JMeter example source code file (JLabeledTextArea.java)

This example JMeter source code file (JLabeledTextArea.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - JMeter tags/keywords

arraylist, arraylist, awt, changeevent, document, event, gui, jlabel, jlabeledtextarea, jlabeledtextarea, jscrollpane, jtextarea, list, override, override, string, string, swing, text, util

The JMeter JLabeledTextArea.java source code

/*
 * 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.event.FocusEvent;
import java.awt.event.FocusListener;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

import javax.swing.JComponent;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.text.Document;

/**
 * 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.
 *
 */
public class JLabeledTextArea extends JPanel implements JLabeledField, FocusListener {
    private static final long serialVersionUID = 240L;

    private JLabel mLabel;

    private JTextArea mTextArea;

    // Maybe move to vector if MT problems occur
    private final ArrayList<ChangeListener> 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 JLabeledTextArea() {
        this("", null);
    }

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

    /**
     * Constructs a new component with the label displaying the passed text.
     *
     * @param pLabel
     *            The text to display in the label.
     * @param docModel the document for the text area
     */
    public JLabeledTextArea(String pLabel, Document docModel) {
        super();
        mLabel = new JLabel(pLabel);
        init();
        if (docModel != null) {
            mTextArea.setDocument(docModel);
        }
    }

    /** {@inheritDoc} */
    public List<JComponent> getComponentList() {
        List<JComponent> comps = new LinkedList();
        comps.add(mLabel);
        comps.add(mTextArea);
        return comps;
    }

    public void setDocumentModel(Document docModel) {
        mTextArea.setDocument(docModel);
    }

    /**
     * Initialises all of the components on this panel.
     */
    private void init() {
        setLayout(new BorderLayout());

        mTextArea = new JTextArea();
        mTextArea.setRows(4);
        mTextArea.setLineWrap(true);
        mTextArea.setWrapStyleWord(true);
        // 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.
        mTextArea.addFocusListener(this);

        // Add the sub components
        this.add(mLabel, BorderLayout.NORTH);
        this.add(new JScrollPane(mTextArea), 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(mTextArea.getText())) {
            notifyChangeListeners();
        }
    }

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

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

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

    /** {@inheritDoc} */
    @Override
    public void setEnabled(boolean enable) {
        super.setEnabled(enable);
        mTextArea.setEnabled(enable);
    }

    /**
     * Registers the text to display in a tool tip.
     * The text displays when the cursor lingers over the component.
     * @param text the string to display; if the text is null,
     *      the tool tip is turned off for this component
     */
    @Override
    public void setToolTipText(String text) {
        mTextArea.setToolTipText(text);
    }

    /**
      * Returns the tooltip string that has been set with setToolTipText
      * @return the text of the tool tip
      */
    @Override
    public String getToolTipText() {
        return mTextArea.getToolTipText();
    }

    /**
     * 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.
     */
    private void notifyChangeListeners() {
        ChangeEvent ce = new ChangeEvent(this);
        for (int index = 0; index < mChangeListeners.size(); index++) {
            mChangeListeners.get(index).stateChanged(ce);
        }
    }
}