iText实战--根据绝对位置添加内容

3.1 direct content 概念简介

pdf内容的4个层级

层级1：在text和graphics底下，PdfWriter.getDirectContentUnder()

层级2：graphics层，Chunk, Images背景，PdfPCell的边界等

层级3：text层，Chunks, Phrases, Paragraphs 内容等

层级4：在text和graphics顶上，PdfWriter.getDirectContent()

import java.io.FileOutputStream;
import java.io.IOException;import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Element;
import com.itextpdf.text.Font;
import com.itextpdf.text.Image;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.Font.FontFamily;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfWriter;public class FestivalOpening {/** The resulting PDF. */public static final String RESULT= "D:/data/iText/inAction/chapter03/festival_opening.pdf";/** The movie poster. */public static final String RESOURCE = "E:/study/PDF/SourceCodeiText/itext-book/book/resources/img/loa.jpg";/*** Main method.* @param    args    no arguments needed* @throws DocumentException * @throws IOException*/public static void main(String[] args)throws IOException, DocumentException {// step 1Document document = new Document(PageSize.POSTCARD, 30, 30, 30, 30);// step 2PdfWriter writer= PdfWriter.getInstance(document, new FileOutputStream(RESULT));// step 3document.open();// step 4// Create and add a ParagraphParagraph p= new Paragraph("Foobar Film Festival", new Font(FontFamily.HELVETICA, 22));p.setAlignment(Element.ALIGN_CENTER);document.add(p);// Create and add an ImageImage img = Image.getInstance(RESOURCE);img.setAbsolutePosition((PageSize.POSTCARD.getWidth() - img.getScaledWidth()) / 2,(PageSize.POSTCARD.getHeight() - img.getScaledHeight()) / 2);document.add(img);// Now we go to the next pagedocument.newPage();document.add(p);document.add(img);// Add text on top of the imagePdfContentByte over = writer.getDirectContent();over.saveState();float sinus = (float)Math.sin(Math.PI / 60);float cosinus = (float)Math.cos(Math.PI / 60);BaseFont bf = BaseFont.createFont();over.beginText();over.setTextRenderingMode(PdfContentByte.TEXT_RENDER_MODE_FILL_STROKE);over.setLineWidth(1.5f);over.setRGBColorStroke(0xFF, 0x00, 0x00);over.setRGBColorFill(0xFF, 0xFF, 0xFF);over.setFontAndSize(bf, 36);over.setTextMatrix(cosinus, sinus, -sinus, cosinus, 50, 324);over.showText("SOLD OUT");over.endText();over.restoreState();// Add a rectangle under the imagePdfContentByte under = writer.getDirectContentUnder();under.saveState();under.setRGBColorFill(0xFF, 0xD7, 0x00);under.rectangle(5, 5,PageSize.POSTCARD.getWidth() - 10, PageSize.POSTCARD.getHeight() - 10);under.fill();under.restoreState();// step 5document.close();}
}

Graphics 状态

1、fill()填充四方形，并根据setRGBColorFill()填充，默认无边框

2、fillStroke()填充四方形，并根据setLineWidth()和默认black画边框

3、setRGBColorStroke() 设置边框颜色

4、current transformation matrix（CTM）当前转换矩阵

5、stroke() 仅画边框

6、saveState/rrestoreState 对应入栈、出栈

import java.io.FileOutputStream;
import java.io.IOException;import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Rectangle;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfWriter;public class GraphicsStateStack {/** The resulting PDF. */public static final String RESULT= "D:/data/iText/inAction/chapter03/graphics_state.pdf";/*** Main method.** @param    args    no arguments needed* @throws DocumentException * @throws IOException*/public static void main(String[] args)throws IOException, DocumentException {// step 1Document document = new Document(new Rectangle(200, 120));// step 2PdfWriter writer= PdfWriter.getInstance(document, new FileOutputStream(RESULT));// step 3document.open();// step 4PdfContentByte canvas = writer.getDirectContent();// state 1:canvas.setRGBColorFill(0xFF, 0x45, 0x00);// fill a rectangle in state 1canvas.rectangle(10, 10, 60, 60);canvas.fill();canvas.saveState();// state 2;canvas.setLineWidth(3);canvas.setRGBColorFill(0x8B, 0x00, 0x00);// fill and stroke a rectangle in state 2canvas.rectangle(40, 20, 60, 60);canvas.fillStroke();canvas.saveState();// state 3:canvas.concatCTM(1, 0, 0.1f, 1, 0, 0);canvas.setRGBColorStroke(0xFF, 0x45, 0x00);canvas.setRGBColorFill(0xFF, 0xD7, 0x00);// fill and stroke a rectangle in state 3canvas.rectangle(70, 30, 60, 60);canvas.fillStroke();canvas.restoreState();// stroke a rectangle in state 2canvas.rectangle(100, 40, 60, 60);canvas.stroke();canvas.restoreState();// fill and stroke a rectangle in state 1canvas.rectangle(130, 50, 60, 60);canvas.fillStroke();// step 5document.close();}
}

Text 状态

1、showText()，设置显示的文本

2、setTextRenderingMode()设置边框模式，setLineWidth()设置边框宽度，默认无边框

3、setFontAndSize() 设置字体和大小

4、setTextMatrix() 设置字体矩阵

5、setRGBColorStoke() 设置边框颜色

6、setRGBColorFill() 设置填充颜色

3.2 根据绝对定位添加Text

PdfContentByte.showTextAligned（）

测量字符串

        Chunk c;String foobar = "Foobar Film Festival";// Measuring a String in HelveticaFont helvetica = new Font(FontFamily.HELVETICA, 12);BaseFont bf_helv = helvetica.getCalculatedBaseFont(false);float width_helv = bf_helv.getWidthPoint(foobar, 12);c = new Chunk(foobar + ": " + width_helv, helvetica);document.add(new Paragraph(c));document.add(new Paragraph(String.format("Chunk width: %f", c.getWidthPoint())));// Measuring a String in TimesBaseFont bf_times = BaseFont.createFont("c:/windows/fonts/times.ttf", BaseFont.WINANSI, BaseFont.EMBEDDED);Font times = new Font(bf_times, 12);float width_times = bf_times.getWidthPoint(foobar, 12);c = new Chunk(foobar + ": " + width_times, times);document.add(new Paragraph(c));document.add(new Paragraph(String.format("Chunk width: %f", c.getWidthPoint())));document.add(Chunk.NEWLINE);

字符串上行空间和下行空间

注意：字体大小不是某个字符的高度，而是一行的垂直空间

        // Ascent and descent of the Stringdocument.add(new Paragraph("Ascent Helvetica: "+ bf_helv.getAscentPoint(foobar, 12)));document.add(new Paragraph("Ascent Times: "+ bf_times.getAscentPoint(foobar, 12)));document.add(new Paragraph("Descent Helvetica: "+ bf_helv.getDescentPoint(foobar, 12)));document.add(new Paragraph("Descent Times: "+ bf_times.getDescentPoint(foobar, 12)));

字符串定位

        PdfContentByte canvas = writer.getDirectContent();        // Adding text with PdfContentByte.showTextAligned()canvas.beginText();canvas.setFontAndSize(bf_helv, 12);canvas.showTextAligned(Element.ALIGN_LEFT, foobar, 400, 788, 0);canvas.showTextAligned(Element.ALIGN_RIGHT, foobar, 400, 752, 0);canvas.showTextAligned(Element.ALIGN_CENTER, foobar, 400, 716, 0);canvas.showTextAligned(Element.ALIGN_CENTER, foobar, 400, 680, 30);canvas.showTextAlignedKerned(Element.ALIGN_LEFT, foobar, 400, 644, 0);canvas.endText();

字距调整（KERNING ）

        // Kerned textwidth_helv = bf_helv.getWidthPointKerned(foobar, 12);c = new Chunk(foobar + ": " + width_helv, helvetica);document.add(new Paragraph(c));

ColumnText.showTextAligned()

        // Adding text with ColumnText.showTextAligned()Phrase phrase = new Phrase(foobar, times);ColumnText.showTextAligned(canvas, Element.ALIGN_LEFT, phrase, 200, 572, 0);ColumnText.showTextAligned(canvas, Element.ALIGN_RIGHT, phrase, 200, 536, 0);ColumnText.showTextAligned(canvas, Element.ALIGN_CENTER, phrase, 200, 500, 0);ColumnText.showTextAligned(canvas, Element.ALIGN_CENTER, phrase, 200, 464, 30);ColumnText.showTextAligned(canvas, Element.ALIGN_CENTER, phrase, 200, 428, -30);

短句（Phrase）定位

一个短句（Phrase）能够包含一系列的块（Chunk）。添加短句（Phrase）到绝对定位，可以方便地选择字体、字号和颜色，iText会自动计算短句（Phrase）内每个块（Chunk）的间距。

块：缩放、倾斜、渲染模式（Chunks: Scaling、Skewing、Rendering Mode）

1、setScaling(float scale) 设置缩放比例

2、setSkew(float arg1, float arg2) 设置倾斜，arg1：基线的角度，arg2：字符对基线的角度

3、setTextRenderMode() 设置文本渲染模式

PdfContentByte.TEXT_RENDER_MODE_FILL，默认填充字符形状，无边框

PdfContentByte.TEXT_RENDER_MODE_STROKE，不填充字符，仅边框

PdfContentByte.TEXT_RENDER_MODE_FILL_STROKE，填充字符，带边框

PdfContentByte.TEXT_RENDER_MODE_INVISIBLE，文本不可见

        // Chunk attributesc = new Chunk(foobar, times);c.setHorizontalScaling(0.5f);phrase = new Phrase(c);ColumnText.showTextAligned(canvas, Element.ALIGN_LEFT, phrase, 400, 572, 0);c = new Chunk(foobar, times);c.setSkew(15, 15);phrase = new Phrase(c);ColumnText.showTextAligned(canvas, Element.ALIGN_LEFT, phrase, 400, 536, 0);c = new Chunk(foobar, times);c.setSkew(0, 25);phrase = new Phrase(c);ColumnText.showTextAligned(canvas, Element.ALIGN_LEFT, phrase, 400, 500, 0);c = new Chunk(foobar, times);c.setTextRenderMode(PdfContentByte.TEXT_RENDER_MODE_STROKE, 0.1f, BaseColor.RED);phrase = new Phrase(c);ColumnText.showTextAligned(canvas, Element.ALIGN_LEFT, phrase, 400, 464, 0);c = new Chunk(foobar, times);c.setTextRenderMode(PdfContentByte.TEXT_RENDER_MODE_FILL_STROKE, 1, null);phrase = new Phrase(c);ColumnText.showTextAligned(canvas, Element.ALIGN_LEFT, phrase, 400, 428, -0);

完整示例

import java.io.FileOutputStream;
import java.io.IOException;import com.itextpdf.text.Chunk;
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Element;
import com.itextpdf.text.Font;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.Phrase;
import com.itextpdf.text.Font.FontFamily;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.pdf.ColumnText;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfWriter;
import com.itextpdf.text.BaseColor;public class FoobarFilmFestival {public static final String RESULT= "D:/data/iText/inAction/chapter03/foobar_film_festival.pdf";/*** Main method.** @param    args    no arguments needed* @throws DocumentException * @throws IOException*/public static void main(String[] args)throws IOException, DocumentException {// step 1Document document = new Document();// step 2PdfWriter writer= PdfWriter.getInstance(document, new FileOutputStream(RESULT));// step 3document.open();// step 4Chunk c;String foobar = "Foobar Film Festival";// Measuring a String in HelveticaFont helvetica = new Font(FontFamily.HELVETICA, 12);BaseFont bf_helv = helvetica.getCalculatedBaseFont(false);float width_helv = bf_helv.getWidthPoint(foobar, 12);c = new Chunk(foobar + ": " + width_helv, helvetica);document.add(new Paragraph(c));document.add(new Paragraph(String.format("Chunk width: %f", c.getWidthPoint())));// Measuring a String in TimesBaseFont bf_times = BaseFont.createFont("c:/windows/fonts/times.ttf", BaseFont.WINANSI, BaseFont.EMBEDDED);Font times = new Font(bf_times, 12);float width_times = bf_times.getWidthPoint(foobar, 12);c = new Chunk(foobar + ": " + width_times, times);document.add(new Paragraph(c));document.add(new Paragraph(String.format("Chunk width: %f", c.getWidthPoint())));document.add(Chunk.NEWLINE);// Ascent and descent of the Stringdocument.add(new Paragraph("Ascent Helvetica: "+ bf_helv.getAscentPoint(foobar, 12)));document.add(new Paragraph("Ascent Times: "+ bf_times.getAscentPoint(foobar, 12)));document.add(new Paragraph("Descent Helvetica: "+ bf_helv.getDescentPoint(foobar, 12)));document.add(new Paragraph("Descent Times: "+ bf_times.getDescentPoint(foobar, 12)));document.add(Chunk.NEWLINE);// Kerned textwidth_helv = bf_helv.getWidthPointKerned(foobar, 12);c = new Chunk(foobar + ": " + width_helv, helvetica);document.add(new Paragraph(c));// Drawing lines to see where the text is addedPdfContentByte canvas = writer.getDirectContent();canvas.saveState();canvas.setLineWidth(0.05f);canvas.moveTo(400, 806);canvas.lineTo(400, 626);canvas.moveTo(508.7f, 806);canvas.lineTo(508.7f, 626);canvas.moveTo(280, 788);canvas.lineTo(520, 788);canvas.moveTo(280, 752);canvas.lineTo(520, 752);canvas.moveTo(280, 716);canvas.lineTo(520, 716);canvas.moveTo(280, 680);canvas.lineTo(520, 680);canvas.moveTo(280, 644);canvas.lineTo(520, 644);canvas.stroke();canvas.restoreState();// Adding text with PdfContentByte.showTextAligned()canvas.beginText();canvas.setFontAndSize(bf_helv, 12);canvas.showTextAligned(Element.ALIGN_LEFT, foobar, 400, 788, 0);canvas.showTextAligned(Element.ALIGN_RIGHT, foobar, 400, 752, 0);canvas.showTextAligned(Element.ALIGN_CENTER, foobar, 400, 716, 0);canvas.showTextAligned(Element.ALIGN_CENTER, foobar, 400, 680, 30);canvas.showTextAlignedKerned(Element.ALIGN_LEFT, foobar, 400, 644, 0);canvas.endText();// More lines to see where the text is addedcanvas.saveState();canvas.setLineWidth(0.05f);canvas.moveTo(200, 590);canvas.lineTo(200, 410);canvas.moveTo(400, 590);canvas.lineTo(400, 410);canvas.moveTo(80, 572);canvas.lineTo(520, 572);canvas.moveTo(80, 536);canvas.lineTo(520, 536);canvas.moveTo(80, 500);canvas.lineTo(520, 500);canvas.moveTo(80, 464);canvas.lineTo(520, 464);canvas.moveTo(80, 428);canvas.lineTo(520, 428);canvas.stroke();canvas.restoreState();// Adding text with ColumnText.showTextAligned()Phrase phrase = new Phrase(foobar, times);ColumnText.showTextAligned(canvas, Element.ALIGN_LEFT, phrase, 200, 572, 0);ColumnText.showTextAligned(canvas, Element.ALIGN_RIGHT, phrase, 200, 536, 0);ColumnText.showTextAligned(canvas, Element.ALIGN_CENTER, phrase, 200, 500, 0);ColumnText.showTextAligned(canvas, Element.ALIGN_CENTER, phrase, 200, 464, 30);ColumnText.showTextAligned(canvas, Element.ALIGN_CENTER, phrase, 200, 428, -30);// Chunk attributesc = new Chunk(foobar, times);c.setHorizontalScaling(0.5f);phrase = new Phrase(c);ColumnText.showTextAligned(canvas, Element.ALIGN_LEFT, phrase, 400, 572, 0);c = new Chunk(foobar, times);c.setSkew(15, 15);phrase = new Phrase(c);ColumnText.showTextAligned(canvas, Element.ALIGN_LEFT, phrase, 400, 536, 0);c = new Chunk(foobar, times);c.setSkew(0, 25);phrase = new Phrase(c);ColumnText.showTextAligned(canvas, Element.ALIGN_LEFT, phrase, 400, 500, 0);c = new Chunk(foobar, times);c.setTextRenderMode(PdfContentByte.TEXT_RENDER_MODE_STROKE, 0.1f, BaseColor.RED);phrase = new Phrase(c);ColumnText.showTextAligned(canvas, Element.ALIGN_LEFT, phrase, 400, 464, 0);c = new Chunk(foobar, times);c.setTextRenderMode(PdfContentByte.TEXT_RENDER_MODE_FILL_STROKE, 1, null);phrase = new Phrase(c);ColumnText.showTextAligned(canvas, Element.ALIGN_LEFT, phrase, 400, 428, -0);// step 5document.close();}
}

3.3 使用ColumnText对象

在文本模式下使用ColumnText

在复合模式中使用ColumnText

3.4 创建可重复使用的内容

如何在文档重复添加image？PDF图片的字节存储在单独区域，页面包含一个图片的引用，指向external object（XObject）

Image XObjects

添加图片到顶层

顶层的图片遮盖住文本：Foobar Film Festival

import java.io.FileOutputStream;
import java.io.IOException;import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Element;
import com.itextpdf.text.Font;
import com.itextpdf.text.Image;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.Font.FontFamily;
import com.itextpdf.text.pdf.PdfWriter;public class ImageDirect {/** The resulting PDF. */public static final String RESULT= "D:/data/iText/inAction/chapter03/image_direct.pdf";/** The movie poster. */public static final String RESOURCE= "E:/study/PDF/SourceCodeiText/itext-book/book/resources/img/loa.jpg";public static void main(String[] args)throws IOException, DocumentException {// step 1Document document= new Document(PageSize.POSTCARD, 30, 30, 30, 30);// step 2PdfWriter writer= PdfWriter.getInstance(document, new FileOutputStream(RESULT));writer.setCompressionLevel(0);// step 3document.open();// step 4Image img = Image.getInstance(RESOURCE);img.setAbsolutePosition((PageSize.POSTCARD.getWidth() - img.getScaledWidth()) / 2,(PageSize.POSTCARD.getHeight() - img.getScaledHeight()) / 2);writer.getDirectContent().addImage(img);Paragraph p = new Paragraph("Foobar Film Festival", new Font(FontFamily.HELVETICA, 22));p.setAlignment(Element.ALIGN_CENTER);document.add(p);// step 5document.close();}
}

倾斜图片

import java.io.FileOutputStream;
import java.io.IOException;import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Image;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.pdf.PdfWriter;public class ImageSkew {/** The resulting PDF. */public static final String RESULT = "D:/data/iText/inAction/chapter03/image_skew.pdf";/** The movie poster. */public static final String RESOURCE = "E:/study/PDF/SourceCodeiText/itext-book/book/resources/img/loa.jpg";/*** Main method.** @param    args    no arguments needed* @throws DocumentException * @throws IOException*/public static void main(String[] args)throws IOException, DocumentException {// step 1Document document = new Document(PageSize.POSTCARD.rotate());// step 2PdfWriter writer = PdfWriter.getInstance(document,new FileOutputStream(RESULT));writer.setCompressionLevel(0);// step 3document.open();// step 4Image img = Image.getInstance(RESOURCE);// Add the image to the upper layerwriter.getDirectContent().addImage(img,img.getWidth(), 0, 0.35f * img.getHeight(),0.65f * img.getHeight(), 30, 30);// step 5document.close();}
}

内嵌图片

PdfWriter.getDirectContent().addImage(img, true)

import java.io.FileOutputStream;
import java.io.IOException;import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Image;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.pdf.PdfWriter;public class ImageInline {/** The resulting PDF. */public static final String RESULT= "D:/data/iText/inAction/chapter03/image_inline.pdf";/** The movie poster. */public static final String RESOURCE= "E:/study/PDF/SourceCodeiText/itext-book/book/resources/img/loa.jpg";/*** Main method.** @param    args    no arguments needed* @throws DocumentException * @throws IOException*/public static void main(String[] args)throws IOException, DocumentException {// step 1Document document = new Document(PageSize.POSTCARD, 30, 30, 30, 30);// step 2PdfWriter writer = PdfWriter.getInstance(document,new FileOutputStream(RESULT));writer.setCompressionLevel(0);// step 3document.open();// step 4Image img = Image.getInstance(RESOURCE);img.setAbsolutePosition((PageSize.POSTCARD.getWidth() - img.getScaledWidth()) / 2,(PageSize.POSTCARD.getHeight() - img.getScaledHeight()) / 2);writer.getDirectContent().addImage(img, true);// step 5document.close();}
}

PdfTemplate 对象

PdfTemplate：XObject的别称

PdfTemplate是一个PDF内容流，它是任何图形对象的序列。PdfTemplate扩展PdfContentByte并继承所有其方法。

        PdfContentByte canvas = writer.getDirectContent();// Create the XObjectPdfTemplate celluloid = canvas.createTemplate(595, 84.2f);celluloid.rectangle(8, 8, 579, 68);for (float f = 8.25f; f < 581; f+= 6.5f) {celluloid.roundRectangle(f, 8.5f, 6, 3, 1.5f);celluloid.roundRectangle(f, 72.5f, 6, 3, 1.5f);}celluloid.setGrayFill(0.1f);celluloid.eoFill();// Write the XObject to the OutputStreamwriter.releaseTemplate(celluloid);// Add the XObject 10 timesfor (int i = 0; i < 10; i++) {canvas.addTemplate(celluloid, 0, i * 84.2f);}// Go to the next pagedocument.newPage();// Add the XObject 10 timesfor (int i = 0; i < 10; i++) {canvas.addTemplate(celluloid, 0, i * 84.2f);}