Configuration.java

package com.sun.pdfview;

/**
 * Since there is no context that is passed between the various classes that
 * perform the pdf parsing and rendering, we introduce this class to at least
 * globally configure PDFRenderer.
 *
 * Typically you would configure the global instance before using any other
 * PDFRenderer API.
 */
public class Configuration {
	private static Configuration INSTANCE;

    /** whether grey scale images will be converted to ARGB */
    private boolean convertGreyscaleImagesToArgb = true;
    /** threshold in pixels after which images are rendered in chunks (disabled by default) */
    private int thresholdForBandedImageRendering = 0;
    /** whether color convert op should be used or not for parsing an image*/
    private boolean avoidColorConvertOp = false;
    /** Use blur before image resize to enhance the result (Antialias) **/
    private boolean useBlurResizingForImages = true;

    
	public static synchronized Configuration getInstance() {
		if (INSTANCE == null) {
			INSTANCE = new Configuration();
		}
		return INSTANCE;
	}

    /**
	 * Enables or disables the conversion of greyscale images to ARGB.
	 * Disabling this may have a lower memory overhead with high resolution
	 * (e.g. scanned) images. Note that this has to be called before
	 * {@link #getImage()} is called to have an effect.
	 *
	 * Enabled by default.
	 * @param aFlag whether greyscale images shall be converted to ARGB.
	 */
	public void setConvertGreyscaleImagesToArgb(boolean aFlag) {
		convertGreyscaleImagesToArgb = aFlag;
	}

	/**
	 * Returns <code>true</code> if greyscale images will be converted to ARGB
	 */
	public boolean isConvertGreyscaleImagesToArgb() {
		return convertGreyscaleImagesToArgb;
	}

	/**
	 * If an image is higher than the given size (in pixels) then
	 * the image will be rendered in chunks, rather than as one big image.
	 * This may lead to lower memory consumption for e.g. scanned PDFs with
	 * large images.
	 *
	 * Set to a value <= 0 to disable banded image rendering.
	 * Defaults to 0 (off)
	 *
	 * @param aSize the height threshold at which to enable banded image rendering
	 */
	public void setThresholdForBandedImageRendering(int aSize) {
		thresholdForBandedImageRendering = aSize;
	}

	/**
	 * Returns the image height threshold at which to enable banded image rendering.
	 * @return the threshold value, or a value <= 0 if banded rendering is disabled
	 */
	public int getThresholdForBandedImageRendering() {
		return thresholdForBandedImageRendering;
	}

	/**
	 * Is the color converting op switched on or off?
	 * @return - the usage of this color convert op 
	 */
    public boolean isAvoidColorConvertOp() {
        return avoidColorConvertOp;
    }
    
    /** 
     * Set this to false to switch off the
     * use of this color convert op which may segfault on some platforms
     * due to a variety of problems related to thread safety and
     * the native cmm library underlying this conversion op, e.g.,
     * https://forums.oracle.com/forums/thread.jspa?threadID=1261882&;tstart=225&messageID=5356357
     * (Unix platforms seem the most affected)
     * 
     * If the system is bug-free, though, this does make use
     * of native libraries and sees a not insignificant speed-up,
     * though it's still not exactly fast. If we don't run this op
     * now, it's performed at some later stage, but without using
     * the native code
     * @param avoidColorConvertOp
     */
    public void setAvoidColorConvertOp(boolean avoidColorConvertOp) {
        this.avoidColorConvertOp = avoidColorConvertOp;
    }

    /**
     * Use blur before image resize to enhance the result (Antialias)?
     * @return the useBlurResizingForImages
     */
    public boolean isUseBlurResizingForImages() {
        return useBlurResizingForImages;
    }

    /**
     * Use blur before image resize to enhance the result (Antialias)
     * 
     * @param useBlurResizingForImages 
     */
    public void setUseBlurResizingForImages(boolean useBlurResizingForImages) {
        this.useBlurResizingForImages = useBlurResizingForImages;
    }

}