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 * Copyright (c) 1995, 2019, 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 java.awt;

import java.awt.font.FontRenderContext;

import java.awt.font.GlyphVector;

import java.awt.font.LineMetrics;

import java.awt.font.TextAttribute;

import java.awt.font.TextLayout;

import java.awt.geom.AffineTransform;

import java.awt.geom.Point2D;

import java.awt.geom.Rectangle2D;

import java.awt.peer.FontPeer;

import java.io.*;

import java.lang.ref.SoftReference;

import java.nio.file.Files;

import java.security.AccessController;

import java.security.PrivilegedExceptionAction;

import java.text.AttributedCharacterIterator.Attribute;

import java.text.CharacterIterator;

import java.util.EventListener;

import java.util.Hashtable;

import java.util.Locale;

import java.util.Map;

import sun.awt.ComponentFactory;

import sun.font.StandardGlyphVector;

import sun.font.AttributeMap;

import sun.font.AttributeValues;

import sun.font.CompositeFont;

import sun.font.CreatedFontTracker;

import sun.font.Font2D;

import sun.font.Font2DHandle;

import sun.font.FontAccess;

import sun.font.FontDesignMetrics;

import sun.font.FontManager;

import sun.font.FontManagerFactory;

import sun.font.FontUtilities;

import sun.font.GlyphLayout;

import sun.font.FontLineMetrics;

import sun.font.CoreMetrics;

import static sun.font.EAttribute.*;

/**

 * The {@code Font} class represents fonts, which are used to

 * render text in a visible way.

 * A font provides the information needed to map sequences of

 * <em>characters</em> to sequences of <em>glyphs</em>

 * and to render sequences of glyphs on {@code Graphics} and

 * {@code Component} objects.

 *

 * <h2>Characters and Glyphs</h2>

 *

 * A <em>character</em> is a symbol that represents an item such as a letter,

 * a digit, or punctuation in an abstract way. For example, {@code 'g'},

 * LATIN SMALL LETTER G, is a character.

 * <p>

 * A <em>glyph</em> is a shape used to render a character or a sequence of

 * characters. In simple writing systems, such as Latin, typically one glyph

 * represents one character. In general, however, characters and glyphs do not

 * have one-to-one correspondence. For example, the character 'á'

 * LATIN SMALL LETTER A WITH ACUTE, can be represented by

 * two glyphs: one for 'a' and one for '´'. On the other hand, the

 * two-character string "fi" can be represented by a single glyph, an

 * "fi" ligature. In complex writing systems, such as Arabic or the South

 * and South-East Asian writing systems, the relationship between characters

 * and glyphs can be more complicated and involve context-dependent selection

 * of glyphs as well as glyph reordering.

 *

 * A font encapsulates the collection of glyphs needed to render a selected set

 * of characters as well as the tables needed to map sequences of characters to

 * corresponding sequences of glyphs.

 *

 * <h2>Physical and Logical Fonts</h2>

 *

 * The Java Platform distinguishes between two kinds of fonts:

 * <em>physical</em> fonts and <em>logical</em> fonts.

 * <p>

 * <em>Physical</em> fonts are the actual font libraries containing glyph data

 * and tables to map from character sequences to glyph sequences, using a font

 * technology such as TrueType or PostScript Type 1.

 * All implementations of the Java Platform must support TrueType fonts;

 * support for other font technologies is implementation dependent.

 * Physical fonts may use names such as Helvetica, Palatino, HonMincho, or

 * any number of other font names.

 * Typically, each physical font supports only a limited set of writing

 * systems, for example, only Latin characters or only Japanese and Basic

 * Latin.

 * The set of available physical fonts varies between configurations.

 * Applications that require specific fonts can bundle them and instantiate

 * them using the {@link #createFont createFont} method.

 * <p>

 * <em>Logical</em> fonts are the five font families defined by the Java

 * platform which must be supported by any Java runtime environment:

 * Serif, SansSerif, Monospaced, Dialog, and DialogInput.

 * These logical fonts are not actual font libraries. Instead, the logical

 * font names are mapped to physical fonts by the Java runtime environment.

 * The mapping is implementation and usually locale dependent, so the look

 * and the metrics provided by them vary.

 * Typically, each logical font name maps to several physical fonts in order to

 * cover a large range of characters.

 * <p>

 * Peered AWT components, such as {@link Label Label} and

 * {@link TextField TextField}, can only use logical fonts.

 * <p>

 * For a discussion of the relative advantages and disadvantages of using

 * physical or logical fonts, see the

 * <a href="https://docs.oracle.com/javase/tutorial/2d/text/fonts.html#advantages-and-disadvantages">

 *    Physical and Logical Fonts</a>

 * in <a href="https://docs.oracle.com/javase/tutorial/index.html">The Java Tutorials</a>

 * document.

 *

 * <h2>Font Faces and Names</h2>

 *

 * A {@code Font}

 * can have many faces, such as heavy, medium, oblique, gothic and

 * regular. All of these faces have similar typographic design.

 * <p>

 * There are three different names that you can get from a

 * {@code Font} object.  The <em>logical font name</em> is simply the

 * name that was used to construct the font.

 * The <em>font face name</em>, or just <em>font name</em> for

 * short, is the name of a particular font face, like Helvetica Bold. The

 * <em>family name</em> is the name of the font family that determines the

 * typographic design across several faces, like Helvetica.

 * <p>

 * The {@code Font} class represents an instance of a font face from

 * a collection of  font faces that are present in the system resources

 * of the host system.  As examples, Arial Bold and Courier Bold Italic

 * are font faces.  There can be several {@code Font} objects

 * associated with a font face, each differing in size, style, transform

 * and font features.

 * <p>

 * Glyphs may not always be rendered with the requested properties (e.g, font

 * and style) due to platform limitations such as the absence of suitable

 * platform fonts to implement a logical font.

 * <p>

 * The {@link GraphicsEnvironment#getAllFonts() getAllFonts} method

 * of the {@code GraphicsEnvironment} class returns an

 * array of all font faces available in the system. These font faces are

 * returned as {@code Font} objects with a size of 1, identity

 * transform and default font features. These

 * base fonts can then be used to derive new {@code Font} objects

 * with varying sizes, styles, transforms and font features via the

 * {@code deriveFont} methods in this class.

 *

 * <h2>Font and TextAttribute</h2>

 *

 * <p>{@code Font} supports most

 * {@code TextAttribute}s.  This makes some operations, such as

 * rendering underlined text, convenient since it is not

 * necessary to explicitly construct a {@code TextLayout} object.

 * Attributes can be set on a Font by constructing or deriving it

 * using a {@code Map} of {@code TextAttribute} values.

 *

 * <p>The values of some {@code TextAttributes} are not

 * serializable, and therefore attempting to serialize an instance of

 * {@code Font} that has such values will not serialize them.

 * This means a Font deserialized from such a stream will not compare

 * equal to the original Font that contained the non-serializable

 * attributes.  This should very rarely pose a problem

 * since these attributes are typically used only in special

 * circumstances and are unlikely to be serialized.

 *

 * <ul>

 * <li>{@code FOREGROUND} and {@code BACKGROUND} use

 * {@code Paint} values. The subclass {@code Color} is

 * serializable, while {@code GradientPaint} and

 * {@code TexturePaint} are not.</li>

 * <li>{@code CHAR_REPLACEMENT} uses

 * {@code GraphicAttribute} values.  The subclasses

 * {@code ShapeGraphicAttribute} and

 * {@code ImageGraphicAttribute} are not serializable.</li>

 * <li>{@code INPUT_METHOD_HIGHLIGHT} uses

 * {@code InputMethodHighlight} values, which are

 * not serializable.  See {@link java.awt.im.InputMethodHighlight}.</li>

 * </ul>

 *

 * <p>Clients who create custom subclasses of {@code Paint} and

 * {@code GraphicAttribute} can make them serializable and

 * avoid this problem.  Clients who use input method highlights can

 * convert these to the platform-specific attributes for that

 * highlight on the current platform and set them on the Font as

 * a workaround.

 *

 * <p>The {@code Map}-based constructor and

 * {@code deriveFont} APIs ignore the FONT attribute, and it is

 * not retained by the Font; the static {@link #getFont} method should

 * be used if the FONT attribute might be present.  See {@link

 * java.awt.font.TextAttribute#FONT} for more information.</p>

 *

 * <p>Several attributes will cause additional rendering overhead

 * and potentially invoke layout.  If a {@code Font} has such

 * attributes, the <code>{@link #hasLayoutAttributes()}</code> method

 * will return true.</p>

 *

 * <p>Note: Font rotations can cause text baselines to be rotated.  In

 * order to account for this (rare) possibility, font APIs are

 * specified to return metrics and take parameters 'in

 * baseline-relative coordinates'.  This maps the 'x' coordinate to

 * the advance along the baseline, (positive x is forward along the

 * baseline), and the 'y' coordinate to a distance along the

 * perpendicular to the baseline at 'x' (positive y is 90 degrees

 * clockwise from the baseline vector).  APIs for which this is

 * especially important are called out as having 'baseline-relative

 * coordinates.'

 */

public class Font implements java.io.Serializable

{

    private static class FontAccessImpl extends FontAccess {

        public Font2D getFont2D(Font font) {

            return font.getFont2D();

        }

        public void setFont2D(Font font, Font2DHandle handle) {

            font.font2DHandle = handle;

        }

        public void setCreatedFont(Font font) {

            font.createdFont = true;

        }

        public boolean isCreatedFont(Font font) {

            return font.createdFont;

        }

        @Override

        public FontPeer getFontPeer(final Font font) {

            return font.getFontPeer();

        }

    }

    static {

        /* ensure that the necessary native libraries are loaded */

        Toolkit.loadLibraries();

        initIDs();

        FontAccess.setFontAccess(new FontAccessImpl());

    }

    /**

     * This is now only used during serialization.  Typically

     * it is null.

     *

     * @serial

     * @see #getAttributes()

     */

    private Hashtable<Object, Object> fRequestedAttributes;

    /*

     * Constants to be used for logical font family names.

     */

    /**

     * A String constant for the canonical family name of the

     * logical font "Dialog". It is useful in Font construction

     * to provide compile-time verification of the name.

     * @since 1.6

     */

    public static final String DIALOG = "Dialog";

    /**

     * A String constant for the canonical family name of the

     * logical font "DialogInput". It is useful in Font construction

     * to provide compile-time verification of the name.

     * @since 1.6

     */

    public static final String DIALOG_INPUT = "DialogInput";

    /**

     * A String constant for the canonical family name of the

     * logical font "SansSerif". It is useful in Font construction

     * to provide compile-time verification of the name.

     * @since 1.6

     */

    public static final String SANS_SERIF = "SansSerif";

    /**

     * A String constant for the canonical family name of the

     * logical font "Serif". It is useful in Font construction

     * to provide compile-time verification of the name.

     * @since 1.6

     */

    public static final String SERIF = "Serif";

    /**

     * A String constant for the canonical family name of the

     * logical font "Monospaced". It is useful in Font construction

     * to provide compile-time verification of the name.

     * @since 1.6

     */

    public static final String MONOSPACED = "Monospaced";

    /*

     * Constants to be used for styles. Can be combined to mix

     * styles.

     */

    /**

     * The plain style constant.

     */

    public static final int PLAIN       = 0;

    /**

     * The bold style constant.  This can be combined with the other style

     * constants (except PLAIN) for mixed styles.

     */

    public static final int BOLD        = 1;

    /**

     * The italicized style constant.  This can be combined with the other

     * style constants (except PLAIN) for mixed styles.

     */

    public static final int ITALIC      = 2;

    /**

     * The baseline used in most Roman scripts when laying out text.

     */

    public static final int ROMAN_BASELINE = 0;

    /**

     * The baseline used in ideographic scripts like Chinese, Japanese,

     * and Korean when laying out text.

     */

    public static final int CENTER_BASELINE = 1;

    /**

     * The baseline used in Devanagari and similar scripts when laying

     * out text.

     */

    public static final int HANGING_BASELINE = 2;

    /**

     * Identify a font resource of type TRUETYPE.

     * Used to specify a TrueType font resource to the

     * {@link #createFont} method.

     * The TrueType format was extended to become the OpenType

     * format, which adds support for fonts with Postscript outlines,

     * this tag therefore references these fonts, as well as those

     * with TrueType outlines.

     * @since 1.3

     */

    public static final int TRUETYPE_FONT = 0;

    /**

     * Identify a font resource of type TYPE1.

     * Used to specify a Type1 font resource to the

     * {@link #createFont} method.

     * @since 1.5

     */

    public static final int TYPE1_FONT = 1;

    /**

     * The logical name of this {@code Font}, as passed to the

     * constructor.

     * @since 1.0

     *

     * @serial

     * @see #getName

     */

    protected String name;

    /**

     * The style of this {@code Font}, as passed to the constructor.

     * This style can be PLAIN, BOLD, ITALIC, or BOLD+ITALIC.

     * @since 1.0

     *

     * @serial

     * @see #getStyle()

     */

    protected int style;

    /**

     * The point size of this {@code Font}, rounded to integer.

     * @since 1.0

     *

     * @serial

     * @see #getSize()

     */

    protected int size;

    /**

     * The point size of this {@code Font} in {@code float}.

     *

     * @serial

     * @see #getSize()

     * @see #getSize2D()

     */

    protected float pointSize;

    /**

     * The platform specific font information.

     */

    private transient FontPeer peer;

    private transient long pData;       // native JDK1.1 font pointer

    private transient Font2DHandle font2DHandle;

    private transient AttributeValues values;

    private transient boolean hasLayoutAttributes;

    /*

     * If the origin of a Font is a created font then this attribute

     * must be set on all derived fonts too.

     */

    private transient boolean createdFont = false;

    /*

     * This is true if the font transform is not identity.  It

     * is used to avoid unnecessary instantiation of an AffineTransform.

     */

    private transient boolean nonIdentityTx;

    /*

     * A cached value used when a transform is required for internal

     * use.  This must not be exposed to callers since AffineTransform

     * is mutable.

     */

    private static final AffineTransform identityTx = new AffineTransform();

    /*

     * JDK 1.1 serialVersionUID

     */

    private static final long serialVersionUID = -4206021311591459213L;

    /**

     * Gets the peer of this {@code Font}.

     *

     * @return the peer of the {@code Font}.

     */

    private FontPeer getFontPeer() {

        if(peer == null) {

            Toolkit tk = Toolkit.getDefaultToolkit();

            if (tk instanceof ComponentFactory) {

                peer = ((ComponentFactory) tk).getFontPeer(name, style);

            }

        }

        return peer;

    }

    /**

     * Return the AttributeValues object associated with this

     * font.  Most of the time, the internal object is null.

     * If required, it will be created from the 'standard'

     * state on the font.  Only non-default values will be

     * set in the AttributeValues object.

     *

     * <p>Since the AttributeValues object is mutable, and it

     * is cached in the font, care must be taken to ensure that

     * it is not mutated.

     */

    private AttributeValues getAttributeValues() {

        if (values == null) {

            AttributeValues valuesTmp = new AttributeValues();

            valuesTmp.setFamily(name);

            valuesTmp.setSize(pointSize); // expects the float value.

            if ((style & BOLD) != 0) {

                valuesTmp.setWeight(2); // WEIGHT_BOLD

            }

            if ((style & ITALIC) != 0) {

                valuesTmp.setPosture(.2f); // POSTURE_OBLIQUE

            }

            valuesTmp.defineAll(PRIMARY_MASK); // for streaming compatibility

            values = valuesTmp;

        }

        return values;

    }

    private Font2D getFont2D() {

        FontManager fm = FontManagerFactory.getInstance();

        if (font2DHandle == null) {

            font2DHandle =

                fm.findFont2D(name, style,

                              FontManager.LOGICAL_FALLBACK).handle;

        }

        /* Do not cache the de-referenced font2D. It must be explicitly

         * de-referenced to pick up a valid font in the event that the

         * original one is marked invalid

         */

        return font2DHandle.font2D;

    }

    /**

     * Creates a new {@code Font} from the specified name, style and

     * point size.