com.mxgraph.util

Class mxCurve

java.lang.Object

com.mxgraph.util.mxCurve

public class mxCurve
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
static String	CORE_CURVE Defines the key for the central curve index
protected Map<String,Double>	curveLengths The curve lengths of the curves
List<mxPoint>	guidePoints The points this curve is drawn through.
protected Map<String,double[]>	intervals An array of arrays of intervals.
static mxLine	INVALID_POSITION Indicates that an invalid position on a curve was requested
static String	LABEL_CURVE Defines the key for the label curve index
protected double	labelBuffer Offset of the label curve from the curve the label curve is based on.
protected double	maxXBounds
protected double	maxYBounds
protected double	minXBounds
protected double	minYBounds
protected Map<String,mxPoint[]>	points A collection of arrays of curve points
protected boolean	valid Whether or not the curve currently holds valid values

Constructor Summary

Constructors

Constructor and Description
mxCurve()
mxCurve(List<mxPoint> points)

Method Summary

Modifier and Type	Method and Description
mxPoint	collisionMove(String index, mxRectangle rect, double buffer) Returns a point to move the input rectangle to, in order to attempt to place the rectangle away from the curve.
protected void	createCoreCurve() Creates the core curve that is based on the guide points passed into this class instance
protected void	createLabelCurve()
protected mxPoint[]	getBaseLabelCurve() Returns the curve the label curve is too be based on
mxRectangle	getBounds()
double	getCurveLength(String index)
mxLine	getCurveParallel(String index, double distance) Returns a unit vector parallel to the curve at the specified distance along the curve.
mxPoint[]	getCurvePoints(String index) Obtains the points that make up the curve for the specified curve index.
mxPoint[]	getCurveSection(String index, double start, double end) Returns a section of the curve as an array of points
List<mxPoint>	getGuidePoints()
double[]	getIntervals(String index)
protected int	getLowerIndexOfSegment(String index, double distance) Calculates the index of the lower point on the segment that contains the point distance along the
mxRectangle	getRelativeFromAbsPoint(mxPoint absPoint, String index) Calculates the position of an absolute in terms relative to this curve.
protected mxPoint	intersectRectPerimeterPoint(String curveIndex, mxRectangle rect, int indexSeg) Returns the point at which this curve segment intersects the boundary of the given rectangle, if it does so.
protected int	intersectRectPerimeterSeg(String index, mxRectangle rect) Utility method to determine within which segment the specified rectangle intersects the specified curve
protected int	intersectRectPerimeterSeg(String index, mxRectangle rect, int startSegment) Utility method to determine within which segment the specified rectangle intersects the specified curve.
boolean	intersectsRect(Rectangle rect) Returns whether or not the rectangle passed in hits any part of this curve.
mxPoint	intersectsRectPerimeter(String index, mxRectangle rect) Returns the point at which this curve intersects the boundary of the given rectangle, if it does so.
double	intersectsRectPerimeterDist(String index, mxRectangle rect) Returns the distance from the start of the curve at which this curve intersects the boundary of the given rectangle, if it does so.
boolean	isLabelReversed() Whether or not the label curve starts from the end target and traces to the start of the branch
protected void	populateIntervals(String index)
void	setLabelBuffer(double buffer)
protected void	updateBounds(double pointX, double pointY) Updates the total bounds of this curve, increasing any dimensions, if necessary, to fit in the specified point
void	updateCurve(List<mxPoint> newPoints) Updates the existing curve using the points passed in.
protected boolean	validateCurve() Method must be called before any attempt to access curve information

Methods inherited from class java.lang.Object

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

Field Detail

points

protected Map<String,mxPoint[]> points

A collection of arrays of curve points

minXBounds

protected double minXBounds

maxXBounds

protected double maxXBounds

minYBounds

protected double minYBounds

maxYBounds

protected double maxYBounds

intervals

protected Map<String,double[]> intervals

An array of arrays of intervals. These intervals define the distance along the edge (0 to 1) that each point lies

curveLengths

protected Map<String,Double> curveLengths

The curve lengths of the curves

CORE_CURVE

public static String CORE_CURVE

Defines the key for the central curve index

LABEL_CURVE

public static String LABEL_CURVE

Defines the key for the label curve index

INVALID_POSITION

public static mxLine INVALID_POSITION

Indicates that an invalid position on a curve was requested

labelBuffer

protected double labelBuffer

Offset of the label curve from the curve the label curve is based on. If you wish to set this value, do so directly after creation of the curve. The first time the curve is used the label curve will be created with whatever value is contained in this variable. Changes to it after that point will have no effect.

guidePoints

public List<mxPoint> guidePoints

The points this curve is drawn through. These are typically control points and are at distances from each other that straight lines between them do not describe a smooth curve. This class takes these guiding points and creates a finer set of internal points that visually appears to be a curve when linked by straight lines

valid

protected boolean valid

Whether or not the curve currently holds valid values

Constructor Detail

mxCurve

public mxCurve()

mxCurve

public mxCurve(List<mxPoint> points)

Method Detail

setLabelBuffer

public void setLabelBuffer(double buffer)

getBounds

public mxRectangle getBounds()

getLowerIndexOfSegment

protected int getLowerIndexOfSegment(String index,
                                     double distance)

Calculates the index of the lower point on the segment that contains the point distance along the

getCurveParallel

public mxLine getCurveParallel(String index,
                               double distance)

Returns a unit vector parallel to the curve at the specified distance along the curve. To obtain the angle the vector makes with (1,0) perform Math.atan(segVectorY/segVectorX).

Parameters:

index - the curve index specifying the curve to analyse

distance - the distance from start to end of curve (0.0...1.0)

Returns:

a unit vector at the specified point on the curve represented as a line, parallel with the curve. If the distance or curve is invalid, mxCurve.INVALID_POSITION is returned

getCurveSection

public mxPoint[] getCurveSection(String index,
                                 double start,
                                 double end)

Returns a section of the curve as an array of points

Parameters:

index - the curve index specifying the curve to analyse

start - the start position of the curve segment (0.0...1.0)

end - the end position of the curve segment (0.0...1.0)

Returns:

a sequence of point representing the curve section or null if it cannot be calculated

intersectsRect

public boolean intersectsRect(Rectangle rect)

Returns whether or not the rectangle passed in hits any part of this curve.

Parameters:

rect - the rectangle to detect for a hit

Returns:

whether or not the rectangle hits this curve

intersectsRectPerimeter

public mxPoint intersectsRectPerimeter(String index,
                                       mxRectangle rect)

Returns the point at which this curve intersects the boundary of the given rectangle, if it does so. If it does not intersect, null is returned. If it intersects multiple times, the first intersection from the start end of the curve is returned.

Parameters:

index - the curve index specifying the curve to analyse

rect - the whose boundary is to be tested for intersection with this curve

Returns:

the point at which this curve intersects the boundary of the given rectangle, if it does so. If it does not intersect, null is returned.

intersectsRectPerimeterDist

public double intersectsRectPerimeterDist(String index,
                                          mxRectangle rect)

Returns the distance from the start of the curve at which this curve intersects the boundary of the given rectangle, if it does so. If it does not intersect, -1 is returned. If it intersects multiple times, the first intersection from the start end of the curve is returned.

Parameters:

index - the curve index specifying the curve to analyse

rect - the whose boundary is to be tested for intersection with this curve

Returns:

the distance along the curve from the start at which the intersection occurs

collisionMove

public mxPoint collisionMove(String index,
                             mxRectangle rect,
                             double buffer)

Returns a point to move the input rectangle to, in order to attempt to place the rectangle away from the curve. NOTE: Curves are scaled, the input rectangle should be also.

Parameters:

index - the curve index specifying the curve to analyse

rect - the rectangle that is to be moved

buffer - the amount by which the rectangle is to be moved, beyond the dimensions of the rect

Returns:

the point to move the top left of the input rect to , otherwise null if no point can be determined

intersectRectPerimeterSeg

protected int intersectRectPerimeterSeg(String index,
                                        mxRectangle rect)

Utility method to determine within which segment the specified rectangle intersects the specified curve

Parameters:

index - the curve index specifying the curve to analyse

rect - the whose boundary is to be tested for intersection with this curve

Returns:

the point at which this curve intersects the boundary of the given rectangle, if it does so. If it does not intersect, -1 is returned

intersectRectPerimeterSeg

protected int intersectRectPerimeterSeg(String index,
                                        mxRectangle rect,
                                        int startSegment)

Utility method to determine within which segment the specified rectangle intersects the specified curve. This method specifies which segment to start searching at.

Parameters:

index - the curve index specifying the curve to analyse

rect - the whose boundary is to be tested for intersection with this curve

startSegment - the segment to start searching at. To start at the beginning of the curve, use 1, not 0.

Returns:

the point at which this curve intersects the boundary of the given rectangle, if it does so. If it does not intersect, -1 is returned

intersectRectPerimeterPoint

protected mxPoint intersectRectPerimeterPoint(String curveIndex,
                                              mxRectangle rect,
                                              int indexSeg)

Returns the point at which this curve segment intersects the boundary of the given rectangle, if it does so. If it does not intersect, null is returned.

Parameters:

curveIndex - the curve index specifying the curve to analyse

rect - the whose boundary is to be tested for intersection with this curve

indexSeg - the segments on this curve being checked

Returns:

the point at which this curve segment intersects the boundary of the given rectangle, if it does so. If it does not intersect, null is returned.

getRelativeFromAbsPoint

public mxRectangle getRelativeFromAbsPoint(mxPoint absPoint,
                                           String index)

Calculates the position of an absolute in terms relative to this curve.

Parameters:

absPoint - the point whose relative point is to calculated

index - the index of the curve whom the relative position is to be calculated from

Returns:

an mxRectangle where the x is the distance along the curve (0 to 1), y is the orthogonal offset from the closest segment on the curve and (width, height) is an additional Cartesian offset applied after the other calculations

createCoreCurve

protected void createCoreCurve()

Creates the core curve that is based on the guide points passed into this class instance

isLabelReversed

public boolean isLabelReversed()

Whether or not the label curve starts from the end target and traces to the start of the branch

Returns:

whether the label curve is reversed

createLabelCurve

protected void createLabelCurve()

getBaseLabelCurve

protected mxPoint[] getBaseLabelCurve()

Returns the curve the label curve is too be based on

populateIntervals

protected void populateIntervals(String index)

updateCurve

public void updateCurve(List<mxPoint> newPoints)

Updates the existing curve using the points passed in.

Parameters:

newPoints - the new guide points

getCurvePoints

public mxPoint[] getCurvePoints(String index)

Obtains the points that make up the curve for the specified curve index. If that curve, or the core curve that other curves are based on have not yet been created, then they are lazily created. If creation is impossible, null is returned

Parameters:

index - the key specifying the curve

Returns:

the points making up that curve, or null

getIntervals

public double[] getIntervals(String index)

getCurveLength

public double getCurveLength(String index)

validateCurve

protected boolean validateCurve()

Method must be called before any attempt to access curve information

Returns:

whether or not the curve may be used

updateBounds

protected void updateBounds(double pointX,
                            double pointY)

Updates the total bounds of this curve, increasing any dimensions, if necessary, to fit in the specified point

getGuidePoints

public List<mxPoint> getGuidePoints()

Returns:

the guidePoints