/*
* TextSpan.java
* Transform
*
* Copyright (c) 2001-2010 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.text;
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;
import com.flagstone.transform.datatype.Color;
import com.flagstone.transform.exception.IllegalArgumentRangeException;
/**
* TextSpan is used to display a group of characters with a selected font and
* colour. TextSpan objects are used in {@link DefineText} and
* {@link DefineText2} to display a line or block of text.
*
* <p>
* TextSpan contains a list of Character objects which identify the glyphs
* that will be displayed along with style information that sets the colour of
* the text, the size of the font and the relative placement of the line within
* a block of text.
* </p>
*
* <p>
* Whether the alpha channel in the colour needs to be specified depends on the
* class the Text is added to. The DefineText2 class supports transparent text
* while DefineText class does not.
* </p>
*
* <p>
* The x and y offsets are used to control how several TextSpan objects are laid
* out to create a block of text. The y offset is specified relative to the
* bottom edge of the bounding rectangle, which is actually closer to the top of
* the screen as the direction of the y-axis is from the top to the bottom of
* the screen. In this respect Flash is counter-intuitive. Lines with higher
* offset values are displayed below lines with lower offsets.
* </p>
*
* <p>
* The x and y offsets are also optional and may be set to the constant
* VALUE_NOT_SET when more than one TextSpan object is created. If the y offset
* is not specified then a TextSpan object is displayed on the same line as the
* previous TextSpan. If the x offset is not specified then the TextSpan is
* displayed after the previous TextSpan. This makes it easy to lay text out on
* a single line.
* </p>
*
* <p>
* Similarly the font and colour information is optional. The values from a
* previous TextSpan object will be used if they are not set.
* </p>
*
* <p>
* The creation and layout of the glyphs to create the text is too onerous to
* perform from scratch. It is easier and more convenient to use the
* {@link com.flagstone.transform.util.text.TextTable} class to create the
* TextSpan objects.
* </p>
*
* @see DefineText
* @see DefineText2
* @see com.flagstone.transform.util.text.TextTable
* @see com.flagstone.transform.util.font.Font
*/
@SuppressWarnings("PMD.CyclomaticComplexity")
public final class TextSpan implements SWFEncodeable, Copyable<TextSpan> {
/** Format string used in toString() method. */
private static final String FORMAT = "TextSpan: { identifier=%d; color=%s;"
+ " offsetX=%d; offsetY=%d; height=%d; characters=%s}";
/** The colour used to draw the text. */
private Color color;
/** The offset on the x-axis of the text span, within the text block. */
private Integer offsetX;
/** The offset on the y-axis of the text span, within the text block. */
private Integer offsetY;
/** The unique identifier of the font used to render the text. */
private Integer identifier;
/** The height of the text in twips. */
private Integer height;
/** The list of characters to be displayed. */
private List<GlyphIndex> characters;
/** Indicates whether the text contains font or layout information. */
private transient boolean hasStyle;
/** Indicate that a font is specified. */
private transient boolean hasFont;
/** Indicate that a colour is specified. */
private transient boolean hasColor;
/** Indicate that an x offset is specified. */
private transient boolean hasX;
/** Indicate that an y offset is specified. */
private transient boolean hasY;
/**
* Creates and initialises a TextSpan object using values encoded
* in the Flash binary format.
*
* @param coder
* an SWFDecoder object that contains the encoded Flash data.
*
* @param context
* a Context object used to manage the decoders for different
* type of object and to pass information on how objects are
* decoded.
*
* @throws IOException
* if an error occurs while decoding the data.
*/
public TextSpan(final SWFDecoder coder,
final Context context) throws IOException {
final int bits = coder.readByte();
hasFont = (bits & Coder.BIT3) != 0;
hasColor = (bits & Coder.BIT2) != 0;
hasY = (bits & Coder.BIT1) != 0;
hasX = (bits & Coder.BIT0) != 0;
if (hasFont) {
identifier = coder.readUnsignedShort();
}
if (hasColor) {
color = new Color(coder, context);
}
if (hasX) {
offsetX = coder.readSignedShort();
}
if (hasY) {
offsetY = coder.readSignedShort();
}
if (hasFont) {
height = coder.readSignedShort();
}
final int charCount = coder.readByte();
characters = new ArrayList<GlyphIndex>(charCount);
for (int i = 0; i < charCount; i++) {
characters.add(new GlyphIndex(coder, context));
}
coder.alignToByte();
}
/**
* Creates a Text object, specifying the colour and position of the
* following Text.
*
* @param uid
* the identifier of the font that the text will be rendered in.
* Must be in the range 1..65535.
* @param aHeight
* the height of the text in the chosen font. Must be in the
* range 1..65535.
* @param aColor
* the colour of the text.
* @param xOffset
* the location of the text relative to the left edge of the
* bounding rectangle enclosing the text.
* @param yOffset
* the location of the text relative to the bottom edge of the
* bounding rectangle enclosing the text.
* @param list
* a list of Character objects. Must not be null.
*/
public TextSpan(final Integer uid, final Integer aHeight,
final Color aColor, final Integer xOffset, final Integer yOffset,
final List<GlyphIndex> list) {
setIdentifier(uid);
setHeight(aHeight);
setColor(aColor);
setOffsetX(xOffset);
setOffsetY(yOffset);
setCharacters(list);
}
/**
* Creates and initialises a TextSpan object using the values copied
* from another TextSpan object.
*
* @param object
* a TextSpan object from which the values will be
* copied.
*/
public TextSpan(final TextSpan object) {
identifier = object.identifier;
color = object.color;
offsetX = object.offsetX;
offsetY = object.offsetY;
height = object.height;
characters = new ArrayList<GlyphIndex>(object.characters);
}
/**
* Get the identifier of the font in which the text will be displayed.
*
* @return the unique identifier of the font.
*/
public Integer getIdentifier() {
return identifier;
}
/**
* Get the colour used to display the text.
*
* @return the text colour.
*/
public Color getColor() {
return color;
}
/**
* Get the location of the start of the text relative to the left edge
* of the bounding rectangle in twips.
*
* @return the left offset.
*/
public Integer getOffsetX() {
return offsetX;
}
/**
* Get the location of the start of the text relative to the bottom edge
* of the bounding rectangle in twips.
*
* @return the top offset.
*/
public Integer getOffsetY() {
return offsetY;
}
/**
* Get the height of the text.
*
* @return the size, in twips, of the font used to display the text.
*/
public Integer getHeight() {
return height;
}
/**
* Sets the identifier of the font in which the text will be displayed.
*
* @param uid
* the identifier of the font that the text will be rendered in.
* Must be in the range 1..65535.
*/
public void setIdentifier(final Integer uid) {
if ((uid != null) && ((uid < 1) || (uid > Coder.USHORT_MAX))) {
throw new IllegalArgumentRangeException(
1, Coder.USHORT_MAX, uid);
}
identifier = uid;
}
/**
* Sets the colour of the font in which the text will be displayed.
*
* @param aColor
* the colour of the text.
*/
public void setColor(final Color aColor) {
color = aColor;
}
/**
* Sets the location of the start of the text relative to the left edge of
* the bounding rectangle in twips.
*
* @param offset
* the location of the text relative to the left edge of the
* bounding rectangle enclosing the text. Must be in the range
* -32768..32767 or null if no offset is specified.
*/
public void setOffsetX(final Integer offset) {
if ((offset != null)
&& ((offset < Coder.SHORT_MIN)
|| (offset > Coder.SHORT_MAX))) {
throw new IllegalArgumentRangeException(
Coder.SHORT_MIN, Coder.SHORT_MAX, offset);
}
offsetX = offset;
}
/**
* Sets the location of the start of the text relative to the bottom edge of
* the bounding rectangle in twips.
*
* @param offset
* the location of the text relative to the bottom edge of the
* bounding rectangle enclosing the text. Must be in the range
* -32768..32767 or null if no offset is specified.
*/
public void setOffsetY(final Integer offset) {
if ((offset != null)
&& ((offset < Coder.SHORT_MIN)
|| (offset > Coder.SHORT_MAX))) {
throw new IllegalArgumentRangeException(
Coder.SHORT_MIN, Coder.SHORT_MAX, offset);
}
offsetY = offset;
}
/**
* Sets the height of the text in twips.
*
* @param aHeight
* the height of the text in the chosen font. Must be in the
* range 0..65535.
*/
public void setHeight(final Integer aHeight) {
if ((aHeight < 0) || (aHeight > Coder.USHORT_MAX)) {
throw new IllegalArgumentRangeException(
0, Coder.USHORT_MAX, aHeight);
}
height = aHeight;
}
/**
* Adds an Character object to the list of characters.
*
* @param aCharacter
* an Character object. Must not be null.
* @return this object.
*/
public TextSpan add(final GlyphIndex aCharacter) {
characters.add(aCharacter);
return this;
}
/**
* Returns the list of characters to be displayed.
*
* @return the list of Character objects.
*/
public List<GlyphIndex> getCharacters() {
return characters;
}
/**
* Sets the list of characters to be displayed.
*
* @param list
* a list of Character objects. Must not be null.
*/
public void setCharacters(final List<GlyphIndex> list) {
if (list == null) {
throw new IllegalArgumentException();
}
characters = list;
}
/** {@inheritDoc} */
public TextSpan copy() {
return new TextSpan(this);
}
@Override
public String toString() {
return String.format(FORMAT, identifier, color, offsetX, offsetY,
height, characters);
}
/** {@inheritDoc} */
@SuppressWarnings({"PMD.NPathComplexity", "PMD.CyclomaticComplexity" })
public int prepareToEncode(final Context context) {
// CHECKSTYLE:OFF
hasFont = (identifier != null) && (height != null);
hasColor = color != null;
hasX = offsetX != null;
hasY = offsetY != null;
hasStyle = hasFont || hasColor || hasX || hasY;
int length = 1;
if (hasStyle) {
length += (hasFont) ? 2 : 0;
length += (hasColor) ? (context.contains(Context.TRANSPARENT) ? 4
: 3) : 0;
length += (hasY) ? 2 : 0;
length += (hasX) ? 2 : 0;
length += (hasFont) ? 2 : 0;
}
length += 1;
if (!characters.isEmpty()) {
final int glyphSize = context.get(Context.GLYPH_SIZE);
final int advanceSize = context.get(Context.ADVANCE_SIZE);
int numberOfBits = (glyphSize + advanceSize) * characters.size();
numberOfBits += (numberOfBits % 8 > 0) ? 8 - (numberOfBits % 8) : 0;
length += numberOfBits >> 3;
}
return length;
// CHECKSTYLE:ON
}
/** {@inheritDoc} */
@SuppressWarnings({"PMD.NPathComplexity", "PMD.CyclomaticComplexity" })
public void encode(final SWFEncoder coder, final Context context)
throws IOException {
int bits = Coder.BIT7;
bits |= hasFont ? Coder.BIT3 : 0;
bits |= hasColor ? Coder.BIT2 : 0;
bits |= hasY ? Coder.BIT1 : 0;
bits |= hasX ? Coder.BIT0 : 0;
coder.writeByte(bits);
if (hasStyle) {
if (hasFont) {
coder.writeShort(identifier);
}
if (hasColor) {
color.encode(coder, context);
}
if (hasX) {
coder.writeShort(offsetX);
}
if (hasY) {
coder.writeShort(offsetY);
}
if (hasFont) {
coder.writeShort(height);
}
}
coder.writeByte(characters.size());
for (final GlyphIndex index : characters) {
index.encode(coder, context);
}
coder.alignToByte();
}
/**
* The number of bits used to encode the glyph indices.
* @return the number of bits used to encode each glyph index.
*/
protected int glyphBits() {
int numberOfBits = 0;
for (final GlyphIndex index : characters) {
numberOfBits = Math.max(numberOfBits, Coder.unsignedSize(index
.getGlyphIndex()));
}
return numberOfBits;
}
/**
* The number of bits used to encode the advances.
* @return the number of bits used to encode each advance.
*/
protected int advanceBits() {
int numberOfBits = 0;
for (final GlyphIndex index : characters) {
numberOfBits = Math.max(numberOfBits, Coder.size(index
.getAdvance()));
}
return numberOfBits;
}
}