basiclabelui.java

JAVA 所有包

/*
 * @(#)BasicLabelUI.java	1.91 06/03/20
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package javax.swing.plaf.basic;

import sun.swing.SwingUtilities2;
import sun.swing.DefaultLookup;
import sun.swing.UIAction;
import javax.swing.*;
import javax.swing.plaf.*;
import javax.swing.text.View;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Rectangle;
import java.awt.Insets;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Font;
import java.awt.FontMetrics;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

/**
 * A Windows L&F implementation of LabelUI.  This implementation 
 * is completely static, i.e. there's only one UIView implementation 
 * that's shared by all JLabel objects.
 *
 * @version 1.91 03/20/06
 * @author Hans Muller
 */
public class BasicLabelUI extends LabelUI implements  PropertyChangeListener
{
   /**
    * The default <code>BasicLabelUI</code> instance. This field might
    * not be used. To change the default instance use a subclass which
    * overrides the <code>createUI</code> method, and place that class
    * name in defaults table under the key "LabelUI".
    */ 
    protected static BasicLabelUI labelUI = new BasicLabelUI();
    private final static BasicLabelUI SAFE_BASIC_LABEL_UI = new BasicLabelUI();

    static void loadActionMap(LazyActionMap map) {
        map.put(new Actions(Actions.PRESS));
	map.put(new Actions(Actions.RELEASE));
    }

    /**
     * Forwards the call to SwingUtilities.layoutCompoundLabel().
     * This method is here so that a subclass could do Label specific
     * layout and to shorten the method name a little.
     * 
     * @see SwingUtilities#layoutCompoundLabel
     */
    protected String layoutCL(
        JLabel label,                  
        FontMetrics fontMetrics, 
        String text, 
        Icon icon, 
        Rectangle viewR, 
        Rectangle iconR, 
        Rectangle textR)
    {
        return SwingUtilities.layoutCompoundLabel(
            (JComponent) label,
            fontMetrics,
            text,
            icon,
            label.getVerticalAlignment(),
            label.getHorizontalAlignment(),
            label.getVerticalTextPosition(),
            label.getHorizontalTextPosition(),
            viewR,
            iconR,
            textR,
            label.getIconTextGap());
    }

    /**
     * Paint clippedText at textX, textY with the labels foreground color.
     * 
     * @see #paint
     * @see #paintDisabledText
     */
    protected void paintEnabledText(JLabel l, Graphics g, String s, int textX, int textY)
    {
        int mnemIndex = l.getDisplayedMnemonicIndex();
        g.setColor(l.getForeground());
        SwingUtilities2.drawStringUnderlineCharAt(l, g, s, mnemIndex,
                                                     textX, textY);
    }


    /**
     * Paint clippedText at textX, textY with background.lighter() and then 
     * shifted down and to the right by one pixel with background.darker().
     * 
     * @see #paint
     * @see #paintEnabledText
     */
    protected void paintDisabledText(JLabel l, Graphics g, String s, int textX, int textY)
    {
        int accChar = l.getDisplayedMnemonicIndex();
        Color background = l.getBackground();
        g.setColor(background.brighter());
        SwingUtilities2.drawStringUnderlineCharAt(l, g, s, accChar,
                                                   textX + 1, textY + 1);
        g.setColor(background.darker());
        SwingUtilities2.drawStringUnderlineCharAt(l, g, s, accChar,
                                                   textX, textY);
    }


    /* These rectangles/insets are allocated once for this shared LabelUI
     * implementation.  Re-using rectangles rather than allocating
     * them in each paint call halved the time it took paint to run.
     */
    private static Rectangle paintIconR = new Rectangle();
    private static Rectangle paintTextR = new Rectangle();
    private static Rectangle paintViewR = new Rectangle();
    private static Insets paintViewInsets = new Insets(0, 0, 0, 0);
    

    /** 
     * Paint the label text in the foreground color, if the label
     * is opaque then paint the entire background with the background
     * color.  The Label text is drawn by paintEnabledText() or
     * paintDisabledText().  The locations of the label parts are computed
     * by layoutCL.
     * 
     * @see #paintEnabledText
     * @see #paintDisabledText
     * @see #layoutCL
     */
    public void paint(Graphics g, JComponent c) 
    {
        JLabel label = (JLabel)c;
        String text = label.getText();
        Icon icon = (label.isEnabled()) ? label.getIcon() : label.getDisabledIcon();

        if ((icon == null) && (text == null)) {
            return;
        }

        FontMetrics fm = SwingUtilities2.getFontMetrics(label, g);
        String clippedText = layout(label, fm, c.getWidth(), c.getHeight());

        if (icon != null) {
            icon.paintIcon(c, g, paintIconR.x, paintIconR.y);
        }

        if (text != null) {
	    View v = (View) c.getClientProperty(BasicHTML.propertyKey);
	    if (v != null) {
		v.paint(g, paintTextR);
	    } else {
		int textX = paintTextR.x;
		int textY = paintTextR.y + fm.getAscent();
		
		if (label.isEnabled()) {
		    paintEnabledText(label, g, clippedText, textX, textY);
		}
		else {
		    paintDisabledText(label, g, clippedText, textX, textY);
		}
	    }
        }
    }

    private String layout(JLabel label, FontMetrics fm,
                          int width, int height) {
        Insets insets = label.getInsets(paintViewInsets);
        String text = label.getText();
        Icon icon = (label.isEnabled()) ? label.getIcon() :
                                          label.getDisabledIcon();
        paintViewR.x = insets.left;
        paintViewR.y = insets.top;
        paintViewR.width = width - (insets.left + insets.right);
        paintViewR.height = height - (insets.top + insets.bottom);
        paintIconR.x = paintIconR.y = paintIconR.width = paintIconR.height = 0;
        paintTextR.x = paintTextR.y = paintTextR.width = paintTextR.height = 0;
        return layoutCL(label, fm, text, icon, paintViewR, paintIconR,
                        paintTextR);
    }


    /* These rectangles/insets are allocated once for this shared LabelUI
     * implementation.  Re-using rectangles rather than allocating
     * them in each getPreferredSize call sped up the method substantially.
     */
    private static Rectangle iconR = new Rectangle();
    private static Rectangle textR = new Rectangle();
    private static Rectangle viewR = new Rectangle();
    private static Insets viewInsets = new Insets(0, 0, 0, 0);


    public Dimension getPreferredSize(JComponent c) 
    {
        JLabel label = (JLabel)c;
        String text = label.getText();
        Icon icon = (label.isEnabled()) ? label.getIcon() :
                                          label.getDisabledIcon();
        Insets insets = label.getInsets(viewInsets);
        Font font = label.getFont();

        int dx = insets.left + insets.right;
        int dy = insets.top + insets.bottom;

        if ((icon == null) && 
            ((text == null) || 
             ((text != null) && (font == null)))) {
            return new Dimension(dx, dy);
        }
        else if ((text == null) || ((icon != null) && (font == null))) {
            return new Dimension(icon.getIconWidth() + dx, 
                                 icon.getIconHeight() + dy);
        }
        else {
            FontMetrics fm = label.getFontMetrics(font);

            iconR.x = iconR.y = iconR.width = iconR.height = 0;
            textR.x = textR.y = textR.width = textR.height = 0;
            viewR.x = dx;
            viewR.y = dy;
            viewR.width = viewR.height = Short.MAX_VALUE;

            layoutCL(label, fm, text, icon, viewR, iconR, textR);
            int x1 = Math.min(iconR.x, textR.x);
            int x2 = Math.max(iconR.x + iconR.width, textR.x + textR.width);