TreeNode.java

/*
 * Copyright 2017 OmniFaces
 *
 * Licensed 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.omnifaces.component.tree;

import static org.omnifaces.util.Components.validateHasChild;
import static org.omnifaces.util.Components.validateHasDirectParent;
import static org.omnifaces.util.Components.validateHasNoParent;

import javax.faces.component.FacesComponent;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.event.PhaseId;

import org.omnifaces.model.tree.TreeModel;
import org.omnifaces.util.State;

/**
 * <p>
 * The <code><o:treeNode></code> is an {@link UIComponent} that represents a single tree node within a parent
 * {@link Tree} component. Within this component, the <code>var</code> attribute of the parent {@link Tree}
 * component will expose the tree node. Each of its children is processed by {@link TreeNodeItem}.
 * <p>
 * The <code>level</code> attribute can be used to specify for which tree node level as obtained by
 * {@link TreeModel#getLevel()} this component should render the children by {@link TreeNodeItem}. The root tree node
 * has level 0.
 *
 * @author Bauke Scholtz
 * @see Tree
 * @see TreeNodeItem
 */
@FacesComponent(TreeNode.COMPONENT_TYPE)
public class TreeNode extends TreeFamily {

	// Public constants -----------------------------------------------------------------------------------------------

	/** The standard component type. */
	public static final String COMPONENT_TYPE = "org.omnifaces.component.tree.TreeNode";

	// Private constants ----------------------------------------------------------------------------------------------

	private enum PropertyKeys {
		// Cannot be uppercased. They have to exactly match the attribute names.
		level;
	}

	// Variables ------------------------------------------------------------------------------------------------------

	private final State state = new State(getStateHelper());

	// Actions --------------------------------------------------------------------------------------------------------

	/**
	 * Validate the component hierarchy.
	 * @throws IllegalStateException When the direct parent component isn't of type {@link Tree}, or when this
	 * component is nested in another {@link TreeNode}, or when there aren't any children of type {@link TreeNodeItem}.
	 */
	@Override
	protected void validateHierarchy() {
		validateHasDirectParent(this, Tree.class);
		validateHasNoParent(this, TreeNode.class);
		validateHasChild(this, TreeNodeItem.class);
	}

	/**
	 * This method is by design only called by {@link Tree#processTreeNode(FacesContext, PhaseId)} as it maintains all
	 * the nodes.
	 * @see Tree#processTreeNode(FacesContext, PhaseId)
	 */
	@Override
	protected void process(FacesContext context, PhaseId phaseId) {
		if (!isRendered()) {
			return;
		}

		processSuper(context, phaseId);
	}

	// Getters/setters ------------------------------------------------------------------------------------------------

	/**
	 * Returns the level for which this node should render the items.
	 * @return The level for which this node should render the items.
	 */
	public Integer getLevel() {
		return state.get(PropertyKeys.level);
	}

	/**
	 * Sets the level for which this node should render the items.
	 * @param level The level for which this node should render the items.
	 */
	public void setLevel(Integer level) {
		state.put(PropertyKeys.level, level);
	}

}