ilog.views.maps

Class IlvSDMHierarchyExpandManager

java.lang.Object

ilog.views.maps.IlvSDMHierarchyExpandManager

All Implemented Interfaces:

TransformerListener, EventListener

public class IlvSDMHierarchyExpandManager
extends Object
implements TransformerListener

Provides automatic expansion and collapsing of SDM groups of symbols when the map scale changes.
In addition, it provides features that compute and enforce group/child location relationships when one or the other is changed.
Example of use:

 
 IlvSDMHierarchyExpandManager em=new IlvSDMHierarchyExpandManager(engine);
 // Root groups are expanded below scale 1/2 000 000.
 em.addHierarchyLevelExpansionScale(0,2000000);
 // Level 1 groups are expanded below scale 1/1 000 000.
 em.addHierarchyLevelExpansionScale(1,1000000);
 // Enforce that moving children updates a group location, and moving groups nudges children in the same direction.
 em.setAutoComputeGroupLocation(true); 
 // Listen to view changes in scale.
 view.addTransformerListener(em);
 

This class acts on specific node properties such as "longitude", "latitude" and "visible".

Since:

JViews 8.0

Constructor Summary

Constructors

Constructor and Description
IlvSDMHierarchyExpandManager(IlvSDMEngine engine) Creates a new IlvSDMHierarchyExpandManager.

Method Summary

Modifier and Type	Method and Description
void	addHierarchyLevelExpansionScale(int hierarchyLevel, double mapScale) Adds a scale limit at which the selected hierarchy level is expanded.
protected void	expandGroup(IlvSDMNode group, boolean expand) Expands or collapses a group.
IlvSDMEngine	getEngine() Returns the engine the IlvSDMHierarchyExpandManager acts upon.
double	getHierarchyLevelExpansionScale(int hierarchyLevel) Retrieves the first scale limit for which the groups are expanded.
protected boolean	isCollapsed(IlvSDMNode node) Checks if a group is collapsed by checking the presence of the "collapsed" pseudo class.
protected boolean	isExpanded(IlvSDMNode node) Checks if a group is expanded by checking the presence of the "expanded" pseudo class.
protected boolean	isGroup(IlvSDMNode node) Method used throughout the class to check if an SDM node is a group or not.
protected void	moveGroupAtBarycenter(IlvSDMNode group) Computes the longitude and latitude to use for a group of nodes.
protected void	nudgeNode(IlvSDMNode node, String property, double offset) Changes the node property by adding the offset.
void	removeHierarchyLevelExpansionScale(int hierarchyLevel) Removes a scale limit for a hierarchy level.
void	setAutoComputeGroupLocation(boolean computeGroupLocation) Makes sure the location of groups (longitude and latitude) is correct relative to their children.
void	transformerChanged(TransformerChangedEvent event) When the view transformer is changed, this method checks the expansion scales set through addHierarchyLevelExpansionScale(int, double) and expands or collapses the relevant groups, according to their hierarchy level.

Methods inherited from class java.lang.Object

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

Constructor Detail

IlvSDMHierarchyExpandManager

public IlvSDMHierarchyExpandManager(IlvSDMEngine engine)

Creates a new IlvSDMHierarchyExpandManager.

Parameters:

engine - The engine the expand/collapse manager acts on.

Method Detail

getEngine

public IlvSDMEngine getEngine()

Returns the engine the IlvSDMHierarchyExpandManager acts upon.

Returns:

The engine the IlvSDMHierarchyExpandManager acts upon.

addHierarchyLevelExpansionScale

public void addHierarchyLevelExpansionScale(int hierarchyLevel,
                                            double mapScale)

Adds a scale limit at which the selected hierarchy level is expanded. Example: em.setHierarchyLevelExpansionScale(1,10000); expands the first level of hierarchy when the scale becomes smaller than 1/10000.

Parameters:

hierarchyLevel - The level of the groups in the SDM model hierarchy (0 means a root group).

mapScale - The inverse of the scale for which the group will be first expanded.

getHierarchyLevelExpansionScale

public double getHierarchyLevelExpansionScale(int hierarchyLevel)

Retrieves the first scale limit for which the groups are expanded. If a specific scale has not been specified, the scale for a smaller hierarchy level is returned.

Parameters:

hierarchyLevel - The level of the groups in the SDM model hierarchy (0 means a root group).

Returns:

The inverse of the scale or 0 if no limit is set.

See Also:

addHierarchyLevelExpansionScale(int, double)

removeHierarchyLevelExpansionScale

public void removeHierarchyLevelExpansionScale(int hierarchyLevel)

Removes a scale limit for a hierarchy level.

Parameters:

hierarchyLevel - The level of the groups in the SDM model hierarchy (0 means a root group).

See Also:

addHierarchyLevelExpansionScale(int, double)

setAutoComputeGroupLocation

public void setAutoComputeGroupLocation(boolean computeGroupLocation)

Makes sure the location of groups (longitude and latitude) is correct relative to their children. This method also attaches a listener to coordinate property changes that update the group location whenever the children move.

Parameters:

computeGroupLocation - If true, enforces group location.

See Also:

setAutoComputeGroupLocation(boolean), moveGroupAtBarycenter(IlvSDMNode), nudgeNode(IlvSDMNode, String, double)

nudgeNode

protected void nudgeNode(IlvSDMNode node,
                         String property,
                         double offset)

Changes the node property by adding the offset. This method also moves children (if any) by the same amount.

Parameters:

node - The node to move.

property - The property changed (latitude or longitude).

offset - The offset to apply relative to the current value.

See Also:

setAutoComputeGroupLocation(boolean)

isGroup

protected boolean isGroup(IlvSDMNode node)

Method used throughout the class to check if an SDM node is a group or not. The default implementation checks if the node has children.

Parameters:

node - The node to check.

Returns:

If true, the node is a group.

moveGroupAtBarycenter

protected void moveGroupAtBarycenter(IlvSDMNode group)

Computes the longitude and latitude to use for a group of nodes. The default implementation computes the mean latitude and longitude of all children (recursively) and sets them as the new latitude and longitude of the group.

Parameters:

group - The group of nodes to compute the location for.

transformerChanged

public void transformerChanged(TransformerChangedEvent event)

When the view transformer is changed, this method checks the expansion scales set through addHierarchyLevelExpansionScale(int, double) and expands or collapses the relevant groups, according to their hierarchy level.

Specified by:

transformerChanged in interface TransformerListener

Parameters:

event - The modification event.

isExpanded

protected boolean isExpanded(IlvSDMNode node)

Checks if a group is expanded by checking the presence of the "expanded" pseudo class.

Parameters:

node - The node to check.

Returns:

If true, the pseudo class is present.

isCollapsed

protected boolean isCollapsed(IlvSDMNode node)

Checks if a group is collapsed by checking the presence of the "collapsed" pseudo class.

Parameters:

node - The node to check.

Returns:

If true, the pseudo class is present.

expandGroup

protected void expandGroup(IlvSDMNode group,
                           boolean expand)

Expands or collapses a group. This method recursively checks and enforces the presence of the "collapsed" and "expanded" pseudo classes, and changes the "visible" property of the group and its children.

• Expanding a group means making sure it is visible, has the "expanded" pseudo class, has its children hidden, and its subgroups collapsed.
• Collapsing a group means making sure it is invisible, has the "collapsed" pseudo class, has its children showing, and its subgroups expanded.

Parameters:

group - The group to expand or collapse.

expand - Set to true for expanding and false for collapsing.