basictextpaneui.java

java jdk 1.4的源码

/*
 * @(#)BasicTextPaneUI.java	1.67 03/01/23
 *
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package javax.swing.plaf.basic;

import java.awt.*;
import java.awt.event.*;
import java.beans.*;
import javax.swing.*;
import javax.swing.text.*;
import javax.swing.plaf.*;
import javax.swing.border.*;


/**
 * Provides the look and feel for a styled text editor.
 * <p>
 * <strong>Warning:</strong>
 * Serialized objects of this class will not be compatible with
 * future Swing releases. The current serialization support is
 * appropriate for short term storage or RMI between applications running
 * the same version of Swing.  As of 1.4, support for long term storage
 * of all JavaBeans<sup><font size="-2">TM</font></sup>
 * has been added to the <code>java.beans</code> package.
 * Please see {@link java.beans.XMLEncoder}.
 *
 * @author  Timothy Prinzing
 * @version 1.67 01/23/03
 */
public class BasicTextPaneUI extends BasicEditorPaneUI {

    /**
     * Creates a UI for the JTextPane.
     *
     * @param c the JTextPane object
     * @return the UI
     */
    public static ComponentUI createUI(JComponent c) {
        return new BasicTextPaneUI();
    }

    /**
     * Creates a new BasicTextPaneUI.
     */
    public BasicTextPaneUI() {
	super();
    }

    /**
     * Fetches the name used as a key to lookup properties through the
     * UIManager.  This is used as a prefix to all the standard
     * text properties.
     *
     * @return the name ("TextPane")
     */
    protected String getPropertyPrefix() {
	return "TextPane";
    }

    public void installUI(JComponent c) {
        super.installUI(c);
        updateForeground(c.getForeground());
        updateFont(c.getFont());
    }

    /**
     * This method gets called when a bound property is changed
     * on the associated JTextComponent.  This is a hook
     * which UI implementations may change to reflect how the
     * UI displays bound properties of JTextComponent subclasses.
     * If the font, foreground or document has changed, the
     * the appropriate property is set in the default style of
     * the document.
     *
     * @param evt the property change event
     */
    protected void propertyChange(PropertyChangeEvent evt) {
	super.propertyChange(evt);

	String name = evt.getPropertyName();

	if (name.equals("foreground")) {
            updateForeground((Color)evt.getNewValue());
	} else if (name.equals("font")) {
            updateFont((Font)evt.getNewValue());
	} else if (name.equals("document")) {
            JComponent comp = getComponent();
            updateForeground(comp.getForeground());
            updateFont(comp.getFont());
        }
    }

    /**
     * Update the color in the default style of the document.
     *
     * @param color the new color to use or null to remove the color attribute
     *              from the document's style
     */
    private void updateForeground(Color color) {
        StyledDocument doc = (StyledDocument)getComponent().getDocument();
        Style style = doc.getStyle(StyleContext.DEFAULT_STYLE);

        if (style == null) {
            return;
        }

        if (color == null) {
            style.removeAttribute(StyleConstants.Foreground);
        } else {
            StyleConstants.setForeground(style, color);
        }
    }
    
    /**
     * Update the font in the default style of the document.
     *
     * @param font the new font to use or null to remove the font attribute
     *             from the document's style
     */
    private void updateFont(Font font) {
        StyledDocument doc = (StyledDocument)getComponent().getDocument();
        Style style = doc.getStyle(StyleContext.DEFAULT_STYLE);

        if (style == null) {
            return;
        }

        if (font == null) {
            style.removeAttribute(StyleConstants.FontFamily);
            style.removeAttribute(StyleConstants.FontSize);
            style.removeAttribute(StyleConstants.Bold);
            style.removeAttribute(StyleConstants.Italic);
        } else {
            StyleConstants.setFontFamily(style, font.getName());
            StyleConstants.setFontSize(style, font.getSize());
            StyleConstants.setBold(style, font.isBold());
            StyleConstants.setItalic(style, font.isItalic());
        }
    }

}