"

 COPYRIGHT (c) 1995 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.

"

'From Smalltalk/X, Version:2.10.5 on 15-apr-1995 at 12:14:46 pm'!

Layout subclass:#LayoutOrigin

	 instanceVariableNames:'leftFraction topFraction leftOffset

		topOffset'

	 classVariableNames:''

	 poolDictionaries:''

	 category:'Graphics-Geometry'

!

!LayoutOrigin class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1995 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 is provided to make porting of existing ST-80 applications

    easier. Instances can be used to control the geometry of a subview, within

    its superview. It provides the same functionality as a relative origin

    combined with insets.

    A layoutOrigin controls the origin of a subcomponent, given a fractional

    component and an offset component.

    See also:

	LayoutFrame AlignmentOrigin Layout

    Notice: this class was implemented using protocol information

    from alpha testers - it may not be complete or compatible to

    the corresponding ST-80 class. If you encounter any incompatibilities,

    please forward a note to the ST/X team.

"

!

examples

"

    using a LayoutOrigin, to control the top-left origins position of

    a component (i.e. origin at:0.5@0.5):

	|top button|

	top := StandardSystemView new.

	top extent:300@300.

	button := Button label:'component'.

	top add:button in:(LayoutOrigin new

				leftFraction:0.5;

				topFraction:0.5).

	top open

    like above, but adds an additional offset:

    (i.e. center of component at:0.5@0.5 OFFSET by 10@20):

	|top button|

	top := StandardSystemView new.

	top extent:300@300.

	button := Button label:'component'.

	top add:button in:(LayoutOrigin new

				leftFraction:0.5;

				topFraction:0.5;

				leftOffset:10;

				topOffset:20).

	top open

"

!

version

! !

!LayoutOrigin class methodsFor:'instance creation'!

fractionalFromPoint:aPoint

    "given a point, create a layoutOrigin representing the same 

     relative origin."

    ^ (self new) leftFraction:aPoint x topFraction:aPoint y

    "

     LayoutOrigin fractionalFromPoint:0.5@0.5

    "

!

offsetFromPoint:aPoint

    "given a point, create a layoutOrigin representing the same 

     absolute (pixel) origin."

    ^ self new leftOffset:aPoint x topOffset:aPoint y

    "

     LayoutOrigin offsetFromPoint:100@100

    "

!

fromPoint:aPoint

    "return a new LayoutOrigin from  aPoint.

     If the coordinates are between 0 and 1, take

     them as fractional parts (relative to superview).

     Otherwise, treat them as absolute offsets."

    |x y layout|

    x := aPoint x.

    y := aPoint y.

    layout := self new.

    ((x between:0 and:1)

    and:[y between:0 and:1]) ifTrue:[

	layout leftFraction:x topFraction:y

    ] ifFalse:[

	layout leftOffset:x topOffset:y

    ].

    ^ layout

    "

     LayoutOrigin fromPoint:100@100

     LayoutOrigin fromPoint:0.5@0.5

     LayoutOrigin fromPoint:0.5@100

    "

! !

!LayoutOrigin methodsFor:'printing & storing'!

displayString

    ^ (self class name) , '(' 

	, 'l: ' , leftFraction displayString

	, '+' , leftOffset displayString

	, ' t: ' , topFraction displayString

	, '+' , topOffset displayString

	, ')'

! !

!LayoutOrigin methodsFor:'accessing'!

leftFraction:something

    "set leftFraction"

    leftFraction := something.

!

leftFraction

    "return leftFraction"

    ^ leftFraction

!

leftOffset:something

    "set leftOffset"

    leftOffset := something.

!

leftOffset

    "return leftOffset"

    ^ leftOffset

!

leftFraction:something offset:o

    "set leftFraction and offset"

    leftFraction := something.

    leftOffset := o

!

topFraction:something

    "set topFraction"

    topFraction := something.

!

topFraction

    "return topFraction"

    ^ topFraction

!

topOffset:something

    "set topOffset"

    topOffset := something.

!

topOffset

    "return topOffset"

    ^ topOffset

!

topFraction:something offset:o

    "set topFraction and offset"

    topFraction := something.

    topOffset := o

!

leftFraction:newLeft topFraction:newTop 

    "set leftFraction and topFraction"

    leftFraction := newLeft.

    topFraction := newTop.

!

leftOffset:newLeft topOffset:newTop 

    "set leftOffset and topOffset"

    leftOffset := newLeft.

    topOffset := newTop.

! !

!LayoutOrigin methodsFor:'queries'!

rectangleRelativeTo:superRectangle preferred:prefRect

    |x y|

    leftOffset isNil ifTrue:[

	x := 0

    ] ifFalse:[

	x := leftOffset

    ].

    topOffset isNil ifTrue:[

	y := 0

    ] ifFalse:[

	y := topOffset

    ].

    leftFraction notNil ifTrue:[

	x := x + (superRectangle width * leftFraction)

    ].

    topFraction notNil ifTrue:[

	y := y + (superRectangle height * topFraction)

    ].

    ^ Rectangle origin:x@y extent:prefRect extent

    "

     |superRect lO|

     superRect := 0@0 corner:100@100.

     lO := (LayoutOrigin new).

     lO leftFraction:0.5;

	topFraction:0.5.

     lO rectangleRelativeTo:superRect preferred:(0@0 corner:30@30)

    "

!

origin

    ^ leftFraction asFloat @ topFraction asFloat

! !

!LayoutOrigin methodsFor:'initialization'!

initialize

    leftOffset := topOffset := 0.

    leftFraction := topFraction := 0.

! !

!LayoutOrigin methodsFor:'converting'!

literalArrayEncoding

    "encode myself as an array.

     The encoding is: 

	(#LayoutOrigin orgOffsX relOrgX orgOffsY relOrgY)

    "

    ^ Array

	with:self class name asSymbol

	with:leftOffset

	with:leftFraction

	with:topOffset

	with:topFraction

    "

      LayoutOrigin new fromLiteralArrayEncoding:#(#LayoutOrigin 70 0 2 0)

      (LayoutOrigin new leftOffset:10; leftFraction:0.2;

		       topOffset:20; topFraction:0.4) literalArrayEncoding 

    "

    "Modified: 1.9.1995 / 02:43:48 / claus"

!

fromLiteralArrayEncoding:encoding

    "read my values from an encoding.

     The encoding is supposed to be of the form: 

	(#LayoutOrigin orgOffsX relOrgX orgOffsY relOrgY)

     This is the reverse operation to #literalArrayEncoding."

    leftOffset := encoding at:2.

    leftFraction := encoding at:3.

    topOffset := encoding at:4.

    topFraction := encoding at:5.

    "

      LayoutOrigin new fromLiteralArrayEncoding:#(#LayoutOrigin 70 0 2 0)

    "

! !