"
 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.
"

PanelView subclass:#VerticalPanelView
       instanceVariableNames:''
       classVariableNames:''
       poolDictionaries:''
       category:'Views-Layout'
!

VerticalPanelView comment:'
COPYRIGHT (c) 1989 by Claus Gittinger
	      All Rights Reserved

$Header: /cvs/stx/stx/libwidg/VerticalPanelView.st,v 1.7 1994-11-21 16:45:46 claus Exp $
'!

!VerticalPanelView 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.
"
!

version
"
$Header: /cvs/stx/stx/libwidg/VerticalPanelView.st,v 1.7 1994-11-21 16:45:46 claus Exp $
"
!

documentation
"
    a View which arranges its child-views in a vertical column.
    All real work is done in PanelView - except the layout computation is
    redefined here.

    The layout is controlled by two instance variables. 
    The vertical layout can be any of:

	#top            arrange elements at the top
	#topSpace       arrange elements at the top, start with spacing
	#bottom         arrange elements at the bottom
	#bottomSpace    arrange elements at the bottom, start with spacing
	#center         arrange elements in the center
	#spread         spread elements evenly
	#fit            like spread, but resize elements for tight packing

    the horizontal layout can be:

	#left           place element at the left
	#leftSpace      place element at the left, offset by horizontalSpace
	#center         place it horizontally centered
	#right          place it at the right
	#rightSpace     place it at the right, offset by horizontalSpace
	#fit            resize elements horizontally to fit this panel

    The defaults is #centered for both directions.
    The layout is changed by the messages #verticalLayout: and #horizontalLayout:.
    For backward compatibility (to times, where only vLayout existed), the simple
    #layout: does the same as #verticalLayout:. Do not use this old method.
"
!

examples
"
    example: default layout (centered)

	|v p b1 b2 b3|

	v := StandardSystemView new.
	p := VerticalPanelView in:v.
	p origin:(0.0 @ 0.0) corner:(1.0 @ 1.0).
	b1 := Button label:'button1' in:p.
	b2 := Button label:'button2' in:p.
	b3 := Button label:'button3' in:p.
	v extent:100 @ 300.
	v open


    example: top-layout

	|v p b1 b2 b3|

	v := StandardSystemView new.
	p := VerticalPanelView in:v.
	p verticalLayout:#top.
	p origin:(0.0 @ 0.0) corner:(1.0 @ 1.0).
	b1 := Button label:'button1' in:p.
	b2 := Button label:'button2' in:p.
	b3 := Button label:'button3' in:p.
	v extent:100 @ 300.
	v open


    example: bottom-layout

	|v p b1 b2 b3|

	v := StandardSystemView new.
	p := VerticalPanelView in:v.
	p verticalLayout:#bottom.
	p origin:(0.0 @ 0.0) corner:(1.0 @ 1.0).
	b1 := Button label:'button1' in:p.
	b2 := Button label:'button2' in:p.
	b3 := Button label:'button3' in:p.
	v extent:100 @ 300.
	v open


    example: spread-layout

	|v p b1 b2 b3|

	v := StandardSystemView new.
	p := VerticalPanelView in:v.
	p verticalLayout:#spread.
	p origin:(0.0 @ 0.0) corner:(1.0 @ 1.0).
	b1 := Button label:'button1' in:p.
	b2 := Button label:'button2' in:p.
	b3 := Button label:'button3' in:p.
	v extent:100 @ 300.
	v open

    example: from top, each at left:

	|v p b1 b2 b3|

	v := StandardSystemView new.
	p := VerticalPanelView in:v.
	p verticalLayout:#top.
	p horizontalLayout:#left.
	p origin:(0.0 @ 0.0) corner:(1.0 @ 1.0).
	b1 := Button label:'button1' in:p.
	b2 := Button label:'button2' in:p.
	b3 := Button label:'button3' in:p.
	v extent:100 @ 300.
	v open

    example: centered, right:

	|v p b1 b2 b3|

	v := StandardSystemView new.
	p := VerticalPanelView in:v.
	p verticalLayout:#centered.
	p horizontalLayout:#right.
	p origin:(0.0 @ 0.0) corner:(1.0 @ 1.0).
	b1 := Button label:'button1' in:p.
	b2 := Button label:'button2' in:p.
	b3 := Button label:'button3' in:p.
	v extent:100 @ 300.
	v open

    you should try more examples, combining spacing and different
    verticalLayout:/horizontalLayout: combinations.
"
! !

!VerticalPanelView methodsFor:'accessing'!

horizontalLayout
    "return the horizontal layout as symbol.
     the returned value is one of
	#left 
	#leftSpace 
	#center
	#right 
	#rightSpace 
	#fit 
      the default is #centered
    "

    ^ hLayout
!

verticalLayout
    "return the vertical layout as a symbol.
     the returned value is one of
	#top
	#topSpace
	#spread
	#fit
	#center
	#bottom
	#bottomSpace
      the default is #centered
    "

    ^ vLayout
!

horizontalLayout:aSymbol
    "change the horizontal layout as symbol.
     The argument, aSymbol must be one of:
	#left 
	#leftSpace 
	#center
	#right 
	#rightSpace 
	#fit 
      the default (if never changed) is #centered
    "

    (hLayout ~~ aSymbol) ifTrue:[
	hLayout := aSymbol.
	self layoutChanged
    ]
!

verticalLayout:aSymbol
    "change the vertical layout as a symbol.
     The argument, aSymbol must be one of:
	#top
	#topSpace
	#spread
	#fit
	#center
	#bottom
	#bottomSpace
      the default (if never changed) is #centered
    "

    (vLayout ~~ aSymbol) ifTrue:[
	vLayout := aSymbol.
	self layoutChanged
    ]
!

layout
    "leftover for historic reasons - do not use any more"

    self verticalLayout
!

layout:aSymbol
    "leftover for historic reasons - do not use any more"

    self verticalLayout:aSymbol
! !


!VerticalPanelView methodsFor:'queries'!

preferedExtent
    "return a good extent, one that makes subviews fit"

    |sumOfHeights maxWidth maxHeight|

    subViews isNil ifTrue:[^ horizontalSpace @ verticalSpace].

    "compute net height needed"

    sumOfHeights := 0.
    maxWidth := 0.
    maxHeight := 0.

    subViews do:[:child |
	|childsPreference|

	childsPreference := child preferedExtent.
	sumOfHeights := sumOfHeights + childsPreference y.
	maxHeight := maxHeight max:childsPreference y.
	maxWidth := maxWidth max:childsPreference x.

"/        sumOfHeights := sumOfHeights + child heightIncludingBorder.
"/        maxWidth := maxWidth max:(child widthIncludingBorder).
"/        maxHeight := maxHeight max:(child heightIncludingBorder).
    ].
    borderWidth ~~ 0 ifTrue:[
	sumOfHeights := sumOfHeights + (horizontalSpace * 2).
	maxWidth := maxWidth + (horizontalSpace * 2).
    ].
    vLayout == #fit ifTrue:[
	sumOfHeights := maxHeight * subViews size.
	borderWidth ~~ 0 ifTrue:[
	    sumOfHeights := sumOfHeights + (verticalSpace * 2).
	]
    ] ifFalse:[
	sumOfHeights := sumOfHeights + ((subViews size - 1) * verticalSpace).
    ].

    ((hLayout == #leftSpace) or:[hLayout == #rightSpace]) ifTrue:[
	maxWidth := maxWidth + horizontalSpace
    ] ifFalse:[
	((hLayout == #fit) or:[hLayout == #center]) ifTrue:[
	    maxWidth := maxWidth + (horizontalSpace * 2)
	]        
    ].
    ^ maxWidth @ sumOfHeights
! !

!VerticalPanelView methodsFor:'layout'!

setChildPositions
    "(re)compute position of every child"

    |ypos space sumOfHeights numChilds l hEach|

    subViews isNil ifTrue:[^ self].

    space := verticalSpace.
    numChilds := subViews size.

    vLayout == #fit ifTrue:[
	"
	 adjust childs extents and set origins.
	 Be careful to avoid accumulation of rounding errors
	"
	hEach := (height - (margin * 2) - (numChilds + 1 * space) + borderWidth) / numChilds.
	ypos := space + margin - borderWidth.
    ] ifFalse:[

	"
	 compute net height needed
	"
	sumOfHeights := subViews inject:0 into:[:sumSoFar :child | sumSoFar + child heightIncludingBorder].

	l := vLayout.
	((l == #center) and:[numChilds == 1]) ifTrue:[
	    l := #spread
	].

	"
	 compute position of topmost subview and space between them;
	 if they do hardly fit, leave no space between them 
	"
	(sumOfHeights >= (height - (margin * 2))) ifTrue:[
	    "
	     if we  have not enough space for all the elements, 
	     fill them tight, and show what can be shown (at least)
	    "
	    ypos := 0.
	    space := 0
	] ifFalse:[
	    ((l == #bottom) or:[l == #bottomSpace]) ifTrue:[
		ypos := height - (space * numChilds) - sumOfHeights.
    "
		borderWidth == 0 ifTrue:[
		    ypos := ypos + space 
		].
    "           
		l == #bottomSpace ifTrue:[
		    ypos > space ifTrue:[
			ypos := ypos - space
		    ]
		].

		ypos < 0 ifTrue:[
		    space := space min:(height - sumOfHeights) // (numChilds + 1).
		    ypos := height - (space * numChilds) - sumOfHeights.
		]
	    ] ifFalse: [
		(l == #spread) ifTrue:[
		    space := (height - sumOfHeights) // (numChilds + 1).
		    ypos := space.
		    (space == 0) ifTrue:[
			ypos := (height - sumOfHeights) // 2
		    ]
		] ifFalse: [
		    ((l == #top) or:[l == #topSpace]) ifTrue:[
    "
			borderWidth == 0 ifTrue:[
			    ypos := 0
			] ifFalse:[
			    ypos := verticalSpace
			].
    "
			space := space min:(height - sumOfHeights) // (numChilds + 1).
			l == #topSpace ifTrue:[
			    ypos := space.
			] ifFalse:[
			    ypos := 0
			]
		    ] ifFalse:[
			"center"
			ypos := (height - (sumOfHeights
					     + ((numChilds - 1) * space))) // 2.
			ypos < 0 ifTrue:[
			    space := (height - sumOfHeights) // (numChilds + 1).
			    ypos := (height - (sumOfHeights
					   + ((numChilds - 1) * space))) // 2.
			]
		    ]
		]
	    ]
	].
    ].

    "
     now set positions
    "
    subViews do:[:child |
	|xpos|

	hLayout == #left ifTrue:[
	    xpos := 0
	] ifFalse:[
	    hLayout == #leftSpace ifTrue:[
		xpos := horizontalSpace
	    ] ifFalse:[
		hLayout == #right ifTrue:[
		    xpos := width - child widthIncludingBorder
		] ifFalse:[
		    hLayout == #rightSpace ifTrue:[
			xpos := width - horizontalSpace - child widthIncludingBorder.
		    ] ifFalse:[
			hLayout == #fit ifTrue:[
			    xpos := horizontalSpace.
			    child width:(width - (horizontalSpace + child borderWidth * 2))
			] ifFalse:[
			   "centered"
			    xpos := (width - child widthIncludingBorder) // 2.
			]
		    ]
		]
	    ]
	].
	(xpos < 0) ifTrue:[ xpos := 0 ].

	vLayout == #fit ifTrue:[
	    child origin:(xpos @ ypos rounded)
		  corner:(xpos + (child width))
			 @ (ypos + hEach - (child borderWidth)) rounded.
	    ypos := ypos + hEach + "(child borderWidth * 2) +" space
	] ifFalse:[
	    child origin:(xpos@ypos).
	    ypos := ypos + (child heightIncludingBorder) + space
	]
    ]
! !