| /* |
| * Copyright (c) 1998, 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 |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * @author Charlton Innovations, Inc. |
| */ |
| |
| package java.awt.font; |
| |
| import java.awt.RenderingHints; |
| import static java.awt.RenderingHints.*; |
| import java.awt.geom.AffineTransform; |
| |
| /** |
| * The <code>FontRenderContext</code> class is a container for the |
| * information needed to correctly measure text. The measurement of text |
| * can vary because of rules that map outlines to pixels, and rendering |
| * hints provided by an application. |
| * <p> |
| * One such piece of information is a transform that scales |
| * typographical points to pixels. (A point is defined to be exactly 1/72 |
| * of an inch, which is slightly different than |
| * the traditional mechanical measurement of a point.) A character that |
| * is rendered at 12pt on a 600dpi device might have a different size |
| * than the same character rendered at 12pt on a 72dpi device because of |
| * such factors as rounding to pixel boundaries and hints that the font |
| * designer may have specified. |
| * <p> |
| * Anti-aliasing and Fractional-metrics specified by an application can also |
| * affect the size of a character because of rounding to pixel |
| * boundaries. |
| * <p> |
| * Typically, instances of <code>FontRenderContext</code> are |
| * obtained from a {@link java.awt.Graphics2D Graphics2D} object. A |
| * <code>FontRenderContext</code> which is directly constructed will |
| * most likely not represent any actual graphics device, and may lead |
| * to unexpected or incorrect results. |
| * <p> |
| * @see java.awt.RenderingHints#KEY_TEXT_ANTIALIASING |
| * @see java.awt.RenderingHints#KEY_FRACTIONALMETRICS |
| * @see java.awt.Graphics2D#getFontRenderContext() |
| * @see java.awt.font.LineMetrics |
| */ |
| |
| public class FontRenderContext { |
| private transient AffineTransform tx; |
| private transient Object aaHintValue; |
| private transient Object fmHintValue; |
| private transient boolean defaulting; |
| |
| /** |
| * Constructs a new <code>FontRenderContext</code> |
| * object. |
| * |
| */ |
| protected FontRenderContext() { |
| aaHintValue = VALUE_TEXT_ANTIALIAS_DEFAULT; |
| fmHintValue = VALUE_FRACTIONALMETRICS_DEFAULT; |
| defaulting = true; |
| } |
| |
| /** |
| * Constructs a <code>FontRenderContext</code> object from an |
| * optional {@link AffineTransform} and two <code>boolean</code> |
| * values that determine if the newly constructed object has |
| * anti-aliasing or fractional metrics. |
| * In each case the boolean values <CODE>true</CODE> and <CODE>false</CODE> |
| * correspond to the rendering hint values <CODE>ON</CODE> and |
| * <CODE>OFF</CODE> respectively. |
| * <p> |
| * To specify other hint values, use the constructor which |
| * specifies the rendering hint values as parameters : |
| * {@link #FontRenderContext(AffineTransform, Object, Object)}. |
| * @param tx the transform which is used to scale typographical points |
| * to pixels in this <code>FontRenderContext</code>. If null, an |
| * identity transform is used. |
| * @param isAntiAliased determines if the newly constructed object |
| * has anti-aliasing. |
| * @param usesFractionalMetrics determines if the newly constructed |
| * object has fractional metrics. |
| */ |
| public FontRenderContext(AffineTransform tx, |
| boolean isAntiAliased, |
| boolean usesFractionalMetrics) { |
| if (tx != null && !tx.isIdentity()) { |
| this.tx = new AffineTransform(tx); |
| } |
| if (isAntiAliased) { |
| aaHintValue = VALUE_TEXT_ANTIALIAS_ON; |
| } else { |
| aaHintValue = VALUE_TEXT_ANTIALIAS_OFF; |
| } |
| if (usesFractionalMetrics) { |
| fmHintValue = VALUE_FRACTIONALMETRICS_ON; |
| } else { |
| fmHintValue = VALUE_FRACTIONALMETRICS_OFF; |
| } |
| } |
| |
| /** |
| * Constructs a <code>FontRenderContext</code> object from an |
| * optional {@link AffineTransform} and two <code>Object</code> |
| * values that determine if the newly constructed object has |
| * anti-aliasing or fractional metrics. |
| * @param tx the transform which is used to scale typographical points |
| * to pixels in this <code>FontRenderContext</code>. If null, an |
| * identity tranform is used. |
| * @param aaHint - one of the text antialiasing rendering hint values |
| * defined in {@link java.awt.RenderingHints java.awt.RenderingHints}. |
| * Any other value will throw <code>IllegalArgumentException</code>. |
| * {@link java.awt.RenderingHints#VALUE_TEXT_ANTIALIAS_DEFAULT VALUE_TEXT_ANTIALIAS_DEFAULT} |
| * may be specified, in which case the mode used is implementation |
| * dependent. |
| * @param fmHint - one of the text fractional rendering hint values defined |
| * in {@link java.awt.RenderingHints java.awt.RenderingHints}. |
| * {@link java.awt.RenderingHints#VALUE_FRACTIONALMETRICS_DEFAULT VALUE_FRACTIONALMETRICS_DEFAULT} |
| * may be specified, in which case the mode used is implementation |
| * dependent. |
| * Any other value will throw <code>IllegalArgumentException</code> |
| * @throws IllegalArgumentException if the hints are not one of the |
| * legal values. |
| * @since 1.6 |
| */ |
| public FontRenderContext(AffineTransform tx, Object aaHint, Object fmHint){ |
| if (tx != null && !tx.isIdentity()) { |
| this.tx = new AffineTransform(tx); |
| } |
| try { |
| if (KEY_TEXT_ANTIALIASING.isCompatibleValue(aaHint)) { |
| aaHintValue = aaHint; |
| } else { |
| throw new IllegalArgumentException("AA hint:" + aaHint); |
| } |
| } catch (Exception e) { |
| throw new IllegalArgumentException("AA hint:" +aaHint); |
| } |
| try { |
| if (KEY_FRACTIONALMETRICS.isCompatibleValue(fmHint)) { |
| fmHintValue = fmHint; |
| } else { |
| throw new IllegalArgumentException("FM hint:" + fmHint); |
| } |
| } catch (Exception e) { |
| throw new IllegalArgumentException("FM hint:" +fmHint); |
| } |
| } |
| |
| /** |
| * Indicates whether or not this <code>FontRenderContext</code> object |
| * measures text in a transformed render context. |
| * @return <code>true</code> if this <code>FontRenderContext</code> |
| * object has a non-identity AffineTransform attribute. |
| * <code>false</code> otherwise. |
| * @see java.awt.font.FontRenderContext#getTransform |
| * @since 1.6 |
| */ |
| public boolean isTransformed() { |
| if (!defaulting) { |
| return tx != null; |
| } else { |
| return !getTransform().isIdentity(); |
| } |
| } |
| |
| /** |
| * Returns the integer type of the affine transform for this |
| * <code>FontRenderContext</code> as specified by |
| * {@link java.awt.geom.AffineTransform#getType()} |
| * @return the type of the transform. |
| * @see AffineTransform |
| * @since 1.6 |
| */ |
| public int getTransformType() { |
| if (!defaulting) { |
| if (tx == null) { |
| return AffineTransform.TYPE_IDENTITY; |
| } else { |
| return tx.getType(); |
| } |
| } else { |
| return getTransform().getType(); |
| } |
| } |
| |
| /** |
| * Gets the transform that is used to scale typographical points |
| * to pixels in this <code>FontRenderContext</code>. |
| * @return the <code>AffineTransform</code> of this |
| * <code>FontRenderContext</code>. |
| * @see AffineTransform |
| */ |
| public AffineTransform getTransform() { |
| return (tx == null) ? new AffineTransform() : new AffineTransform(tx); |
| } |
| |
| /** |
| * Returns a boolean which indicates whether or not some form of |
| * antialiasing is specified by this <code>FontRenderContext</code>. |
| * Call {@link #getAntiAliasingHint() getAntiAliasingHint()} |
| * for the specific rendering hint value. |
| * @return <code>true</code>, if text is anti-aliased in this |
| * <code>FontRenderContext</code>; <code>false</code> otherwise. |
| * @see java.awt.RenderingHints#KEY_TEXT_ANTIALIASING |
| * @see #FontRenderContext(AffineTransform,boolean,boolean) |
| * @see #FontRenderContext(AffineTransform,Object,Object) |
| */ |
| public boolean isAntiAliased() { |
| return !(aaHintValue == VALUE_TEXT_ANTIALIAS_OFF || |
| aaHintValue == VALUE_TEXT_ANTIALIAS_DEFAULT); |
| } |
| |
| /** |
| * Returns a boolean which whether text fractional metrics mode |
| * is used in this <code>FontRenderContext</code>. |
| * Call {@link #getFractionalMetricsHint() getFractionalMetricsHint()} |
| * to obtain the corresponding rendering hint value. |
| * @return <code>true</code>, if layout should be performed with |
| * fractional metrics; <code>false</code> otherwise. |
| * in this <code>FontRenderContext</code>. |
| * @see java.awt.RenderingHints#KEY_FRACTIONALMETRICS |
| * @see #FontRenderContext(AffineTransform,boolean,boolean) |
| * @see #FontRenderContext(AffineTransform,Object,Object) |
| */ |
| public boolean usesFractionalMetrics() { |
| return !(fmHintValue == VALUE_FRACTIONALMETRICS_OFF || |
| fmHintValue == VALUE_FRACTIONALMETRICS_DEFAULT); |
| } |
| |
| /** |
| * Return the text anti-aliasing rendering mode hint used in this |
| * <code>FontRenderContext</code>. |
| * This will be one of the text antialiasing rendering hint values |
| * defined in {@link java.awt.RenderingHints java.awt.RenderingHints}. |
| * @return text anti-aliasing rendering mode hint used in this |
| * <code>FontRenderContext</code>. |
| * @since 1.6 |
| */ |
| public Object getAntiAliasingHint() { |
| if (defaulting) { |
| if (isAntiAliased()) { |
| return VALUE_TEXT_ANTIALIAS_ON; |
| } else { |
| return VALUE_TEXT_ANTIALIAS_OFF; |
| } |
| } |
| return aaHintValue; |
| } |
| |
| /** |
| * Return the text fractional metrics rendering mode hint used in this |
| * <code>FontRenderContext</code>. |
| * This will be one of the text fractional metrics rendering hint values |
| * defined in {@link java.awt.RenderingHints java.awt.RenderingHints}. |
| * @return the text fractional metrics rendering mode hint used in this |
| * <code>FontRenderContext</code>. |
| * @since 1.6 |
| */ |
| public Object getFractionalMetricsHint() { |
| if (defaulting) { |
| if (usesFractionalMetrics()) { |
| return VALUE_FRACTIONALMETRICS_ON; |
| } else { |
| return VALUE_FRACTIONALMETRICS_OFF; |
| } |
| } |
| return fmHintValue; |
| } |
| |
| /** |
| * Return true if obj is an instance of FontRenderContext and has the same |
| * transform, antialiasing, and fractional metrics values as this. |
| * @param obj the object to test for equality |
| * @return <code>true</code> if the specified object is equal to |
| * this <code>FontRenderContext</code>; <code>false</code> |
| * otherwise. |
| */ |
| public boolean equals(Object obj) { |
| try { |
| return equals((FontRenderContext)obj); |
| } |
| catch (ClassCastException e) { |
| return false; |
| } |
| } |
| |
| /** |
| * Return true if rhs has the same transform, antialiasing, |
| * and fractional metrics values as this. |
| * @param rhs the <code>FontRenderContext</code> to test for equality |
| * @return <code>true</code> if <code>rhs</code> is equal to |
| * this <code>FontRenderContext</code>; <code>false</code> |
| * otherwise. |
| * @since 1.4 |
| */ |
| public boolean equals(FontRenderContext rhs) { |
| if (this == rhs) { |
| return true; |
| } |
| if (rhs == null) { |
| return false; |
| } |
| |
| /* if neither instance is a subclass, reference values directly. */ |
| if (!rhs.defaulting && !defaulting) { |
| if (rhs.aaHintValue == aaHintValue && |
| rhs.fmHintValue == fmHintValue) { |
| |
| return tx == null ? rhs.tx == null : tx.equals(rhs.tx); |
| } |
| return false; |
| } else { |
| return |
| rhs.getAntiAliasingHint() == getAntiAliasingHint() && |
| rhs.getFractionalMetricsHint() == getFractionalMetricsHint() && |
| rhs.getTransform().equals(getTransform()); |
| } |
| } |
| |
| /** |
| * Return a hashcode for this FontRenderContext. |
| */ |
| public int hashCode() { |
| int hash = tx == null ? 0 : tx.hashCode(); |
| /* SunHints value objects have identity hashcode, so we can rely on |
| * this to ensure that two equal FRC's have the same hashcode. |
| */ |
| if (defaulting) { |
| hash += getAntiAliasingHint().hashCode(); |
| hash += getFractionalMetricsHint().hashCode(); |
| } else { |
| hash += aaHintValue.hashCode(); |
| hash += fmHintValue.hashCode(); |
| } |
| return hash; |
| } |
| } |
