org.apache.pdfbox.filter.DecodeOptions Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of pdfbox Show documentation
Show all versions of pdfbox Show documentation
The Apache PDFBox library is an open source Java tool for working with PDF documents.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.pdfbox.filter;
import java.awt.Rectangle;
/**
* Options that may be passed to a Filter to request special handling when decoding the stream.
* Filters may not honor some or all of the specified options, and so callers should check the
* honored flag if further processing relies on the options being used.
*/
public class DecodeOptions
{
/**
* Default decode options. The honored flag for this instance is always true, as it represents
* the default behavior.
*/
public static final DecodeOptions DEFAULT = new FinalDecodeOptions(true);
private Rectangle sourceRegion = null;
private int subsamplingX = 1, subsamplingY = 1, subsamplingOffsetX = 0, subsamplingOffsetY = 0;
private boolean filterSubsampled = false;
/**
* Constructs an empty DecodeOptions instance
*/
public DecodeOptions()
{
// this constructor is intentionally left empty
}
/**
* Constructs an instance specifying the region of the image that should be decoded. The actual
* region will be clipped to the dimensions of the image.
*
* @param sourceRegion Region of the source image that should be decoded
*/
public DecodeOptions(Rectangle sourceRegion)
{
this.sourceRegion = sourceRegion;
}
/**
* Constructs an instance specifying the region of the image that should be decoded. The actual
* region will be clipped to the dimensions of the image.
*
* @param x x-coordinate of the top-left corner of the region to be decoded
* @param y y-coordinate of the top-left corner of the region to be decoded
* @param width Width of the region to be decoded
* @param height Height of the region to be decoded
*/
public DecodeOptions(int x, int y, int width, int height)
{
this(new Rectangle(x, y, width, height));
}
/**
* Constructs an instance specifying the image should be decoded using subsampling. The
* subsampling will be the same for the X and Y axes.
*
* @param subsampling The number of rows and columns to advance in the source for each pixel in
* the decoded image.
*/
public DecodeOptions(int subsampling)
{
subsamplingX = subsampling;
subsamplingY = subsampling;
}
/**
* When decoding an image, the part of the image that should be decoded, or null if the entire
* image is needed.
*
* @return The source region to decode, or null if the entire image should be decoded
*/
public Rectangle getSourceRegion()
{
return sourceRegion;
}
/**
* Sets the region of the source image that should be decoded. The region will be clipped to the
* dimensions of the source image. Setting this value to null will result in the entire image
* being decoded.
*
* @param sourceRegion The source region to decode, or null if the entire image should be
* decoded.
*/
public void setSourceRegion(Rectangle sourceRegion)
{
this.sourceRegion = sourceRegion;
}
/**
* When decoding an image, the number of columns to advance in the source for every pixel
* decoded.
*
* @return The x-axis subsampling value
*/
public int getSubsamplingX()
{
return subsamplingX;
}
/**
* Sets the number of columns to advance in the source for every pixel decoded
*
* @param ssX The x-axis subsampling value
*/
public void setSubsamplingX(int ssX)
{
this.subsamplingX = ssX;
}
/**
* When decoding an image, the number of rows to advance in the source for every pixel decoded.
*
* @return The y-axis subsampling value
*/
public int getSubsamplingY()
{
return subsamplingY;
}
/**
* Sets the number of rows to advance in the source for every pixel decoded
*
* @param ssY The y-axis subsampling value
*/
public void setSubsamplingY(int ssY)
{
this.subsamplingY = ssY;
}
/**
* When decoding an image, the horizontal offset for subsampling
*
* @return The x-axis subsampling offset
*/
public int getSubsamplingOffsetX()
{
return subsamplingOffsetX;
}
/**
* Sets the horizontal subsampling offset for decoding images
*
* @param ssOffsetX The x-axis subsampling offset
*/
public void setSubsamplingOffsetX(int ssOffsetX)
{
this.subsamplingOffsetX = ssOffsetX;
}
/**
* When decoding an image, the vertical offset for subsampling
*
* @return The y-axis subsampling offset
*/
public int getSubsamplingOffsetY()
{
return subsamplingOffsetY;
}
/**
* Sets the vertical subsampling offset for decoding images
*
* @param ssOffsetY The y-axis subsampling offset
*/
public void setSubsamplingOffsetY(int ssOffsetY)
{
this.subsamplingOffsetY = ssOffsetY;
}
/**
* Flag used by the filter to specify if it performed subsampling.
*
* Some filters may be unable or unwilling to apply subsampling, and so the caller must check
* this flag after decoding.
*
* @return True if the filter applied the options specified by this instance, false otherwise.
*/
public boolean isFilterSubsampled()
{
return filterSubsampled;
}
/**
* Used internally by filters to signal they have applied subsampling as requested by this
* options instance.
*
* @param filterSubsampled Value specifying if the filter could meet the requested options.
* Usually a filter will only call this with the value true, as the default value
* for the flag is false.
*/
void setFilterSubsampled(boolean filterSubsampled)
{
this.filterSubsampled = filterSubsampled;
}
/**
* Helper class for reusable instances which may not be modified.
*/
private static class FinalDecodeOptions extends DecodeOptions
{
FinalDecodeOptions(boolean filterSubsampled)
{
super.setFilterSubsampled(filterSubsampled);
}
@Override
public void setSourceRegion(Rectangle sourceRegion)
{
throw new UnsupportedOperationException("This instance may not be modified.");
}
@Override
public void setSubsamplingX(int ssX)
{
throw new UnsupportedOperationException("This instance may not be modified.");
}
@Override
public void setSubsamplingY(int ssY)
{
throw new UnsupportedOperationException("This instance may not be modified.");
}
@Override
public void setSubsamplingOffsetX(int ssOffsetX)
{
throw new UnsupportedOperationException("This instance may not be modified.");
}
@Override
public void setSubsamplingOffsetY(int ssOffsetY)
{
throw new UnsupportedOperationException("This instance may not be modified.");
}
@Override
void setFilterSubsampled(boolean filterSubsampled)
{
// Silently ignore the request.
}
}
}