/*

 * Copyright (c) 2002, 2013, 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 sun.swing;

import java.security.*;

import java.lang.reflect.*;

import java.awt.*;

import static java.awt.RenderingHints.*;

import java.awt.event.*;

import java.awt.font.*;

import java.awt.geom.*;

import java.awt.print.PrinterGraphics;

import java.text.CharacterIterator;

import java.text.AttributedCharacterIterator;

import java.text.AttributedString;

import javax.swing.*;

import javax.swing.event.TreeModelEvent;

import javax.swing.text.Highlighter;

import javax.swing.text.JTextComponent;

import javax.swing.text.DefaultHighlighter;

import javax.swing.text.DefaultCaret;

import javax.swing.table.TableCellRenderer;

import javax.swing.table.TableColumnModel;

import javax.swing.tree.TreeModel;

import javax.swing.tree.TreePath;

import sun.swing.PrintColorUIResource;

import sun.swing.ImageIconUIResource;

import sun.print.ProxyPrintGraphics;

import sun.awt.*;

import sun.security.action.GetPropertyAction;

import sun.security.util.SecurityConstants;

import java.io.*;

import java.util.*;

import sun.font.FontDesignMetrics;

import sun.font.FontUtilities;

import sun.java2d.SunGraphicsEnvironment;

import java.util.concurrent.Callable;

import java.util.concurrent.Future;

import java.util.concurrent.FutureTask;

/**

 * A collection of utility methods for Swing.

 * <p>

 * <b>WARNING:</b> While this class is public, it should not be treated as

 * public API and its API may change in incompatable ways between dot dot

 * releases and even patch releases. You should not rely on this class even

 * existing.

 *

 */

public class SwingUtilities2 {

    /**

     * The <code>AppContext</code> key for our one <code>LAFState</code>

     * instance.

     */

    public static final Object LAF_STATE_KEY =

            new StringBuffer("LookAndFeel State");

    // Maintain a cache of CACHE_SIZE fonts and the left side bearing

     // of the characters falling into the range MIN_CHAR_INDEX to

     // MAX_CHAR_INDEX. The values in fontCache are created as needed.

     private static LSBCacheEntry[] fontCache;

     // Windows defines 6 font desktop properties, we will therefore only

     // cache the metrics for 6 fonts.

     private static final int CACHE_SIZE = 6;

     // nextIndex in fontCache to insert a font into.

     private static int nextIndex;

     // LSBCacheEntry used to search in fontCache to see if we already

     // have an entry for a particular font

     private static LSBCacheEntry searchKey;

     // getLeftSideBearing will consult all characters that fall in the

     // range MIN_CHAR_INDEX to MAX_CHAR_INDEX.

     private static final int MIN_CHAR_INDEX = (int)'W';

     private static final int MAX_CHAR_INDEX = (int)'W' + 1;

    public static final FontRenderContext DEFAULT_FRC =

        new FontRenderContext(null, false, false);

    /**

     * A JComponent client property is used to determine text aa settings.

     * To avoid having this property persist between look and feels changes

     * the value of the property is set to null in JComponent.setUI

     */

    public static final Object AA_TEXT_PROPERTY_KEY =

                          new StringBuffer("AATextInfoPropertyKey");

    /**

     * Attribute key for the content elements.  If it is set on an element, the

     * element is considered to be a line break.

     */

    public static final String IMPLIED_CR = "CR";

    /**

     * Used to tell a text component, being used as an editor for table

     * or tree, how many clicks it took to start editing.

     */

    private static final StringBuilder SKIP_CLICK_COUNT =

        new StringBuilder("skipClickCount");

    /* Presently this class assumes default fractional metrics.

     * This may need to change to emulate future platform L&Fs.

     */

    public static class AATextInfo {

        private static AATextInfo getAATextInfoFromMap(Map hints) {

            Object aaHint   = hints.get(KEY_TEXT_ANTIALIASING);

            Object contHint = hints.get(KEY_TEXT_LCD_CONTRAST);

            if (aaHint == null ||

                aaHint == VALUE_TEXT_ANTIALIAS_OFF ||

                aaHint == VALUE_TEXT_ANTIALIAS_DEFAULT) {

                return null;

            } else {

                return new AATextInfo(aaHint, (Integer)contHint);

            }

        }

        public static AATextInfo getAATextInfo(boolean lafCondition) {

            SunToolkit.setAAFontSettingsCondition(lafCondition);

            Toolkit tk = Toolkit.getDefaultToolkit();

            Object map = tk.getDesktopProperty(SunToolkit.DESKTOPFONTHINTS);

            if (map instanceof Map) {

                return getAATextInfoFromMap((Map)map);

            } else {

                return null;

            }

        }

        Object aaHint;

        Integer lcdContrastHint;

        FontRenderContext frc;

        /* These are rarely constructed objects, and only when a complete

         * UI is being updated, so the cost of the tests here is minimal

         * and saves tests elsewhere.

         * We test that the values are ones we support/expect.

         */

        public AATextInfo(Object aaHint, Integer lcdContrastHint) {

            if (aaHint == null) {

                throw new InternalError("null not allowed here");

            }

            if (aaHint == VALUE_TEXT_ANTIALIAS_OFF ||

                aaHint == VALUE_TEXT_ANTIALIAS_DEFAULT) {

                throw new InternalError("AA must be on");

            }

            this.aaHint = aaHint;

            this.lcdContrastHint = lcdContrastHint;

            this.frc = new FontRenderContext(null, aaHint,

                                             VALUE_FRACTIONALMETRICS_DEFAULT);

        }

    }

    /**

     * Key used in client properties used to indicate that the

     * <code>ComponentUI</code> of the JComponent instance should be returned.

     */

    public static final Object COMPONENT_UI_PROPERTY_KEY =

                            new StringBuffer("ComponentUIPropertyKey");

    /** Client Property key for the text maximal offsets for BasicMenuItemUI */

    public static final StringUIClientPropertyKey BASICMENUITEMUI_MAX_TEXT_OFFSET =

        new StringUIClientPropertyKey ("maxTextOffset");

    // security stuff

    private static Field inputEvent_CanAccessSystemClipboard_Field = null;

    private static final String UntrustedClipboardAccess =

        "UNTRUSTED_CLIPBOARD_ACCESS_KEY";

    //all access to  charsBuffer is to be synchronized on charsBufferLock

    private static final int CHAR_BUFFER_SIZE = 100;

    private static final Object charsBufferLock = new Object();

    private static char[] charsBuffer = new char[CHAR_BUFFER_SIZE];

    static {

        fontCache = new LSBCacheEntry[CACHE_SIZE];

    }

    /**

     * Fill the character buffer cache.  Return the buffer length.

     */

    private static int syncCharsBuffer(String s) {

        int length = s.length();

        if ((charsBuffer == null) || (charsBuffer.length < length)) {

            charsBuffer = s.toCharArray();

        } else {

            s.getChars(0, length, charsBuffer, 0);

        }

        return length;

    }

    /**

     * checks whether TextLayout is required to handle characters.

     *

     * @param text characters to be tested

     * @param start start

     * @param limit limit

     * @return <tt>true</tt>  if TextLayout is required

     *         <tt>false</tt> if TextLayout is not required

     */

    public static final boolean isComplexLayout(char[] text, int start, int limit) {

        return FontUtilities.isComplexText(text, start, limit);

    }

    //

    // WARNING WARNING WARNING WARNING WARNING WARNING

    // Many of the following methods are invoked from older API.

    // As this older API was not passed a Component, a null Component may

    // now be passsed in.  For example, SwingUtilities.computeStringWidth

    // is implemented to call SwingUtilities2.stringWidth, the

    // SwingUtilities variant does not take a JComponent, as such

    // SwingUtilities2.stringWidth can be passed a null Component.

    // In other words, if you add new functionality to these methods you

    // need to gracefully handle null.

    //

    /**

     * Returns whether or not text should be drawn antialiased.

     *

     * @param c JComponent to test.

     * @return Whether or not text should be drawn antialiased for the

     *         specified component.

     */

    public static AATextInfo drawTextAntialiased(JComponent c) {

        if (c != null) {

            /* a non-null property implies some form of AA requested */

            return (AATextInfo)c.getClientProperty(AA_TEXT_PROPERTY_KEY);

        }

        // No component, assume aa is off

        return null;

    }

    /**

     * Returns the left side bearing of the first character of string. The

     * left side bearing is calculated from the passed in

     * FontMetrics.  If the passed in String is less than one

     * character {@code 0} is returned.

     *

     * @param c JComponent that will display the string

     * @param fm FontMetrics used to measure the String width

     * @param string String to get the left side bearing for.

     * @throws NullPointerException if {@code string} is {@code null}

     *

     * @return the left side bearing of the first character of string

     * or {@code 0} if the string is empty

     */

    public static int getLeftSideBearing(JComponent c, FontMetrics fm,

                                         String string) {

        if ((string == null) || (string.length() == 0)) {

            return 0;

        }

        return getLeftSideBearing(c, fm, string.charAt(0));

    }

    /**

     * Returns the left side bearing of the first character of string. The

     * left side bearing is calculated from the passed in FontMetrics.

     *

     * @param c JComponent that will display the string

     * @param fm FontMetrics used to measure the String width

     * @param firstChar Character to get the left side bearing for.

     */

    public static int getLeftSideBearing(JComponent c, FontMetrics fm,

                                         char firstChar) {

        int charIndex = (int) firstChar;

        if (charIndex < MAX_CHAR_INDEX && charIndex >= MIN_CHAR_INDEX) {

            byte[] lsbs = null;

            FontRenderContext frc = getFontRenderContext(c, fm);

            Font font = fm.getFont();

            synchronized (SwingUtilities2.class) {

                LSBCacheEntry entry = null;

                if (searchKey == null) {

                    searchKey = new LSBCacheEntry(frc, font);

                } else {

                    searchKey.reset(frc, font);

                }

                // See if we already have an entry for this pair

                for (LSBCacheEntry cacheEntry : fontCache) {

                    if (searchKey.equals(cacheEntry)) {

                        entry = cacheEntry;

                        break;

                    }

                }

                if (entry == null) {

                    // No entry for this pair, add it.

                    entry = searchKey;

                    fontCache[nextIndex] = searchKey;

                    searchKey = null;

                    nextIndex = (nextIndex + 1) % CACHE_SIZE;

                }

                return entry.getLeftSideBearing(firstChar);

            }

        }

        return 0;

    }

    /**

     * Returns the FontMetrics for the current Font of the passed

     * in Graphics.  This method is used when a Graphics

     * is available, typically when painting.  If a Graphics is not

     * available the JComponent method of the same name should be used.

     * <p>

     * Callers should pass in a non-null JComponent, the exception

     * to this is if a JComponent is not readily available at the time of

     * painting.

     * <p>

     * This does not necessarily return the FontMetrics from the

     * Graphics.

     *

     * @param c JComponent requesting FontMetrics, may be null

     * @param g Graphics Graphics

     */

    public static FontMetrics getFontMetrics(JComponent c, Graphics g) {

        return getFontMetrics(c, g, g.getFont());

    }

    /**

     * Returns the FontMetrics for the specified Font.

     * This method is used when a Graphics is available, typically when

     * painting.  If a Graphics is not available the JComponent method of

     * the same name should be used.

     * <p>

     * Callers should pass in a non-null JComonent, the exception

     * to this is if a JComponent is not readily available at the time of

     * painting.

     * <p>

     * This does not necessarily return the FontMetrics from the

     * Graphics.

     *

     * @param c JComponent requesting FontMetrics, may be null

     * @param c Graphics Graphics

     * @param font Font to get FontMetrics for

     */

    public static FontMetrics getFontMetrics(JComponent c, Graphics g,

                                             Font font) {

        if (c != null) {

            // Note: We assume that we're using the FontMetrics

            // from the widget to layout out text, otherwise we can get

            // mismatches when printing.

            return c.getFontMetrics(font);

        }

        return Toolkit.getDefaultToolkit().getFontMetrics(font);

    }

    /**

     * Returns the width of the passed in String.

     * If the passed String is <code>null</code>, returns zero.

     *

     * @param c JComponent that will display the string, may be null

     * @param fm FontMetrics used to measure the String width

     * @param string String to get the width of

     */

    public static int stringWidth(JComponent c, FontMetrics fm, String string){

        if (string == null || string.equals("")) {

            return 0;

        }

        boolean needsTextLayout = ((c != null) &&

                (c.getClientProperty(TextAttribute.NUMERIC_SHAPING) != null));

        if (needsTextLayout) {

            synchronized(charsBufferLock) {

                int length = syncCharsBuffer(string);

                needsTextLayout = isComplexLayout(charsBuffer, 0, length);

            }

        }

        if (needsTextLayout) {

            TextLayout layout = createTextLayout(c, string,

                                    fm.getFont(), fm.getFontRenderContext());

            return (int) layout.getAdvance();

        } else {

            return fm.stringWidth(string);

        }

    }

    /**

     * Clips the passed in String to the space provided.

     *

     * @param c JComponent that will display the string, may be null

     * @param fm FontMetrics used to measure the String width

     * @param string String to display

     * @param availTextWidth Amount of space that the string can be drawn in

     * @return Clipped string that can fit in the provided space.

     */

    public static String clipStringIfNecessary(JComponent c, FontMetrics fm,

                                               String string,

                                               int availTextWidth) {

        if ((string == null) || (string.equals("")))  {

            return "";

        }

        int textWidth = SwingUtilities2.stringWidth(c, fm, string);

        if (textWidth > availTextWidth) {

            return SwingUtilities2.clipString(c, fm, string, availTextWidth);

        }

        return string;

    }

    /**

     * Clips the passed in String to the space provided.  NOTE: this assumes

     * the string does not fit in the available space.

     *

     * @param c JComponent that will display the string, may be null

     * @param fm FontMetrics used to measure the String width

     * @param string String to display

     * @param availTextWidth Amount of space that the string can be drawn in

     * @return Clipped string that can fit in the provided space.

     */

    public static String clipString(JComponent c, FontMetrics fm,

                                    String string, int availTextWidth) {

        // c may be null here.

        String clipString = "...";

        availTextWidth -= SwingUtilities2.stringWidth(c, fm, clipString);

        if (availTextWidth <= 0) {

            //can not fit any characters

            return clipString;

        }

        boolean needsTextLayout;

        synchronized (charsBufferLock) {

            int stringLength = syncCharsBuffer(string);

            needsTextLayout =

                isComplexLayout(charsBuffer, 0, stringLength);

            if (!needsTextLayout) {

                int width = 0;

                for (int nChars = 0; nChars < stringLength; nChars++) {

                    width += fm.charWidth(charsBuffer[nChars]);

                    if (width > availTextWidth) {

                        string = string.substring(0, nChars);

                        break;

                    }

                }

            }

        }

        if (needsTextLayout) {

            FontRenderContext frc = getFontRenderContext(c, fm);

            AttributedString aString = new AttributedString(string);

            if (c != null) {

                aString.addAttribute(TextAttribute.NUMERIC_SHAPING,

                        c.getClientProperty(TextAttribute.NUMERIC_SHAPING));

            }

            LineBreakMeasurer measurer =

                new LineBreakMeasurer(aString.getIterator(), frc);

            int nChars = measurer.nextOffset(availTextWidth);

            string = string.substring(0, nChars);

        }

        return string + clipString;

    }

    /**

     * Draws the string at the specified location.

     *

     * @param c JComponent that will display the string, may be null

     * @param g Graphics to draw the text to

     * @param text String to display

     * @param x X coordinate to draw the text at

     * @param y Y coordinate to draw the text at

     */

    public static void drawString(JComponent c, Graphics g, String text,

                                  int x, int y) {

        // c may be null

        // All non-editable widgets that draw strings call into this

        // methods.  By non-editable that means widgets like JLabel, JButton

        // but NOT JTextComponents.

        if ( text == null || text.length() <= 0 ) { //no need to paint empty strings

            return;

        }

        if (isPrinting(g)) {

            Graphics2D g2d = getGraphics2D(g);

            if (g2d != null) {

                /* The printed text must scale linearly with the UI.

                 * Calculate the width on screen, obtain a TextLayout with

                 * advances for the printer graphics FRC, and then justify

                 * it to fit in the screen width. This distributes the spacing

                 * more evenly than directly laying out to the screen advances.

                 */

                String trimmedText = trimTrailingSpaces(text);

                if (!trimmedText.isEmpty()) {

                    float screenWidth = (float) g2d.getFont().getStringBounds

                            (trimmedText, DEFAULT_FRC).getWidth();

                    TextLayout layout = createTextLayout(c, text, g2d.getFont(),

                                                       g2d.getFontRenderContext());

                    layout = layout.getJustifiedLayout(screenWidth);

                    /* Use alternate print color if specified */