"

 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.

"

Geometric subclass:#Rectangle

	instanceVariableNames:'left top width height'

	classVariableNames:''

	poolDictionaries:''

	category:'Graphics-Geometry'

!

!Rectangle 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

"

    Rectangles represent a rectangular area in 2D space.

    notice, my implementation does not use origin/corner as instance objects

    but left/top/width/height to save space and allocations. This means, that my

    Rectangles cannot be used to represent Rectangles in a higher than 2D

    space. (i.e. only valid if origin/corner are 2D Points)

    (aside from that, you will not see any difference from the outside)

    Instance variables:

        left           <Number>        the left coordinate (i.e origin x)

        top            <Number>        the top coordinate (i.e origin y)

        width          <Number>        the width of the rectangle

        height         <Number>        the height of the rectangle

    I am not certain, if implementing Rectangle different was a good idea - 

    subclasses may expect things to be different ...

    Therefore, this may change.

    [author:]

        Claus Gittinger

"

! !

!Rectangle class methodsFor:'instance creation'!

fromUser

    "let user specify a rectangle on the screen, return it"

    ^ Screen current rectangleFromUser

    "

     Rectangle fromUser     

    "

!

left:left right:right top:top bottom:bottom

    "create and return a new Rectangle giving left, top, right and bottom coordinates"

    ^ (self basicNew) left:left right:right top:top bottom:bottom

!

left:left top:top right:right bottom:bottom

    "create and return a new Rectangle giving left, top, right and bottom coordinates"

    ^ (self basicNew) left:left top:top right:right bottom:bottom

!

left:left top:top width:w height:h

    "create and return a new Rectangle giving left and top coordinates

     and width, height"

%{  /* NOCONTEXT */

    REGISTER OBJ newRect;

    OBJ t;

    int spc;

    if (__CanDoQuickNew(OHDR_SIZE + 4*sizeof(OBJ))) {

	if (self == Rectangle) {

	    /*

	     * short cut - rectangles are created so often ...

	     */

	    __qCheckedAlignedNew(newRect, OHDR_SIZE + 4*sizeof(OBJ));

	    __InstPtr(newRect)->o_class = Rectangle;

	    __InstPtr(newRect)->i_instvars[0] = left;

	    __InstPtr(newRect)->i_instvars[1] = top;

	    __InstPtr(newRect)->i_instvars[2] = w;

	    __InstPtr(newRect)->i_instvars[3] = h;

	    if (! (__bothSmallInteger(left, top) && 

		   __bothSmallInteger(w, h))) {

		spc = __qSpace(newRect);

		__STORE_SPC(newRect, left, spc);

		__STORE_SPC(newRect, top, spc);

		__STORE_SPC(newRect, w, spc);

		__STORE_SPC(newRect, h, spc);

	    }

	    RETURN ( newRect );

	}

    }

%}

.

    ^ (self basicNew) left:left top:top width:w height:h

!

origin:origin corner:corner

    "create and return a new Rectangle giving top-left and bottom-right points"

    ^ (self basicNew) origin:origin corner:corner

!

origin:origin extent:extent

    "create and return a new Rectangle giving top-left point and extent point"

%{  /* NOCONTEXT */

    REGISTER OBJ newRect;

    OBJ t;

    int spc;

    if (__CanDoQuickNew(OHDR_SIZE + 4*sizeof(OBJ))) {

        /*

	 * short cut - rectangles are created so often ...

	 */

	if (self == Rectangle) {

	    if (__isPoint(origin) && __isPoint(extent)) {

		__qCheckedAlignedNew(newRect, OHDR_SIZE + 4*sizeof(OBJ));

		__InstPtr(newRect)->o_class = Rectangle;

		spc = __qSpace(newRect);

		t = __PointInstPtr(origin)->p_x;

		__InstPtr(newRect)->i_instvars[0] = t;

		__STORE_SPC(newRect, t, spc);

		t = __PointInstPtr(origin)->p_y;

		__InstPtr(newRect)->i_instvars[1] = t;

		__STORE_SPC(newRect, t, spc);

		t = __PointInstPtr(extent)->p_x;

		__InstPtr(newRect)->i_instvars[2] = t;

		__STORE_SPC(newRect, t, spc);

		t = __PointInstPtr(extent)->p_y;

		__InstPtr(newRect)->i_instvars[3] = t;

		__STORE_SPC(newRect, t, spc);

		RETURN ( newRect );

	    }

	}

    }

%}

.

    ^ (self basicNew) origin:origin extent:extent

! !

!Rectangle methodsFor:'accessing'!

area

    "return the area 

     - for screen Rectangles this is the number of pixels"

    ^ width * height

!

bottom

    "return the y coordinate of the bottom"

    ^ (top + height)

!

bottom:aNumber

    "set the bottom edge"

    height := aNumber - top

!

bottomCenter

    "return the bottom center point"

    ^ (left + (width // 2)) @ (top + height)

!

bottomLeft

    "return the bottom-left point"

    ^ left @ (top + height)

!

bottomRight

    "return the bottom-right point"

    ^ (left + width) @ (top + height)

!

center

    "return the point in the center of the receiver"

    ^ (left + (width // 2)) @ (top + (height // 2))

!

corner

    "return the corner"

    ^ (left + width) @ (top + height)

!

corner:aPoint

    "set the bottom-right corner"

    width := aPoint x - left.

    height := aPoint y - top

!

extent

    "return the extent"

    ^ width @ height

!

extent:aPoint

    "set the extent from the argument, aPoint with width taken from aPoint x

     and height taken from aPoint y"

    width := aPoint x.

    height := aPoint y

!

height

    "return the height of the rectangle"

    ^ height

!

left

    "return the x-coordinate of the top-left origin"

    ^ left

!

left:aNumber

    "set the left edge"

    width := width + (left - aNumber).

    left := aNumber

!

left:newLeft right:right top:newTop bottom:bottom

    "set the rectangle given left, top, right and bottom coordinates."

    left := newLeft.

    top := newTop.

    width := right - left.

    height := bottom - top

!

left:newLeft top:newTop right:right bottom:bottom

    "set the rectangle given left, top, right and bottom coordinates"

    left := newLeft.

    top := newTop.

    width := right - left.

    height := bottom - top

!

left:newLeft top:newTop width:newWidth height:newHeight

    "set the rectangle given left, top coordinates and width, height"

    left := newLeft.

    top := newTop.

    width := newWidth.

    height := newHeight

!

leftCenter

    "return the left center point"

    ^ left @ (top + (height // 2))

!

origin

    "return the origin"

    ^ left @ top

!

origin:aPoint

    "set the top-left origin. The corner remains unchanged."

    |newTop newLeft|

    newTop := aPoint y.

    newLeft := aPoint x.

    height := height + (top - newTop).

    width := width + (left - newLeft).

    left := newLeft.

    top := newTop

!

origin:origin corner:corner

    "set both origin and corner"

    left := origin x.

    top := origin y.

    width := corner x - left.

    height := corner y - top

!

origin:origin extent:extent

    "set both origin and extent"

    left := origin x.

    top := origin y.

    width := extent x.

    height := extent y

!

right

    "return the x coordinate of the right"

    ^ (left + width)

!

right:aNumber

    "set the right edge"

    width := aNumber - left

!

rightCenter

    "return the right center point"

    ^ (left + width) @ (top + (height // 2))

!

top

    "return the y-coordinate of the top-left"

    ^ top

!

top:aNumber

    "set the top edge"

    height := height + (top - aNumber).

    top := aNumber

!

topCenter

    "return the top center point"

    ^ (left + (width // 2)) @ top

!

topLeft

    "return the top-left point - the same as origin"

    ^ left @ top

!

topLeft:aPoint

    "Set the top and left edges.

     The bottom right remains unchanged."

    |newTop|

    newTop := aPoint y.

    height := height + (top - newTop).

    top := newTop.

    width := aPoint x - left

!

topRight

    "return the top-right point"

    ^ (left + width) @ top

!

topRight:aPoint

    "Set the top and right edges. 

     The bottom left remains unchanged."

    |newTop|

    newTop := aPoint y.

    height := height + (top - newTop).

    top := newTop.

    width := aPoint x - left

!

width

    "return the width of the rectangle"

    ^ width

! !

!Rectangle methodsFor:'comparing'!

= aRectangle

    "return true, if the argument aRectangle represents the same

     rectangle as the receiver"

%{  /* NOCONTEXT */

    /*

     * because rectangles are often compared in the graphics code,

     * handle the common case quickly

     */

    if (__isNonNilObject(aRectangle) 

     && __qClass(aRectangle) == Rectangle) {

	if ((__InstPtr(self)->i_instvars[0] == __InstPtr(aRectangle)->i_instvars[0])

	 && (__InstPtr(self)->i_instvars[1] == __InstPtr(aRectangle)->i_instvars[1])

	 && (__InstPtr(self)->i_instvars[2] == __InstPtr(aRectangle)->i_instvars[2])

	 && (__InstPtr(self)->i_instvars[3] == __InstPtr(aRectangle)->i_instvars[3])) {

	    RETURN ( true );

	}

	if (__bothSmallInteger(__InstPtr(self)->i_instvars[0], __InstPtr(aRectangle)->i_instvars[0])

	 && __bothSmallInteger(__InstPtr(self)->i_instvars[1], __InstPtr(aRectangle)->i_instvars[1])

	 && __bothSmallInteger(__InstPtr(self)->i_instvars[2], __InstPtr(aRectangle)->i_instvars[2])

	 && __bothSmallInteger(__InstPtr(self)->i_instvars[3], __InstPtr(aRectangle)->i_instvars[3])) {

	    RETURN ( false );

	}

    }

%}.

    (aRectangle species ~~ self species) ifTrue:[^ false].

    left = aRectangle left ifFalse:[^ false].

    top = aRectangle top ifFalse:[^ false].

    width = aRectangle width ifFalse:[^ false].

    height = aRectangle height ifFalse:[^ false].

    ^ true

!

hash

    "return an integer useful for hashing -

     redefined since = is redefined here"

    ^ ((left hash bitShift:16) bitXor:(top hash bitShift:16))

      + ((width hash) bitXor:(height hash))

! !

!Rectangle methodsFor:'converting'!

asFractionalLayout

    "return a layoutFrame in which fractions (top, left, bottom, right)

     are taken from corresponding edges of the receiver.

     You have to make certain that those are in 0..1."

    |l|

    l := LayoutFrame new.

    l

	leftFraction:(self left);

	rightFraction:(self right);

	topFraction:(self top);

	bottomFraction:(self bottom).

    ^ l

    "

     (0.5@0.5 corner:0.75@0.75) asFractionalLayout 

     (0.5@0.5 corner:0.75@0.75) asOffsetLayout      

     (0.5@0.5 corner:0.75@0.75) asLayout        

    "

!

asLayout

    "return a layoutFrame in which offsets (top, left, bottom, right)

     are taken from corresponding edges of the receiver.

     If all values are between 0.0 .. 1.0, a fractionalLayout is created,

     otherwise, an offsetLayout"

    |newLayout left right top bot|

    newLayout := LayoutFrame new.

    left := (self left).