y.layout
Class SliderEdgeLabelModel

java.lang.Object
  y.layout.SliderEdgeLabelModel

All Implemented Interfaces:

EdgeLabelModel

public class SliderEdgeLabelModel
extends Object
implements EdgeLabelModel

An edge label model that allows placement of labels at a set of continuous positions along both sides of an edge or directly on the edge path.

The set of positions can be influenced by specifying the density value that controls the spacing between adjacent label positions. Furthermore, it's possible to specify distance values that control the distance between label and edge and between label and nodes.

Nested Class Summary

static class

SliderEdgeLabelModel.ModelParameter Encodes the model parameters for the two slider edge label models specified by CENTER_SLIDER and SIDE_SLIDER.

Field Summary

static byte	CENTER_RATIO Symbolic ratio specifier.
static byte	CENTER_SLIDER Symbolic model specifier.
static byte	HEAD_RATIO Symbolic ratio specifier.
static byte	LEFT_RATIO Symbolic ratio specifier.
static byte	RIGHT_RATIO Symbolic ratio specifier.
static byte	SIDE_SLIDER Symbolic model specifier.
static byte	TAIL_RATIO Symbolic ratio specifier.

Constructor Summary

SliderEdgeLabelModel(byte mode)
Returns a new instance of SliderEdgeLabelModel.

Method Summary

Object	createModelParameter(YRectangle labelBounds, EdgeLayout edgeLayout, NodeLayout sourceNode, NodeLayout targetNode) Creates a model parameter that represents the given edge label context best within this model.
Object	getDefaultParameter() Returns a model parameter that encodes the default position of this model's allowed edge label positions.
YList	getLabelCandidates(EdgeLabelLayout label, EdgeLayout edgeLayout, NodeLayout sourceNode, NodeLayout targetNode) Returns a list of candidate positions for the given edge label.
YPoint	getLabelPlacement(YDimension labelSize, EdgeLayout edgeLayout, NodeLayout sourceNode, NodeLayout targetNode, Object para) Returns the coordinates of the upper-left corner of the label position encoded by the given model parameter.
YVector	getOffsetVec(double dx, double dy, double width, double height, byte labelPosition) Returns the offset vector for a given edge label and a given edge segment.
void	setDensity(double density) Sets the density to generate label candidate positions.
void	setDistances(double minDistance, double maxDistance) Sets the minimum and maximum distances between the label's bounding box and the edge's path.
void	setNodeBorderDistance(double value) Sets the minimal distance between the label's bounding box and a node's borders.

Methods inherited from class java.lang.Object

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

Field Detail

CENTER_SLIDER

public static final byte CENTER_SLIDER

Symbolic model specifier. Chooses continuous label positions directly on the edge path.

See Also:

Constant Field Values

SIDE_SLIDER

public static final byte SIDE_SLIDER

Symbolic model specifier. Chooses continuous label positions along the sides of the edge path.

See Also:

Constant Field Values

CENTER_RATIO

public static final byte CENTER_RATIO

Symbolic ratio specifier. Valid only in conjunction with label model CENTER_SLIDER.

See Also:

Constant Field Values

TAIL_RATIO

public static final byte TAIL_RATIO

Symbolic ratio specifier. Valid only in conjunction with label model SIDE_SLIDER. Determines a label to be right of or below the edge's path.

See Also:

Constant Field Values

HEAD_RATIO

public static final byte HEAD_RATIO

Symbolic ratio specifier. Valid only in conjunction with label model SIDE_SLIDER. Determines a label to be left of or above the edge's path.

See Also:

Constant Field Values

LEFT_RATIO

public static final byte LEFT_RATIO

Symbolic ratio specifier. Valid only in conjunction with label model SIDE_SLIDER. Determines a label to be left of the edge's path.

See Also:

Constant Field Values

RIGHT_RATIO

public static final byte RIGHT_RATIO

Symbolic ratio specifier. Valid only in conjunction with label model SIDE_SLIDER. Determines a label to be right of the edge's path.

See Also:

Constant Field Values

Constructor Detail

SliderEdgeLabelModel

public SliderEdgeLabelModel(byte mode)

Returns a new instance of SliderEdgeLabelModel.

Parameters:

mode - Determines which slider model to use. Possible values are either CENTER_SLIDER or SIDE_SLIDER.

Method Detail

setDistances

public void setDistances(double minDistance,
                         double maxDistance)

Sets the minimum and maximum distances between the label's bounding box and the edge's path.

Parameters:

minDistance - The minimal distance between label and edge.

maxDistance - The maximal distance between label and edge.

setDensity

public void setDensity(double density)

Sets the density to generate label candidate positions.

A density value of 1.0 (which is the default) generates the most possible candidate positions without overlap.

Parameters:

density - The density value. It has a range of 0.0 to 1.0.

setNodeBorderDistance

public void setNodeBorderDistance(double value)

Sets the minimal distance between the label's bounding box and a node's borders.

Parameters:

value - The distance between label and node border.

getDefaultParameter

public Object getDefaultParameter()

Returns a model parameter that encodes the default position of this model's allowed edge label positions.

The default positions for both slider edge label models are relative to the first edge segment, either at the beginning of the segment (SIDE_SLIDER model) or at its middle (CENTER_SLIDER model).

Specified by:

getDefaultParameter in interface EdgeLabelModel

Returns:

A model parameter that can be passed to the EdgeLabelModel.getLabelPlacement(YDimension, EdgeLayout, NodeLayout, NodeLayout, Object) method.

getLabelPlacement

public YPoint getLabelPlacement(YDimension labelSize,
                                EdgeLayout edgeLayout,
                                NodeLayout sourceNode,
                                NodeLayout targetNode,
                                Object para)

Description copied from interface: EdgeLabelModel

Returns the coordinates of the upper-left corner of the label position encoded by the given model parameter.

Specified by:

getLabelPlacement in interface EdgeLabelModel

Parameters:

labelSize - The size of the label that should be placed.

edgeLayout - The layout of the edge to which the label belongs.

sourceNode - The layout of the source node of the label owning edge.

targetNode - The layout of the target node of the label owning edge.

para - The model parameter that describes the abstract position of the label within this model. The parameter must have been generated by this model.

Returns:

The coordinates of the upper-left corner of a label position.

getLabelCandidates

public YList getLabelCandidates(EdgeLabelLayout label,
                                EdgeLayout edgeLayout,
                                NodeLayout sourceNode,
                                NodeLayout targetNode)

Returns a list of candidate positions for the given edge label. The number of candidates and their respective locations are computed depending on the geometries of both label and edge.

Specified by:

getLabelCandidates in interface EdgeLabelModel

Parameters:

label - The label for which candidates should be generated.

edgeLayout - The layout of the edge to which the label belongs.

sourceNode - The layout of the source node of the label owning edge.

targetNode - The layout of the target node of the label owning edge.

Returns:

A list of EdgeLabelCandidate objects.

createModelParameter

public Object createModelParameter(YRectangle labelBounds,
                                   EdgeLayout edgeLayout,
                                   NodeLayout sourceNode,
                                   NodeLayout targetNode)

Description copied from interface: EdgeLabelModel

Creates a model parameter that represents the given edge label context best within this model. The created model parameter represents the closest parameter representation of the given label location that can be achieved within this model.

Specified by:

createModelParameter in interface EdgeLabelModel

Parameters:

labelBounds - The bounds of the label for which a parameter representation is sought.

edgeLayout - The layout of the edge to which the label belongs.

sourceNode - The layout of the source node of the label owning edge.

targetNode - The layout of the target node of the label owning edge.

Returns:

A model parameter that can be passed to the EdgeLabelModel.getLabelPlacement(YDimension, EdgeLayout, NodeLayout, NodeLayout, Object) method.

getOffsetVec

public YVector getOffsetVec(double dx,
                            double dy,
                            double width,
                            double height,
                            byte labelPosition)

Returns the offset vector for a given edge label and a given edge segment. The offset vector describes where to move a label candidate such that it keeps a certain distance to the edge's path.

Parameters:

dx - x-coordinates delta for an edge segment.

dy - y-coordinates delta for an edge segment.

width - The label's width.

height - The label's height.

labelPosition - One of the symbolic ratio specifiers CENTER_RATIO, LEFT_RATIO, or RIGHT_RATIO.

Returns:

An offset vector.