/*
* Copyright 2008 by Kevin Day.
*
* The contents of this file are subject to the Mozilla Public License Version 1.1
* (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the License.
*
* The Original Code is 'iText, a free JAVA-PDF library'.
*
* The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
* the Initial Developer are Copyright (C) 1999-2008 by Bruno Lowagie.
* All Rights Reserved.
* Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
* are Copyright (C) 2000-2008 by Paulo Soares. All Rights Reserved.
*
* Contributor(s): all the names of the contributors are added in the source code
* where applicable.
*
* Alternatively, the contents of this file may be used under the terms of the
* LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
* provisions of LGPL are applicable instead of those above. If you wish to
* allow use of your version of this file only under the terms of the LGPL
* License and not to allow others to use your version of this file under
* the MPL, indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by the LGPL.
* If you do not delete the provisions above, a recipient may use your version
* of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the MPL as stated above or under the terms of the GNU
* Library General Public License as published by the Free Software Foundation;
* either version 2 of the License, or any later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Library general Public License for more
* details.
*
* If you didn't download this code from the following link, you should check if
* you aren't using an obsolete version:
* http://www.lowagie.com/iText/
*/
package com.spilowagie.text.pdf.parser;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Stack;
import com.spilowagie.text.ExceptionConverter;
import com.spilowagie.text.pdf.CMapAwareDocumentFont;
import com.spilowagie.text.pdf.DocumentFont;
import com.spilowagie.text.pdf.PRIndirectReference;
import com.spilowagie.text.pdf.PRTokeniser;
import com.spilowagie.text.pdf.PdfArray;
import com.spilowagie.text.pdf.PdfContentParser;
import com.spilowagie.text.pdf.PdfDictionary;
import com.spilowagie.text.pdf.PdfLiteral;
import com.spilowagie.text.pdf.PdfName;
import com.spilowagie.text.pdf.PdfNumber;
import com.spilowagie.text.pdf.PdfString;
/**
* Processor for a PDF content Stream.
* @since 2.1.4
*/
public abstract class PdfContentStreamProcessor {
/** A map with all supported operators operators (PDF syntax). */
private Map operators;
/** Resources for the content stream. */
private PdfDictionary resources;
/** Stack keeping track of the graphics state. */
private Stack gsStack = new Stack();
/** Text matrix. */
private Matrix textMatrix;
/** Text line matrix. */
private Matrix textLineMatrix;
/**
* Creates a new PDF Content Stream Processor.
*/
public PdfContentStreamProcessor() {
populateOperators();
reset();
}
/**
* Loads all the supported graphics and text state operators in a map.
*/
private void populateOperators(){
operators = new LinkedHashMap();
operators.put("q", new PushGraphicsState());
operators.put("Q", new PopGraphicsState());
operators.put("cm", new ModifyCurrentTransformationMatrix());
operators.put("gs", new ProcessGraphicsStateResource());
operators.put("Tc", new SetTextCharacterSpacing());
operators.put("Tw", new SetTextWordSpacing());
operators.put("Tz", new SetTextHorizontalScaling());
operators.put("TL", new SetTextLeading());
operators.put("Tf", new SetTextFont());
operators.put("Tr", new SetTextRenderMode());
operators.put("Ts", new SetTextRise());
operators.put("BT", new BeginText());
operators.put("ET", new EndText());
operators.put("Td", new TextMoveStartNextLine());
operators.put("TD", new TextMoveStartNextLineWithLeading());
operators.put("Tm", new TextSetTextMatrix());
operators.put("T*", new TextMoveNextLine());
operators.put("Tj", new ShowText());
operators.put("'", new MoveNextLineAndShowText());
operators.put("\"", new MoveNextLineAndShowTextWithSpacing());
operators.put("TJ", new ShowTextArray());
}
/**
* Resets the graphics state stack, matrices and resources.
*/
public void reset(){
gsStack.removeAllElements();
gsStack.add(new GraphicsState());
textMatrix = null;
textLineMatrix = null;
resources = null;
}
/**
* Returns the current graphics state.
* @return the graphics state
*/
public GraphicsState gs(){
return (GraphicsState)gsStack.peek();
}
/**
* Returns the current text matrix.
* @return the text matrix
* @since 2.1.5
*/
public Matrix getCurrentTextMatrix(){
return textMatrix;
}
/**
* Returns the current line matrix.
* @return the line matrix
* @since 2.1.5
*/
public Matrix getCurrentTextLineMatrix(){
return textLineMatrix;
}
/**
* Invokes an operator.
* @param operator the PDF Syntax of the operator
* @param operands a list with operands
*/
public void invokeOperator(PdfLiteral operator, ArrayList operands){
ContentOperator op = (ContentOperator)operators.get(operator.toString());
if (op == null){
//System.out.println("Skipping operator " + operator);
return;
}
op.invoke(this, operator, operands);
}
/**
* Decodes a PdfString (which will contain glyph ids encoded in the font's encoding)
* based on the active font, and determine the unicode equivalent
* @param in the String that needs to be encoded
* @return the encoded String
* @since 2.1.7
*/
private String decode(PdfString in){
byte[] bytes = in.getBytes();
return gs().font.decode(bytes, 0, bytes.length);
}
/**
* Displays text.
* @param text the text that needs to be displayed
* @param nextTextMatrix a text matrix
*/
abstract public void displayText(String text, Matrix nextTextMatrix);
/**
* Gets the width of a String.
* @param string the string that needs measuring
* @param tj text adjustment
* @return the width of a String
*/
public float getStringWidth(String string, float tj){
DocumentFont font = gs().font;
char[] chars = string.toCharArray();
float totalWidth = 0;
for (int i = 0; i < chars.length; i++) {
float w = font.getWidth(chars[i]) / 1000.0f;
float wordSpacing = chars[i] == 32 ? gs().wordSpacing : 0f;
totalWidth += ((w - tj/1000f) * gs().fontSize + gs().characterSpacing + wordSpacing) * gs().horizontalScaling;
}
return totalWidth;
}
/**
* Displays text.
* @param string the text to display
* @param tj the text adjustment
*/
public void displayPdfString(PdfString string, float tj){
String unicode = decode(string);
float width = getStringWidth(unicode, tj); // this is width in unscaled units - we have to normalize by the Tm scaling
Matrix nextTextMatrix = new Matrix(width, 0).multiply(textMatrix);
displayText(unicode, nextTextMatrix);
textMatrix = nextTextMatrix;
}
/**
* Processes PDF syntax
* @param contentBytes the bytes of a content stream
* @param resources the resources that come with the content stream
*/
public void processContent(byte[] contentBytes, PdfDictionary resources){
reset();
this.resources = resources;
try {
PdfContentParser ps = new PdfContentParser(new PRTokeniser(contentBytes));
ArrayList operands = new ArrayList();
while (ps.parse(operands).size() > 0){
PdfLiteral operator = (PdfLiteral)operands.get(operands.size()-1);
invokeOperator(operator, operands);
}
}
catch (Exception e) {
throw new ExceptionConverter(e);
}
}
/**
* A content operator implementation (TJ).
*/
private static class ShowTextArray implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
PdfArray array = (PdfArray)operands.get(0);
float tj = 0;
for (Iterator i = array.listIterator(); i.hasNext(); ) {
Object entryObj = i.next();
if (entryObj instanceof PdfString){
processor.displayPdfString((PdfString)entryObj, tj);
tj = 0;
} else {
tj = ((PdfNumber)entryObj).floatValue();
}
}
}
}
/**
* A content operator implementation (").
*/
private static class MoveNextLineAndShowTextWithSpacing implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
PdfNumber aw = (PdfNumber)operands.get(0);
PdfNumber ac = (PdfNumber)operands.get(1);
PdfString string = (PdfString)operands.get(2);
ArrayList twOperands = new ArrayList(1);
twOperands.add(0, aw);
processor.invokeOperator(new PdfLiteral("Tw"), twOperands);
ArrayList tcOperands = new ArrayList(1);
tcOperands.add(0, ac);
processor.invokeOperator(new PdfLiteral("Tc"), tcOperands);
ArrayList tickOperands = new ArrayList(1);
tickOperands.add(0, string);
processor.invokeOperator(new PdfLiteral("'"), tickOperands);
}
}
/**
* A content operator implementation (').
*/
private static class MoveNextLineAndShowText implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
processor.invokeOperator(new PdfLiteral("T*"), new ArrayList(0));
processor.invokeOperator(new PdfLiteral("Tj"), operands);
}
}
/**
* A content operator implementation (Tj).
*/
private static class ShowText implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
PdfString string = (PdfString)operands.get(0);
processor.displayPdfString(string, 0);
}
}
/**
* A content operator implementation (T*).
*/
private static class TextMoveNextLine implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
ArrayList tdoperands = new ArrayList(2);
tdoperands.add(0, new PdfNumber(0));
tdoperands.add(1, new PdfNumber(processor.gs().leading));
processor.invokeOperator(new PdfLiteral("Td"), tdoperands);
}
}
/**
* A content operator implementation (Tm).
*/
private static class TextSetTextMatrix implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
float a = ((PdfNumber)operands.get(0)).floatValue();
float b = ((PdfNumber)operands.get(1)).floatValue();
float c = ((PdfNumber)operands.get(2)).floatValue();
float d = ((PdfNumber)operands.get(3)).floatValue();
float e = ((PdfNumber)operands.get(4)).floatValue();
float f = ((PdfNumber)operands.get(5)).floatValue();
processor.textLineMatrix = new Matrix(a, b, c, d, e, f);
processor.textMatrix = processor.textLineMatrix;
}
}
/**
* A content operator implementation (TD).
*/
private static class TextMoveStartNextLineWithLeading implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
float ty = ((PdfNumber)operands.get(1)).floatValue();
ArrayList tlOperands = new ArrayList(1);
tlOperands.add(0, new PdfNumber(-ty));
processor.invokeOperator(new PdfLiteral("TL"), tlOperands);
processor.invokeOperator(new PdfLiteral("Td"), operands);
}
}
/**
* A content operator implementation (Td).
*/
private static class TextMoveStartNextLine implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
float tx = ((PdfNumber)operands.get(0)).floatValue();
float ty = ((PdfNumber)operands.get(1)).floatValue();
Matrix translationMatrix = new Matrix(tx, ty);
processor.textMatrix = translationMatrix.multiply(processor.textLineMatrix);
processor.textLineMatrix = processor.textMatrix;
}
}
/**
* A content operator implementation (Tf).
*/
private static class SetTextFont implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
PdfName fontResourceName = (PdfName)operands.get(0);
float size = ((PdfNumber)operands.get(1)).floatValue();
PdfDictionary fontsDictionary = processor.resources.getAsDict(PdfName.FONT);
CMapAwareDocumentFont font = new CMapAwareDocumentFont((PRIndirectReference)fontsDictionary.get(fontResourceName));
processor.gs().font = font;
processor.gs().fontSize = size;
}
}
/**
* A content operator implementation (Tr).
*/
private static class SetTextRenderMode implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
PdfNumber render = (PdfNumber)operands.get(0);
processor.gs().renderMode = render.intValue();
}
}
/**
* A content operator implementation (Ts).
*/
private static class SetTextRise implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
PdfNumber rise = (PdfNumber)operands.get(0);
processor.gs().rise = rise.floatValue();
}
}
/**
* A content operator implementation (TL).
*/
private static class SetTextLeading implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
PdfNumber leading = (PdfNumber)operands.get(0);
processor.gs().leading = leading.floatValue();
}
}
/**
* A content operator implementation (Tz).
*/
private static class SetTextHorizontalScaling implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
PdfNumber scale = (PdfNumber)operands.get(0);
processor.gs().horizontalScaling = scale.floatValue();
}
}
/**
* A content operator implementation (Tc).
*/
private static class SetTextCharacterSpacing implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
PdfNumber charSpace = (PdfNumber)operands.get(0);
processor.gs().characterSpacing = charSpace.floatValue();
}
}
/**
* A content operator implementation (Tw).
*/
private static class SetTextWordSpacing implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
PdfNumber wordSpace = (PdfNumber)operands.get(0);
processor.gs().wordSpacing = wordSpace.floatValue();
}
}
/**
* A content operator implementation (gs).
*/
private static class ProcessGraphicsStateResource implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
PdfName dictionaryName = (PdfName)operands.get(0);
PdfDictionary extGState = processor.resources.getAsDict(PdfName.EXTGSTATE);
if (extGState == null)
throw new IllegalArgumentException("Resources do not contain ExtGState entry. Unable to process operator " + operator);
PdfDictionary gsDic = extGState.getAsDict(dictionaryName);
if (gsDic == null)
throw new IllegalArgumentException(dictionaryName + " is an unknown graphics state dictionary");
// at this point, all we care about is the FONT entry in the GS dictionary
PdfArray fontParameter = gsDic.getAsArray(PdfName.FONT);
if (fontParameter != null){
CMapAwareDocumentFont font = new CMapAwareDocumentFont((PRIndirectReference)fontParameter.getPdfObject(0));
float size = fontParameter.getAsNumber(1).floatValue();
processor.gs().font = font;
processor.gs().fontSize = size;
}
}
}
/**
* A content operator implementation (q).
*/
private static class PushGraphicsState implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
GraphicsState gs = (GraphicsState) processor.gsStack.peek();
GraphicsState copy = new GraphicsState(gs);
processor.gsStack.push(copy);
}
}
/**
* A content operator implementation (cm).
*/
private static class ModifyCurrentTransformationMatrix implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
float a = ((PdfNumber)operands.get(0)).floatValue();
float b = ((PdfNumber)operands.get(1)).floatValue();
float c = ((PdfNumber)operands.get(2)).floatValue();
float d = ((PdfNumber)operands.get(3)).floatValue();
float e = ((PdfNumber)operands.get(4)).floatValue();
float f = ((PdfNumber)operands.get(5)).floatValue();
Matrix matrix = new Matrix(a, b, c, d, e, f);
GraphicsState gs = (GraphicsState)processor.gsStack.peek();
gs.ctm = gs.ctm.multiply(matrix);
}
}
/**
* A content operator implementation (Q).
*/
private static class PopGraphicsState implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
processor.gsStack.pop();
}
}
/**
* A content operator implementation (BT).
*/
private static class BeginText implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
processor.textMatrix = new Matrix();
processor.textLineMatrix = processor.textMatrix;
}
}
/**
* A content operator implementation (ET).
*/
private static class EndText implements ContentOperator{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList operands) {
processor.textMatrix = null;
processor.textLineMatrix = null;
}
}
}