/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.wicket.extensions.markup.html.repeater.tree;
import java.util.Set;
import org.apache.wicket.Component;
import org.apache.wicket.IGenericComponent;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.core.request.handler.IPartialPageRequestHandler;
import org.apache.wicket.extensions.markup.html.repeater.util.ProviderSubset;
import org.apache.wicket.markup.html.panel.Panel;
import org.apache.wicket.markup.repeater.DefaultItemReuseStrategy;
import org.apache.wicket.markup.repeater.IItemReuseStrategy;
import org.apache.wicket.markup.repeater.Item;
import org.apache.wicket.model.IModel;
/**
* Abstract base class for {@link NestedTree} and {@link TableTree}. Uses its model for storing the
* {@link State} of its nodes.
*
* Note that a tree has no notion of a <em>selection</em>. Handling state of nodes besides
* expanse/collapse is irrelevant to a tree implementation.
*
* @see #newContentComponent(String, IModel)
*
* @author svenmeier
* @param <T>
* the node type
*/
public abstract class AbstractTree<T> extends Panel implements IGenericComponent<Set<T>, AbstractTree<T>>
{
private static final long serialVersionUID = 1L;
private ITreeProvider<T> provider;
private IItemReuseStrategy itemReuseStrategy;
protected AbstractTree(String id, ITreeProvider<T> provider)
{
this(id, provider, null);
}
protected AbstractTree(String id, ITreeProvider<T> provider, IModel<? extends Set<T>> state)
{
super(id, state);
if (provider == null)
{
throw new IllegalArgumentException("argument [provider] cannot be null");
}
this.provider = provider;
}
/**
* Sets the item reuse strategy. This strategy controls the creation of {@link Item}s.
*
* @see IItemReuseStrategy
*
* @param strategy
* item reuse strategy
* @return this for chaining
*/
public AbstractTree<T> setItemReuseStrategy(IItemReuseStrategy strategy)
{
this.itemReuseStrategy = strategy;
return this;
}
/**
* @return currently set item reuse strategy. Defaults to <code>DefaultItemReuseStrategy</code>
* if none was set.
*
* @see DefaultItemReuseStrategy
*/
public IItemReuseStrategy getItemReuseStrategy()
{
if (itemReuseStrategy == null)
{
return DefaultItemReuseStrategy.getInstance();
}
return itemReuseStrategy;
}
/**
* Get the provider of the tree nodes.
*
* @return provider
*/
public ITreeProvider<T> getProvider()
{
return provider;
}
/**
* Delegate to {@link #newModel()} if none is inited in super implementation.
*/
@Override
protected IModel<?> initModel()
{
IModel<?> model = super.initModel();
if (model == null)
{
model = newModel();
}
return model;
}
/**
* Factory method for a model, by default creates a model containing a {@link ProviderSubset}.
* Depending on your {@link ITreeProvider}'s model you might consider to provide a custom
* {@link Set} implementation.
* <p>
* Note: The contained {@link Set} has at least to implement {@link Set#add(Object)},
* {@link Set#remove(Object)} and {@link Set#contains(Object)}.
*
* @return model for this tree
*/
protected IModel<Set<T>> newModel()
{
return new ProviderSubset<>(provider).createModel();
}
/**
* Expand the given node, tries to update the affected branch if the change happens on an
* {@link AjaxRequestTarget}.
*
* @param t
* the node to expand
*
* @see #getModelObject()
* @see Set#add(Object)
* @see #updateBranch(Object, IPartialPageRequestHandler)
*/
public void expand(T t)
{
modelChanging();
getModelObject().add(t);
modelChanged();
getRequestCycle().find(IPartialPageRequestHandler.class).ifPresent(
target -> updateBranch(t, target)
);
}
/**
* Collapse the given node, tries to update the affected branch if the change happens on an
* {@link AjaxRequestTarget}.
*
* @param t
* the object to collapse
*
* @see #getModelObject()
* @see Set#remove(Object)
* @see #updateBranch(Object, IPartialPageRequestHandler)
*/
public void collapse(T t)
{
modelChanging();
getModelObject().remove(t);
modelChanged();
getRequestCycle().find(IPartialPageRequestHandler.class).ifPresent(
target -> updateBranch(t, target)
);
}
/**
* Get the given node's {@link State}.
*
* @param t
* the node to get state for
* @return state
*
* @see #getModelObject()
* @see Set#contains(Object)
*/
public State getState(T t)
{
if (getModelObject().contains(t))
{
return State.EXPANDED;
}
else
{
return State.COLLAPSED;
}
}
/**
* Overridden to detach the {@link ITreeProvider}.
*/
@Override
protected void onDetach()
{
provider.detach();
super.onDetach();
}
/**
* Create a new component for a node.
*
* @param id
* the component id
* @param model
* the model containing the node
* @return created component
*/
public Component newNodeComponent(String id, final IModel<T> model)
{
return new Node<T>(id, this, model)
{
private static final long serialVersionUID = 1L;
@Override
protected Component createContent(String id, IModel<T> model)
{
return AbstractTree.this.newContentComponent(id, model);
}
};
}
/**
* Create a new component for the content of a node.
*
* @param id
* the component id
* @param model
* the model containing the node
* @return created component
*/
protected abstract Component newContentComponent(String id, IModel<T> model);
/**
* Convenience method to update a single branch on an {@link AjaxRequestTarget}. Does nothing if
* the given node is currently not visible.
*
* @param node
* node to update
* @param target
* request target must not be @code null}
*/
public abstract void updateBranch(T node, IPartialPageRequestHandler target);
/**
* Convenience method to update a single node on an {@link AjaxRequestTarget}. Does nothing if
* the given node is currently not visible.
*
* @param node
* node to update
* @param target
* request target must not be @code null}
*/
public abstract void updateNode(T node, IPartialPageRequestHandler target);
/**
* The state of a node.
*/
public enum State {
/**
* The node is collapsed, i.e. its children are not iterated.
*/
COLLAPSED,
/**
* The node is expanded, i.e. its children are iterated.
*/
EXPANDED
}
}