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/*
 * Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package javax.swing.plaf.basic;

import sun.swing.SwingUtilities2;
import sun.swing.DefaultLookup;
import sun.swing.UIAction;
import sun.awt.AppContext;

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.

Author:Hans Muller
/**
 * 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.
 *
 * @author Hans Muller
 */
public class BasicLabelUI extends LabelUI implements  PropertyChangeListener
{
   
The default BasicLabelUI instance. This field might
not be used. To change the default instance use a subclass which
overrides the createUI method, and place that class
name in defaults table under the key "LabelUI".

/**
    * 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 static final Object BASIC_LABEL_UI_KEY = new Object();

    private Rectangle paintIconR = new Rectangle();
    private Rectangle paintTextR = new Rectangle();

    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 Also:
  • layoutCompoundLabel.layoutCompoundLabel
/**
     * 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 Also:
/**
     * 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 Also:
/**
     * 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);
    }

    
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 Also:
/**
     * 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(null);
        String text = label.getText();
        Icon icon = (label.isEnabled()) ? label.getIcon() :
                                          label.getDisabledIcon();
        Rectangle paintViewR = new Rectangle();
        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);
    }

    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(null);
        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);

            Rectangle iconR = new Rectangle();
            Rectangle textR = new Rectangle();
            Rectangle viewR = new Rectangle();
            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);
            int y1 = Math.min(iconR.y, textR.y);
            int y2 = Math.max(iconR.y + iconR.height, textR.y + textR.height);
            Dimension rv = new Dimension(x2 - x1, y2 - y1);

            rv.width += dx;
            rv.height += dy;
            return rv;
        }
    }


    
Returns:getPreferredSize(c)
/**
     * @return getPreferredSize(c)
     */
    public Dimension getMinimumSize(JComponent c) {
        Dimension d = getPreferredSize(c);
        View v = (View) c.getClientProperty(BasicHTML.propertyKey);
        if (v != null) {
            d.width -= v.getPreferredSpan(View.X_AXIS) - v.getMinimumSpan(View.X_AXIS);
        }
        return d;
    }

    
Returns:getPreferredSize(c)
/**
     * @return getPreferredSize(c)
     */
    public Dimension getMaximumSize(JComponent c) {
        Dimension d = getPreferredSize(c);
        View v = (View) c.getClientProperty(BasicHTML.propertyKey);
        if (v != null) {
            d.width += v.getMaximumSpan(View.X_AXIS) - v.getPreferredSpan(View.X_AXIS);
        }
        return d;
    }

    
Returns the baseline.

Throws:
See Also:
Since:1.6
/**
     * Returns the baseline.
     *
     * @throws NullPointerException {@inheritDoc}
     * @throws IllegalArgumentException {@inheritDoc}
     * @see javax.swing.JComponent#getBaseline(int, int)
     * @since 1.6
     */
    public int getBaseline(JComponent c, int width, int height) {
        super.getBaseline(c, width, height);
        JLabel label = (JLabel)c;
        String text = label.getText();
        if (text == null || "".equals(text) || label.getFont() == null) {
            return -1;
        }
        FontMetrics fm = label.getFontMetrics(label.getFont());
        layout(label, fm, width, height);
        return BasicHTML.getBaseline(label, paintTextR.y, fm.getAscent(),
                                     paintTextR.width, paintTextR.height);
    }

    
Returns an enum indicating how the baseline of the component
changes as the size changes.

Throws:
  • NullPointerException – {@inheritDoc}
See Also:
Since:1.6
/**
     * Returns an enum indicating how the baseline of the component
     * changes as the size changes.
     *
     * @throws NullPointerException {@inheritDoc}
     * @see javax.swing.JComponent#getBaseline(int, int)
     * @since 1.6
     */
    public Component.BaselineResizeBehavior getBaselineResizeBehavior(
            JComponent c) {
        super.getBaselineResizeBehavior(c);
        if (c.getClientProperty(BasicHTML.propertyKey) != null) {
            return Component.BaselineResizeBehavior.OTHER;
        }
        switch(((JLabel)c).getVerticalAlignment()) {
        case JLabel.TOP:
            return Component.BaselineResizeBehavior.CONSTANT_ASCENT;
        case JLabel.BOTTOM:
            return Component.BaselineResizeBehavior.CONSTANT_DESCENT;
        case JLabel.CENTER:
            return Component.BaselineResizeBehavior.CENTER_OFFSET;
        }
        return Component.BaselineResizeBehavior.OTHER;
    }


    public void installUI(JComponent c) {
        installDefaults((JLabel)c);
        installComponents((JLabel)c);
        installListeners((JLabel)c);
        installKeyboardActions((JLabel)c);
    }


    public void uninstallUI(JComponent c) {
        uninstallDefaults((JLabel)c);
        uninstallComponents((JLabel)c);
        uninstallListeners((JLabel)c);
        uninstallKeyboardActions((JLabel)c);
    }

     protected void installDefaults(JLabel c){
         LookAndFeel.installColorsAndFont(c, "Label.background", "Label.foreground", "Label.font");
         LookAndFeel.installProperty(c, "opaque", Boolean.FALSE);
      }

    protected void installListeners(JLabel c){
        c.addPropertyChangeListener(this);
    }

    protected void installComponents(JLabel c){
        BasicHTML.updateRenderer(c, c.getText());
        c.setInheritsPopupMenu(true);
    }

    protected void installKeyboardActions(JLabel l) {
        int dka = l.getDisplayedMnemonic();
        Component lf = l.getLabelFor();
        if ((dka != 0) && (lf != null)) {
            LazyActionMap.installLazyActionMap(l, BasicLabelUI.class,
                                               "Label.actionMap");
            InputMap inputMap = SwingUtilities.getUIInputMap
                            (l, JComponent.WHEN_IN_FOCUSED_WINDOW);
            if (inputMap == null) {
                inputMap = new ComponentInputMapUIResource(l);
                SwingUtilities.replaceUIInputMap(l,
                                JComponent.WHEN_IN_FOCUSED_WINDOW, inputMap);
            }
            inputMap.clear();
            inputMap.put(KeyStroke.getKeyStroke(dka, ActionEvent.ALT_MASK,
                                              false), "press");
        }
        else {
            InputMap inputMap = SwingUtilities.getUIInputMap
                            (l, JComponent.WHEN_IN_FOCUSED_WINDOW);
            if (inputMap != null) {
                inputMap.clear();
            }
        }
    }

    protected void uninstallDefaults(JLabel c){
    }

    protected void uninstallListeners(JLabel c){
        c.removePropertyChangeListener(this);
    }

    protected void uninstallComponents(JLabel c){
        BasicHTML.updateRenderer(c, "");
    }

    protected void uninstallKeyboardActions(JLabel c) {
        SwingUtilities.replaceUIInputMap(c, JComponent.WHEN_FOCUSED, null);
        SwingUtilities.replaceUIInputMap(c, JComponent.WHEN_IN_FOCUSED_WINDOW,
                                       null);
        SwingUtilities.replaceUIActionMap(c, null);
    }

    public static ComponentUI createUI(JComponent c) {
         if (System.getSecurityManager() != null) {
             AppContext appContext = AppContext.getAppContext();
             BasicLabelUI safeBasicLabelUI = 
                     (BasicLabelUI) appContext.get(BASIC_LABEL_UI_KEY);
             if (safeBasicLabelUI == null) {
                 safeBasicLabelUI = new BasicLabelUI();
                 appContext.put(BASIC_LABEL_UI_KEY, safeBasicLabelUI);
             }
             return safeBasicLabelUI;
         }   
         return labelUI;
    }

    public void propertyChange(PropertyChangeEvent e) {
        String name = e.getPropertyName();
        if (name == "text" || "font" == name || "foreground" == name) {
            // remove the old html view client property if one
            // existed, and install a new one if the text installed
            // into the JLabel is html source.
            JLabel lbl = ((JLabel) e.getSource());
            String text = lbl.getText();
            BasicHTML.updateRenderer(lbl, text);
        }
        else if (name == "labelFor" || name == "displayedMnemonic") {
            installKeyboardActions((JLabel) e.getSource());
        }
    }

    // When the accelerator is pressed, temporarily make the JLabel
    // focusTraversable by registering a WHEN_FOCUSED action for the
    // release of the accelerator.  Then give it focus so it can
    // prevent unwanted keyTyped events from getting to other components.
    private static class Actions extends UIAction {
        private static final String PRESS = "press";
        private static final String RELEASE = "release";

        Actions(String key) {
            super(key);
        }

        public void actionPerformed(ActionEvent e) {
            JLabel label = (JLabel)e.getSource();
            String key = getName();
            if (key == PRESS) {
                doPress(label);
            }
            else if (key == RELEASE) {
                doRelease(label);
            }
        }

        private void doPress(JLabel label) {
            Component labelFor = label.getLabelFor();
            if (labelFor != null && labelFor.isEnabled()) {
                InputMap inputMap = SwingUtilities.getUIInputMap(label, JComponent.WHEN_FOCUSED);
                if (inputMap == null) {
                    inputMap = new InputMapUIResource();
                    SwingUtilities.replaceUIInputMap(label, JComponent.WHEN_FOCUSED, inputMap);
                }
                int dka = label.getDisplayedMnemonic();
                inputMap.put(KeyStroke.getKeyStroke(dka, ActionEvent.ALT_MASK, true), RELEASE);
                // Need this if ALT is released before the accelerator
                inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_ALT, 0, true), RELEASE);
                label.requestFocus();
            }
        }

        private void doRelease(JLabel label) {
            Component labelFor = label.getLabelFor();
            if (labelFor != null && labelFor.isEnabled()) {
                InputMap inputMap = SwingUtilities.getUIInputMap(label, JComponent.WHEN_FOCUSED);
                if (inputMap != null) {
                    // inputMap should never be null.
                    inputMap.remove(KeyStroke.getKeyStroke(label.getDisplayedMnemonic(), ActionEvent.ALT_MASK, true));
                    inputMap.remove(KeyStroke.getKeyStroke(KeyEvent.VK_ALT, 0, true));
                }
                if (labelFor instanceof Container &&
                        ((Container) labelFor).isFocusCycleRoot()) {
                    labelFor.requestFocus();
                } else {
                    SwingUtilities2.compositeRequestFocus(labelFor);
                }
            }
        }
    }
}