charger.obj

Class GEdge

Object

charger.obj.GraphObject

charger.obj.GEdge

Direct Known Subclasses:

Arrow, Coref, CustomEdge, GenSpecLink

public abstract class GEdge
extends GraphObject

Abstract superclass for arrows and co-referent links. Assume that an edge has exactly two end objects. displayRect consists of a tiny rectangle at the midpt for selection purposes

Author:

Harry S. Delugach ( delugach@uah.edu ) Copyright (c) 1998-2020 by Harry S. Delugach.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	GEdge.Direction used for labeling the connected nodes; i.e., a "from" node

Nested classes/interfaces inherited from class charger.obj.GraphObject

GraphObject.Kind, GraphObject.ObjectIDComparator

Field Summary

Fields

Modifier and Type	Field and Description
(package private) Point2D.Double	arrowEndPoint1 one back corner of the arrow.
(package private) Point2D.Double	arrowEndPoint2 another back corner of the arrow.
(package private) GeneralPath	arrowHeadShape Arrowhead triangle to be filled in when drawing an arrow.
(package private) Point2D.Double	arrowPoint the "point" of the arrow.
EdgeAttributes	edgeAttributes used for indicating the node isn't connected
GraphObject	fromObj
Point2D.Double	fromPt remembers its source point as set.
(package private) Point2D.Double	midPoint remembers its middle point as set.
GraphObject	toObj
Point2D.Double	toPt remembers its destination point as set.

Fields inherited from class charger.obj.GraphObject

backColor, defaultDim, defaultSelectColor, defaultWrapColumns, defaultWrapLabels, displayRect3D, foreColor, highlightColor, history, isSelected, labelFont, myKind, objectID, objectMargin, ownerGraph, TerritorialLimit, textLabel, textLabelLowerLeftPt

Constructor Summary

Constructors

Constructor and Description
GEdge() Constructs a new GEdge with label "-".
GEdge(GraphObject FromOne, GraphObject ToOne) Constructs a new GEdge with label "-" going from one object to another.

Method Summary

Modifier and Type	Method and Description
void	abandonObject() Does everything but the actual removal (de-allocation)
static boolean	areLinked(GNode go1, GNode go2) Determines whether the two charger nodes are linked together, by any GEdge.
boolean	commitToKnowledgeBase(KnowledgeBase kb) needed for GraphLayout interface
void	detachFromGNodes() Finds the endpoint nodes of the edge, and removes the edge from each of their lists
void	drawArrowHead(Graphics2D g, boolean filled, boolean printing) Uses the instance variables arrowPoint, arrowEndPoint1 and arrowEndPoint2 to speed up drawing
void	drawBorder(Graphics2D g, Color borderColor) Currently empty, may be used in the future.
protected void	finalize()
static Point2D.Double	findClippingPoint(Point2D.Double fromPt, Point2D.Double toPt, Shape s) Assuming that there's a shape at the toPt, find the clipping point on its boundary along a line from the fromPt to the toPt.
static Point2D.Double	findClippingPointRectangle(Point2D.Double fromPt, Rectangle2D.Double rect) Given a point and a rectangle, find that point on the rectangle that lies on the edge between the given point and the center of the rectangle
static Point2D.Double	findClippingPointShape(Point2D.Double fromPt, Point2D.Double toPt, Shape shape) Finds the clipping point for an arbitrary shape.
private float	getArrowHeadAngle()
int	getArrowHeadHeight()
private float	getArrowHeadLength()
int	getArrowHeadWidth()
double	getEdgeThickness()
float	getLength()
protected Shape	getObjectShapeForClipping(GraphObject go) Determines the appropriate rectangle to use as object boundaries when drawing edges
Shape	getShape() Obtain the Shape object that represents the selectable region of this object.
GEdge.Direction	howLinked(GNode gn) Tells which end of the current link (if either) is the given GNode.
void	initializeArrowHead()
GraphObject	linkedTo(GNode gn) Tells whether the given node is linked at all with this GEdge.
void	makeArrowPoints(double howFar) Convenience method for pre-calculating the arrow points for this edge (if needed).
void	makeArrowPoints(Point2D.Double fromPt, Point2D.Double toPt, double howFar) Sets the variables arrowPoint, arrowEndPoint1 and arrowEndPoint2 to speed up drawing.
void	placeEdge() Determines the placement of a GEdge.
void	setArrowHeadHeight(int arrowHeadHeight)
void	setArrowHeadWidth(int arrowHeadWidth)
void	setColor() Sets the colors of a GEdge to black.
void	setEdgeThickness(double edgeThickness)
String	toString() Currently empty, may be used in the future.
boolean	unCommitFromKnowledgeBase(KnowledgeBase kb) Subclasses will implement this method in order to perform whatever object-specific actions are appropriate for removing this object from the knowledge base.

Methods inherited from class charger.obj.GraphObject

addHistoryRecord, adjustCustomDisplayRect, draw, findDominantContext, forceMove, forgetObject, getBestFontMetrics, getCenter, getColor, getDepth, getDim, getDisplayRect, getDisplayRect3D, getHistory, getLabelFont, getMinimumContentSize, getObjectLocator, getOutermostGraph, getOwnerFrame, getOwnerGraph, getShapeForDrawing, getTextLabel, getTextLabelSize, getUpperLeft, getWrapColumns, getWrapLabels, isNegated, isNegativelyNested, listToString, listToStringXML, putInCorrectContext, putInCorrectContext, resizeIfNecessary, resizeIfNecessary, selfCleanup, setBackground, setCenter, setCenterOnly, setColor, setDepth, setDim, setDim, setDisplayRect, setDisplayRect, setDisplayRect3D, setForeground, setLabelFont, setNegated, setOwnerGraph, setTextLabel, setTextLabel, setTextLabel, setUpperLeft, setUpperLeft

Methods inherited from class Object

clone, equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

fromObj

public GraphObject fromObj

toObj

public GraphObject toObj

edgeAttributes

public EdgeAttributes edgeAttributes

used for indicating the node isn't connected

fromPt

public Point2D.Double fromPt

remembers its source point as set.

toPt

public Point2D.Double toPt

remembers its destination point as set.

midPoint

Point2D.Double midPoint

remembers its middle point as set.

arrowPoint

Point2D.Double arrowPoint

the "point" of the arrow.

See Also:

makeArrowPoints(double)

arrowEndPoint1

Point2D.Double arrowEndPoint1

one back corner of the arrow.

See Also:

makeArrowPoints(double)

arrowEndPoint2

Point2D.Double arrowEndPoint2

another back corner of the arrow.

See Also:

makeArrowPoints(double)

arrowHeadShape

GeneralPath arrowHeadShape

Arrowhead triangle to be filled in when drawing an arrow.

See Also:

arrowPoint, arrowEndPoint1, arrowEndPoint2

Constructor Detail

GEdge

public GEdge()

Constructs a new GEdge with label "-".

GEdge

public GEdge(GraphObject FromOne,
             GraphObject ToOne)

Constructs a new GEdge with label "-" going from one object to another.

Parameters:

FromOne - edge starts here

ToOne - edge ends here

Method Detail

getShape

public Shape getShape()

Description copied from class: GraphObject

Obtain the Shape object that represents the selectable region of this object.

Specified by:

getShape in class GraphObject

Returns:

the display rectangle

getLength

public float getLength()

Returns:

the length of the diagonal.

setColor

public void setColor()

Sets the colors of a GEdge to black. May be overridden in a sub-class.

Overrides:

setColor in class GraphObject

getArrowHeadLength

private float getArrowHeadLength()

getArrowHeadAngle

private float getArrowHeadAngle()

getArrowHeadWidth

public int getArrowHeadWidth()

setArrowHeadWidth

public void setArrowHeadWidth(int arrowHeadWidth)

getArrowHeadHeight

public int getArrowHeadHeight()

setArrowHeadHeight

public void setArrowHeadHeight(int arrowHeadHeight)

getEdgeThickness

public double getEdgeThickness()

setEdgeThickness

public void setEdgeThickness(double edgeThickness)

initializeArrowHead

public void initializeArrowHead()

drawBorder

public void drawBorder(Graphics2D g,
                       Color borderColor)

Currently empty, may be used in the future.

Specified by:

drawBorder in class GraphObject

Parameters:

g - Graphics context on which the object is to be rendered

borderColor - the color to draw

toString

public String toString()

Currently empty, may be used in the future.

Overrides:

toString in class GraphObject

See Also:

IOManager

abandonObject

public void abandonObject()

Does everything but the actual removal (de-allocation)

Specified by:

abandonObject in class GraphObject

detachFromGNodes

public void detachFromGNodes()

Finds the endpoint nodes of the edge, and removes the edge from each of their lists

finalize

protected void finalize()
                 throws Throwable

Overrides:

finalize in class GraphObject

Throws:

Throwable

placeEdge

public void placeEdge()

Determines the placement of a GEdge. Uses the display rectangles of its linked components, rather than their centers. Pre-calculates the coordinates of its arrow points (whether used or not) for efficiency.

See Also:

GraphObject#displayRect, getObjectShapeForClipping(charger.obj.GraphObject)

getObjectShapeForClipping

protected Shape getObjectShapeForClipping(GraphObject go)

Determines the appropriate rectangle to use as object boundaries when drawing edges

Parameters:

go - The object whose boundary rectangle is sought.

Returns:

The boundary rectangle for the object.

makeArrowPoints

public void makeArrowPoints(double howFar)

Convenience method for pre-calculating the arrow points for this edge (if needed). Gets the end points from the edge's known end objects

Parameters:

howFar - How far from the "from" object to draw the arrowhead. Ranges from 0 to 1.0;

makeArrowPoints

public void makeArrowPoints(Point2D.Double fromPt,
                            Point2D.Double toPt,
                            double howFar)

Sets the variables arrowPoint, arrowEndPoint1 and arrowEndPoint2 to speed up drawing. Knows nothing about clipping the edge for rectangles, shapes, etc. That must be done elsewhere. We assume that an arrowhead is a triangle, one of whose vertices is on the line, while the other two are equidistant from the line.

Parameters:

fromPt - the beginning point of the edge

toPt - the end point of the edge

howFar - where the arrow should go where start is 0.0 and end is 1.0

See Also:

makeArrowPoints(double), drawArrowHead(java.awt.Graphics2D, boolean, boolean)

drawArrowHead

public void drawArrowHead(Graphics2D g,
                          boolean filled,
                          boolean printing)

Uses the instance variables arrowPoint, arrowEndPoint1 and arrowEndPoint2 to speed up drawing

Parameters:

g - Graphics context on which to draw

filled - Whether to fill in the arrow head or not

printing - Whether we are drawing to print or to display on screen (not used)

See Also:

makeArrowPoints(double)

findClippingPoint

public static Point2D.Double findClippingPoint(Point2D.Double fromPt,
                                               Point2D.Double toPt,
                                               Shape s)

Assuming that there's a shape at the toPt, find the clipping point on its boundary along a line from the fromPt to the toPt.

findClippingPointRectangle

public static Point2D.Double findClippingPointRectangle(Point2D.Double fromPt,
                                                        Rectangle2D.Double rect)

Given a point and a rectangle, find that point on the rectangle that lies on the edge between the given point and the center of the rectangle

Parameters:

fromPt - any point on the canvas; assume it is outside the rectangle

rect - the rectangle we want to intersect -- assume its center point is the other end of the line

Returns:

a point on the rectangle that is also on the edge between fromPt and r's center.

findClippingPointShape

public static Point2D.Double findClippingPointShape(Point2D.Double fromPt,
                                                    Point2D.Double toPt,
                                                    Shape shape)

Finds the clipping point for an arbitrary shape.

Parameters:

fromPt - origin of the line

toPt - other end of the line (assumed to be inside the shape)

shape - the general shape to be analyzed. If toPt is not inside the shape, or if fromPt is already inside the shape, strange things will happen.

areLinked

public static boolean areLinked(GNode go1,
                                GNode go2)

Determines whether the two charger nodes are linked together, by any GEdge.

Parameters:

go1 - one node

go2 - another node

Returns:

true if there is any GEdge connecting the two; false otherwise.

linkedTo

public GraphObject linkedTo(GNode gn)

Tells whether the given node is linked at all with this GEdge.

Parameters:

gn - is one end of the link

Returns:

the node to which gn is connected via the GEdge, null if gn is not linked

howLinked

public GEdge.Direction howLinked(GNode gn)

Tells which end of the current link (if either) is the given GNode.

Parameters:

gn - is a possible end of the link

Returns:

GEdge.Direction.FROM if gn is the "from" node for the link, or GEdge.Direction.TO if gn is its "to" node.

See Also:

GEdge.Direction.FROM, GEdge.Direction.TO, GEdge.Direction.UNLINKED

commitToKnowledgeBase

public boolean commitToKnowledgeBase(KnowledgeBase kb)

needed for GraphLayout interface

Overrides:

commitToKnowledgeBase in class GraphObject

unCommitFromKnowledgeBase

public boolean unCommitFromKnowledgeBase(KnowledgeBase kb)

Description copied from class: GraphObject

Subclasses will implement this method in order to perform whatever object-specific actions are appropriate for removing this object from the knowledge base.

Overrides:

unCommitFromKnowledgeBase in class GraphObject