IlvRandomLayout Class Reference

The main class for the Random Layout algorithm. More...

#include <ilviews/layout/random.h>

Inheritance diagram for IlvRandomLayout:

List of all members.

Public Member Functions
	IlvRandomLayout ()
	Creates a new instance of the Random Layout algorithm.
IlvLayoutLinkStyle	getLinkStyle () const
	Returns the current option for the style of the shape of the links.
void	setLinkStyle (IlvLayoutLinkStyle linkStyle)
	Sets the option for the style of the shape of the links.
IlBoolean	supportsLayoutRegion () const
	Indicates that this layout class can control the size of the drawing of the grapher to fit (exactly or approximately) a user-defined region (a rectangle) or a user-defined manager view.
IlBoolean	supportsPreserveFixedNodes () const
	Indicates that this layout class allows the user to specify fixed nodes.
IlBoolean	supportsRandomGenerator () const
	Indicates that this layout class uses randomly-generated numbers that can be initialized with a user-defined seed value.
Protected Member Functions
void	layout ()
	Computes the layout using the Random Layout algorithm.

---

Detailed Description

The main class for the Random Layout algorithm.

Library: ilvrandom

This is the simplest layout algorithm. The nodes are moved at randomly-computed positions inside a user-defined region.

Sample drawing produced by the Random Layout algorithm:

See the corresponding chapter of the User's Manual for details on the algorithm, the types of graphs for which this algorithm can be used, the features and limitations, code samples, and so on.

Note that the initial position of the nodes (at the moment you start the layout) does not affect the resulting layout. However, nodes specified as fixed are not moved if you call the method setPreserveFixedNodes(IlBoolean) with an IlTrue argument.

Note the following points:

• The initial position of the nodes (at the moment you start the layout) does not affect the resulting layout. However, nodes specified as fixed are not moved if you call the method setPreserveFixedNodes(IlBoolean) with an IlTrue argument.
• The algorithm supports multiple links between the same pair of nodes.

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Constructor & Destructor Documentation

IlvRandomLayout::IlvRandomLayout

(

)

Creates a new instance of the Random Layout algorithm.

To indicate the grapher you want to lay out, use the method attach(IlvGrapher*).
To indicate the graph model you want to lay out, use the method attach(IlvGraphModel*).
To perform the layout, use the method performLayout.
To modify the layout parameters, use the different methods provided in this class and its superclass.

See also:

IlvGraphLayout::attach(IlvGrapher*)

IlvGraphLayout::attach(IlvGraphModel*)

IlvGraphLayout::performLayout()

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Member Function Documentation

IlvLayoutLinkStyle IlvRandomLayout::getLinkStyle

(

)

const

Returns the current option for the style of the shape of the links.

Returns:

The style of the shape of the links.

See also:

setLinkStyle

void IlvRandomLayout::layout

(

)

[protected, virtual]

Computes the layout using the Random Layout algorithm.

To start the layout, call the IlvGraphLayout::performLayout method.

See also:

IlvGraphLayout::performLayout()

IlvGraphLayout::getLayoutRegion(IlvRect&)

Implements IlvGraphLayout.

void IlvRandomLayout::setLinkStyle

(

IlvLayoutLinkStyle

linkStyle

)

Sets the option for the style of the shape of the links.

Valid values are IlvLayoutStraightLineLinkStyle (the links are given a straight-line shape) and IlvLayoutNoReshapeLinkStyle (no reshape is performed on the links).

This feature can be useful if the graph contains links that have intermediate points and are not straight-line links, for instance IlvPolylineLinkImage} links with intermediate points. With the option IlvLayoutStraightLineLinkStyle, if the method isLinkReplacementAllowed returns IlTrue, the layout calls the method IlvGraphModel::ensureStraightLineLinks() to ensure that all the links have a straight-line shape. Note that in this case the links that cannot have a straight-line shape can be replaced with new links of a different type. For details, see the documentation of the method IlvGraphModel::ensureStraightLineLinks().

The default value is IlvLayoutStraightLineLinkStyle.

Parameters:

linkStyle

The style of the shape of the links.

See also:

getLinkStyle

IlBoolean IlvRandomLayout::supportsLayoutRegion

(

)

const [virtual]

Indicates that this layout class can control the size of the drawing of the grapher to fit (exactly or approximately) a user-defined region (a rectangle) or a user-defined manager view.

Returns:

Always IlTrue.

See also:

IlvGraphLayout::setLayoutRegion(IlvView*)

IlvGraphLayout::setLayoutRegion(IlvView*, const IlvRect&)

IlvGraphLayout::setLayoutRegion(const IlvRect&)

IlvGraphLayout::getLayoutRegion(IlvRect&)

Reimplemented from IlvGraphLayout.

IlBoolean IlvRandomLayout::supportsPreserveFixedNodes

(

)

const [virtual]

Indicates that this layout class allows the user to specify fixed nodes.

Fixed nodes are not moved during the layout if the method setPreserveFixedNodes(IlBoolean) is called with an IlTrue argument.

Returns:

Always IlTrue.

See also:

IlvGraphLayout::setPreserveFixedNodes(IlBoolean)

IlvGraphLayout::isPreserveFixedNodes

Reimplemented from IlvGraphLayout.

IlBoolean IlvRandomLayout::supportsRandomGenerator

(

)

const [virtual]

Indicates that this layout class uses randomly-generated numbers that can be initialized with a user-defined seed value.

When you perform the layout several times on the same graph and use the same user-defined seed value, you obtain the same drawing of the grapher. If you want different drawings each time you perform the layout, you should modify the seed value and call the method setUseSeedValueForRandomGenerator(IlBoolean) with an IlTrue argument.

Returns:

Always IlTrue.

See also:

setSeedValueForRandomGenerator(IlUShort)

getSeedValueForRandomGenerator

setUseSeedValueForRandomGenerator(IlBoolean)

isUseSeedValueForRandomGenerator

Reimplemented from IlvGraphLayout.