org.gephi.preview.plugin.renderers

Class ArrowRenderer

java.lang.Object

org.gephi.preview.plugin.renderers.ArrowRenderer

All Implemented Interfaces:

Renderer

public class ArrowRenderer
extends Object
implements Renderer

Author:

Yudi Xue, Mathieu Bastian

Constructor Summary

Constructors

Constructor and Description
ArrowRenderer()

Method Summary

Modifier and Type	Method and Description
CanvasSize	getCanvasSize(Item item, PreviewProperties properties) Compute the canvas size of the item to render.
String	getDisplayName() Provides an user friendly name for the renderer.
PreviewProperty[]	getProperties() Returns all associated properties for this renderer.
boolean	isRendererForitem(Item item, PreviewProperties properties) Based on properties, determine whether this renderer is valid to render Item.
boolean	needsItemBuilder(ItemBuilder itemBuilder, PreviewProperties properties) Based on the itemBuilder class and the properties, determine whether this renderer needs the given itemBuilder to be executed before rendering.
void	preProcess(PreviewModel previewModel) This method is called before rendering for all renderers and initializes items' additional attributes or run complex algorithms.
void	render(Item item, RenderTarget target, PreviewProperties properties) Render item to target using the global properties and item data.

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrowRenderer

public ArrowRenderer()

Method Detail

preProcess

public void preProcess(PreviewModel previewModel)

Description copied from interface: Renderer

This method is called before rendering for all renderers and initializes items' additional attributes or run complex algorithms.

This method has access to any item using the getItems() methods of the preview model.

No data should be stored in the renderer itself but put in items using Item.setData(java.lang.String, java.lang.Object). Global states can be stored in properties using PreviewProperties.putValue(java.lang.String, java.lang.Object).

Specified by:

preProcess in interface Renderer

Parameters:

previewModel - the model to get items from

render

public void render(Item item,
                   RenderTarget target,
                   PreviewProperties properties)

Description copied from interface: Renderer

Render item to target using the global properties and item data.

The target can be one of the default target G2DTarget, SVGTarget or PDFTarget. Each target contains an access to it's drawing canvas so the renderer can draw visual items.

Specified by:

render in interface Renderer

Parameters:

item - the item to be rendered

target - the target to render the item on

properties - the central properties

getCanvasSize

public CanvasSize getCanvasSize(Item item,
                                PreviewProperties properties)

Description copied from interface: Renderer

Compute the canvas size of the item to render. The returned CanvasSize has to embed the whole item to render. If the canvas size cannot be computed, a CanvasSize with both width and height equlal to zero is returned.

Specified by:

getCanvasSize in interface Renderer

Parameters:

item - the item to get the canvas size

properties - the current properties

Returns:

the item canvas size

getProperties

public PreviewProperty[] getProperties()

Description copied from interface: Renderer

Returns all associated properties for this renderer. Properties can be built using static PreviewProperty.createProperty() methods.

Specified by:

getProperties in interface Renderer

Returns:

a properties array

isRendererForitem

public boolean isRendererForitem(Item item,
                                 PreviewProperties properties)

Description copied from interface: Renderer

Based on properties, determine whether this renderer is valid to render Item.

Additional states in properties helps to make a decision, including:

• PreviewProperty.DIRECTED: If the graph is directed
• PreviewProperty.MOVING: Specific to the Processing target, this is true if the user is currently moving the canvas. Renderers other than the node renderer usually render nothing while the user is moving to speeds things up.

Specified by:

isRendererForitem in interface Renderer

Parameters:

item - the item to be tested

properties - the current properties

Returns:

true if item can be rendered by this renderer, false otherwise

needsItemBuilder

public boolean needsItemBuilder(ItemBuilder itemBuilder,
                                PreviewProperties properties)

Description copied from interface: Renderer

Based on the itemBuilder class and the properties, determine whether this renderer needs the given itemBuilder to be executed before rendering.

This is used for avoiding building unnecessary items while refreshing preview.

You can simply return true if the builder builds items that this renderer renders, but you can also check the current properties to see if your renderer is going to produce any graphic.

Additional states in properties helps to make a decision, including:

• PreviewProperty.DIRECTED: If the graph is directed
• PreviewProperty.MOVING: Specific to the Processing target, this is true if the user is currently moving the canvas. Renderers other than the node renderer usually render nothing while the user is moving to speeds things up.

Specified by:

needsItemBuilder in interface Renderer

Parameters:

itemBuilder - builder that your renderer may need

properties - the current properties

Returns:

true if you are going to use built items for rendering, false otherwise

getDisplayName

public String getDisplayName()

Description copied from interface: Renderer

Provides an user friendly name for the renderer. This name will appear in the renderers manager UI.

Specified by:

getDisplayName in interface Renderer

Returns:

User friendly renderer name, not null