GlyphAlignment.java

/*
 * GlyphAlignment.java
 * Transform
 *
 * Copyright (c) 2009-2010 Flagstone Software Ltd. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *  * Neither the name of Flagstone Software Ltd. nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

package com.flagstone.transform.font;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import com.flagstone.transform.coder.Coder;
import com.flagstone.transform.coder.Context;
import com.flagstone.transform.coder.Copyable;
import com.flagstone.transform.coder.SWFDecoder;
import com.flagstone.transform.coder.SWFEncodeable;
import com.flagstone.transform.coder.SWFEncoder;

/**
 * GlyphAlignment holds the alignment zones for a font glyph.
 */
public final class GlyphAlignment implements SWFEncodeable,
            Copyable<GlyphAlignment> {

    /** Format string used in toString() method. */
    private static final String FORMAT = "GlyphAlignment: { alignments=%s;"
            + " alignX=%s; alignY=%s}";

    /** Alignments for a glyph. */
    private List<AlignmentZone> alignments;
    /** Flags describing alignments. */
    private transient int masks;

    /**
     * Creates and initialises a GlyphAlignment object using values encoded
     * in the Flash binary format.
     *
     * @param coder
     *            an SWFDecoder object that contains the encoded Flash data.
     *
     * @throws IOException
     *             if an error occurs while decoding the data.
     */
    public GlyphAlignment(final SWFDecoder coder) throws IOException {
        final int count = coder.readByte();

        alignments = new ArrayList<AlignmentZone>(count);

        for (int i = 0; i < count; i++) {
            alignments.add(new AlignmentZone(coder));
        }
        masks = coder.readByte();
    }

    /**
     * Creates a new GlyphAlignment with the alignment zones.
     * @param list the list of alignment zones for the glyph.
     * @param xAlign whether there is a horizontal alignment zone.
     * @param yAlign whether there is a vertical alignment zone.
     */
    public GlyphAlignment(final List<AlignmentZone> list, final boolean xAlign,
            final boolean yAlign) {
        setAlignments(list);
        setAlignmentX(xAlign);
        setAlignmentY(yAlign);
    }

    /**
     * Creates and initialises a GlyphAlignment object using the values copied
     * from another GlyphAlignment object.
     *
     * @param object
     *            a GlyphAlignment object from which the values will be
     *            copied.
     */
    public GlyphAlignment(final GlyphAlignment object) {
        alignments = new ArrayList<AlignmentZone>(object.alignments);
        masks = object.masks;
    }

    /**
     * Does the list of alignment zones contain a horizontal alignment.
     * @return true if the list contains the alignment for the width of a glyph.
     */
    public boolean alignmentX() {
        return (masks & 0x01) != 0;
    }

    /**
     * Indicates that the list of alignment zones contain a horizontal
     * alignment.
     * @param hasAlign true if the list contains the alignment for the width
     * of a glyph, false otherwise.
     */
    public void setAlignmentX(final boolean hasAlign) {
        masks &= ~Coder.BIT0;
        if (hasAlign) {
            masks |= Coder.BIT0;
        }
    }

    /**
     * Does the list of alignment zones contain a vertical alignment.
     * @return true if the list contains the alignment for the height of
     * a glyph.
     */
    public boolean alignmentY() {
        return (masks & Coder.BIT1) != 0;
    }

    /**
     * Indicates that the list of alignment zones contain a vertical
     * alignment.
     * @param hasAlign true if the list contains the alignment for the height
     * of a glyph, false otherwise.
     */
    public void setAlignmentY(final boolean hasAlign) {
        masks &= ~Coder.BIT1;
        if (hasAlign) {
            masks |= Coder.BIT1;
        }
    }

    /**
     * Get the list of alignment zones.
     * @return a list of AlignmentZones describing the alignment areas for a
     * glyph.
     */
    public List<AlignmentZone> getAlignments() {
        return alignments;
    }

    /**
     * Set the list of alignment zones.
     * @param list a list of AlignmentZones describing the alignment areas for
     * a glyph.
     */
    public void setAlignments(final List<AlignmentZone> list) {
        alignments = list;
    }

    /** {@inheritDoc} */
    public GlyphAlignment copy() {
        return new GlyphAlignment(this);
    }

    @Override
    public String toString() {
        return String.format(FORMAT, alignments, String.valueOf(alignmentX()),
                String.valueOf(alignmentY()));
    }

    /** {@inheritDoc} */
    public int prepareToEncode(final Context context) {
        // CHECKSTYLE IGNORE MagicNumberCheck FOR NEXT 1 LINES
        return 10;
    }

    /** {@inheritDoc} */
    public void encode(final SWFEncoder coder, final Context context)
            throws IOException {
        coder.writeByte(2);

        for (final AlignmentZone zone : alignments) {
            zone.encode(coder, context);
        }
        coder.writeByte(masks);
    }
}