode - scroll action is performed after movement

     of scroller (i.e. when mouse-button is finally released).

     This is forwarded to the scroller here."

    thumb asynchronousOperation

!

scrollAction:aBlock

    "set the action, aBlock to be performed when the scroller is moved.

     This is forwarded to the scroller here."

    thumb scrollAction:aBlock

!

scrollDownAction

    "return the action which is performed on scroll-down.

     (vertical scrollBars)"

    ^ button2 action

    "Created: 28.5.1997 / 15:52:39 / cg"

    "Modified: 28.5.1997 / 15:53:56 / cg"

!

scrollDownAction:aBlock

    "set the action, aBlock to be performed when the down-button is pressed.

     (for vertical scrollBars)"

    button2 action:aBlock

    "Modified: 28.5.1997 / 15:51:39 / cg"

!

scrollLeftAction

    "return the action which is performed on scroll-left

     (for horizontal scrollBars)"

    ^ button1 action

    "Created: 28.5.1997 / 15:51:22 / cg"

!

scrollLeftAction:aBlock

    "set the action to be performed on scroll-left.

     (for horizontal scrollBars)"

    button1 action:aBlock

    "Created: 28.5.1997 / 15:52:55 / cg"

!

scrollRightAction

    "return the action which is performed on scroll-right.

     (for horizontal scrollBars)"

    ^ button2 action

    "Created: 28.5.1997 / 15:53:15 / cg"

!

scrollRightAction:aBlock

    "set the action  to be performed on scroll-right.

     (for horizontal scrollBars)"

    button2 action:aBlock

    "Created: 28.5.1997 / 15:53:30 / cg"

!

scrollUpAction

    "return the action which is performed on scroll-up.

     (for vertical scrollBars)"

    ^ button1 action

    "Created: 28.5.1997 / 15:53:51 / cg"

!

scrollUpAction:aBlock

    "set the action, aBlock to be performed when the up-button is pressed.

     (for vertical scrollBars)"

    button1 action:aBlock

    "Modified: 28.5.1997 / 15:51:33 / cg"

!

synchronousOperation

    "set synchronous-mode - scroll action is performed for every movement

     of scroller.

     This is forwarded to the scroller here."

    thumb synchronousOperation

! !

!ScrollBar methodsFor:'accessing-components'!

downButton

    "return the down-button

     (Please: only use this direct access for special applications)"

    ^ button2

    "

     |v|

     v := ScrollableView for:EditTextView.

     v scrolledView contents:('/etc/passwd' asFilename contentsOfEntireFile).

     v scrollBar upButton activeForegroundColor:Color red.

     v scrollBar downButton activeForegroundColor:Color red.

     v open

    "

!

thumb 

    "return the thumb (i.e. the scroller subview)

     (Please: only use this direct access for special applications)"

    ^ thumb

    "

     |v|

     v := ScrollableView for:EditTextView.

     v scrolledView contents:('/etc/passwd' asFilename contentsOfEntireFile).

     v scrollBar thumb thumbColor:(Color red).

     v open

    "

    "Modified: 1.3.1996 / 19:15:50 / cg"

!

upButton

    "return the up-button

     (Please: only use this direct access for special applications)"

    ^ button1

    "

     |v|

     v := ScrollableView for:EditTextView.

     v scrolledView contents:('/etc/passwd' asFilename contentsOfEntireFile).

     v scrollBar upButton foregroundColor:(Color red).

     v scrollBar upButton enteredForegroundColor:(Color red lightened).

     v scrollBar downButton foregroundColor:(Color green).

     v scrollBar downButton enteredForegroundColor:(Color green lightened).

     v open

    "

! !

!ScrollBar methodsFor:'accessing-look'!

thumbColor:aColor

    "set the thumbs color"

    thumb thumbColor:aColor

!

upButtonLabel:label1 downButtonLabel:label2

    "set the labels shown in the buttons.

     Because of the fixed button sizes, this only makes sense with 

     single-character strings or small bitmaps."

    button1 label:label1.

    button2 label:label2.

    self setElementPositions.

    "not bad:

     |v|

     v := ScrollableView for:EditTextView.

     v scrolledView contents:('/etc/passwd' asFilename contentsOfEntireFile).

     v scrollBar upButtonLabel:'+' downButtonLabel:'-'.

     v open

    "

    "also possible :

     |v|

     v := ScrollableView for:EditTextView.

     v scrolledView contents:('/etc/passwd' asFilename contentsOfEntireFile).

     v scrollBar upButtonLabel:'u' downButtonLabel:'d'.

     v open

    "

    "BAD example:

     |v|

     v := ScrollableView for:EditTextView.

     v scrolledView contents:('/etc/passwd' asFilename contentsOfEntireFile).

     v scrollBar upButtonLabel:'up' downButtonLabel:'down'.

     v open

    "

    "Modified: 1.3.1996 / 19:06:50 / cg"

! !

!ScrollBar methodsFor:'change & update'!

update:something with:aParameter from:changedObject

    changedObject == thumb ifTrue:[

	self enableDisableButtons

    ]

! !

!ScrollBar methodsFor:'events'!

keyPress:key x:x y:y

    <resource: #keyboard (#BeginOfText #EndOfText)>

    (key == #BeginOfText) ifTrue:[

        self scrollToBeginning.

        ^ self

    ].

    (key == #EndOfText) ifTrue:[

        self scrollToEnd.

        ^ self

    ].

    super keyPress:key x:x y:y

    "Created: 6.3.1996 / 17:58:02 / cg"

    "Modified: 7.3.1996 / 13:18:19 / cg"

!

sizeChanged:how

    "when my size changes, I have to resize/reposition the subviews.

     Also, if I became too small, hide thumb/buttons."

    |upHeight downHeight thumbHeight upAndDownHeight bwn sep2

    button1 isNil ifTrue:[^ self].

    thumb isNil ifTrue:[^ self].

    button2 isNil ifTrue:[^ self].

    style := styleSheet name.

    bwn := borderWidth negated + margin.