"

 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.

"

"{ Package: 'stx:libwidg' }"

SimpleView subclass:#PanelView

	instanceVariableNames:'hLayout vLayout verticalSpace horizontalSpace mustRearrange

		elementsChangeSize ignoreInvisibleComponents'

	classVariableNames:''

	poolDictionaries:''

	category:'Views-Layout'

!

!PanelView 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 is a view for holding subviews. (layout-widget ?)

    Instances of PanelView try to get all their subviews into them,

    arranging subviews left-to-right, top-to-bottom.

    If you dont like its layout, define a new subclass or use one of

    the existing subclasses: HorizontalPanelView and VerticalPanelView.

    The panel assumes, that the elements do not resize themselfes, after it

    became visible. This is not true for all widgets (buttons or labels may

    like to change). If you have changing elements, tell this to the panel

    with 'aPanel elementsChangeSize:true'. In that case, the panel will react

    to size changes, and reorganize things.

    PanelViews normally delay the actual positioning/sizing of their elements,

    until actually displayed. This is useful, if more elements are to

    be added, to avoid repeated configuration of the elements.

    If you want to query for the relative position of an element BEFORE

    the view is visible, you have to send #setChildPositionsIfChanged before

    doing so (otherwise, you may get invalid origins from the subviews). As

    an example, the modalBoxes do so before showing themselfes to ask for the

    position of the ok-button relative to the top-left box-origin, in order to

    position the ok-button under the mouse-pointer.

    [Instance variables:]

	hLayout         <Symbol>        controls horizontal layout; ignored in this

					class, but used in Horizontal- and

					VerticalPanelViews. See more info there.

	vLayout         <Symbol>        controls vertical layout; ignored in this

					class, but used in Horizontal- and

					VerticalPanelViews. See more info there.

	horizontalSpace <Integer>       number of pixels to use as space between elements

					defaults to ViewSpacing, which is 1mm

	verticalSpace   <Integer>       number of pixels to use as space between elements

					defaults to ViewSpacing, which is 1mm

	mustRearrange   <Boolean>       internal flag, if rearrangement is needed

	elementsChangeSize   

			<Boolean>       if true, the panel takes care of this situation.

					By default, this is false.

	ignoreInvisibleComponents

			<Boolean>       if true, invisible (i.e. hidden) views

					are not considered in the layout computation.

					If false, they will lead to additional space

					between visible components.

					The default is false.

    [author:]

	Claus Gittinger

"

!

examples

"

    The generic panelView simply tries to get its

    components arranged for fitting them all into

    its area. No special layout is done, except for

    horizontal/vertical spacings.

    The view is filled top-left to bottom-right

    with subcomponents. Subcomponents are not resized.

    example:

                                                                        [exBegin]

        |v p b1 b2 b3|

        v := StandardSystemView new.

        v label:'panel'.

        p := PanelView 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:300 @ 100.

        v open

                                                                        [exEnd]

   invisible component not considered in layout:

                                                                        [exBegin]

        |v p b1 b2 b3|

        v := StandardSystemView new.

        v label:'panel'.

        p := PanelView 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.

        b2 beInvisible.

        b3 := Button label:'button3' in:p.

        v extent:300 @ 100.

        v open

                                                                        [exEnd]

   invisible component considered in layout:

                                                                        [exBegin]

        |v p b1 b2 b3|

        v := StandardSystemView new.

        v label:'panel'.

        p := PanelView in:v.

        p origin:(0.0 @ 0.0) corner:(1.0 @ 1.0).

        p ignoreInvisibleComponents:false.

        b1 := Button label:'button1' in:p.

        b2 := Button label:'button2' in:p.

        b2 beInvisible.

        b3 := Button label:'button3' in:p.

        v extent:300 @ 100.

        v open

                                                                        [exEnd]

"

! !

!PanelView methodsFor:'accessing'!

elementsChangeSize

    "tell the panel if elements are to change their size by themselfes

     (for example, Labels or Buttons may do so if their contents changes).

     Setting this flag will make the panel reorganize the elements whenever

     any element changes its size."

    ^ elementsChangeSize 

!

elementsChangeSize:aBoolean

    "tell the panel if elements are to change their size by themselfes

     (for example, Labels or Buttons may do so if their contents changes).

     Setting this flag will make the panel reorganize the elements whenever

     any element changes its size."

    elementsChangeSize ~~ aBoolean ifTrue:[

        elementsChangeSize := aBoolean.

        aBoolean ifTrue:[

            self makeMyselfDependentOnSubviews.

        ].

    ].

!

hierarchicalIndexOfChild:aView

    ^ aView hierarchicalIndexInList:subViews

!

horizontalLayout

    "not supported by this view"

    ^ nil

!

horizontalLayout:aLayoutSymbol

    "not supported by this view"

!

horizontalSpace

    "return the horizontal space between elements on pixels (default is 1mm)"

    ^ horizontalSpace 

!

horizontalSpace:numberOfPixels

    "set the horizontal space between elements on pixels (default is 1mm)"

    horizontalSpace ~= numberOfPixels ifTrue:[

	horizontalSpace := numberOfPixels.

	self layoutChanged

    ]

!

ignoreInvisibleComponents

    "return the flag which controls if invisible (unrealized)

     components should be ignored in the layout computation.

     By default, it is false, which means that invisible components will

     lead to a visible space between visible components"

    ^ ignoreInvisibleComponents

!

ignoreInvisibleComponents:aBoolean

    "set/clears the flag which controls if invisible (unrealized)

     components should be ignored in the layout computation.

     By default, it is false, which means that invisible components will

     lead to a visible space between visible components."

    (ignoreInvisibleComponents ~~ aBoolean) ifTrue:[

        aBoolean ifTrue:[

            self makeMyselfDependentOnSubviews.

        ].

        ignoreInvisibleComponents := aBoolean.

        self layoutChanged

    ]

    "Modified: / 20.7.1998 / 14:12:38 / cg"

!

space:numberOfPixels

    "set the space between elements in pixels (default is 1mm) for both directions"

    (verticalSpace ~= numberOfPixels 

    or:[horizontalSpace ~= numberOfPixels]) ifTrue:[

	horizontalSpace := numberOfPixels.

	verticalSpace := numberOfPixels.

	self layoutChanged

    ]

!

verticalLayout

    "not supported by this view"

    ^ nil

!

verticalLayout:aLayoutSymbol

    "not supported by this view"

!

verticalSpace

    "return the vertical space between elements on pixels (default is 1mm)"

    ^ verticalSpace 

!

verticalSpace:numberOfPixels

    "set the vertical space between elements (in pixels).

     The default is computed for 1mm spacing."

    verticalSpace ~= numberOfPixels ifTrue:[

	verticalSpace := numberOfPixels.

	self layoutChanged

    ]

! !

!PanelView methodsFor:'adding & removing subviews'!

addComponent:aComponent

    "redefined to recompute layout when a component is added"

    super addComponent:aComponent.

    self addedView:aComponent

    "Created: 28.1.1997 / 17:44:18 / cg"

!

addSubView:aView

    "redefined to recompute layout when a subview is added"

    super addSubView:aView.

    self addedView:aView

!

addSubView:newView after:aView

    "redefined to recompute layout when a subview is added"

    super addSubView:newView after:aView.

    self addedView:newView

    "Modified: 15.7.1996 / 10:15:04 / cg"

!

addSubView:newView before:aView

    "redefined to recompute layout when a subview is added"

    super addSubView:newView before:aView.

    self addedView:newView

    "Modified: 15.7.1996 / 10:14:39 / cg"

!

removeSubView:aView

    "redefined to recompute layout when a subview is removed"

    super removeSubView:aView.

    aView removeDependent:self.

    self layoutChanged

! !

!PanelView methodsFor:'enumerating subviews'!

changeSequenceOrderFor:aSubView to:anIndex

    "change a subview's position in the subviews collection.

     This affects the arrangemnt of the views."

    |success|

    success := super changeSequenceOrderFor:aSubView to:anIndex.

    success ifTrue:[

        self layoutChanged.

    ].

    ^ success

    "

     |panel comp1 comp2 comp3|

     panel := HorizontalPanelView new.

     comp1 := Label label:'one' in:panel.

     comp2 := Label label:'two' in:panel.

     comp3 := Label label:'three' in:panel.

     panel open.

     Delay waitForSeconds:3.

     panel changeSequenceOrderFor:comp2 to:3.

     Delay waitForSeconds:3.

     panel changeSequenceOrderFor:comp2 to:1.

    "

    "Modified: / 17.1.1998 / 00:13:43 / cg"

! !

!PanelView methodsFor:'event handling'!

sizeChanged:how

    "my size has changed - must rearrange elements"

    super sizeChanged:how.

    self layoutChanged

!

update:something with:aParameter from:changedObject

    "an element changed its size"

    something == #sizeOfView ifTrue:[

        elementsChangeSize ifTrue:[

            self layoutChanged.

        ].

        ^ self

    ].

"/    something == #preferredExtent ifTrue:[

"/        elementsChangeSize ifTrue:[

"/            self layoutChanged.

"/        ].

"/        ^ self

"/    ].

    something == #visibility ifTrue:[

        ignoreInvisibleComponents ifTrue:[

            self layoutChanged.

        ].

        ^ self

    ].

    ^ super update:something with:aParameter from:changedObject

    "Modified: 28.1.1997 / 17:52:44 / cg"

! !

!PanelView methodsFor:'focus handling'!

wantsFocusWithButtonPress

    "no, do not catch the keyboard focus on button click"

    ^ false

! !

!PanelView methodsFor:'initialization'!

initialize

    super initialize.

    hLayout := vLayout := #center.  "/ notice, this is ignored in this class

				    "/ used by subclasses only

    verticalSpace := ViewSpacing.

    horizontalSpace := ViewSpacing.

    mustRearrange := elementsChangeSize := false.

    ignoreInvisibleComponents := true.

!

realize

    mustRearrange ifTrue:[

	self setChildPositions

    ].

    super realize

!

resize

    super resize.

    mustRearrange ifTrue:[

	self setChildPositions

    ].

!

setChildPositionsIfChanged

    "set all of my child positions - this is usually delayed,

     until the panel is actually shown (since we dont know, if more

     elements are to be added) thus avoiding repositioning the elements

     over and over. However, sometimes it is nescessary, to force positioning

     the elements, for example, before querying the relative position of

     an element (modalBoxes do so, to position the ok-button under the mouse

     pointer)."

    mustRearrange ifTrue:[

	self setChildPositions

    ].

! !

!PanelView methodsFor:'layout'!

preferredExtent

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

     Note that width is considered as given, and compute height here."

    |subViews xpos totalHeight maxHeightInRow first|

    "/ If I have an explicit preferredExtent..

    explicitExtent notNil ifTrue:[

        ^ explicitExtent

    ].

    "/ If I have a cached preferredExtent value..

    preferredExtent notNil ifTrue:[

        ^ preferredExtent

    ].

    subViews := self subViewsToConsider.

    subViews isEmptyOrNil ifTrue:[

        ^ super preferredExtent.

    ].

    xpos := horizontalSpace.

    totalHeight := 0.

    maxHeightInRow := 0.

    first := true.

    subViews do:[:eachChild | |childPreferredExtent|

        childPreferredExtent := eachChild preferredExtent.

        "go to next row, if this subview won't fit"

        first ifFalse: [

            (xpos + childPreferredExtent x + horizontalSpace) > width

            ifTrue: [

                xpos := horizontalSpace.

                totalHeight := totalHeight + maxHeightInRow + verticalSpace.

                maxHeightInRow := 0.

            ]

        ].

        xpos := xpos + (childPreferredExtent x) + horizontalSpace.

        (maxHeightInRow < (childPreferredExtent y)) ifTrue:[

            maxHeightInRow := childPreferredExtent y.

        ].