JDK8/Java8源码在线阅读
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*
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* published by the Free Software Foundation. Oracle designates this
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* 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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package javax.imageio;
import java.awt.Dimension;
import java.util.Locale;
/**
* A class describing how a stream is to be encoded. Instances of
* this class or its subclasses are used to supply prescriptive
* "how-to" information to instances of <code>ImageWriter</code>.
*
* <p> A plug-in for a specific image format may define a subclass of
* this class, and return objects of that class from the
* <code>getDefaultWriteParam</code> method of its
* <code>ImageWriter</code> implementation. For example, the built-in
* JPEG writer plug-in will return instances of
* <code>javax.imageio.plugins.jpeg.JPEGImageWriteParam</code>.
*
* <p> The region of the image to be written is determined by first
* intersecting the actual bounds of the image with the rectangle
* specified by <code>IIOParam.setSourceRegion</code>, if any. If the
* resulting rectangle has a width or height of zero, the writer will
* throw an <code>IIOException</code>. If the intersection is
* non-empty, writing will commence with the first subsampled pixel
* and include additional pixels within the intersected bounds
* according to the horizontal and vertical subsampling factors
* specified by {@link IIOParam#setSourceSubsampling
* IIOParam.setSourceSubsampling}.
*
* <p> Individual features such as tiling, progressive encoding, and
* compression may be set in one of four modes.
* <code>MODE_DISABLED</code> disables the features;
* <code>MODE_DEFAULT</code> enables the feature with
* writer-controlled parameter values; <code>MODE_EXPLICIT</code>
* enables the feature and allows the use of a <code>set</code> method
* to provide additional parameters; and
* <code>MODE_COPY_FROM_METADATA</code> copies relevant parameter
* values from the stream and image metadata objects passed to the
* writer. The default for all features is
* <code>MODE_COPY_FROM_METADATA</code>. Non-standard features
* supplied in subclasses are encouraged, but not required to use a
* similar scheme.
*
* <p> Plug-in writers may extend the functionality of
* <code>ImageWriteParam</code> by providing a subclass that implements
* additional, plug-in specific interfaces. It is up to the plug-in
* to document what interfaces are available and how they are to be
* used. Writers will silently ignore any extended features of an
* <code>ImageWriteParam</code> subclass of which they are not aware.
* Also, they may ignore any optional features that they normally
* disable when creating their own <code>ImageWriteParam</code>
* instances via <code>getDefaultWriteParam</code>.
*
* <p> Note that unless a query method exists for a capability, it must
* be supported by all <code>ImageWriter</code> implementations
* (<i>e.g.</i> progressive encoding is optional, but subsampling must be
* supported).
*
*
* @see ImageReadParam
*/
public class ImageWriteParam extends IIOParam {
/**
* A constant value that may be passed into methods such as
* <code>setTilingMode</code>, <code>setProgressiveMode</code>,
* and <code>setCompressionMode</code> to disable a feature for
* future writes. That is, when this mode is set the stream will
* <b>not</b> be tiled, progressive, or compressed, and the
* relevant accessor methods will throw an
* <code>IllegalStateException</code>.
*
* @see #MODE_EXPLICIT
* @see #MODE_COPY_FROM_METADATA
* @see #MODE_DEFAULT
* @see #setProgressiveMode
* @see #getProgressiveMode
* @see #setTilingMode
* @see #getTilingMode
* @see #setCompressionMode
* @see #getCompressionMode
*/
public static final int MODE_DISABLED = 0;
/**
* A constant value that may be passed into methods such as
* <code>setTilingMode</code>,
* <code>setProgressiveMode</code>, and
* <code>setCompressionMode</code> to enable that feature for
* future writes. That is, when this mode is enabled the stream
* will be tiled, progressive, or compressed according to a
* sensible default chosen internally by the writer in a plug-in
* dependent way, and the relevant accessor methods will
* throw an <code>IllegalStateException</code>.
*
* @see #MODE_DISABLED
* @see #MODE_EXPLICIT
* @see #MODE_COPY_FROM_METADATA
* @see #setProgressiveMode
* @see #getProgressiveMode
* @see #setTilingMode
* @see #getTilingMode
* @see #setCompressionMode
* @see #getCompressionMode
*/
public static final int MODE_DEFAULT = 1;
/**
* A constant value that may be passed into methods such as
* <code>setTilingMode</code> or <code>setCompressionMode</code>
* to enable a feature for future writes. That is, when this mode
* is set the stream will be tiled or compressed according to
* additional information supplied to the corresponding
* <code>set</code> methods in this class and retrievable from the
* corresponding <code>get</code> methods. Note that this mode is
* not supported for progressive output.
*
* @see #MODE_DISABLED
* @see #MODE_COPY_FROM_METADATA
* @see #MODE_DEFAULT
* @see #setProgressiveMode
* @see #getProgressiveMode
* @see #setTilingMode
* @see #getTilingMode
* @see #setCompressionMode
* @see #getCompressionMode
*/
public static final int MODE_EXPLICIT = 2;
/**
* A constant value that may be passed into methods such as
* <code>setTilingMode</code>, <code>setProgressiveMode</code>, or
* <code>setCompressionMode</code> to enable that feature for
* future writes. That is, when this mode is enabled the stream
* will be tiled, progressive, or compressed based on the contents
* of stream and/or image metadata passed into the write
* operation, and any relevant accessor methods will throw an
* <code>IllegalStateException</code>.
*
* <p> This is the default mode for all features, so that a read
* including metadata followed by a write including metadata will
* preserve as much information as possible.
*
* @see #MODE_DISABLED
* @see #MODE_EXPLICIT
* @see #MODE_DEFAULT
* @see #setProgressiveMode
* @see #getProgressiveMode
* @see #setTilingMode
* @see #getTilingMode
* @see #setCompressionMode
* @see #getCompressionMode
*/
public static final int MODE_COPY_FROM_METADATA = 3;
// If more modes are added, this should be updated.
private static final int MAX_MODE = MODE_COPY_FROM_METADATA;
/**
* A <code>boolean</code> that is <code>true</code> if this
* <code>ImageWriteParam</code> allows tile width and tile height
* parameters to be set. By default, the value is
* <code>false</code>. Subclasses must set the value manually.
*
* <p> Subclasses that do not support writing tiles should ensure
* that this value is set to <code>false</code>.
*/
protected boolean canWriteTiles = false;
/**
* The mode controlling tiling settings, which Must be
* set to one of the four <code>MODE_*</code> values. The default
* is <code>MODE_COPY_FROM_METADATA</code>.
*
* <p> Subclasses that do not writing tiles may ignore this value.
*
* @see #MODE_DISABLED
* @see #MODE_EXPLICIT
* @see #MODE_COPY_FROM_METADATA
* @see #MODE_DEFAULT
* @see #setTilingMode
* @see #getTilingMode
*/
protected int tilingMode = MODE_COPY_FROM_METADATA;
/**
* An array of preferred tile size range pairs. The default value
* is <code>null</code>, which indicates that there are no
* preferred sizes. If the value is non-<code>null</code>, it
* must have an even length of at least two.
*
* <p> Subclasses that do not support writing tiles may ignore
* this value.
*
* @see #getPreferredTileSizes
*/
protected Dimension[] preferredTileSizes = null;
/**
* A <code>boolean</code> that is <code>true</code> if tiling
* parameters have been specified.
*
* <p> Subclasses that do not support writing tiles may ignore
* this value.
*/
protected boolean tilingSet = false;
/**
* The width of each tile if tiling has been set, or 0 otherwise.
*
* <p> Subclasses that do not support tiling may ignore this
* value.
*/
protected int tileWidth = 0;
/**
* The height of each tile if tiling has been set, or 0 otherwise.
* The initial value is <code>0</code>.
*
* <p> Subclasses that do not support tiling may ignore this
* value.
*/
protected int tileHeight = 0;
/**
* A <code>boolean</code> that is <code>true</code> if this
* <code>ImageWriteParam</code> allows tiling grid offset
* parameters to be set. By default, the value is
* <code>false</code>. Subclasses must set the value manually.
*
* <p> Subclasses that do not support writing tiles, or that
* support writing but not offsetting tiles must ensure that this
* value is set to <code>false</code>.
*/
protected boolean canOffsetTiles = false;
/**
* The amount by which the tile grid origin should be offset
* horizontally from the image origin if tiling has been set,
* or 0 otherwise. The initial value is <code>0</code>.
*
* <p> Subclasses that do not support offsetting tiles may ignore
* this value.
*/
protected int tileGridXOffset = 0;
/**
* The amount by which the tile grid origin should be offset
* vertically from the image origin if tiling has been set,
* or 0 otherwise. The initial value is <code>0</code>.
*
* <p> Subclasses that do not support offsetting tiles may ignore
* this value.
*/
protected int tileGridYOffset = 0;
/**
* A <code>boolean</code> that is <code>true</code> if this
* <code>ImageWriteParam</code> allows images to be written as a
* progressive sequence of increasing quality passes. By default,
* the value is <code>false</code>. Subclasses must set the value
* manually.
*
* <p> Subclasses that do not support progressive encoding must
* ensure that this value is set to <code>false</code>.
*/
protected boolean canWriteProgressive = false;
/**
* The mode controlling progressive encoding, which must be set to
* one of the four <code>MODE_*</code> values, except
* <code>MODE_EXPLICIT</code>. The default is
* <code>MODE_COPY_FROM_METADATA</code>.
*
* <p> Subclasses that do not support progressive encoding may
* ignore this value.
*
* @see #MODE_DISABLED
* @see #MODE_EXPLICIT
* @see #MODE_COPY_FROM_METADATA
* @see #MODE_DEFAULT
* @see #setProgressiveMode
* @see #getProgressiveMode
*/
protected int progressiveMode = MODE_COPY_FROM_METADATA;
/**
* A <code>boolean</code> that is <code>true</code> if this writer
* can write images using compression. By default, the value is
* <code>false</code>. Subclasses must set the value manually.
*
* <p> Subclasses that do not support compression must ensure that
* this value is set to <code>false</code>.
*/
protected boolean canWriteCompressed = false;
/**
* The mode controlling compression settings, which must be set to
* one of the four <code>MODE_*</code> values. The default is
* <code>MODE_COPY_FROM_METADATA</code>.
*
* <p> Subclasses that do not support compression may ignore this
* value.
*
* @see #MODE_DISABLED
* @see #MODE_EXPLICIT
* @see #MODE_COPY_FROM_METADATA
* @see #MODE_DEFAULT
* @see #setCompressionMode
* @see #getCompressionMode
*/
protected int compressionMode = MODE_COPY_FROM_METADATA;
/**
* An array of <code>String</code>s containing the names of the
* available compression types. Subclasses must set the value
* manually.
*
* <p> Subclasses that do not support compression may ignore this
* value.
*/
protected String[] compressionTypes = null;
/**
* A <code>String</code> containing the name of the current
* compression type, or <code>null</code> if none is set.
*
* <p> Subclasses that do not support compression may ignore this
* value.
*/
protected String compressionType = null;
/**
* A <code>float</code> containing the current compression quality
* setting. The initial value is <code>1.0F</code>.
*
* <p> Subclasses that do not support compression may ignore this
* value.
*/
protected float compressionQuality = 1.0F;
/**
* A <code>Locale</code> to be used to localize compression type
* names and quality descriptions, or <code>null</code> to use a
* default <code>Locale</code>. Subclasses must set the value
* manually.
*/
protected Locale locale = null;
/**
* Constructs an empty <code>ImageWriteParam</code>. It is up to
* the subclass to set up the instance variables properly.
*/
protected ImageWriteParam() {}
/**
* Constructs an <code>ImageWriteParam</code> set to use a
* given <code>Locale</code>.
*
* @param locale a <code>Locale</code> to be used to localize
* compression type names and quality descriptions, or
* <code>null</code>.
*/
public ImageWriteParam(Locale locale) {
this.locale = locale;
}
// Return a deep copy of the array
private static Dimension[] clonePreferredTileSizes(Dimension[] sizes) {
if (sizes == null) {
return null;
}
Dimension[] temp = new Dimension[sizes.length];
for (int i = 0; i < sizes.length; i++) {
temp[i] = new Dimension(sizes[i]);
}
return temp;
}
/**
* Returns the currently set <code>Locale</code>, or
* <code>null</code> if only a default <code>Locale</code> is
* supported.
*
* @return the current <code>Locale</code>, or <code>null</code>.
*/
public Locale getLocale() {
return locale;
}
/**
* Returns <code>true</code> if the writer can perform tiling
* while writing. If this method returns <code>false</code>, then
* <code>setTiling</code> will throw an
* <code>UnsupportedOperationException</code>.
*
* @return <code>true</code> if the writer supports tiling.
*
* @see #canOffsetTiles()
* @see #setTiling(int, int, int, int)
*/
public boolean canWriteTiles() {
return canWriteTiles;
}
/**
* Returns <code>true</code> if the writer can perform tiling with
* non-zero grid offsets while writing. If this method returns
* <code>false</code>, then <code>setTiling</code> will throw an
* <code>UnsupportedOperationException</code> if the grid offset
* arguments are not both zero. If <code>canWriteTiles</code>
* returns <code>false</code>, this method will return
* <code>false</code> as well.
*
* @return <code>true</code> if the writer supports non-zero tile
* offsets.
*
* @see #canWriteTiles()
* @see #setTiling(int, int, int, int)
*/
public boolean canOffsetTiles() {
return canOffsetTiles;
}
/**
* Determines whether the image will be tiled in the output
* stream and, if it will, how the tiling parameters will be
* determined. The modes are interpreted as follows:
*
* <ul>
*
* <li><code>MODE_DISABLED</code> - The image will not be tiled.
* <code>setTiling</code> will throw an
* <code>IllegalStateException</code>.
*
* <li><code>MODE_DEFAULT</code> - The image will be tiled using
* default parameters. <code>setTiling</code> will throw an
* <code>IllegalStateException</code>.
*
* <li><code>MODE_EXPLICIT</code> - The image will be tiled
* according to parameters given in the {@link #setTiling setTiling}
* method. Any previously set tiling parameters are discarded.
*
* <li><code>MODE_COPY_FROM_METADATA</code> - The image will
* conform to the metadata object passed in to a write.
* <code>setTiling</code> will throw an
* <code>IllegalStateException</code>.
*
* </ul>
*
* @param mode The mode to use for tiling.
*
* @exception UnsupportedOperationException if
* <code>canWriteTiles</code> returns <code>false</code>.
* @exception IllegalArgumentException if <code>mode</code> is not
* one of the modes listed above.
*
* @see #setTiling
* @see #getTilingMode
*/
public void setTilingMode(int mode) {
if (canWriteTiles() == false) {
throw new UnsupportedOperationException("Tiling not supported!");
}
if (mode < MODE_DISABLED || mode > MAX_MODE) {
throw new IllegalArgumentException("Illegal value for mode!");
}
this.tilingMode = mode;
if (mode == MODE_EXPLICIT) {
unsetTiling();
}
}
/**
* Returns the current tiling mode, if tiling is supported.
* Otherwise throws an <code>UnsupportedOperationException</code>.
*
* @return the current tiling mode.
*
* @exception UnsupportedOperationException if
* <code>canWriteTiles</code> returns <code>false</code>.
*
* @see #setTilingMode
*/
public int getTilingMode() {
if (!canWriteTiles()) {
throw new UnsupportedOperationException("Tiling not supported");
}
return tilingMode;
}
/**
* Returns an array of <code>Dimension</code>s indicating the
* legal size ranges for tiles as they will be encoded in the
* output file or stream. The returned array is a copy.
*
* <p> The information is returned as a set of pairs; the first
* element of a pair contains an (inclusive) minimum width and
* height, and the second element contains an (inclusive) maximum
* width and height. Together, each pair defines a valid range of
* sizes. To specify a fixed size, use the same width and height
* for both elements. To specify an arbitrary range, a value of
* <code>null</code> is used in place of an actual array of
* <code>Dimension</code>s.
*
* <p> If no array is specified on the constructor, but tiling is
* allowed, then this method returns <code>null</code>.
*
* @exception UnsupportedOperationException if the plug-in does
* not support tiling.
*
* @return an array of <code>Dimension</code>s with an even length
* of at least two, or <code>null</code>.
*/
public Dimension[] getPreferredTileSizes() {
if (!canWriteTiles()) {
throw new UnsupportedOperationException("Tiling not supported");
}
return clonePreferredTileSizes(preferredTileSizes);
}
/**
* Specifies that the image should be tiled in the output stream.
* The <code>tileWidth</code> and <code>tileHeight</code>
* parameters specify the width and height of the tiles in the
* file. If the tile width or height is greater than the width or
* height of the image, the image is not tiled in that dimension.
*
* <p> If <code>canOffsetTiles</code> returns <code>false</code>,
* then the <code>tileGridXOffset</code> and
* <code>tileGridYOffset</code> parameters must be zero.
*
* @param tileWidth the width of each tile.
* @param tileHeight the height of each tile.
* @param tileGridXOffset the horizontal offset of the tile grid.
* @param tileGridYOffset the vertical offset of the tile grid.
*
* @exception UnsupportedOperationException if the plug-in does not
* support tiling.
* @exception IllegalStateException if the tiling mode is not
* <code>MODE_EXPLICIT</code>.
* @exception UnsupportedOperationException if the plug-in does not
* support grid offsets, and the grid offsets are not both zero.
* @exception IllegalArgumentException if the tile size is not
* within one of the allowable ranges returned by
* <code>getPreferredTileSizes</code>.
* @exception IllegalArgumentException if <code>tileWidth</code>
* or <code>tileHeight</code> is less than or equal to 0.
*
* @see #canWriteTiles
* @see #canOffsetTiles
* @see #getTileWidth()
* @see #getTileHeight()
* @see #getTileGridXOffset()
* @see #getTileGridYOffset()
*/
public void setTiling(int tileWidth,
int tileHeight,
int tileGridXOffset,
int tileGridYOffset) {
if (!canWriteTiles()) {
throw new UnsupportedOperationException("Tiling not supported!");
}
if (getTilingMode() != MODE_EXPLICIT) {
throw new IllegalStateException("Tiling mode not MODE_EXPLICIT!");
}
if (tileWidth <= 0 || tileHeight <= 0) {
throw new IllegalArgumentException
("tile dimensions are non-positive!");
}
boolean tilesOffset = (tileGridXOffset != 0) || (tileGridYOffset != 0);
if (!canOffsetTiles() && tilesOffset) {
throw new UnsupportedOperationException("Can't offset tiles!");
}
if (preferredTileSizes != null) {
boolean ok = true;
for (int i = 0; i < preferredTileSizes.length; i += 2) {
Dimension min = preferredTileSizes[i];
Dimension max = preferredTileSizes[i+1];
if ((tileWidth < min.width) ||
(tileWidth > max.width) ||
(tileHeight < min.height) ||
(tileHeight > max.height)) {
ok = false;
break;
}
}
if (!ok) {
throw new IllegalArgumentException("Illegal tile size!");
}
}
this.tilingSet = true;
this.tileWidth = tileWidth;
this.tileHeight = tileHeight;
this.tileGridXOffset = tileGridXOffset;
this.tileGridYOffset = tileGridYOffset;
}
/**
* Removes any previous tile grid parameters specified by calls to
* <code>setTiling</code>.
*
* <p> The default implementation sets the instance variables
* <code>tileWidth</code>, <code>tileHeight</code>,
* <code>tileGridXOffset</code>, and
* <code>tileGridYOffset</code> to <code>0</code>.
*
* @exception UnsupportedOperationException if the plug-in does not
* support tiling.
* @exception IllegalStateException if the tiling mode is not
* <code>MODE_EXPLICIT</code>.
*
* @see #setTiling(int, int, int, int)
*/
public void unsetTiling() {
if (!canWriteTiles()) {
throw new UnsupportedOperationException("Tiling not supported!");
}
if (getTilingMode() != MODE_EXPLICIT) {
throw new IllegalStateException("Tiling mode not MODE_EXPLICIT!");
}
this.tilingSet = false;
this.tileWidth = 0;
this.tileHeight = 0;
this.tileGridXOffset = 0;
this.tileGridYOffset = 0;
}
/**
* Returns the width of each tile in an image as it will be
* written to the output stream. If tiling parameters have not
* been set, an <code>IllegalStateException</code> is thrown.
*
* @return the tile width to be used for encoding.
*
* @exception UnsupportedOperationException if the plug-in does not
* support tiling.
* @exception IllegalStateException if the tiling mode is not
* <code>MODE_EXPLICIT</code>.
* @exception IllegalStateException if the tiling parameters have
* not been set.
*
* @see #setTiling(int, int, int, int)
* @see #getTileHeight()
*/
public int getTileWidth() {
if (!canWriteTiles()) {
throw new UnsupportedOperationException("Tiling not supported!");
}
if (getTilingMode() != MODE_EXPLICIT) {
throw new IllegalStateException("Tiling mode not MODE_EXPLICIT!");
}
if (!tilingSet) {
throw new IllegalStateException("Tiling parameters not set!");
}
return tileWidth;
}
/**
* Returns the height of each tile in an image as it will be written to
* the output stream. If tiling parameters have not
* been set, an <code>IllegalStateException</code> is thrown.
*
* @return the tile height to be used for encoding.
*
* @exception UnsupportedOperationException if the plug-in does not
* support tiling.
* @exception IllegalStateException if the tiling mode is not
* <code>MODE_EXPLICIT</code>.
* @exception IllegalStateException if the tiling parameters have
* not been set.
*
* @see #setTiling(int, int, int, int)
* @see #getTileWidth()
*/
public int getTileHeight() {
if (!canWriteTiles()) {
throw new UnsupportedOperationException("Tiling not supported!");
}
if (getTilingMode() != MODE_EXPLICIT) {
throw new IllegalStateException("Tiling mode not MODE_EXPLICIT!");
}
if (!tilingSet) {
throw new IllegalStateException("Tiling parameters not set!");
}
return tileHeight;
}
/**
* Returns the horizontal tile grid offset of an image as it will
* be written to the output stream. If tiling parameters have not
* been set, an <code>IllegalStateException</code> is thrown.
*
* @return the tile grid X offset to be used for encoding.
*
* @exception UnsupportedOperationException if the plug-in does not
* support tiling.
* @exception IllegalStateException if the tiling mode is not
* <code>MODE_EXPLICIT</code>.
* @exception IllegalStateException if the tiling parameters have
* not been set.
*
* @see #setTiling(int, int, int, int)
* @see #getTileGridYOffset()
*/
public int getTileGridXOffset() {
if (!canWriteTiles()) {
throw new UnsupportedOperationException("Tiling not supported!");
}
if (getTilingMode() != MODE_EXPLICIT) {
throw new IllegalStateException("Tiling mode not MODE_EXPLICIT!");
}
if (!tilingSet) {
throw new IllegalStateException("Tiling parameters not set!");
}
return tileGridXOffset;
}
/**
* Returns the vertical tile grid offset of an image as it will
* be written to the output stream. If tiling parameters have not
* been set, an <code>IllegalStateException</code> is thrown.
*
* @return the tile grid Y offset to be used for encoding.
*
* @exception UnsupportedOperationException if the plug-in does not
* support tiling.
* @exception IllegalStateException if the tiling mode is not
* <code>MODE_EXPLICIT</code>.
* @exception IllegalStateException if the tiling parameters have
* not been set.
*
* @see #setTiling(int, int, int, int)
* @see #getTileGridXOffset()
*/
public int getTileGridYOffset() {
if (!canWriteTiles()) {
throw new UnsupportedOperationException("Tiling not supported!");
}
if (getTilingMode() != MODE_EXPLICIT) {
throw new IllegalStateException("Tiling mode not MODE_EXPLICIT!");
}
if (!tilingSet) {
throw new IllegalStateException("Tiling parameters not set!");
}
return tileGridYOffset;
}
/**
* Returns <code>true</code> if the writer can write out images
* as a series of passes of progressively increasing quality.
*
* @return <code>true</code> if the writer supports progressive
* encoding.
*
* @see #setProgressiveMode
* @see #getProgressiveMode
*/
public boolean canWriteProgressive() {
return canWriteProgressive;
}
/**
* Specifies that the writer is to write the image out in a
* progressive mode such that the stream will contain a series of
* scans of increasing quality. If progressive encoding is not
* supported, an <code>UnsupportedOperationException</code> will
* be thrown.
*
* <p> The mode argument determines how
* the progression parameters are chosen, and must be either
* <code>MODE_DISABLED</code>,
* <code>MODE_COPY_FROM_METADATA</code>, or
* <code>MODE_DEFAULT</code>. Otherwise an
* <code>IllegalArgumentException</code> is thrown.
*
* <p> The modes are interpreted as follows:
*
* <ul>
* <li><code>MODE_DISABLED</code> - No progression. Use this to
* turn off progression.
*
* <li><code>MODE_COPY_FROM_METADATA</code> - The output image
* will use whatever progression parameters are found in the
* metadata objects passed into the writer.
*
* <li><code>MODE_DEFAULT</code> - The image will be written
* progressively, with parameters chosen by the writer.
* </ul>
*
* <p> The default is <code>MODE_COPY_FROM_METADATA</code>.
*
* @param mode The mode for setting progression in the output
* stream.
*
* @exception UnsupportedOperationException if the writer does not
* support progressive encoding.
* @exception IllegalArgumentException if <code>mode</code> is not
* one of the modes listed above.
*
* @see #getProgressiveMode
*/
public void setProgressiveMode(int mode) {
if (!canWriteProgressive()) {
throw new UnsupportedOperationException(
"Progressive output not supported");
}
if (mode < MODE_DISABLED || mode > MAX_MODE) {
throw new IllegalArgumentException("Illegal value for mode!");
}
if (mode == MODE_EXPLICIT) {
throw new IllegalArgumentException(
"MODE_EXPLICIT not supported for progressive output");
}
this.progressiveMode = mode;
}
/**
* Returns the current mode for writing the stream in a
* progressive manner.
*
* @return the current mode for progressive encoding.
*
* @exception UnsupportedOperationException if the writer does not
* support progressive encoding.
*
* @see #setProgressiveMode
*/
public int getProgressiveMode() {
if (!canWriteProgressive()) {
throw new UnsupportedOperationException
("Progressive output not supported");
}
return progressiveMode;
}
/**
* Returns <code>true</code> if this writer supports compression.
*
* @return <code>true</code> if the writer supports compression.
*/
public boolean canWriteCompressed() {
return canWriteCompressed;
}
/**
* Specifies whether compression is to be performed, and if so how
* compression parameters are to be determined. The <code>mode</code>
* argument must be one of the four modes, interpreted as follows:
*
* <ul>
* <li><code>MODE_DISABLED</code> - If the mode is set to
* <code>MODE_DISABLED</code>, methods that query or modify the
* compression type or parameters will throw an
* <code>IllegalStateException</code> (if compression is
* normally supported by the plug-in). Some writers, such as JPEG,
* do not normally offer uncompressed output. In this case, attempting
* to set the mode to <code>MODE_DISABLED</code> will throw an
* <code>UnsupportedOperationException</code> and the mode will not be
* changed.
*
* <li><code>MODE_EXPLICIT</code> - Compress using the
* compression type and quality settings specified in this
* <code>ImageWriteParam</code>. Any previously set compression
* parameters are discarded.
*
* <li><code>MODE_COPY_FROM_METADATA</code> - Use whatever
* compression parameters are specified in metadata objects
* passed in to the writer.
*
* <li><code>MODE_DEFAULT</code> - Use default compression
* parameters.
* </ul>
*
* <p> The default is <code>MODE_COPY_FROM_METADATA</code>.
*
* @param mode The mode for setting compression in the output
* stream.
*
* @exception UnsupportedOperationException if the writer does not
* support compression, or does not support the requested mode.
* @exception IllegalArgumentException if <code>mode</code> is not
* one of the modes listed above.
*
* @see #getCompressionMode
*/
public void setCompressionMode(int mode) {
if (!canWriteCompressed()) {
throw new UnsupportedOperationException(
"Compression not supported.");
}
if (mode < MODE_DISABLED || mode > MAX_MODE) {
throw new IllegalArgumentException("Illegal value for mode!");
}
this.compressionMode = mode;
if (mode == MODE_EXPLICIT) {
unsetCompression();
}
}
/**
* Returns the current compression mode, if compression is
* supported.
*
* @return the current compression mode.
*
* @exception UnsupportedOperationException if the writer does not
* support compression.
*
* @see #setCompressionMode
*/
public int getCompressionMode() {
if (!canWriteCompressed()) {
throw new UnsupportedOperationException(
"Compression not supported.");
}
return compressionMode;
}
/**
* Returns a list of available compression types, as an array or
* <code>String</code>s, or <code>null</code> if a compression
* type may not be chosen using these interfaces. The array
* returned is a copy.
*
* <p> If the writer only offers a single, mandatory form of
* compression, it is not necessary to provide any named
* compression types. Named compression types should only be
* used where the user is able to make a meaningful choice
* between different schemes.
*
* <p> The default implementation checks if compression is
* supported and throws an
* <code>UnsupportedOperationException</code> if not. Otherwise,
* it returns a clone of the <code>compressionTypes</code>
* instance variable if it is non-<code>null</code>, or else
* returns <code>null</code>.
*
* @return an array of <code>String</code>s containing the
* (non-localized) names of available compression types, or
* <code>null</code>.
*
* @exception UnsupportedOperationException if the writer does not
* support compression.
*/
public String[] getCompressionTypes() {
if (!canWriteCompressed()) {
throw new UnsupportedOperationException(
"Compression not supported");
}
if (compressionTypes == null) {
return null;
}
return (String[])compressionTypes.clone();
}
/**
* Sets the compression type to one of the values indicated by
* <code>getCompressionTypes</code>. If a value of
* <code>null</code> is passed in, any previous setting is
* removed.
*
* <p> The default implementation checks whether compression is
* supported and the compression mode is
* <code>MODE_EXPLICIT</code>. If so, it calls
* <code>getCompressionTypes</code> and checks if
* <code>compressionType</code> is one of the legal values. If it
* is, the <code>compressionType</code> instance variable is set.
* If <code>compressionType</code> is <code>null</code>, the
* instance variable is set without performing any checking.
*
* @param compressionType one of the <code>String</code>s returned
* by <code>getCompressionTypes</code>, or <code>null</code> to
* remove any previous setting.
*
* @exception UnsupportedOperationException if the writer does not
* support compression.
* @exception IllegalStateException if the compression mode is not
* <code>MODE_EXPLICIT</code>.
* @exception UnsupportedOperationException if there are no
* settable compression types.
* @exception IllegalArgumentException if
* <code>compressionType</code> is non-<code>null</code> but is not
* one of the values returned by <code>getCompressionTypes</code>.
*
* @see #getCompressionTypes
* @see #getCompressionType
* @see #unsetCompression
*/
public void setCompressionType(String compressionType) {
if (!canWriteCompressed()) {
throw new UnsupportedOperationException(
"Compression not supported");
}
if (getCompressionMode() != MODE_EXPLICIT) {
throw new IllegalStateException
("Compression mode not MODE_EXPLICIT!");
}
String[] legalTypes = getCompressionTypes();
if (legalTypes == null) {
throw new UnsupportedOperationException(
"No settable compression types");
}
if (compressionType != null) {
boolean found = false;
if (legalTypes != null) {
for (int i = 0; i < legalTypes.length; i++) {
if (compressionType.equals(legalTypes[i])) {
found = true;
break;
}
}
}
if (!found) {
throw new IllegalArgumentException("Unknown compression type!");
}
}
this.compressionType = compressionType;
}
/**
* Returns the currently set compression type, or
* <code>null</code> if none has been set. The type is returned
* as a <code>String</code> from among those returned by
* <code>getCompressionTypes</code>.
* If no compression type has been set, <code>null</code> is
* returned.
*
* <p> The default implementation checks whether compression is
* supported and the compression mode is
* <code>MODE_EXPLICIT</code>. If so, it returns the value of the
* <code>compressionType</code> instance variable.
*
* @return the current compression type as a <code>String</code>,
* or <code>null</code> if no type is set.
*
* @exception UnsupportedOperationException if the writer does not
* support compression.
* @exception IllegalStateException if the compression mode is not
* <code>MODE_EXPLICIT</code>.
*
* @see #setCompressionType
*/
public String getCompressionType() {
if (!canWriteCompressed()) {
throw new UnsupportedOperationException(
"Compression not supported.");
}
if (getCompressionMode() != MODE_EXPLICIT) {
throw new IllegalStateException
("Compression mode not MODE_EXPLICIT!");
}
return compressionType;
}
/**
* Removes any previous compression type and quality settings.
*
* <p> The default implementation sets the instance variable
* <code>compressionType</code> to <code>null</code>, and the
* instance variable <code>compressionQuality</code> to
* <code>1.0F</code>.
*
* @exception UnsupportedOperationException if the plug-in does not
* support compression.
* @exception IllegalStateException if the compression mode is not
* <code>MODE_EXPLICIT</code>.
*
* @see #setCompressionType
* @see #setCompressionQuality
*/
public void unsetCompression() {
if (!canWriteCompressed()) {
throw new UnsupportedOperationException(
"Compression not supported");
}
if (getCompressionMode() != MODE_EXPLICIT) {
throw new IllegalStateException
("Compression mode not MODE_EXPLICIT!");
}
this.compressionType = null;
this.compressionQuality = 1.0F;
}
/**
* Returns a localized version of the name of the current
* compression type, using the <code>Locale</code> returned by
* <code>getLocale</code>.
*
* <p> The default implementation checks whether compression is
* supported and the compression mode is
* <code>MODE_EXPLICIT</code>. If so, if
* <code>compressionType</code> is <code>non-null</code> the value
* of <code>getCompressionType</code> is returned as a
* convenience.
*
* @return a <code>String</code> containing a localized version of
* the name of the current compression type.
*
* @exception UnsupportedOperationException if the writer does not
* support compression.
* @exception IllegalStateException if the compression mode is not
* <code>MODE_EXPLICIT</code>.
* @exception IllegalStateException if no compression type is set.
*/
public String getLocalizedCompressionTypeName() {
if (!canWriteCompressed()) {
throw new UnsupportedOperationException(
"Compression not supported.");
}
if (getCompressionMode() != MODE_EXPLICIT) {
throw new IllegalStateException
("Compression mode not MODE_EXPLICIT!");
}
if (getCompressionType() == null) {
throw new IllegalStateException("No compression type set!");
}
return getCompressionType();
}
/**
* Returns <code>true</code> if the current compression type
* provides lossless compression. If a plug-in provides only
* one mandatory compression type, then this method may be
* called without calling <code>setCompressionType</code> first.
*
* <p> If there are multiple compression types but none has
* been set, an <code>IllegalStateException</code> is thrown.
*
* <p> The default implementation checks whether compression is
* supported and the compression mode is
* <code>MODE_EXPLICIT</code>. If so, if
* <code>getCompressionTypes()</code> is <code>null</code> or
* <code>getCompressionType()</code> is non-<code>null</code>
* <code>true</code> is returned as a convenience.
*
* @return <code>true</code> if the current compression type is
* lossless.
*
* @exception UnsupportedOperationException if the writer does not
* support compression.
* @exception IllegalStateException if the compression mode is not
* <code>MODE_EXPLICIT</code>.
* @exception IllegalStateException if the set of legal
* compression types is non-<code>null</code> and the current
* compression type is <code>null</code>.
*/
public boolean isCompressionLossless() {
if (!canWriteCompressed()) {
throw new UnsupportedOperationException(
"Compression not supported");
}
if (getCompressionMode() != MODE_EXPLICIT) {
throw new IllegalStateException
("Compression mode not MODE_EXPLICIT!");
}
if ((getCompressionTypes() != null) &&
(getCompressionType() == null)) {
throw new IllegalStateException("No compression type set!");
}
return true;
}
/**
* Sets the compression quality to a value between <code>0</code>
* and <code>1</code>. Only a single compression quality setting
* is supported by default; writers can provide extended versions
* of <code>ImageWriteParam</code> that offer more control. For
* lossy compression schemes, the compression quality should
* control the tradeoff between file size and image quality (for
* example, by choosing quantization tables when writing JPEG
* images). For lossless schemes, the compression quality may be
* used to control the tradeoff between file size and time taken
* to perform the compression (for example, by optimizing row
* filters and setting the ZLIB compression level when writing
* PNG images).
*
* <p> A compression quality setting of 0.0 is most generically
* interpreted as "high compression is important," while a setting of
* 1.0 is most generically interpreted as "high image quality is
* important."
*
* <p> If there are multiple compression types but none has been
* set, an <code>IllegalStateException</code> is thrown.
*
* <p> The default implementation checks that compression is
* supported, and that the compression mode is
* <code>MODE_EXPLICIT</code>. If so, if
* <code>getCompressionTypes()</code> returns <code>null</code> or
* <code>compressionType</code> is non-<code>null</code> it sets
* the <code>compressionQuality</code> instance variable.
*
* @param quality a <code>float</code> between <code>0</code>and
* <code>1</code> indicating the desired quality level.
*
* @exception UnsupportedOperationException if the writer does not
* support compression.
* @exception IllegalStateException if the compression mode is not
* <code>MODE_EXPLICIT</code>.
* @exception IllegalStateException if the set of legal
* compression types is non-<code>null</code> and the current
* compression type is <code>null</code>.
* @exception IllegalArgumentException if <code>quality</code> is
* not between <code>0</code>and <code>1</code>, inclusive.
*
* @see #getCompressionQuality
*/
public void setCompressionQuality(float quality) {
if (!canWriteCompressed()) {
throw new UnsupportedOperationException(
"Compression not supported");
}
if (getCompressionMode() != MODE_EXPLICIT) {
throw new IllegalStateException
("Compression mode not MODE_EXPLICIT!");
}
if (getCompressionTypes() != null && getCompressionType() == null) {
throw new IllegalStateException("No compression type set!");
}
if (quality < 0.0F || quality > 1.0F) {
throw new IllegalArgumentException("Quality out-of-bounds!");
}
this.compressionQuality = quality;
}
/**
* Returns the current compression quality setting.
*
* <p> If there are multiple compression types but none has been
* set, an <code>IllegalStateException</code> is thrown.
*
* <p> The default implementation checks that compression is
* supported and that the compression mode is
* <code>MODE_EXPLICIT</code>. If so, if
* <code>getCompressionTypes()</code> is <code>null</code> or
* <code>getCompressionType()</code> is non-<code>null</code>, it
* returns the value of the <code>compressionQuality</code>
* instance variable.
*
* @return the current compression quality setting.
*
* @exception UnsupportedOperationException if the writer does not
* support compression.
* @exception IllegalStateException if the compression mode is not
* <code>MODE_EXPLICIT</code>.
* @exception IllegalStateException if the set of legal
* compression types is non-<code>null</code> and the current
* compression type is <code>null</code>.
*
* @see #setCompressionQuality
*/
public float getCompressionQuality() {
if (!canWriteCompressed()) {
throw new UnsupportedOperationException(
"Compression not supported.");
}
if (getCompressionMode() != MODE_EXPLICIT) {
throw new IllegalStateException
("Compression mode not MODE_EXPLICIT!");
}
if ((getCompressionTypes() != null) &&
(getCompressionType() == null)) {
throw new IllegalStateException("No compression type set!");
}
return compressionQuality;
}
/**
* Returns a <code>float</code> indicating an estimate of the
* number of bits of output data for each bit of input image data
* at the given quality level. The value will typically lie
* between <code>0</code> and <code>1</code>, with smaller values
* indicating more compression. A special value of
* <code>-1.0F</code> is used to indicate that no estimate is
* available.
*
* <p> If there are multiple compression types but none has been set,
* an <code>IllegalStateException</code> is thrown.
*
* <p> The default implementation checks that compression is
* supported and the compression mode is
* <code>MODE_EXPLICIT</code>. If so, if
* <code>getCompressionTypes()</code> is <code>null</code> or
* <code>getCompressionType()</code> is non-<code>null</code>, and
* <code>quality</code> is within bounds, it returns
* <code>-1.0</code>.
*
* @param quality the quality setting whose bit rate is to be
* queried.
*
* @return an estimate of the compressed bit rate, or
* <code>-1.0F</code> if no estimate is available.
*
* @exception UnsupportedOperationException if the writer does not
* support compression.
* @exception IllegalStateException if the compression mode is not
* <code>MODE_EXPLICIT</code>.
* @exception IllegalStateException if the set of legal
* compression types is non-<code>null</code> and the current
* compression type is <code>null</code>.
* @exception IllegalArgumentException if <code>quality</code> is
* not between <code>0</code>and <code>1</code>, inclusive.
*/
public float getBitRate(float quality) {
if (!canWriteCompressed()) {
throw new UnsupportedOperationException(
"Compression not supported.");
}
if (getCompressionMode() != MODE_EXPLICIT) {
throw new IllegalStateException
("Compression mode not MODE_EXPLICIT!");
}
if ((getCompressionTypes() != null) &&
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