charvax.swing.JLabel.java Source code

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Here is the source code for charvax.swing.JLabel.java

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/* class JLabel
 *
 * Copyright (C) 2001-2003  R M Pitman
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package charvax.swing;

import charva.awt.*;
import charva.awt.event.KeyEvent;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * A display area for a short text string.  A label cannot react to keyboard
 * events and cannot receive the keyboard focus.
 */
public class JLabel extends JComponent {

    /**
     * Construct an empty label.
     */
    public JLabel() {
        this("", SwingConstants.LEFT);
    }

    /**
     * Construct a JLabel with the specified text.
     */
    public JLabel(String text_) {
        this(text_, SwingConstants.LEFT);
    }

    /**
     * Use this constructor if you want to set the alignment to something
     * other than left-aligned.
     */
    public JLabel(String text_, int align_) {
        _labeltext = text_;
        _width = text_.length();
        switch (align_) {
        case SwingConstants.LEFT:
            _alignmentX = LEFT_ALIGNMENT;
            break;
        case SwingConstants.CENTER:
            _alignmentX = CENTER_ALIGNMENT;
            break;
        case SwingConstants.RIGHT:
            _alignmentX = RIGHT_ALIGNMENT;
            break;
        }
    }

    public void setLength(int length_) {
        _width = length_;
    }

    public Dimension minimumSize() {
        return this.getSize();
    }

    public void draw() {

        // Draw the border if it exists
        super.draw();

        /* Get the absolute origin of this component.
         */
        Point origin = getLocationOnScreen();
        Insets insets = super.getInsets();
        origin.translate(insets.left, insets.top);

        Toolkit term = Toolkit.getDefaultToolkit();
        term.setCursor(origin);

        // we'll sort out justification and video-attributes etc later.
        StringBuffer buf = new StringBuffer(_labeltext);
        int textlength = _labeltext.length();
        if (_width > textlength) {
            for (int i = textlength; i < _width; i++)
                buf.append(' ');
        } else if (_width < textlength)
            buf.setLength(_width); // truncate

        int colorpair = getCursesColor();
        int attribute = (getFont().getStyle() == Font.BOLD) ? Toolkit.A_BOLD : Toolkit.A_NORMAL;
        term.addString(buf.toString(), attribute, colorpair);
    }

    /**
     * This may be wrong, but it'll do for now.
     */
    public Dimension getSize() {
        return new Dimension(this.getWidth(), this.getHeight());
    }

    public int getWidth() {
        Insets insets = super.getInsets();
        return _width + insets.left + insets.right;
    }

    public int getHeight() {
        Insets insets = super.getInsets();
        return 1 + insets.top + insets.bottom;
    }

    public synchronized void setText(String label_) {
        _labeltext = label_;

        /* If the text is shorter than it was previously, blank out the
         * previous text.  In practice this means that the label grows
         * in length but never shrinks.
         */
        if (label_.length() > _width)
            _width = label_.length();

        /* If this component is already displayed, generate a PaintEvent
         * and post it onto the queue.
         */
        repaint();
    }

    public String getText() {
        return _labeltext;
    }

    /**
     * This component will not receive focus when Tab or Shift-Tab is pressed.
     */
    public boolean isFocusTraversable() {
        return false;
    }

    /**
     * The JLabel class ignores key events. A JLabel should never
     * have input focus anyway.
     */
    public void processKeyEvent(KeyEvent ke_) {
    }

    /**
     * The JLabel component never gets the keyboard input focus.
     */
    public void requestFocus() {
    }

    public void debug(int level_) {
        for (int i = 0; i < level_; i++)
            System.err.print("    ");
        System.err.println("JLabel origin=" + _origin + " size=" + getSize() + " label=" + _labeltext);
    }

    public String toString() {
        return "JLabel: [" + getText() + "]";
    }

    //====================================================================
    // INSTANCE VARIABLES

    private String _labeltext;
    private int _width;
    private static final Log LOG = LogFactory.getLog(JLabel.class);
}