/*

 * Copyright (c) 1997, 2008, 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

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

 */

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 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 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);

    }

    /**

     * Paints the label text with the foreground color, if the label is opaque

     * then paints the entire background with the background color. The Label

     * text is drawn by {@link #paintEnabledText} or {@link #paintDisabledText}.

     * The locations of the label parts are computed by {@link #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;

        }

    }

    /**

     * @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;

    }

    /**

     * @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 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 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();

        }

        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();

                // Need this when the sticky keys are enabled

                inputMap.put(KeyStroke.getKeyStroke(dka, 0, 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.

                    int dka = label.getDisplayedMnemonic();

                    inputMap.remove(KeyStroke.getKeyStroke(dka, 0, true));

                    inputMap.remove(KeyStroke.getKeyStroke(KeyEvent.VK_ALT, 0, true));

                }

                if (labelFor instanceof Container &&

                        ((Container) labelFor).isFocusCycleRoot()) {

                    labelFor.requestFocus();

                } else {

                    SwingUtilities2.compositeRequestFocus(labelFor);

                }

            }

        }

    }

}