edu.uci.ics.jung.visualization.picking

Class ShapePickSupport<V,E>

java.lang.Object

edu.uci.ics.jung.visualization.picking.ShapePickSupport<V,E>

All Implemented Interfaces:

GraphElementAccessor<V,E>

Direct Known Subclasses:

LayoutLensShapePickSupport, ViewLensShapePickSupport

public class ShapePickSupport<V,E>
extends Object
implements GraphElementAccessor<V,E>

A GraphElementAccessor that returns elements whose Shape contains the specified pick point or region.

Author:

Tom Nelson

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ShapePickSupport.Style The available picking heuristics: Style.CENTERED: returns the element whose center is closest to the pick point.

Field Summary

Fields

Modifier and Type	Field and Description
protected float	pickSize
protected ShapePickSupport.Style	style The current picking heuristic for this instance.
protected VisualizationServer<V,E>	vv The VisualizationServer in which the this instance is being used for picking.

Constructor Summary

Constructors

Constructor and Description
ShapePickSupport(VisualizationServer<V,E> vv) Create a ShapePickSupport for the specified VisualizationServer with a default pick footprint.
ShapePickSupport(VisualizationServer<V,E> vv, float pickSize) Creates a ShapePickSupport for the vv VisualizationServer, with the specified pick footprint and the default pick style.

Method Summary

Modifier and Type	Method and Description
protected boolean	edgesAreFiltered() Quick test to allow optimization of getFilteredEdges().
E	getEdge(Layout<V,E> layout, double x, double y) Returns an edge whose shape intersects the 'pickArea' footprint of the passed x,y, coordinates.
protected Collection<E>	getFilteredEdges(Layout<V,E> layout)
protected Collection<V>	getFilteredVertices(Layout<V,E> layout)
float	getPickSize() Returns the size of the edge picking area.
ShapePickSupport.Style	getStyle() Returns the style of picking used by this instance.
V	getVertex(Layout<V,E> layout, double x, double y) Returns the vertex, if any, whose shape contains (x, y).
Collection<V>	getVertices(Layout<V,E> layout, Shape shape) Returns the vertices whose layout coordinates are contained in Shape.
protected boolean	isEdgeRendered(Context<Graph<V,E>,E> context) Returns true if this edge and its endpoints in this graph are all included in the collections of elements to be rendered, and false otherwise.
protected boolean	isVertexRendered(Context<Graph<V,E>,V> context) Returns true if this vertex in this graph is included in the collections of elements to be rendered, and false otherwise.
void	setPickSize(float pickSize) Sets the size of the edge picking area.
void	setStyle(ShapePickSupport.Style style) Specifies the style of picking to be used by this instance.
protected boolean	verticesAreFiltered() Quick test to allow optimization of getFilteredVertices().

Methods inherited from class java.lang.Object

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

Field Detail

pickSize

protected float pickSize

vv

protected VisualizationServer<V,E> vv

The VisualizationServer in which the this instance is being used for picking. Used to retrieve properties such as the layout, renderer, vertex and edge shapes, and coordinate transformations.

style

protected ShapePickSupport.Style style

The current picking heuristic for this instance. Defaults to CENTERED.

Constructor Detail

ShapePickSupport

public ShapePickSupport(VisualizationServer<V,E> vv,
                        float pickSize)

Creates a ShapePickSupport for the vv VisualizationServer, with the specified pick footprint and the default pick style. The VisualizationServer is used to access properties of the current visualization (layout, renderer, coordinate transformations, vertex/edge shapes, etc.).

Parameters:

vv - source of the current Layout.

pickSize - the size of the pick footprint for line edges

ShapePickSupport

public ShapePickSupport(VisualizationServer<V,E> vv)

Create a ShapePickSupport for the specified VisualizationServer with a default pick footprint. of size 2.

Parameters:

vv - the visualization server used for rendering

Method Detail

getStyle

public ShapePickSupport.Style getStyle()

Returns the style of picking used by this instance. This specifies which of the elements, among those whose shapes contain the pick point, is returned. The available styles are:

• Style.CENTERED: returns the element whose center is closest to the pick point.
• Style.LOWEST: returns the first such element encountered. (If the element collection has a consistent ordering, this will also be the element "on the bottom", that is, the one which is rendered first.)
• Style.HIGHEST: returns the last such element encountered. (If the element collection has a consistent ordering, this will also be the element "on the top", that is, the one which is rendered last.)

Returns:

the style of picking used by this instance

setStyle

public void setStyle(ShapePickSupport.Style style)

Specifies the style of picking to be used by this instance. This specifies which of the elements, among those whose shapes contain the pick point, will be returned. The available styles are:

• Style.CENTERED: returns the element whose center is closest to the pick point.
• Style.LOWEST: returns the first such element encountered. (If the element collection has a consistent ordering, this will also be the element "on the bottom", that is, the one which is rendered first.)
• Style.HIGHEST: returns the last such element encountered. (If the element collection has a consistent ordering, this will also be the element "on the top", that is, the one which is rendered last.)

Parameters:

style - the style to set

getVertex

public V getVertex(Layout<V,E> layout,
                   double x,
                   double y)

Returns the vertex, if any, whose shape contains (x, y). If (x,y) is contained in more than one vertex's shape, returns the vertex whose center is closest to the pick point.

Specified by:

getVertex in interface GraphElementAccessor<V,E>

Parameters:

layout - the layout instance that records the positions for all vertices

x - the x coordinate of the pick point

y - the y coordinate of the pick point

Returns:

the vertex whose shape contains (x,y), and whose center is closest to the pick point

getVertices

public Collection<V> getVertices(Layout<V,E> layout,
                                 Shape shape)

Returns the vertices whose layout coordinates are contained in Shape. The shape is in screen coordinates, and the graph vertices are transformed to screen coordinates before they are tested for inclusion.

Specified by:

getVertices in interface GraphElementAccessor<V,E>

Returns:

the Collection of vertices whose layout coordinates are contained in shape.

getEdge

public E getEdge(Layout<V,E> layout,
                 double x,
                 double y)

Returns an edge whose shape intersects the 'pickArea' footprint of the passed x,y, coordinates.

Specified by:

getEdge in interface GraphElementAccessor<V,E>

Parameters:

layout - the context in which the location is defined

x - the x coordinate of the location

y - the y coordinate of the location

Returns:

an edge whose shape intersects the pick area centered on the location (x,y)

getFilteredVertices

protected Collection<V> getFilteredVertices(Layout<V,E> layout)

getFilteredEdges

protected Collection<E> getFilteredEdges(Layout<V,E> layout)

verticesAreFiltered

protected boolean verticesAreFiltered()

Quick test to allow optimization of getFilteredVertices().

Returns:

true if there is an active vertex filtering mechanism for this visualization, false otherwise

edgesAreFiltered

protected boolean edgesAreFiltered()

Quick test to allow optimization of getFilteredEdges().

Returns:

true if there is an active edge filtering mechanism for this visualization, false otherwise

isVertexRendered

protected boolean isVertexRendered(Context<Graph<V,E>,V> context)

Returns true if this vertex in this graph is included in the collections of elements to be rendered, and false otherwise.

Parameters:

context - the vertex and graph to be queried

Returns:

true if this vertex is included in the collections of elements to be rendered, false otherwise.

isEdgeRendered

protected boolean isEdgeRendered(Context<Graph<V,E>,E> context)

Returns true if this edge and its endpoints in this graph are all included in the collections of elements to be rendered, and false otherwise.

Parameters:

context - the edge and graph to be queried

Returns:

true if this edge and its endpoints are all included in the collections of elements to be rendered, false otherwise.

getPickSize

public float getPickSize()

Returns the size of the edge picking area. The picking area is square; the size is specified as the length of one side, in view coordinates.

Returns:

the size of the edge picking area

setPickSize

public void setPickSize(float pickSize)

Sets the size of the edge picking area.

Parameters:

pickSize - the length of one side of the (square) picking area, in view coordinates