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* 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.click.examples.page.tree;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import org.apache.click.Context;
import org.apache.click.control.Checkbox;
import org.apache.click.control.FieldSet;
import org.apache.click.control.Form;
import org.apache.click.control.Reset;
import org.apache.click.control.Submit;
import org.apache.click.examples.page.BorderPage;
import org.apache.click.examples.util.ExampleUtils;
import org.apache.click.extras.tree.CheckboxTree;
import org.apache.click.extras.tree.Tree;
import org.apache.click.extras.tree.TreeListener;
import org.apache.click.extras.tree.TreeNode;
/**
* Example usage of the {@link CheckboxTree} control.
*/
public class CheckboxTreePage extends BorderPage implements TreeListener {
private static final long serialVersionUID = 1L;
public static final String TREE_NODES_SESSION_KEY = "checkboxTreeNodes";
private CheckboxTree tree;
private Form form;
private Submit okSubmit;
private Reset resetBtn;
// Event Handlers --------------------------------------------------------
/**
* @see org.apache.click.Page#onInit()
*/
@Override
public void onInit() {
super.onInit();
// The checkbox tree needs to be placed inside a form so all the
// checkbox values can be submitted to the server when we submit
// the form.
form = new Form("form");
//Create the tree and tree model and add it to the page
tree = buildTree();
tree.addListener(this);
// Add the tree to the form.
form.add(tree);
okSubmit = new Submit("select", "Select");
resetBtn = new Reset("reset", "Reset");
form.add(okSubmit);
form.add(resetBtn);
addControl(form);
//Build the options user interface for users to interactively
//change the tree values.
buildOptionsUI();
}
// Public Methods ---------------------------------------------------------
/**
* Creates and return a new tree instance.
*
* @return a new CheckboxTree instance
*/
public CheckboxTree createTree() {
return new CheckboxTree("checkboxTree");
}
/**
* Build the tree model and stores it in the session.
*
* @return a new CheckboxTree instance
*/
public CheckboxTree buildTree() {
tree = createTree();
//Try and load the already stored nodes from the session.
//If this is the first time we access the page, this method
//will return null, indicating no nodes is stored.
TreeNode existingRootNode = loadNodesFromSession();
if(existingRootNode != null) {
//OK we had already nodes stored in the session, so no need
//to rebuild them. We attach the root node and return.
tree.setRootNode(existingRootNode);
return tree;
}
//Create a node representing the root directory with the specified
//parameter as the value. Because an id is not specified, a random
//one will be generated by the node. By default the root node is
//not rendered by the tree. This can be changed by calling
//tree.setRootNodeDisplayed(true).
TreeNode root = new TreeNode("c:");
//Create a new directory, setting the root directory as its parent. Here
//we do specify a id as the 2nd argument, so no id is generated.
TreeNode dev = new TreeNode("dev","1", root);
//The following 3 nodes represent files in the directory, setting the
//dev node as their parent. Note the false argument to the constructor.
//This means that the specific node does not support child nodes, and
//it will be rendered as a leaf icon. If children are supported (the
//default value) then even if the node is a leaf, it will still be rendered
//as a collapsed icon. In the example a default leaf node will be
//rendered as a directory, and a node that does not support children is
//rendered as a file.
// Also note the node with the long text, will cause the tree to overflow
// and add scrollbars
new TreeNode("java.pdf", "1.1", dev, false);
new TreeNode("JEE 6 - the new fantastic approach to write better software (apparently)", "1.2", dev, false);
new TreeNode("ruby.pdf", "1.3", dev, false);
//We continue constructing the rest of the tree
TreeNode programFiles = new TreeNode("program files", "2", root);
new TreeNode("Adobe", "2.1", programFiles);
TreeNode download = new TreeNode("downloads","3", root);
TreeNode web = new TreeNode("web", "3.1", download);
new TreeNode("html.pdf", "3.1.1", web, false);
new TreeNode("css.html", "3.1.2", web, false);
TreeNode databases = new TreeNode("databases", "3.2", download);
TreeNode relationalDb = new TreeNode("relational", "3.2.1", databases);
new TreeNode("mysql.html", "3.2.1.1", relationalDb, false);
new TreeNode("oracle.pdf", "3.2.1.2", relationalDb, false);
new TreeNode("postgres", "3.2.1.3", relationalDb, false);
TreeNode objectDb = new TreeNode("object", "3.2.2", databases);
new TreeNode("db4o.html", "3.2.2.1", objectDb, false);
//Attach the root node containing all the other nodes to the tree
tree.setRootNode(root);
//By default root node is not displayed in browser. Here we expand it,
//so that the root's children are visible.
expandRoot();
//Store the tree nodes in the session so on the next request we do not
//have to rebuild it. Also because we keep the tree nodes in the session
//the nodes will keep their state between requests.
storeNodesInSession(root);
return tree;
}
// TreeListener Support ---------------------------------------------------
/**
* This method, which implements TreeListener, is called when a node is selected
*/
public void nodeSelected(Tree tree, TreeNode node, Context context, boolean oldValue) {
List list = getModelValue("selected");
list.add(node);
}
/**
* This method, which implements TreeListener, is called when a node is deselected
*/
public void nodeDeselected(Tree tree, TreeNode node, Context context, boolean oldValue) {
List list = getModelValue("deselected");
list.add(node);
}
/**
* This method, which implements TreeListener, is called when a node is expanded
*/
public void nodeExpanded(Tree tree, TreeNode node, Context context, boolean oldValue) {
List list = getModelValue("expanded");
list.add(node);
}
/**
* This method, which implements TreeListener, is called when a node is collapsed
*/
public void nodeCollapsed(Tree tree, TreeNode node, Context context, boolean oldValue) {
List list = getModelValue("collapsed");
list.add(node);
}
/**
* Returns the value for the specified name from the page's model.
* If a value is not found, a new ArrayList is created and added to the model.
*/
private List getModelValue(String name) {
List list = (List) getModel().get(name);
if(list == null) {
list = new ArrayList();
addModel(name, list);
}
return list;
}
// NOTE -------------------------------------------------------------------
//The code below is not specific to tree control usage.
private Form optionsForm;
private Checkbox jsEnabled = new Checkbox("jsEnabled", "JavaScript Enabled");
private Checkbox rootNodeDisplayed = new Checkbox("rootNodeDisplayed", "Display root node");
private Checkbox selectChildNodes = new Checkbox("selectChildNodes", "Select child nodes");
private Submit applyOptions = new Submit("apply", "Apply Options", this, "onApplyOptionsClick");
/**
* Called when user submits the options form.
*/
public boolean onApplyOptionsClick() {
//Reset the tree and nodes to default values
resetTree();
//Store the users options in the session
CheckboxTreeOptions options = new CheckboxTreeOptions();
options.javascriptEnabled = jsEnabled.isChecked();
options.rootNodeDisplayed = rootNodeDisplayed.isChecked();
options.selectChildNodes = selectChildNodes.isChecked();
ExampleUtils.setSessionObject(options);
//Apply users new options
applyOptions();
return true;
}
/**
* Builds the user interface for users to change the tree options interactively.
*/
public void buildOptionsUI() {
//Form to handle user selected options
optionsForm = new Form("optionForm");
FieldSet fieldSet = new FieldSet("options", "Form Options");
fieldSet.add(jsEnabled);
fieldSet.add(rootNodeDisplayed);
fieldSet.add(selectChildNodes);
optionsForm.add(fieldSet);
addControl(optionsForm);
optionsForm.add(applyOptions);
//Apply users existing options
applyOptions();
}
/** Form options holder. */
public static class CheckboxTreeOptions implements Serializable {
private static final long serialVersionUID = 1L;
boolean javascriptEnabled= false;
boolean rootNodeDisplayed = false;
boolean selectChildNodes = false;
}
/**
* Reset the tree to initial state
*/
private void resetTree() {
// Remove any Session entries made by Tree
tree.cleanupSession();
//Temporarily disable notification to any tree listeners while we reset the tree
tree.setNotifyListeners(false);
//Clear all current selections so the tree can start afresh with new options enabled
tree.deselectAll();
tree.collapseAll();
//Enable notification to any tree listeners again
tree.setNotifyListeners(true);
if(!rootNodeDisplayed.isChecked()) {
//If rootNodeDisplayed is false, the root node is not displayed in browser. Here we
//expand it, so that the root's children are visible.
expandRoot();
}
}
/**
* Store the tree nodes in the session
*/
private void storeNodesInSession(TreeNode rootNode) {
if (tree.getRootNode() == null) {
return;
}
getContext().getSession().setAttribute(TREE_NODES_SESSION_KEY, rootNode);
}
/**
* Retrieve the tree nodes from the session if available. Otherwise we return
* null.
*/
private TreeNode loadNodesFromSession() {
return (TreeNode) getContext().getSession().getAttribute(TREE_NODES_SESSION_KEY);
}
/**
* Enable javascript so that there are no round trips to server
* when expand and collapsing nodes.
*/
private void enableJavascript(boolean enable) {
//This call enables the client side javascript functionality
tree.setJavascriptEnabled(enable);
}
/**
* Applies the user selected options to the tree like enabling javascript,
* displaying the root node etc.
*/
private void applyOptions() {
//We retrieve our stored options from the session and set the controls state
CheckboxTreeOptions options = (CheckboxTreeOptions)
ExampleUtils.getSessionObject(CheckboxTreeOptions.class);
jsEnabled.setChecked(options.javascriptEnabled);
rootNodeDisplayed.setChecked(options.rootNodeDisplayed);
selectChildNodes.setChecked(options.selectChildNodes);
//Enable or disable javascript functionality based on users current option
enableJavascript(options.javascriptEnabled);
//Indicates if we want to display the root node or not.
tree.setRootNodeDisplayed(options.rootNodeDisplayed);
//Indicates if the tree should recursively select child nodes.
tree.setSelectChildNodes(options.selectChildNodes);
}
/**
* Expand the root but do not notify any tree listeners of the change.
*/
private void expandRoot() {
//Temporarily disable notification to any tree listeners while we expand the root node
tree.setNotifyListeners(false);
tree.expand(tree.getRootNode());
//Enable notification to any tree listeners again
tree.setNotifyListeners(true);
}
}