"

 COPYRIGHT (c) 1996 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.

"

Spline subclass:#ArrowedSpline

	instanceVariableNames:'arrowHeadPositions arrowHeadLength arrowHeadAngle'

	classVariableNames:''

	poolDictionaries:''

	category:'Graphics-Geometry'

!

!ArrowedSpline class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1996 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

"

    ArrowedSplines are like infilled splines, with arrowHeads.

    [see also:]

        Polygon LineSegment Circle EllipticalArc 

        Rectangle Curve Arrow Spline

        GraphicsContext

        StrokingWrapper FillingWrapper

    [author:]

        Claus Gittinger

"

!

examples

"

  arrowedspline:

                                                                        [exBegin]

    |v a|

    v := View extent:100@100.

    a := ArrowedSpline controlPoints:

                (Array with:(20@20)

                       with:(80@80)

                       with:(20@80)).

    v addComponent:((StrokingWrapper on:a) foregroundColor:Color red).

    v open.

                                                                        [exEnd]

  filled arrow:

                                                                        [exBegin]

    |v a|

    v := View extent:100@100.

    a := ArrowedSpline controlPoints:

                (Array with:(20@20)

                       with:(80@80)

                       with:(20@50)

                       with:(90@10)).

    v addComponent:((FillingWrapper on:a) foregroundColor:Color red).

    v open.

                                                                        [exEnd]

  more arrowHeads:

                                                                        [exBegin]

    |v a|

    v := View extent:100@100.

    a := ArrowedSpline controlPoints:

                (Array with:(20@20)

                       with:(80@80)

                       with:(20@50)

                       with:(90@10)).

    a arrowHeadPositions:#(1 4).

    v addComponent:((FillingWrapper on:a) foregroundColor:Color red).

    v open.

                                                                        [exEnd]

  interactive:

                                                                        [exBegin]

    |v points eventCatcher|

    v := StandardSystemView extent:(450 @ 450).

    v label:'ArrowedSpline Example - (click left/middle)'.

    points := OrderedCollection new.

    v openAndWait.

    eventCatcher := Plug new.

    eventCatcher respondTo:#handlesButtonPress:inView:

                      with:[:butt :view | true].

    eventCatcher respondTo:#buttonPress:x:y:view:

                      with:[:butt :x :y :view | 

                            v paint:(Color white).

                            v fillCircle:(x @ y) radius:3.

                            points add:(x @ y).

                            (butt == 1 or:[butt == #select]) ifFalse:[

                                v paint:(Color white).

                                v fillCircle:(x @ y) radius:3.

                                ((ArrowedSpline controlPoints:points)

                                        arrowHeadPositions:(1 to:points size);

                                        arrowHeadLength:15)

                                        displayStrokedOn:v.

                                points := OrderedCollection new.

                            ]

                           ].

    v delegate:(eventCatcher)

                                                                        [exEnd]

"

! !

!ArrowedSpline methodsFor:'accessing'!

arrowHeadAngle

    "return the arrowHeads angle, in degrees.

     The default is defined in Arrow (150 degrees)"

    arrowHeadAngle isNil ifTrue:[^ Arrow defaultAngle].

    ^ arrowHeadAngle

    "Created: 12.5.1996 / 23:13:27 / cg"

    "Modified: 12.5.1996 / 23:14:15 / cg"

!

arrowHeadAngle:angleInDegrees

    "set the arrowHeads angle, in degrees.

     The default is defined in Arrow (150 degrees)"

    arrowHeadAngle := angleInDegrees

    "Created: 12.5.1996 / 23:13:34 / cg"

    "Modified: 12.5.1996 / 23:14:24 / cg"

!

arrowHeadLength

    "return the arrowHeads length, in pixels.

     The default is define in Arrow (8 pixels)"

    arrowHeadLength isNil ifTrue:[^ Arrow defaultLength].

    ^ arrowHeadLength

    "Modified: 13.5.1996 / 00:44:30 / cg"

!

arrowHeadLength:pixels

    "set the arrowHeads length, in pixels.

     The default is defined in Arrow (8 pixels)"

    arrowHeadLength := pixels

    "Created: 12.5.1996 / 23:15:34 / cg"

!

arrowHeadPositions:collectionOfPositions

    "set the arrowHeads positions. Each collections element gives

     theindex of a controlPoint, on which an arrowHead is drawn.

     The default is #(<controlPoints size>) i.e. a single arrowHead

     on the last controlPoint.

     To have arrowHeads on all controlPoints, define arrowHeadPositions

     as (1 to:controlPoints size)"

    arrowHeadPositions := collectionOfPositions

    "Modified: 12.5.1996 / 23:14:24 / cg"

    "Created: 13.5.1996 / 00:47:23 / cg"

! !

!ArrowedSpline methodsFor:'displaying'!

    |arrowHeadPoint len pos positions angle point grad xDis yDis

    positions := arrowHeadPositions.

    positions isNil ifTrue:[

        positions := Array with:(controlPoints size).

    ].

    len := arrowHeadLength.

    len isNil ifTrue:[

        len := Arrow defaultLength

    ].

    angle := arrowHeadAngle.

    angle isNil ifTrue:[

        angle := Arrow defaultAngle

    ].

    angle := angle degreesToRadians.

    positions do:[:index |

        | p deriv|

        p := controlPoints at:index.

        deriv := (firstDerivative at:index).

        deriv isNil ifTrue:[

            deriv := (controlPoints at:index) - (controlPoints at:index-1).

        ].

        deriv x = 0

                    ifTrue: [grad := 9999999]

                    ifFalse: [grad := deriv y / deriv x].

        atn := grad arcTan.

        x1 := len * (angle - atn) cos.

        y1 := len * (angle - atn) sin.

        x2 := len * (angle + atn) cos.

        y2 := len * (angle + atn) sin.

        deriv x = 0 ifTrue: [

            deriv y > 0 ifTrue: [

                p1 := x1 @ (0 - y1).

                p2 := x2 @ (y2).

            ] ifFalse: [

                p1 := 0 - x1 @ (y1).

                p2 := 0 - x2 @ (0 - y2).

            ]

        ] ifFalse: [

            deriv x > 0 ifTrue:[

                p1 := x1 @ (0 - y1).

                p2 := x2 @ (y2).

            ] ifFalse: [

                p1 := 0 - x1 @ (y1).

                p2 := 0 - x2 @ (0 - y2)

            ]

        ].

        filled ifTrue:[

        ] ifFalse:[

        ].

    ].

    aGC lineStyle:savedLineStyle.

    "Created: 13.5.1996 / 00:50:49 / cg"

    "Modified: 13.5.1996 / 00:52:17 / cg"

!

displayFilledOn:aGC

    "display the receiver in the graphicsContext, aGC"

    super displayStrokedOn:aGC.

    self displayArrowsOn:aGC filled:true

    "Created: 13.5.1996 / 00:51:14 / cg"

!

displayStrokedOn:aGC

    "display the receiver in the graphicsContext, aGC"

    super displayStrokedOn:aGC.

    self displayArrowsOn:aGC filled:false

    "Created: 13.5.1996 / 00:51:14 / cg"

    "Modified: 13.5.1996 / 00:52:34 / cg"

! !

!ArrowedSpline class methodsFor:'documentation'!

version

! !