Example usage for com.lowagie.text.pdf PdfTransparencyGroup setIsolated

Introduction

In this page you can find the example usage for com.lowagie.text.pdf PdfTransparencyGroup setIsolated.

Prototype

public void setIsolated(boolean isolated) 

Source Link

Document

Determining the initial backdrop against which its stack is composited.

Usage

From source file:questions.images.TransparentEllipse2.java

public static void main(String[] args) {

    Document document = new Document(PageSize.POSTCARD);
    try {//  w w  w. j  a  v a 2s  .co  m
        PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(RESULT));
        document.open();
        PdfContentByte cb = writer.getDirectContent();

        // clipped image
        cb.ellipse(1, 1, PageSize.POSTCARD.getWidth() - 2, PageSize.POSTCARD.getHeight() - 2);
        cb.clip();
        cb.newPath();
        Image img = Image.getInstance(RESOURCE);
        img.scaleToFit(PageSize.POSTCARD.getWidth(), PageSize.POSTCARD.getHeight());
        cb.addImage(img, PageSize.POSTCARD.getWidth(), 0, 0, PageSize.POSTCARD.getHeight(), 0, 0);

        //Prepare gradation list
        int gradationStep = 40;
        float[] gradationRatioList = new float[gradationStep];
        for (int i = 0; i < gradationStep; i++) {
            gradationRatioList[i] = 1 - (float) Math.sin(Math.toRadians(90.0f / gradationStep * (i + 1)));
        }

        //Create template
        PdfTemplate template = cb.createTemplate(PageSize.POSTCARD.getWidth(), PageSize.POSTCARD.getHeight());

        //Prepare transparent group
        PdfTransparencyGroup transGroup = new PdfTransparencyGroup();
        transGroup.put(PdfName.CS, PdfName.DEVICEGRAY);
        transGroup.setIsolated(true);
        transGroup.setKnockout(false);
        template.setGroup(transGroup);

        //Prepare graphic state
        PdfGState gState = new PdfGState();
        PdfDictionary maskDict = new PdfDictionary();
        maskDict.put(PdfName.TYPE, PdfName.MASK);
        maskDict.put(PdfName.S, new PdfName("Luminosity"));
        maskDict.put(new PdfName("G"), template.getIndirectReference());
        gState.put(PdfName.SMASK, maskDict);
        cb.setGState(gState);

        //Create gradation for mask
        for (int i = 1; i < gradationStep + 1; i++) {
            template.setLineWidth(gradationStep + 1 - i);
            template.setGrayStroke(gradationRatioList[gradationStep - i]);
            template.ellipse(0, 0, PageSize.POSTCARD.getWidth(), PageSize.POSTCARD.getHeight());
            template.stroke();
        }

        //Place template
        cb.addTemplate(template, 0, 0);
    } catch (DocumentException de) {
        System.err.println(de.getMessage());
    } catch (IOException ioe) {
        System.err.println(ioe.getMessage());
    }

    document.close();
}

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