/*
 * 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.jorphan.gui;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

/**
 * A Helper component that wraps a JTextField with a label into a JPanel (this).
 * This component also has an efficient event handling mechanism for handling
 * the text changing in the Text Field. The registered change listeners are only
 * called when the text has changed.
 * 
 * @author S.Coleman
 * @version $Revision: 493784 $
 */
public class JLabeledTextField extends JPanel implements JLabeledField, FocusListener {
	private JLabel mLabel;

	private JTextField mTextField;

	// Maybe move to vector if MT problems occur
	private ArrayList mChangeListeners = new ArrayList(3);

	// A temporary cache for the focus listener
	private String oldValue = "";

	/**
	 * Default constructor, The label and the Text field are left empty.
	 */
	public JLabeledTextField() {
		this("", 20);
	}

	/**
	 * Constructs a new component with the label displaying the passed text.
	 * 
	 * @param pLabel
	 *            The text to in the label.
	 */
	public JLabeledTextField(String pLabel) {
		this(pLabel, 20);
	}

	public JLabeledTextField(String pLabel, int size) {
		super();
		mTextField = createTextField(size);
		mLabel = new JLabel(pLabel);
		mLabel.setLabelFor(mTextField);
		init();
	}

    public JLabeledTextField(String pLabel, Color bk) {
        super();
        mTextField = createTextField(20);
        mLabel = new JLabel(pLabel);
        mLabel.setBackground(bk);
        mLabel.setLabelFor(mTextField);
        this.setBackground(bk);
        init();
    }
    
	public List getComponentList() {
		List comps = new LinkedList();
		comps.add(mLabel);
		comps.add(mTextField);
		return comps;
	}

	public void setEnabled(boolean enable) {
		super.setEnabled(enable);
		mTextField.setEnabled(enable);
	}

	protected JTextField createTextField(int size) {
		return new JTextField(size);
	}

	/**
	 * Initialises all of the components on this panel.
	 */
	private void init() {
		setLayout(new BorderLayout(5, 0));
		// Register the handler for focus listening. This handler will
		// only notify the registered when the text changes from when
		// the focus is gained to when it is lost.
		mTextField.addFocusListener(this);

		// Add the sub components
		add(mLabel, BorderLayout.WEST);
		add(mTextField, BorderLayout.CENTER);
	}

	/**
	 * Callback method when the focus to the Text Field component is lost.
	 * 
	 * @param pFocusEvent
	 *            The focus event that occured.
	 */
	public void focusLost(FocusEvent pFocusEvent) {
		// Compare if the value has changed, since we received focus.
		if (!oldValue.equals(mTextField.getText())) {
			notifyChangeListeners();
		}
	}

	/**
	 * Catch what the value was when focus was gained.
	 */
	public void focusGained(FocusEvent pFocusEvent) {
		oldValue = mTextField.getText();
	}

	/**
	 * Set the text displayed in the label.
	 * 
	 * @param pLabel
	 *            The new label text.
	 */
	public void setLabel(String pLabel) {
		mLabel.setText(pLabel);
	}

	/**
	 * Set the text displayed in the Text Field.
	 * 
	 * @param pText
	 *            The new text to display in the text field.
	 */
	public void setText(String pText) {
		mTextField.setText(pText);
	}

	/**
	 * Returns the text in the Text Field.
	 * 
	 * @return The text in the Text Field.
	 */
	public String getText() {
		return mTextField.getText();
	}

	/**
	 * Returns the text of the label.
	 * 
	 * @return The text of the label.
	 */
	public String getLabel() {
		return mLabel.getText();
	}

	/**
	 * Adds a change listener, that will be notified when the text in the text
	 * field is changed. The ChangeEvent that will be passed to registered
	 * listeners will contain this object as the source, allowing the new text
	 * to be extracted using the {@link #getText() getText} method.
	 * 
	 * @param pChangeListener
	 *            The listener to add
	 */
	public void addChangeListener(ChangeListener pChangeListener) {
		mChangeListeners.add(pChangeListener);
	}

	/**
	 * Removes a change listener.
	 * 
	 * @param pChangeListener
	 *            The change listener to remove.
	 */
	public void removeChangeListener(ChangeListener pChangeListener) {
		mChangeListeners.remove(pChangeListener);
	}

	/**
	 * Notify all registered change listeners that the text in the text field
	 * has changed.
	 */
	protected void notifyChangeListeners() {
		ChangeEvent ce = new ChangeEvent(this);
		for (int index = 0; index < mChangeListeners.size(); index++) {
			((ChangeListener) mChangeListeners.get(index)).stateChanged(ce);
		}
	}
}
