$Header: /cvs/stx/stx/libwidg/VerticalPanelView.st,v 1.6 1994-11-17 14:38:46 claus Exp $

$Header: /cvs/stx/stx/libwidg/VerticalPanelView.st,v 1.6 1994-11-17 14:38:46 claus Exp $

    All real work is done in PanelView - except the layout computation is

    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: top-layout

	p verticalLayout:#top.

    example: bottom-layout

	p verticalLayout:#bottom.

	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.

    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

! !

	|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).

    |ypos space sumOfHeights numChilds l hEach|

    numChilds := subViews size.

    vLayout == #fit ifTrue:[

    ] 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:[

	] ifFalse:[

	    child origin:(xpos@ypos).

	    ypos := ypos + (child heightIncludingBorder) + space