org.un.flex.graphLayout.layout.Hyperbolic2DLayouter

Package	org.un.flex.graphLayout.layout
Class	public class Hyperbolic2DLayouter
Inheritance	Hyperbolic2DLayouter IterativeBaseLayouter BaseLayouter
Implements	ILayoutAlgorithm

This is an implementation of the Hyperbolic 2D layouting algorithm.
For this iterative layout, most of default mouse behavior, namely:
(1) scrolling while background drag, and
(2) node drag-drop
should be turned-off in VisualGraph.

The implementation is a rewrite of Jens Kanschik's Hypergraph implementation in Java. However, apart from the general idea and some variable names, this code improves on hypergraph and also implements additional functionality. Copyright (C) 2003 Jens Kanschik, mail : jensKanschik

Public Properties

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	Property		Defined by
		animInProgress : Boolean Indicator if currently an animation sequence is still in progress.	BaseLayouter
		autoFitEnabled : Boolean	BaseLayouter
		disableAnimation : Boolean If set to true, animation is disabled and direct node location setting occurs (instantaneously).	BaseLayouter
		graph : IGraph Assign a Graph datastructure object to the layouter, every layouter will need one to work and some may allow to set it in their constructor	BaseLayouter
		layoutChanged : Boolean	BaseLayouter
		linkLength : Number This is a NOP in the BaseLayouter class.	BaseLayouter
		projector : IProjector [read-only] Helper Methods - Node Animation, Misc.	Hyperbolic2DLayouter
		vgraph : IVisualGraph Assign a VisualGraph object to the layouter, every layouter will need one to work, some may also offer to set it in their constructor.	BaseLayouter

Protected Properties

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	Property		Defined by
		_animInProgress : Boolean = false Indicator if there is currently an animation in progress	Hyperbolic2DLayouter
		_autoFitEnabled : Boolean = false The indicator if AutoFit should currently be used or not.	BaseLayouter
		currentDrawing : BaseLayoutDrawing Allow to set the reference to the drawing object from derived classes.	BaseLayouter
		_disableAnimation : Boolean = false If set to true, animation is disabled and direct node location setting occurs (instantaneously).	BaseLayouter
		_dragNode : IVisualNode = null	IterativeBaseLayouter
		_graph : IGraph = null All layouters need access to the Graph.	BaseLayouter
		_layoutChanged : Boolean = false This keeps track if the layout has changed and can be accessed by any derived layouter.	BaseLayouter
		_root : INode The current root node of the layout.	BaseLayouter
		_stree : IGTree A spanning tree of the graph, since probably every layout will work on a spanning tree, we keep this one in this base class.	BaseLayouter
		_vgraph : IVisualGraph = null All layouters need access to the VisualGraph.	BaseLayouter

Public Methods

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	Method		Defined by
		Hyperbolic2DLayouter(vg:IVisualGraph = null) Initialization - Constructors, resets	Hyperbolic2DLayouter
		bgDragContinue(event:MouseEvent):void Notifies the layouter of a background drag-in-process event, in case it wants to react to that in special way.	Hyperbolic2DLayouter
		bgDragEvent(event:MouseEvent):void Notifies the layouter of a backgroung drag event, in case it wants to react to that in special way.	Hyperbolic2DLayouter
		bgDropEvent(event:MouseEvent):void This is a NOP for this layouter.	BaseLayouter
		dragContinue(event:MouseEvent, vn:IVisualNode):void This is a NOP for this layouter.	BaseLayouter
		dragEvent(event:MouseEvent, vn:IVisualNode):void This method notifies the layouter about a drag/drop operation.	IterativeBaseLayouter
		dropEvent(event:MouseEvent, vn:IVisualNode):void Mouse Event Handling Methods	Hyperbolic2DLayouter
		layoutPass():Boolean This is the actual method that does a layout pass.	IterativeBaseLayouter
		refreshInit():void This is an initialisation method to do any kind of initialisation before a layout pass.	Hyperbolic2DLayouter
		resetAll():void This should reset all parameters of the layouter, which might not be needed for all layouters, and it is up to each layouter to do something with it.	Hyperbolic2DLayouter

Protected Methods

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	Method		Defined by
		animate():void Performs one animation step.	Hyperbolic2DLayouter
		applyTargetCoordinates(n:INode):void Sets the current absolute target coordinates of a node in the node's vnode.	BaseLayouter
		applyTargetToNodes(vns:Dictionary):void Applies the target coordinates to all nodes that are in the Dictionary object passed as argument.	BaseLayouter
		calculateLayout():void	Hyperbolic2DLayouter
		isStable():Boolean Layout Methods - Computations	Hyperbolic2DLayouter
		layoutIteration():Boolean Do a full calculation iteration of the layout.	IterativeBaseLayouter

Public Constants

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	Constant		Defined by
		ANIMATION_STEPS : int = 10 [static]	Hyperbolic2DLayouter
		DEFAULT_MARGIN : Number = 30 [static] The default margin to be considered when using autoFit.	BaseLayouter
		MINIMUM_NODE_HEIGHT : Number = 5 [static] The default minimum node height to be used if the exact node height cannot be determined yet.	BaseLayouter
		MINIMUM_NODE_WIDTH : Number = 5 [static] The default minimum node width to be used if the exact node height cannot be determined yet.	BaseLayouter

Property detail

_animInProgress

property

protected var _animInProgress:Boolean = false

Indicator if there is currently an animation in progress

projector

property

projector:IProjector [read-only]

Helper Methods - Node Animation, Misc.

Implementation
public function get projector():IProjector

Constructor detail

Hyperbolic2DLayouter

()

constructor

public function Hyperbolic2DLayouter(vg:IVisualGraph = null)

Initialization - Constructors, resets

Parameters

vg:IVisualGraph (default = null)

Method detail

animate

()

method

protected function animate():void

Performs one animation step.

bgDragContinue

()

method

public override function bgDragContinue(event:MouseEvent):void

Notifies the layouter of a background drag-in-process event, in case it wants to react to that in special way.

Parameters

event:MouseEvent

bgDragEvent

()

method

public override function bgDragEvent(event:MouseEvent):void

Notifies the layouter of a backgroung drag event, in case it wants to react to that in special way.

Parameters

event:MouseEvent

calculateLayout

()

method

protected override function calculateLayout():void

dropEvent

()

method

public override function dropEvent(event:MouseEvent, vn:IVisualNode):void

Mouse Event Handling Methods

Parameters

	`event:MouseEvent`

	`vn:IVisualNode`

isStable

()

method

protected override function isStable():Boolean

Layout Methods - Computations

Returns

Boolean

refreshInit

()

method

public override function refreshInit():void

This is an initialisation method to do any kind of initialisation before a layout pass. Not all layouters may require this and thus implement it meaningfully.

resetAll

()

method

public override function resetAll():void

This should reset all parameters of the layouter, which might not be needed for all layouters, and it is up to each layouter to do something with it. It would also stop any existing layouting loops/timers.

Constant detail

ANIMATION_STEPS

constant

public static const ANIMATION_STEPS:int = 10