Package com.helger.commons.hierarchy.visit

Class DefaultHierarchyVisitorCallback<DATATYPE>

java.lang.Object

com.helger.commons.hierarchy.visit.DefaultHierarchyVisitorCallback<DATATYPE>

Type Parameters:

DATATYPE - The type of object in the hierarchy to be iterated

All Implemented Interfaces:

ICallback, IHierarchyVisitorCallback<DATATYPE>

public class DefaultHierarchyVisitorCallback<DATATYPE>
extends Object
implements IHierarchyVisitorCallback<DATATYPE>

The default implementation of the IHierarchyVisitorCallback interface doing nothing except counting levels.

Author:

Philip Helger

Constructor Summary

Constructors

Constructor	Description
DefaultHierarchyVisitorCallback()
DefaultHierarchyVisitorCallback(int nInitialLevel)

Method Summary

Modifier and Type	Method	Description
int	getLevel()
EHierarchyVisitorReturn	onItemAfterChildren(DATATYPE aItem)	Called after eventual children of the current item were visited.
EHierarchyVisitorReturn	onItemBeforeChildren(DATATYPE aItem)	Called before children of the current item are visited.
void	onLevelDown()	Called before the tree walker descends into the next tree level.
void	onLevelUp()	Called after the tree walker ascends into the previous tree level.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.helger.commons.hierarchy.visit.IHierarchyVisitorCallback

begin, end

Constructor Details

DefaultHierarchyVisitorCallback

public DefaultHierarchyVisitorCallback()

DefaultHierarchyVisitorCallback

public DefaultHierarchyVisitorCallback(int nInitialLevel)

Method Details

getLevel

@Nonnegative
public int getLevel()

Specified by:

getLevel in interface IHierarchyVisitorCallback<DATATYPE>

Returns:

The level of the current node within the hierarchy. Always ≥ 0. The root item has level 0.

onLevelDown

@OverridingMethodsMustInvokeSuper
public void onLevelDown()

Description copied from interface: IHierarchyVisitorCallback

Called before the tree walker descends into the next tree level. After this call IHierarchyVisitorCallback.getLevel() should return a value increased by 1.

Specified by:

onLevelDown in interface IHierarchyVisitorCallback<DATATYPE>

onLevelUp

@OverridingMethodsMustInvokeSuper
public void onLevelUp()

Description copied from interface: IHierarchyVisitorCallback

Called after the tree walker ascends into the previous tree level. After this call IHierarchyVisitorCallback.getLevel() should return a value decreased by 1.

Specified by:

onLevelUp in interface IHierarchyVisitorCallback<DATATYPE>

onItemBeforeChildren

@Nonnull
public EHierarchyVisitorReturn onItemBeforeChildren(DATATYPE aItem)

Description copied from interface: IHierarchyVisitorCallback

Called before children of the current item are visited. This method is also to be called if no children are present at all.

Specified by:

onItemBeforeChildren in interface IHierarchyVisitorCallback<DATATYPE>

Parameters:

aItem - The current item. May be null.

Returns:

A non-null status code that determines how to continue iteration.

onItemAfterChildren

@Nonnull
public EHierarchyVisitorReturn onItemAfterChildren(DATATYPE aItem)

Description copied from interface: IHierarchyVisitorCallback

Called after eventual children of the current item were visited. This method is also to be called if no children are present at all. This method has always to be called if IHierarchyVisitorCallback.onItemBeforeChildren(Object) was called.

Specified by:

onItemAfterChildren in interface IHierarchyVisitorCallback<DATATYPE>

Parameters:

aItem - The current item. May be null.

Returns:

A non-null status code that determines how to continue iteration.