Package org.eclipse.zest.layouts.algorithms

Class TreeLayoutAlgorithm

java.lang.Object

org.eclipse.zest.layouts.algorithms.AbstractLayoutAlgorithm

org.eclipse.zest.layouts.algorithms.TreeLayoutAlgorithm

All Implemented Interfaces:

LayoutAlgorithm

public class TreeLayoutAlgorithm
extends AbstractLayoutAlgorithm

The TreeLayoutAlgorithm class implements a simple algorithm to arrange graph nodes in a layered tree-like layout.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	TreeLayoutAlgorithm.Zest1	Deprecated, for removal: This API element is subject to removal in a future version. Use TreeLayoutAlgorithm instead.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	BOTTOM_UP	Tree direction constant for which root is placed at the bottom and branches spread upwards
static final int	LEFT_RIGHT	Tree direction constant for which root is placed at the left and branches spread to the right
static final int	RIGHT_LEFT	Tree direction constant for which root is placed at the right and branches spread to the left
static final int	TOP_DOWN	Tree direction constant for which root is placed at the top and branches spread downwards

Fields inherited from class org.eclipse.zest.layouts.algorithms.AbstractLayoutAlgorithm

context

Constructor Summary

Constructors

Constructor	Description
TreeLayoutAlgorithm()	Create a default Tree Layout.
TreeLayoutAlgorithm(int direction)	Create a Tree Layout with a specified direction.
TreeLayoutAlgorithm(int direction, org.eclipse.draw2d.geometry.Dimension nodeSpace)	Create a Tree Layout with fixed size spacing around nodes.

Method Summary

Modifier and Type	Method	Description
void	applyLayout(boolean clean)	Makes this algorithm perform layout computation and apply it to its context.
int	getDirection()
boolean	isResizing()
void	setDirection(int direction)
void	setLayoutContext(LayoutContext context)	Sets the layout context for this algorithm.
void	setNodeSpace(org.eclipse.draw2d.geometry.Dimension nodeSpace)
void	setResizing(boolean resizing)

Methods inherited from class java.lang.Object

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

Field Details

TOP_DOWN

public static final int TOP_DOWN

Tree direction constant for which root is placed at the top and branches spread downwards

Since:

2.0

See Also:

• Constant Field Values

BOTTOM_UP

public static final int BOTTOM_UP

Tree direction constant for which root is placed at the bottom and branches spread upwards

Since:

2.0

See Also:

• Constant Field Values

LEFT_RIGHT

public static final int LEFT_RIGHT

Tree direction constant for which root is placed at the left and branches spread to the right

Since:

2.0

See Also:

• Constant Field Values

RIGHT_LEFT

public static final int RIGHT_LEFT

Tree direction constant for which root is placed at the right and branches spread to the left

Since:

2.0

See Also:

• Constant Field Values

Constructor Details

TreeLayoutAlgorithm

public TreeLayoutAlgorithm()

Create a default Tree Layout.

TreeLayoutAlgorithm

public TreeLayoutAlgorithm(int direction)

Create a Tree Layout with a specified direction.

Parameters:

direction - The direction, one of BOTTOM_UP, LEFT_RIGHT, RIGHT_LEFT, TOP_DOWN

TreeLayoutAlgorithm

public TreeLayoutAlgorithm(int direction,
 org.eclipse.draw2d.geometry.Dimension nodeSpace)

Create a Tree Layout with fixed size spacing around nodes. If nodeSpace is not null, the layout will size the container to the ideal space to just contain all nodes of fixed size without any overlap. Otherwise, the algorithm will size for the container's available space.

Parameters:

direction - The direction, one of BOTTOM_UP, LEFT_RIGHT, RIGHT_LEFT, TOP_DOWN

nodeSpace - the size to make each node. May be null.

Since:

2.0

Method Details

setNodeSpace

public void setNodeSpace(org.eclipse.draw2d.geometry.Dimension nodeSpace)

Parameters:

nodeSpace - the nodeSpaceSize to set

Since:

2.0

getDirection

public int getDirection()

Since:

2.0

setDirection

public void setDirection(int direction)

Since:

2.0

isResizing

public boolean isResizing()

Returns:

true if this algorithm is set to resize elements

Since:

2.0

setResizing

public void setResizing(boolean resizing)

Parameters:

resizing - true if this algorithm should resize elements (default is false)

Since:

2.0

setLayoutContext

public void setLayoutContext(LayoutContext context)

Description copied from interface: LayoutAlgorithm

Sets the layout context for this algorithm. The receiver will unregister from its previous layout context and register to the new one (registration means for example adding listeners). After a call to this method, the receiving algorithm can compute and cache internal data related to given context and perform an initial layout.

Specified by:

setLayoutContext in interface LayoutAlgorithm

Overrides:

setLayoutContext in class AbstractLayoutAlgorithm

Parameters:

context - a new layout context or null if this algorithm should not perform any layout

applyLayout

public void applyLayout(boolean clean)

Description copied from interface: LayoutAlgorithm

Makes this algorithm perform layout computation and apply it to its context.

Parameters:

clean - if true the receiver should assume that the layout context has changed significantly and recompute the whole layout even if it keeps track of changes with listeners. False can be used after dynamic layout in a context is turned back on so that layout algorithm working in background can apply accumulated changes. Static layout algorithm can ignore this call entirely if clean is false.