Build, write, embed elements in PDF pages using Java

//---------------------------------------------------------------------------------------
// Copyright (c) 2001-2022 by PDFTron Systems Inc. All Rights Reserved.
// Consult legal.txt regarding legal and license information.
//---------------------------------------------------------------------------------------

import com.pdftron.common.Matrix2D;
import com.pdftron.pdf.*;
import com.pdftron.sdf.SDFDoc;
import com.pdftron.filters.*;
import java.io.*;

public class ElementBuilderTest {


    public static void main(String[] args) {
        PDFNet.initialize(PDFTronLicense.Key());

        // Relative path to the folder containing test files.
        String input_path = "../../TestFiles/";
        String output_path = "../../TestFiles/Output/";

        try {
            PDFDoc doc = new PDFDoc();
            ElementBuilder eb = new ElementBuilder();        // ElementBuilder is used to build new
            // Element objects
            ElementWriter writer = new ElementWriter();    // ElementWriter is used to write
            // Elements to the page

            Element element;
            GState gstate;

            // Start a new page ------------------------------------
            Page page = doc.pageCreate(new Rect(0, 0, 612, 794));

            writer.begin(page);    // begin writing to the page

            // Create an Image that can be reused in the document or on the
            // same page.
            Image img = Image.create(doc.getSDFDoc(), (input_path + "peppers.jpg"));

            element = eb.createImage(img, new Matrix2D(img.getImageWidth() / 2, -145, 20, img.getImageHeight() / 2, 200, 150));
            writer.writePlacedElement(element);

            gstate = element.getGState();    // use the same image (just
            // change its matrix)
            gstate.setTransform(200, 0, 0, 300, 50, 450);
            writer.writePlacedElement(element);

            // use the same image again (just change its matrix).
            writer.writePlacedElement(eb.createImage(img, 300, 600, 200, -150));

            writer.end();  // save changes to the current page
            doc.pagePushBack(page);

            // Start a new page ------------------------------------
            // Construct and draw a path object using different styles
            page = doc.pageCreate(new Rect(0, 0, 612, 794));

            writer.begin(page);    // begin writing to this page
            eb.reset();            // Reset the GState to default

            eb.pathBegin();        // start constructing the path
            eb.moveTo(306, 396);
            eb.curveTo(681, 771, 399.75, 864.75, 306, 771);
            eb.curveTo(212.25, 864.75, -69, 771, 306, 396);
            eb.closePath();
            element = eb.pathEnd();            // the path is now finished
            element.setPathFill(true);        // the path should be filled

            // Set the path color space and color
            gstate = element.getGState();
            gstate.setFillColorSpace(ColorSpace.createDeviceCMYK());
            gstate.setFillColor(new ColorPt(1, 0, 0, 0));  // cyan
            gstate.setTransform(0.5, 0, 0, 0.5, -20, 300);
            writer.writePlacedElement(element);

            // Draw the same path using a different stroke color
            element.setPathStroke(true);        // this path is should be
            // filled and stroked
            gstate.setFillColor(new ColorPt(0, 0, 1, 0));  // yellow
            gstate.setStrokeColorSpace(ColorSpace.createDeviceRGB());
            gstate.setStrokeColor(new ColorPt(1, 0, 0));  // red
            gstate.setTransform(0.5, 0, 0, 0.5, 280, 300);
            gstate.setLineWidth(20);
            writer.writePlacedElement(element);

            // Draw the same path with with a given dash pattern
            element.setPathFill(false);    // this path is should be only
            // stroked
            gstate.setStrokeColor(new ColorPt(0, 0, 1));  // blue
            gstate.setTransform(0.5, 0, 0, 0.5, 280, 0);
            double[] dash_pattern = {30};
            gstate.setDashPattern(dash_pattern, 0);
            writer.writePlacedElement(element);

            // Use the path as a clipping path
            writer.writeElement(eb.createGroupBegin());    // Save the graphics
            // state
            // Start constructing the new path (the old path was lost when
            // we created
            // a new Element using CreateGroupBegin()).
            eb.pathBegin();
            eb.moveTo(306, 396);
            eb.curveTo(681, 771, 399.75, 864.75, 306, 771);
            eb.curveTo(212.25, 864.75, -69, 771, 306, 396);
            eb.closePath();
            element = eb.pathEnd();    // path is now constructed
            element.setPathClip(true);    // this path is a clipping path
            element.setPathStroke(true);        // this path should be
            // filled and stroked
            gstate = element.getGState();
            gstate.setTransform(0.5, 0, 0, 0.5, -20, 0);

            writer.writeElement(element);

            writer.writeElement(eb.createImage(img, 100, 300, 400, 600));

            writer.writeElement(eb.createGroupEnd());    // Restore the
            // graphics state

            writer.end();  // save changes to the current page
            doc.pagePushBack(page);


            // Start a new page ------------------------------------
            page = doc.pageCreate(new Rect(0, 0, 612, 794));

            writer.begin(page);    // begin writing to this page
            eb.reset();            // Reset the GState to default

            // Begin writing a block of text
            element = eb.createTextBegin(Font.create(doc, Font.e_times_roman), 12);
            writer.writeElement(element);

            element = eb.createTextRun("Hello World!");
            element.setTextMatrix(10, 0, 0, 10, 0, 600);
            element.getGState().setLeading(15);         // Set the spacing
            // between lines
            writer.writeElement(element);

            writer.writeElement(eb.createTextNewLine());  // New line

            element = eb.createTextRun("Hello World!");
            gstate = element.getGState();
            gstate.setTextRenderMode(GState.e_stroke_text);
            gstate.setCharSpacing(-1.25);
            gstate.setWordSpacing(-1.25);
            writer.writeElement(element);

            writer.writeElement(eb.createTextNewLine());  // New line

            element = eb.createTextRun("Hello World!");
            gstate = element.getGState();
            gstate.setCharSpacing(0);
            gstate.setWordSpacing(0);
            gstate.setLineWidth(3);
            gstate.setTextRenderMode(GState.e_fill_stroke_text);
            gstate.setStrokeColorSpace(ColorSpace.createDeviceRGB());
            gstate.setStrokeColor(new ColorPt(1, 0, 0));    // red
            gstate.setFillColorSpace(ColorSpace.createDeviceCMYK());
            gstate.setFillColor(new ColorPt(1, 0, 0, 0));    // cyan
            writer.writeElement(element);


            writer.writeElement(eb.createTextNewLine());  // New line

            // Set text as a clipping path to the image.
            element = eb.createTextRun("Hello World!");
            gstate = element.getGState();
            gstate.setTextRenderMode(GState.e_clip_text);
            writer.writeElement(element);

            // Finish the block of text
            writer.writeElement(eb.createTextEnd());

            // Draw an image that will be clipped by the above text
            writer.writeElement(eb.createImage(img, 10, 100, 1300, 720));

            writer.end();  // save changes to the current page
            doc.pagePushBack(page);

            // Start a new page ------------------------------------
            //
            // The example illustrates how to embed the external font in a
            // PDF document.
            // The example also shows how ElementReader can be used to copy
            // and modify
            // Elements between pages.

            ElementReader reader = new ElementReader();

            // Start reading Elements from the last page. We will copy all
            // Elements to
            // a new page but will modify the font associated with text.
            reader.begin((doc.getPage(doc.getPageCount())));

            page = doc.pageCreate(new Rect(0, 0, 1300, 794));

            writer.begin(page);    // begin writing to this page
            eb.reset();        // Reset the GState to default

            // Embed an external font in the document.
            Font font;
            File file = new File(input_path, "font.ttf");
            InputStream stream = new FileInputStream(file);
            font = Font.createTrueTypeFont(doc, stream);
            //Alternatively, the font can be created from the file path.
            //font = Font.createTrueTypeFont(doc, (input_path + "font.ttf"));

            while ((element = reader.next()) != null)    // Read page
            // contents
            {
                if (element.getType() == Element.e_text) {
                    element.getGState().setFont(font, 12);
                }

                writer.writeElement(element);
            }

            reader.end();
            writer.end();  // save changes to the current page

            doc.pagePushBack(page);


            // Start a new page ------------------------------------
            //
            // The example illustrates how to embed the external font in a
            // PDF document.
            // The example also shows how ElementReader can be used to copy
            // and modify
            // Elements between pages.

            // Start reading Elements from the last page. We will copy all
            // Elements to
            // a new page but will modify the font associated with text.
            reader.begin(((doc.getPage(doc.getPageCount()))));

            page = doc.pageCreate(new Rect(0, 0, 1300, 794));

            writer.begin(page);    // begin writing to this page
            eb.reset();        // Reset the GState to default

            // Embed an external font in the document.
            Font font2 = Font.createType1Font(doc, (input_path + "Misc-Fixed.pfa"));

            while ((element = reader.next()) != null)    // Read page contents
            {
                if (element.getType() == Element.e_text) {
                    element.getGState().setFont(font2, 12);
                }

                writer.writeElement(element);
            }

            reader.end();
            writer.end();  // save changes to the current page
            doc.pagePushBack(page);


            // Start a new page ------------------------------------
            page = doc.pageCreate();
            writer.begin(page);    // begin writing to this page
            eb.reset();            // Reset the GState to default

            // Begin writing a block of text
            element = eb.createTextBegin(Font.create(doc, Font.e_times_roman), 12);
            element.setTextMatrix(1.5, 0, 0, 1.5, 50, 600);
            element.getGState().setLeading(15);    // Set the spacing between
            // lines
            writer.writeElement(element);

            String para = "A PDF text object consists of operators that can show " +
                    "text strings, move the text position, and set text state and certain " +
                    "other parameters. In addition, there are three parameters that are " +
                    "defined only within a text object and do not persist from one text " +
                    "object to the next: Tm, the text matrix, Tlm, the text line matrix, " +
                    "Trm, the text rendering matrix, actually just an intermediate result " +
                    "that combines the effects of text state parameters, the text matrix " +
                    "(Tm), and the current transformation matrix";

            int para_end = para.length();
            int text_run = 0;
            int text_run_end;

            double para_width = 300; // paragraph width is 300 units
            double cur_width = 0;

            while (text_run < para_end) {
                text_run_end = para.indexOf(' ', text_run);
                if (text_run_end < 0)
                    text_run_end = para_end - 1;

                String text = para.substring(text_run, text_run_end + 1);
                element = eb.createTextRun(text);
                if (cur_width + element.getTextLength() < para_width) {
                    writer.writeElement(element);
                    cur_width += element.getTextLength();
                } else {
                    writer.writeElement(eb.createTextNewLine());  // New
                    text = para.substring(text_run, text_run_end + 1);                                            // line
                    element = eb.createTextRun(text);
                    cur_width = element.getTextLength();
                    writer.writeElement(element);
                }

                text_run = text_run_end + 1;
            }

            // -----------------------------------------------------------------------
            // The following code snippet illustrates how to adjust
            // spacing between
            // characters (text runs).
            element = eb.createTextNewLine();
            writer.writeElement(element);  // Skip 2 lines
            writer.writeElement(element);

            writer.writeElement(eb.createTextRun("An example of space adjustments between inter-characters:"));
            writer.writeElement(eb.createTextNewLine());

            // Write string "AWAY" without space adjustments between
            // characters.
            element = eb.createTextRun("AWAY");
            writer.writeElement(element);

            writer.writeElement(eb.createTextNewLine());

            // Write string "AWAY" with space adjustments between
            // characters.
            element = eb.createTextRun("A");
            writer.writeElement(element);

            element = eb.createTextRun("W");
            element.setPosAdjustment(140);
            writer.writeElement(element);

            element = eb.createTextRun("A");
            element.setPosAdjustment(140);
            writer.writeElement(element);

            element = eb.createTextRun("Y again");
            element.setPosAdjustment(115);
            writer.writeElement(element);

            // Draw the same strings using direct content output...
            writer.flush();  // flush pending Element writing operations.

            // You can also write page content directly to the content
            // stream using
            // ElementWriter.WriteString(...) and
            // ElementWriter.WriteBuffer(...) methods.
            // Note that if you are planning to use these functions you need
            // to be familiar
            // with PDF page content operators (see Appendix A in PDF
            // Reference Manual).
            // Because it is easy to make mistakes during direct output we
            // recommend that
            // you use ElementBuilder and Element interface instead.

            writer.writeString("T* T* "); // Skip 2 lines
            writer.writeString("(Direct output to PDF page content stream:) Tj  T* ");
            writer.writeString("(AWAY) Tj T* ");
            writer.writeString("[(A)140(W)140(A)115(Y again)] TJ ");

            // Finish the block of text
            writer.writeElement(eb.createTextEnd());

            writer.end();  // save changes to the current page
            doc.pagePushBack(page);

            // Start a new page ------------------------------------

            // Image Masks
            //
            // In the opaque imaging model, images mark all areas they
            // occupy on the page as
            // if with opaque paint. All portions of the image, whether
            // black, white, gray,
            // or color, completely obscure any marks that may previously
            // have existed in the
            // same place on the page.
            // In the graphic arts industry and page layout applications,
            // however, it is common
            // to crop or 'mask out' the background of an image and then
            // place the masked image
            // on a different background, allowing the existing background
            // to show through the
            // masked areas. This sample illustrates how to use image masks.

            page = doc.pageCreate();
            writer.begin(page);    // begin writing to the page

            // Create the Image Mask
            MappedFile imgf=new MappedFile(input_path + "imagemask.dat");
            com.pdftron.filters.FilterReader mask_read=new com.pdftron.filters.FilterReader(imgf);

            ColorSpace device_gray = ColorSpace.createDeviceGray();
            Image mask = Image.create(doc, mask_read, 64, 64, 1, device_gray, Image.e_ascii_hex);
            
            mask.getSDFObj().putBool("ImageMask", true);

            element = eb.createRect(0, 0, 612, 794);
            element.setPathStroke(false);
            element.setPathFill(true);
            element.getGState().setFillColorSpace(device_gray);
            element.getGState().setFillColor(new ColorPt(0.8,0,0));
            writer.writePlacedElement(element);

            element = eb.createImage(mask, new Matrix2D(200, 0, 0, -200, 40, 680));
            element.getGState().setFillColor(new ColorPt(0.1,0,0));
            writer.writePlacedElement(element);

            element.getGState().setFillColorSpace(ColorSpace.createDeviceRGB());
            element.getGState().setFillColor(new ColorPt(1, 0, 0));
            element = eb.createImage(mask, new Matrix2D(200, 0, 0, -200, 320, 680));
            writer.writePlacedElement(element);

            element.getGState().setFillColor(new ColorPt(0, 1, 0));
            element = eb.createImage(mask, new Matrix2D(200, 0, 0, -200, 40, 380));
            writer.writePlacedElement(element);

            {
                // This sample illustrates Explicit Masking.
                img = Image.create(doc, (input_path + "peppers.jpg"));

                // mask is the explicit mask for the primary (base) image
                img.setMask(mask);

                element = eb.createImage(img, new Matrix2D(200, 0, 0, -200, 320, 380));
                writer.writePlacedElement(element);
            }

            writer.end();  // save changes to the current page
            doc.pagePushBack(page);

            // Transparency sample ----------------------------------

            // Start a new page -------------------------------------
            page = doc.pageCreate();
            writer.begin(page);    // begin writing to this page
            eb.reset();            // Reset the GState to default

            // Write some transparent text at the bottom of the page.
            element = eb.createTextBegin(Font.create(doc, Font.e_times_roman), 100);

            // Set the text knockout attribute. Text knockout must be set
            // outside of
            // the text group.
            gstate = element.getGState();
            gstate.setTextKnockout(false);
            gstate.setBlendMode(GState.e_bl_difference);
            writer.writeElement(element);

            element = eb.createTextRun("Transparency");
            element.setTextMatrix(1, 0, 0, 1, 30, 30);
            gstate = element.getGState();
            gstate.setFillColorSpace(ColorSpace.createDeviceCMYK());
            gstate.setFillColor(new ColorPt(1, 0, 0, 0));

            gstate.setFillOpacity(0.5);
            writer.writeElement(element);

            // Write the same text on top the old; shifted by 3 points
            element.setTextMatrix(1, 0, 0, 1, 33, 33);
            gstate.setFillColor(new ColorPt(0, 1, 0, 0));
            gstate.setFillOpacity(0.5);

            writer.writeElement(element);
            writer.writeElement(eb.createTextEnd());

            // Draw three overlapping transparent circles.
            eb.pathBegin();        // start constructing the path
            eb.moveTo(459.223, 505.646);
            eb.curveTo(459.223, 415.841, 389.85, 343.04, 304.273, 343.04);
            eb.curveTo(218.697, 343.04, 149.324, 415.841, 149.324, 505.646);
            eb.curveTo(149.324, 595.45, 218.697, 668.25, 304.273, 668.25);
            eb.curveTo(389.85, 668.25, 459.223, 595.45, 459.223, 505.646);
            element = eb.pathEnd();
            element.setPathFill(true);

            gstate = element.getGState();
            gstate.setFillColorSpace(ColorSpace.createDeviceRGB());
            gstate.setFillColor(new ColorPt(0, 0, 1));                     // Blue
            // Circle

            gstate.setBlendMode(GState.e_bl_normal);
            gstate.setFillOpacity(0.5);
            writer.writeElement(element);

            // Translate relative to the Blue Circle
            gstate.setTransform(1, 0, 0, 1, 113, -185);
            gstate.setFillColor(new ColorPt(0, 1, 0));                     // Green
            // Circle
            gstate.setFillOpacity(0.5);
            writer.writeElement(element);

            // Translate relative to the Green Circle
            gstate.setTransform(1, 0, 0, 1, -220, 0);
            gstate.setFillColor(new ColorPt(1, 0, 0));                     // Red
            // Circle
            gstate.setFillOpacity(0.5);
            writer.writeElement(element);

            writer.end();  // save changes to the current page
            doc.pagePushBack(page);

            // End page ------------------------------------

            doc.save((output_path + "element_builder.pdf"), SDFDoc.SaveMode.REMOVE_UNUSED, null);
            // output PDF doc
            doc.close();
            System.out.println("Done. Result saved in element_builder.pdf...");
        } catch (Exception e) {
            e.printStackTrace();
        }

        PDFNet.terminate();
    }
}