0N/A/*
2362N/A * Copyright (c) 2000, 2001, Oracle and/or its affiliates. All rights reserved.
0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
0N/A *
0N/A * This code is free software; you can redistribute it and/or modify it
0N/A * under the terms of the GNU General Public License version 2 only, as
2362N/A * published by the Free Software Foundation. Oracle designates this
0N/A * particular file as subject to the "Classpath" exception as provided
2362N/A * by Oracle in the LICENSE file that accompanied this code.
0N/A *
0N/A * This code is distributed in the hope that it will be useful, but WITHOUT
0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
0N/A * version 2 for more details (a copy is included in the LICENSE file that
0N/A * accompanied this code).
0N/A *
0N/A * You should have received a copy of the GNU General Public License version
0N/A * 2 along with this work; if not, write to the Free Software Foundation,
0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
0N/A *
2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
2362N/A * or visit www.oracle.com if you need additional information or have any
2362N/A * questions.
0N/A */
0N/A
0N/Apackage javax.imageio;
0N/A
0N/Aimport java.awt.Point;
0N/Aimport java.awt.Rectangle;
0N/A
0N/A/**
0N/A * A superclass of all classes describing how streams should be
0N/A * decoded or encoded. This class contains all the variables and
0N/A * methods that are shared by <code>ImageReadParam</code> and
0N/A * <code>ImageWriteParam</code>.
0N/A *
0N/A * <p> This class provides mechanisms to specify a source region and a
0N/A * destination region. When reading, the source is the stream and
0N/A * the in-memory image is the destination. When writing, these are
0N/A * reversed. In the case of writing, destination regions may be used
0N/A * only with a writer that supports pixel replacement.
0N/A * <p>
0N/A * Decimation subsampling may be specified for both readers
0N/A * and writers, using a movable subsampling grid.
0N/A * <p>
0N/A * Subsets of the source and destination bands may be selected.
0N/A *
0N/A */
0N/Apublic abstract class IIOParam {
0N/A
0N/A /**
0N/A * The source region, on <code>null</code> if none is set.
0N/A */
0N/A protected Rectangle sourceRegion = null;
0N/A
0N/A /**
0N/A * The decimation subsampling to be applied in the horizontal
0N/A * direction. By default, the value is <code>1</code>.
0N/A * The value must not be negative or 0.
0N/A */
0N/A protected int sourceXSubsampling = 1;
0N/A
0N/A /**
0N/A * The decimation subsampling to be applied in the vertical
0N/A * direction. By default, the value is <code>1</code>.
0N/A * The value must not be negative or 0.
0N/A */
0N/A protected int sourceYSubsampling = 1;
0N/A
0N/A /**
0N/A * A horizontal offset to be applied to the subsampling grid before
0N/A * subsampling. The first pixel to be used will be offset this
0N/A * amount from the origin of the region, or of the image if no
0N/A * region is specified.
0N/A */
0N/A protected int subsamplingXOffset = 0;
0N/A
0N/A /**
0N/A * A vertical offset to be applied to the subsampling grid before
0N/A * subsampling. The first pixel to be used will be offset this
0N/A * amount from the origin of the region, or of the image if no
0N/A * region is specified.
0N/A */
0N/A protected int subsamplingYOffset = 0;
0N/A
0N/A /**
0N/A * An array of <code>int</code>s indicating which source bands
0N/A * will be used, or <code>null</code>. If <code>null</code>, the
0N/A * set of source bands to be used is as described in the comment
0N/A * for the <code>setSourceBands</code> method. No value should
0N/A * be allowed to be negative.
0N/A */
0N/A protected int[] sourceBands = null;
0N/A
0N/A /**
0N/A * An <code>ImageTypeSpecifier</code> to be used to generate a
0N/A * destination image when reading, or to set the output color type
0N/A * when writing. If non has been setm the value will be
0N/A * <code>null</code>. By default, the value is <code>null</code>.
0N/A */
0N/A protected ImageTypeSpecifier destinationType = null;
0N/A
0N/A /**
0N/A * The offset in the destination where the upper-left decoded
0N/A * pixel should be placed. By default, the value is (0, 0).
0N/A */
0N/A protected Point destinationOffset = new Point(0, 0);
0N/A
0N/A /**
0N/A * The default <code>IIOParamController</code> that will be
0N/A * used to provide settings for this <code>IIOParam</code>
0N/A * object when the <code>activateController</code> method
0N/A * is called. This default should be set by subclasses
0N/A * that choose to provide their own default controller,
0N/A * usually a GUI, for setting parameters.
0N/A *
0N/A * @see IIOParamController
0N/A * @see #getDefaultController
0N/A * @see #activateController
0N/A */
0N/A protected IIOParamController defaultController = null;
0N/A
0N/A /**
0N/A * The <code>IIOParamController</code> that will be
0N/A * used to provide settings for this <code>IIOParam</code>
0N/A * object when the <code>activateController</code> method
0N/A * is called. This value overrides any default controller,
0N/A * even when null.
0N/A *
0N/A * @see IIOParamController
0N/A * @see #setController(IIOParamController)
0N/A * @see #hasController()
0N/A * @see #activateController()
0N/A */
0N/A protected IIOParamController controller = null;
0N/A
0N/A /**
0N/A * Protected constructor may be called only by subclasses.
0N/A */
0N/A protected IIOParam() {
0N/A controller = defaultController;
0N/A }
0N/A
0N/A /**
0N/A * Sets the source region of interest. The region of interest is
0N/A * described as a rectangle, with the upper-left corner of the
0N/A * source image as pixel (0, 0) and increasing values down and to
0N/A * the right. The actual number of pixels used will depend on
0N/A * the subsampling factors set by <code>setSourceSubsampling</code>.
0N/A * If subsampling has been set such that this number is zero,
0N/A * an <code>IllegalStateException</code> will be thrown.
0N/A *
0N/A * <p> The source region of interest specified by this method will
0N/A * be clipped as needed to fit within the source bounds, as well
0N/A * as the destination offsets, width, and height at the time of
0N/A * actual I/O.
0N/A *
0N/A * <p> A value of <code>null</code> for <code>sourceRegion</code>
0N/A * will remove any region specification, causing the entire image
0N/A * to be used.
0N/A *
0N/A * @param sourceRegion a <code>Rectangle</code> specifying the
0N/A * source region of interest, or <code>null</code>.
0N/A *
0N/A * @exception IllegalArgumentException if
0N/A * <code>sourceRegion</code> is non-<code>null</code> and either
0N/A * <code>sourceRegion.x</code> or <code>sourceRegion.y</code> is
0N/A * negative.
0N/A * @exception IllegalArgumentException if
0N/A * <code>sourceRegion</code> is non-<code>null</code> and either
0N/A * <code>sourceRegion.width</code> or
0N/A * <code>sourceRegion.height</code> is negative or 0.
0N/A * @exception IllegalStateException if subsampling is such that
0N/A * this region will have a subsampled width or height of zero.
0N/A *
0N/A * @see #getSourceRegion
0N/A * @see #setSourceSubsampling
0N/A * @see ImageReadParam#setDestinationOffset
0N/A * @see ImageReadParam#getDestinationOffset
0N/A */
0N/A public void setSourceRegion(Rectangle sourceRegion) {
0N/A if (sourceRegion == null) {
0N/A this.sourceRegion = null;
0N/A return;
0N/A }
0N/A
0N/A if (sourceRegion.x < 0) {
0N/A throw new IllegalArgumentException("sourceRegion.x < 0!");
0N/A }
0N/A if (sourceRegion.y < 0){
0N/A throw new IllegalArgumentException("sourceRegion.y < 0!");
0N/A }
0N/A if (sourceRegion.width <= 0) {
0N/A throw new IllegalArgumentException("sourceRegion.width <= 0!");
0N/A }
0N/A if (sourceRegion.height <= 0) {
0N/A throw new IllegalArgumentException("sourceRegion.height <= 0!");
0N/A }
0N/A
0N/A // Throw an IllegalStateException if region falls between subsamples
0N/A if (sourceRegion.width <= subsamplingXOffset) {
0N/A throw new IllegalStateException
0N/A ("sourceRegion.width <= subsamplingXOffset!");
0N/A }
0N/A if (sourceRegion.height <= subsamplingYOffset) {
0N/A throw new IllegalStateException
0N/A ("sourceRegion.height <= subsamplingYOffset!");
0N/A }
0N/A
0N/A this.sourceRegion = (Rectangle)sourceRegion.clone();
0N/A }
0N/A
0N/A /**
0N/A * Returns the source region to be used. The returned value is
0N/A * that set by the most recent call to
0N/A * <code>setSourceRegion</code>, and will be <code>null</code> if
0N/A * there is no region set.
0N/A *
0N/A * @return the source region of interest as a
0N/A * <code>Rectangle</code>, or <code>null</code>.
0N/A *
0N/A * @see #setSourceRegion
0N/A */
0N/A public Rectangle getSourceRegion() {
0N/A if (sourceRegion == null) {
0N/A return null;
0N/A }
0N/A return (Rectangle)sourceRegion.clone();
0N/A }
0N/A
0N/A /**
0N/A * Specifies a decimation subsampling to apply on I/O. The
0N/A * <code>sourceXSubsampling</code> and
0N/A * <code>sourceYSubsampling</code> parameters specify the
0N/A * subsampling period (<i>i.e.</i>, the number of rows and columns
0N/A * to advance after every source pixel). Specifically, a period of
0N/A * 1 will use every row or column; a period of 2 will use every
0N/A * other row or column. The <code>subsamplingXOffset</code> and
0N/A * <code>subsamplingYOffset</code> parameters specify an offset
0N/A * from the region (or image) origin for the first subsampled pixel.
0N/A * Adjusting the origin of the subsample grid is useful for avoiding
0N/A * seams when subsampling a very large source image into destination
0N/A * regions that will be assembled into a complete subsampled image.
0N/A * Most users will want to simply leave these parameters at 0.
0N/A *
0N/A * <p> The number of pixels and scanlines to be used are calculated
0N/A * as follows.
0N/A * <p>
0N/A * The number of subsampled pixels in a scanline is given by
0N/A * <p>
0N/A * <code>truncate[(width - subsamplingXOffset + sourceXSubsampling - 1)
0N/A * / sourceXSubsampling]</code>.
0N/A * <p>
0N/A * If the region is such that this width is zero, an
0N/A * <code>IllegalStateException</code> is thrown.
0N/A * <p>
0N/A * The number of scanlines to be used can be computed similarly.
0N/A *
0N/A * <p>The ability to set the subsampling grid to start somewhere
0N/A * other than the source region origin is useful if the
0N/A * region is being used to create subsampled tiles of a large image,
0N/A * where the tile width and height are not multiples of the
0N/A * subsampling periods. If the subsampling grid does not remain
0N/A * consistent from tile to tile, there will be artifacts at the tile
0N/A * boundaries. By adjusting the subsampling grid offset for each
0N/A * tile to compensate, these artifacts can be avoided. The tradeoff
0N/A * is that in order to avoid these artifacts, the tiles are not all
0N/A * the same size. The grid offset to use in this case is given by:
0N/A * <br>
0N/A * grid offset = [period - (region offset modulo period)] modulo period)
0N/A *
0N/A * <p> If either <code>sourceXSubsampling</code> or
0N/A * <code>sourceYSubsampling</code> is 0 or negative, an
0N/A * <code>IllegalArgumentException</code> will be thrown.
0N/A *
0N/A * <p> If either <code>subsamplingXOffset</code> or
0N/A * <code>subsamplingYOffset</code> is negative or greater than or
0N/A * equal to the corresponding period, an
0N/A * <code>IllegalArgumentException</code> will be thrown.
0N/A *
0N/A * <p> There is no <code>unsetSourceSubsampling</code> method;
0N/A * simply call <code>setSourceSubsampling(1, 1, 0, 0)</code> to
0N/A * restore default values.
0N/A *
0N/A * @param sourceXSubsampling the number of columns to advance
0N/A * between pixels.
0N/A * @param sourceYSubsampling the number of rows to advance between
0N/A * pixels.
0N/A * @param subsamplingXOffset the horizontal offset of the first subsample
0N/A * within the region, or within the image if no region is set.
0N/A * @param subsamplingYOffset the horizontal offset of the first subsample
0N/A * within the region, or within the image if no region is set.
0N/A * @exception IllegalArgumentException if either period is
0N/A * negative or 0, or if either grid offset is negative or greater than
0N/A * the corresponding period.
0N/A * @exception IllegalStateException if the source region is such that
0N/A * the subsampled output would contain no pixels.
0N/A */
0N/A public void setSourceSubsampling(int sourceXSubsampling,
0N/A int sourceYSubsampling,
0N/A int subsamplingXOffset,
0N/A int subsamplingYOffset) {
0N/A if (sourceXSubsampling <= 0) {
0N/A throw new IllegalArgumentException("sourceXSubsampling <= 0!");
0N/A }
0N/A if (sourceYSubsampling <= 0) {
0N/A throw new IllegalArgumentException("sourceYSubsampling <= 0!");
0N/A }
0N/A if (subsamplingXOffset < 0 ||
0N/A subsamplingXOffset >= sourceXSubsampling) {
0N/A throw new IllegalArgumentException
0N/A ("subsamplingXOffset out of range!");
0N/A }
0N/A if (subsamplingYOffset < 0 ||
0N/A subsamplingYOffset >= sourceYSubsampling) {
0N/A throw new IllegalArgumentException
0N/A ("subsamplingYOffset out of range!");
0N/A }
0N/A
0N/A // Throw an IllegalStateException if region falls between subsamples
0N/A if (sourceRegion != null) {
0N/A if (subsamplingXOffset >= sourceRegion.width ||
0N/A subsamplingYOffset >= sourceRegion.height) {
0N/A throw new IllegalStateException("region contains no pixels!");
0N/A }
0N/A }
0N/A
0N/A this.sourceXSubsampling = sourceXSubsampling;
0N/A this.sourceYSubsampling = sourceYSubsampling;
0N/A this.subsamplingXOffset = subsamplingXOffset;
0N/A this.subsamplingYOffset = subsamplingYOffset;
0N/A }
0N/A
0N/A /**
0N/A * Returns the number of source columns to advance for each pixel.
0N/A *
0N/A * <p>If <code>setSourceSubsampling</code> has not been called, 1
0N/A * is returned (which is the correct value).
0N/A *
0N/A * @return the source subsampling X period.
0N/A *
0N/A * @see #setSourceSubsampling
0N/A * @see #getSourceYSubsampling
0N/A */
0N/A public int getSourceXSubsampling() {
0N/A return sourceXSubsampling;
0N/A }
0N/A
0N/A /**
0N/A * Returns the number of rows to advance for each pixel.
0N/A *
0N/A * <p>If <code>setSourceSubsampling</code> has not been called, 1
0N/A * is returned (which is the correct value).
0N/A *
0N/A * @return the source subsampling Y period.
0N/A *
0N/A * @see #setSourceSubsampling
0N/A * @see #getSourceXSubsampling
0N/A */
0N/A public int getSourceYSubsampling() {
0N/A return sourceYSubsampling;
0N/A }
0N/A
0N/A /**
0N/A * Returns the horizontal offset of the subsampling grid.
0N/A *
0N/A * <p>If <code>setSourceSubsampling</code> has not been called, 0
0N/A * is returned (which is the correct value).
0N/A *
0N/A * @return the source subsampling grid X offset.
0N/A *
0N/A * @see #setSourceSubsampling
0N/A * @see #getSubsamplingYOffset
0N/A */
0N/A public int getSubsamplingXOffset() {
0N/A return subsamplingXOffset;
0N/A }
0N/A
0N/A /**
0N/A * Returns the vertical offset of the subsampling grid.
0N/A *
0N/A * <p>If <code>setSourceSubsampling</code> has not been called, 0
0N/A * is returned (which is the correct value).
0N/A *
0N/A * @return the source subsampling grid Y offset.
0N/A *
0N/A * @see #setSourceSubsampling
0N/A * @see #getSubsamplingXOffset
0N/A */
0N/A public int getSubsamplingYOffset() {
0N/A return subsamplingYOffset;
0N/A }
0N/A
0N/A /**
0N/A * Sets the indices of the source bands to be used. Duplicate
0N/A * indices are not allowed.
0N/A *
0N/A * <p> A <code>null</code> value indicates that all source bands
0N/A * will be used.
0N/A *
0N/A * <p> At the time of reading, an
0N/A * <code>IllegalArgumentException</code> will be thrown by the
0N/A * reader or writer if a value larger than the largest available
0N/A * source band index has been specified or if the number of source
0N/A * bands and destination bands to be used differ. The
0N/A * <code>ImageReader.checkReadParamBandSettings</code> method may
0N/A * be used to automate this test.
0N/A *
0N/A * <p> Semantically, a copy is made of the array; changes to the
0N/A * array contents subsequent to this call have no effect on
0N/A * this <code>IIOParam</code>.
0N/A *
0N/A * @param sourceBands an array of integer band indices to be
0N/A * used.
0N/A *
0N/A * @exception IllegalArgumentException if <code>sourceBands</code>
0N/A * contains a negative or duplicate value.
0N/A *
0N/A * @see #getSourceBands
0N/A * @see ImageReadParam#setDestinationBands
0N/A * @see ImageReader#checkReadParamBandSettings
0N/A */
0N/A public void setSourceBands(int[] sourceBands) {
0N/A if (sourceBands == null) {
0N/A this.sourceBands = null;
0N/A } else {
0N/A int numBands = sourceBands.length;
0N/A for (int i = 0; i < numBands; i++) {
0N/A int band = sourceBands[i];
0N/A if (band < 0) {
0N/A throw new IllegalArgumentException("Band value < 0!");
0N/A }
0N/A for (int j = i + 1; j < numBands; j++) {
0N/A if (band == sourceBands[j]) {
0N/A throw new IllegalArgumentException("Duplicate band value!");
0N/A }
0N/A }
0N/A
0N/A }
0N/A this.sourceBands = (int[])(sourceBands.clone());
0N/A }
0N/A }
0N/A
0N/A /**
0N/A * Returns the set of of source bands to be used. The returned
0N/A * value is that set by the most recent call to
0N/A * <code>setSourceBands</code>, or <code>null</code> if there have
0N/A * been no calls to <code>setSourceBands</code>.
0N/A *
0N/A * <p> Semantically, the array returned is a copy; changes to
0N/A * array contents subsequent to this call have no effect on this
0N/A * <code>IIOParam</code>.
0N/A *
0N/A * @return the set of source bands to be used, or
0N/A * <code>null</code>.
0N/A *
0N/A * @see #setSourceBands
0N/A */
0N/A public int[] getSourceBands() {
0N/A if (sourceBands == null) {
0N/A return null;
0N/A }
0N/A return (int[])(sourceBands.clone());
0N/A }
0N/A
0N/A /**
0N/A * Sets the desired image type for the destination image, using an
0N/A * <code>ImageTypeSpecifier</code>.
0N/A *
0N/A * <p> When reading, if the layout of the destination has been set
0N/A * using this method, each call to an <code>ImageReader</code>
0N/A * <code>read</code> method will return a new
0N/A * <code>BufferedImage</code> using the format specified by the
0N/A * supplied type specifier. As a side effect, any destination
0N/A * <code>BufferedImage</code> set by
0N/A * <code>ImageReadParam.setDestination(BufferedImage)</code> will
0N/A * no longer be set as the destination. In other words, this
0N/A * method may be thought of as calling
0N/A * <code>setDestination((BufferedImage)null)</code>.
0N/A *
0N/A * <p> When writing, the destination type maybe used to determine
0N/A * the color type of the image. The <code>SampleModel</code>
0N/A * information will be ignored, and may be <code>null</code>. For
0N/A * example, a 4-banded image could represent either CMYK or RGBA
0N/A * data. If a destination type is set, its
0N/A * <code>ColorModel</code> will override any
0N/A * <code>ColorModel</code> on the image itself. This is crucial
0N/A * when <code>setSourceBands</code> is used since the image's
0N/A * <code>ColorModel</code> will refer to the entire image rather
0N/A * than to the subset of bands being written.
0N/A *
0N/A * @param destinationType the <code>ImageTypeSpecifier</code> to
0N/A * be used to determine the destination layout and color type.
0N/A *
0N/A * @see #getDestinationType
0N/A */
0N/A public void setDestinationType(ImageTypeSpecifier destinationType) {
0N/A this.destinationType = destinationType;
0N/A }
0N/A
0N/A /**
0N/A * Returns the type of image to be returned by the read, if one
0N/A * was set by a call to
0N/A * <code>setDestination(ImageTypeSpecifier)</code>, as an
0N/A * <code>ImageTypeSpecifier</code>. If none was set,
0N/A * <code>null</code> is returned.
0N/A *
0N/A * @return an <code>ImageTypeSpecifier</code> describing the
0N/A * destination type, or <code>null</code>.
0N/A *
0N/A * @see #setDestinationType
0N/A */
0N/A public ImageTypeSpecifier getDestinationType() {
0N/A return destinationType;
0N/A }
0N/A
0N/A /**
0N/A * Specifies the offset in the destination image at which future
0N/A * decoded pixels are to be placed, when reading, or where a
0N/A * region will be written, when writing.
0N/A *
0N/A * <p> When reading, the region to be written within the
0N/A * destination <code>BufferedImage</code> will start at this
0N/A * offset and have a width and height determined by the source
0N/A * region of interest, the subsampling parameters, and the
0N/A * destination bounds.
0N/A *
0N/A * <p> Normal writes are not affected by this method, only writes
0N/A * performed using <code>ImageWriter.replacePixels</code>. For
0N/A * such writes, the offset specified is within the output stream
0N/A * image whose pixels are being modified.
0N/A *
0N/A * <p> There is no <code>unsetDestinationOffset</code> method;
0N/A * simply call <code>setDestinationOffset(new Point(0, 0))</code> to
0N/A * restore default values.
0N/A *
0N/A * @param destinationOffset the offset in the destination, as a
0N/A * <code>Point</code>.
0N/A *
0N/A * @exception IllegalArgumentException if
0N/A * <code>destinationOffset</code> is <code>null</code>.
0N/A *
0N/A * @see #getDestinationOffset
0N/A * @see ImageWriter#replacePixels
0N/A */
0N/A public void setDestinationOffset(Point destinationOffset) {
0N/A if (destinationOffset == null) {
0N/A throw new IllegalArgumentException("destinationOffset == null!");
0N/A }
0N/A this.destinationOffset = (Point)destinationOffset.clone();
0N/A }
0N/A
0N/A /**
0N/A * Returns the offset in the destination image at which pixels are
0N/A * to be placed.
0N/A *
0N/A * <p> If <code>setDestinationOffsets</code> has not been called,
0N/A * a <code>Point</code> with zero X and Y values is returned
0N/A * (which is the correct value).
0N/A *
0N/A * @return the destination offset as a <code>Point</code>.
0N/A *
0N/A * @see #setDestinationOffset
0N/A */
0N/A public Point getDestinationOffset() {
0N/A return (Point)destinationOffset.clone();
0N/A }
0N/A
0N/A /**
0N/A * Sets the <code>IIOParamController</code> to be used
0N/A * to provide settings for this <code>IIOParam</code>
0N/A * object when the <code>activateController</code> method
0N/A * is called, overriding any default controller. If the
0N/A * argument is <code>null</code>, no controller will be
0N/A * used, including any default. To restore the default, use
0N/A * <code>setController(getDefaultController())</code>.
0N/A *
0N/A * @param controller An appropriate
0N/A * <code>IIOParamController</code>, or <code>null</code>.
0N/A *
0N/A * @see IIOParamController
0N/A * @see #getController
0N/A * @see #getDefaultController
0N/A * @see #hasController
0N/A * @see #activateController()
0N/A */
0N/A public void setController(IIOParamController controller) {
0N/A this.controller = controller;
0N/A }
0N/A
0N/A /**
0N/A * Returns whatever <code>IIOParamController</code> is currently
0N/A * installed. This could be the default if there is one,
0N/A * <code>null</code>, or the argument of the most recent call
0N/A * to <code>setController</code>.
0N/A *
0N/A * @return the currently installed
0N/A * <code>IIOParamController</code>, or <code>null</code>.
0N/A *
0N/A * @see IIOParamController
0N/A * @see #setController
0N/A * @see #getDefaultController
0N/A * @see #hasController
0N/A * @see #activateController()
0N/A */
0N/A public IIOParamController getController() {
0N/A return controller;
0N/A }
0N/A
0N/A /**
0N/A * Returns the default <code>IIOParamController</code>, if there
0N/A * is one, regardless of the currently installed controller. If
0N/A * there is no default controller, returns <code>null</code>.
0N/A *
0N/A * @return the default <code>IIOParamController</code>, or
0N/A * <code>null</code>.
0N/A *
0N/A * @see IIOParamController
0N/A * @see #setController(IIOParamController)
0N/A * @see #getController
0N/A * @see #hasController
0N/A * @see #activateController()
0N/A */
0N/A public IIOParamController getDefaultController() {
0N/A return defaultController;
0N/A }
0N/A
0N/A /**
0N/A * Returns <code>true</code> if there is a controller installed
0N/A * for this <code>IIOParam</code> object. This will return
0N/A * <code>true</code> if <code>getController</code> would not
0N/A * return <code>null</code>.
0N/A *
0N/A * @return <code>true</code> if a controller is installed.
0N/A *
0N/A * @see IIOParamController
0N/A * @see #setController(IIOParamController)
0N/A * @see #getController
0N/A * @see #getDefaultController
0N/A * @see #activateController()
0N/A */
0N/A public boolean hasController() {
0N/A return (controller != null);
0N/A }
0N/A
0N/A /**
0N/A * Activates the installed <code>IIOParamController</code> for
0N/A * this <code>IIOParam</code> object and returns the resulting
0N/A * value. When this method returns <code>true</code>, all values
0N/A * for this <code>IIOParam</code> object will be ready for the
0N/A * next read or write operation. If <code>false</code> is
0N/A * returned, no settings in this object will have been disturbed
0N/A * (<i>i.e.</i>, the user canceled the operation).
0N/A *
0N/A * <p> Ordinarily, the controller will be a GUI providing a user
0N/A * interface for a subclass of <code>IIOParam</code> for a
0N/A * particular plug-in. Controllers need not be GUIs, however.
0N/A *
0N/A * @return <code>true</code> if the controller completed normally.
0N/A *
0N/A * @exception IllegalStateException if there is no controller
0N/A * currently installed.
0N/A *
0N/A * @see IIOParamController
0N/A * @see #setController(IIOParamController)
0N/A * @see #getController
0N/A * @see #getDefaultController
0N/A * @see #hasController
0N/A */
0N/A public boolean activateController() {
0N/A if (!hasController()) {
0N/A throw new IllegalStateException("hasController() == false!");
0N/A }
0N/A return getController().activate(this);
0N/A }
0N/A}