org.apache.wicket.markup.head
Class PriorityFirstComparator

java.lang.Object
  org.apache.wicket.markup.head.PriorityFirstComparator

All Implemented Interfaces:

Serializable, Comparator<ResourceAggregator.RecordedHeaderItem>

public class PriorityFirstComparator
extends Object
implements Comparator<ResourceAggregator.RecordedHeaderItem>, Serializable

Implements the default sorting algorithm for HeaderItems. PriorityHeaderItems are moved to the front, inverting the component order to convert the child-first into a parent-first order. If renderPageFirst is true, the head from the markup of a page is moved to the front of the header, directly after the priority header items.

Author:

papegaaij

See Also:

Serialized Form

Nested Class Summary

protected static class

PriorityFirstComparator.HeaderItemType

Constructor Summary

PriorityFirstComparator(boolean renderPageFirst)
Construct.

Method Summary

int	compare(ResourceAggregator.RecordedHeaderItem o1, ResourceAggregator.RecordedHeaderItem o2)
protected int	compareWithinGroup(ResourceAggregator.RecordedHeaderItem o1, ResourceAggregator.RecordedHeaderItem o2) Compares two header items that belong in the same group.
protected PriorityFirstComparator.HeaderItemType	getItemType(ResourceAggregator.RecordedHeaderItem item) Determines the type of the item: priority, page or component.
protected int	inversedComponentOrder(ResourceAggregator.RecordedHeaderItem o1, ResourceAggregator.RecordedHeaderItem o2) Compares two priority header items, converting the child-first order into parent-first.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

equals

Constructor Detail

PriorityFirstComparator

public PriorityFirstComparator(boolean renderPageFirst)

Construct.

Parameters:

renderPageFirst - when true, the header of the page is moved to the front.

Method Detail

compare

public int compare(ResourceAggregator.RecordedHeaderItem o1,
                   ResourceAggregator.RecordedHeaderItem o2)

Specified by:

compare in interface Comparator<ResourceAggregator.RecordedHeaderItem>

compareWithinGroup

protected int compareWithinGroup(ResourceAggregator.RecordedHeaderItem o1,
                                 ResourceAggregator.RecordedHeaderItem o2)

Compares two header items that belong in the same group.

Parameters:

o1 -

o2 -

Returns:

0 by default to preserve the order

inversedComponentOrder

protected int inversedComponentOrder(ResourceAggregator.RecordedHeaderItem o1,
                                     ResourceAggregator.RecordedHeaderItem o2)

Compares two priority header items, converting the child-first order into parent-first.

Parameters:

o1 -

o2 -

Returns:

-1, 0 or 1 if o1 needs to be rendered before, unchanged or after o2.

getItemType

protected PriorityFirstComparator.HeaderItemType getItemType(ResourceAggregator.RecordedHeaderItem item)

Determines the type of the item: priority, page or component.

Parameters:

item -

Returns:

the type of the item