From 6025b6016517c6d898d8957d1d7e03ba71431912 Mon Sep 17 00:00:00 2001
From: tknall <tknall@7b5415b0-85f9-ee4d-85bd-d5d0c3b42d1c>
Date: Fri, 1 Dec 2006 12:20:24 +0000
Subject: Initial import of release 2.2.

git-svn-id: https://joinup.ec.europa.eu/svn/pdf-as/trunk@4 7b5415b0-85f9-ee4d-85bd-d5d0c3b42d1c
---
 src/main/java/org/pdfbox/util/PDFStreamEngine.java | 622 +++++++++++++++++++++
 1 file changed, 622 insertions(+)
 create mode 100644 src/main/java/org/pdfbox/util/PDFStreamEngine.java

(limited to 'src/main/java/org/pdfbox/util/PDFStreamEngine.java')

diff --git a/src/main/java/org/pdfbox/util/PDFStreamEngine.java b/src/main/java/org/pdfbox/util/PDFStreamEngine.java
new file mode 100644
index 0000000..1e05f8a
--- /dev/null
+++ b/src/main/java/org/pdfbox/util/PDFStreamEngine.java
@@ -0,0 +1,622 @@
+/**
+ * Copyright (c) 2003-2005, www.pdfbox.org
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of pdfbox; nor the names of its
+ *    contributors may be used to endorse or promote products derived from this
+ *    software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://www.pdfbox.org
+ *
+ */
+package org.pdfbox.util;
+
+import java.io.IOException;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+import java.util.Stack;
+
+import org.pdfbox.cos.COSObject;
+import org.pdfbox.cos.COSStream;
+import org.pdfbox.exceptions.WrappedIOException;
+
+import org.pdfbox.pdmodel.PDPage;
+import org.pdfbox.pdmodel.PDResources;
+
+import org.pdfbox.pdmodel.font.PDFont;
+
+import org.pdfbox.pdmodel.graphics.PDGraphicsState;
+
+import org.pdfbox.util.operator.OperatorProcessor;
+
+import org.apache.log4j.Logger;
+
+/**
+ * This class will run through a PDF content stream and execute certain operations
+ * and provide a callback interface for clients that want to do things with the stream.
+ * See the PDFTextStripper class for an example of how to use this class.
+ *
+ * @author Ben Litchfield (ben@benlitchfield.com)
+ * @version $Revision: 1.29 $
+ */
+public class PDFStreamEngine
+{
+  private static Logger log = Logger.getLogger(PDFStreamEngine.class);
+
+    static protected final byte[] SPACE_BYTES = { (byte)32 };
+
+    private PDGraphicsState graphicsState = null;
+
+    protected Matrix textMatrix = null;
+    protected Matrix textLineMatrix = null;
+    protected Stack graphicsStack = new Stack();
+    //private PDResources resources = null;
+    
+    protected Map operators = new HashMap();
+    
+    protected Map fontToAverageWidths = new HashMap();
+    
+    protected Stack streamResourcesStack = new Stack();
+    
+    protected PDPage page;
+    
+    /**
+     * This is a simple internal class used by the Stream engine to handle the 
+     * resources stack.
+     */
+    protected static class StreamResources
+    {
+      protected Map fonts;
+      protected Map colorSpaces;
+      protected Map xobjects;
+      protected Map graphicsStates;
+      protected PDResources resources;
+    }
+
+    /**
+     * Constructor.
+     */
+    public PDFStreamEngine()
+    {
+        //default constructor
+    }
+    
+    /**
+     * Constructor with engine properties.  The property keys are all
+     * PDF operators, the values are class names used to execute those
+     * operators.
+     * 
+     * @param properties The engine properties.
+     * 
+     * @throws IOException If there is an error setting the engine properties.
+     */
+    public PDFStreamEngine( Properties properties ) throws IOException
+    {
+        try
+        {
+            Iterator keys = properties.keySet().iterator();
+            while( keys.hasNext() )
+            {
+                String operator = (String)keys.next();
+                String operatorClass = properties.getProperty( operator );
+                if( log.isDebugEnabled() )
+                {
+                    log.debug( "Operator Class: " + operator + "=" + operatorClass );
+                }
+                OperatorProcessor op = (OperatorProcessor)Class.forName( operatorClass ).newInstance();
+                op.setContext( this );
+                operators.put( operator, op );
+            }
+        }
+        catch( Exception e )
+        {
+            throw new WrappedIOException( e );
+        }
+    }
+
+    /**
+     * This will process the contents of the stream.
+     *
+     * @param aPage The page.
+     * @param resources The location to retrieve resources.
+     * @param cosStream the Stream to execute.
+     * 
+     *
+     * @throws IOException if there is an error accessing the stream.
+     */
+    public void processStream( PDPage aPage, PDResources resources, COSStream cosStream ) throws IOException
+    {
+        graphicsState = new PDGraphicsState();
+        textMatrix = null;
+        textLineMatrix = null;
+        graphicsStack.clear();
+        streamResourcesStack.clear();
+        fontToAverageWidths.clear();
+        
+        processSubStream( aPage, resources, cosStream );
+    }
+    
+    /**
+     * Process a sub stream of the current stream.
+     * 
+     * @param aPage The page used for drawing.
+     * @param resources The resources used when processing the stream.
+     * @param cosStream The stream to process.
+     * 
+     * @throws IOException If there is an exception while processing the stream.
+     */
+    public void processSubStream( PDPage aPage, PDResources resources, COSStream cosStream ) throws IOException
+    {
+        page = aPage;
+        if( resources != null )
+        {
+            StreamResources sr = new StreamResources();
+            sr.fonts = resources.getFonts();
+            sr.colorSpaces = resources.getColorSpaces();
+            sr.xobjects = resources.getXObjects();
+            sr.graphicsStates = resources.getGraphicsStates();
+            sr.resources = resources;
+            streamResourcesStack.push(sr);
+        }
+        try
+        {
+            List arguments = new ArrayList();
+            long startTokens = System.currentTimeMillis();
+            List tokens = cosStream.getStreamTokens();
+            long stopTokens = System.currentTimeMillis();
+            if( log.isDebugEnabled() )
+            {
+                log.debug( "Getting tokens time=" + (stopTokens-startTokens) );
+            }
+            if( tokens != null )
+            {
+                Iterator iter = tokens.iterator();
+                while( iter.hasNext() )
+                {
+                    Object next = iter.next();
+                    if( next instanceof COSObject )
+                    {
+                        arguments.add( ((COSObject)next).getObject() );
+                    }
+                    else if( next instanceof PDFOperator )
+                    {
+                        processOperator( (PDFOperator)next, arguments );
+                        arguments = new ArrayList();
+                    }
+                    else
+                    {
+                        arguments.add( next );
+                    }
+                }
+            }
+        }
+        finally
+        {
+            if( resources != null )
+            {
+                streamResourcesStack.pop();
+            }
+        }
+        
+    }
+
+    /**
+     * A method provided as an event interface to allow a subclass to perform
+     * some specific functionality when a character needs to be displayed.
+     *
+     * @param text The character to be displayed.
+     */
+    protected void showCharacter( TextPosition text )
+    {
+        //subclasses can override to provide specific functionality.
+    }
+
+    /**
+     * You should override this method if you want to perform an action when a
+     * string is being shown.
+     *
+     * @param string The string to display.
+     *
+     * @throws IOException If there is an error showing the string
+     */
+    public void showString( byte[] string ) throws IOException
+    {
+        float spaceWidth = 0;
+        float spacing = 0;
+        StringBuffer stringResult = new StringBuffer(string.length);
+        
+        float characterDisplacement = 0;
+        float spaceDisplacement = 0;
+        float fontSize = graphicsState.getTextState().getFontSize();
+        float horizontalScaling = graphicsState.getTextState().getHorizontalScalingPercent()/100f;
+        float rise = graphicsState.getTextState().getRise();
+        final float wordSpacing = graphicsState.getTextState().getWordSpacing();
+        final float characterSpacing = graphicsState.getTextState().getCharacterSpacing();
+        float wordSpacingDisplacement = 0;
+        
+        PDFont font = graphicsState.getTextState().getFont();
+        
+        //This will typically be 1000 but in the case of a type3 font
+        //this might be a different number
+        float glyphSpaceToTextSpaceFactor = 1f/font.getFontMatrix().getValue( 0, 0 );
+        Float averageWidth = (Float)fontToAverageWidths.get( font );
+        if( averageWidth == null )
+        {
+            averageWidth = new Float( font.getAverageFontWidth() );
+            fontToAverageWidths.put( font, averageWidth );
+        }
+
+        Matrix initialMatrix = new Matrix();
+        initialMatrix.setValue(0,0,1);
+        initialMatrix.setValue(0,1,0);
+        initialMatrix.setValue(0,2,0);
+        initialMatrix.setValue(1,0,0);
+        initialMatrix.setValue(1,1,1);
+        initialMatrix.setValue(1,2,0);
+        initialMatrix.setValue(2,0,0);
+        initialMatrix.setValue(2,1,rise);
+        initialMatrix.setValue(2,2,1);
+
+
+        //this
+        int codeLength = 1;
+        Matrix ctm = graphicsState.getCurrentTransformationMatrix();
+        
+        //lets see what the space displacement should be
+        spaceDisplacement = (font.getFontWidth( SPACE_BYTES, 0, 1 )/glyphSpaceToTextSpaceFactor);
+        if( spaceDisplacement == 0 )
+        {
+            spaceDisplacement = (averageWidth.floatValue()/glyphSpaceToTextSpaceFactor);
+            //The average space width appears to be higher than necessary
+            //so lets make it a little bit smaller.
+            spaceDisplacement *= .80f;
+            if( log.isDebugEnabled() )
+            {
+                log.debug( "Font: Space From Average=" + spaceDisplacement );
+            }
+        }
+        int pageRotation = page.findRotation();
+        Matrix trm = initialMatrix.multiply( textMatrix ).multiply( ctm );
+        float x = trm.getValue(2,0);
+        float y = trm.getValue(2,1);
+        if( pageRotation == 0 )
+        {
+            trm.setValue( 2,1, -y + page.findMediaBox().getHeight() );
+        }
+        else if( pageRotation == 90 )
+        {
+            trm.setValue( 2,0, y );
+            trm.setValue( 2,1, x );
+        }
+        else if( pageRotation == 270 )
+        {
+            trm.setValue( 2,0, -y  + page.findMediaBox().getHeight() );
+            trm.setValue( 2,1, x );
+        }
+        for( int i=0; i<string.length; i+=codeLength )
+        {
+            if( log.isDebugEnabled() )
+            {
+                log.debug( "initialMatrix=" + initialMatrix );
+                log.debug( "textMatrix=" + textMatrix );
+                log.debug( "initialMatrix.multiply( textMatrix )=" + initialMatrix.multiply( textMatrix ) );
+                log.debug( "ctm=" + ctm );
+                log.debug( "trm=" + initialMatrix.multiply( textMatrix ).multiply( ctm ) );
+            }
+            codeLength = 1;
+
+            String c = font.encode( string, i, codeLength );
+
+            if( log.isDebugEnabled() )
+            {
+                log.debug( "Character Code=" + string[i] + "='" + c + "'" );
+            }
+            if( c == null && i+1<string.length)
+            {
+                //maybe a multibyte encoding
+                codeLength++;
+                if( log.isDebugEnabled() )
+                {
+                    log.debug( "Multibyte Character Code=" + string[i] + string[i+1] );
+                }
+                c = font.encode( string, i, codeLength );
+            }
+            stringResult.append( c );
+
+            //todo, handle horizontal displacement
+            characterDisplacement += (font.getFontWidth( string, i, codeLength )/glyphSpaceToTextSpaceFactor);
+
+
+            // PDF Spec - 5.5.2 Word Spacing
+            //
+            // Word spacing works the same was as character spacing, but applies
+            // only to the space character, code 32.
+            //
+            // Note: Word spacing is applied to every occurrence of the single-byte
+            // character code 32 in a string.  This can occur when using a simple
+            // font or a composite font that defines code 32 as a single-byte code.
+            // It does not apply to occurrences of the byte value 32 in multiple-byte
+            // codes.
+            //
+            // RDD - My interpretation of this is that only character code 32's that
+            // encode to spaces should have word spacing applied.  Cases have been
+            // observed where a font has a space character with a character code
+            // other than 32, and where word spacing (Tw) was used.  In these cases,
+            // applying word spacing to either the non-32 space or to the character
+            // code 32 non-space resulted in errors consistent with this interpretation.
+            //
+            
+            boolean withCS = false;
+            if( (string[i] == 0x20) && c.equals( " " ) )
+            {
+                spacing += wordSpacing + characterSpacing;
+                withCS = true;
+            }
+            else
+            {
+                spacing += characterSpacing;
+            }
+
+            if( log.isDebugEnabled() )
+            {
+                log.debug( "Checking code '" + c + "' font=" + graphicsState.getTextState().getFont() +
+                     " Tc=" + characterSpacing +
+                     " Tw=" + wordSpacing +
+                     " fontSize=" + fontSize +
+                     " horizontalScaling=" + horizontalScaling +
+                     " totalDisp=" + characterDisplacement +  
+                     " spacing=" + spacing + "(" + withCS + ")" );
+            }
+            // We want to update the textMatrix using the width, in text space units.
+            //
+            
+        }
+        
+        //The adjustment will always be zero.  The adjustment as shown in the
+        //TJ operator will be handled separately.
+        float adjustment=0;
+        //todo, need to compute the horizontal displacement
+        float ty = 0;
+        float tx = ((characterDisplacement-adjustment/glyphSpaceToTextSpaceFactor)*fontSize + spacing)
+                   *horizontalScaling;
+        
+        if( log.isDebugEnabled() )
+        {
+            log.debug( "disp=" + characterDisplacement + " adj=" + adjustment +
+                       " fSize=" + fontSize + " tx=" + tx );
+        }
+        
+        float xScale = trm.getXScale();
+        float yScale = trm.getYScale(); 
+        float xPos = trm.getXPosition();
+        float yPos = trm.getYPosition();
+        spaceWidth = spaceDisplacement * xScale * fontSize;
+        wordSpacingDisplacement = wordSpacing*xScale * fontSize;
+        Matrix td = new Matrix();
+        td.setValue( 2, 0, tx );
+        td.setValue( 2, 1, ty );            
+        
+        if( log.isDebugEnabled() )
+        {
+            log.debug( "TRM=" + trm );
+            log.debug( "TextMatrix before " + textMatrix );
+        }
+        float xPosBefore = textMatrix.getXPosition();
+        float yPosBefore = textMatrix.getYPosition();
+        textMatrix = td.multiply( textMatrix );
+        if( log.isDebugEnabled() )
+        {
+            log.debug( "TextMatrix after " + textMatrix );
+        }
+        float totalStringDisplacement = 0;
+        if( pageRotation == 0 )
+        {
+            totalStringDisplacement = (textMatrix.getXPosition() - xPosBefore);
+        }
+        else if( pageRotation == 90 )
+        {
+            totalStringDisplacement = (textMatrix.getYPosition() - yPosBefore);
+        }
+        else if( pageRotation == 270 )
+        {
+            totalStringDisplacement = (yPosBefore - textMatrix.getYPosition());
+        }
+        showCharacter(
+                new TextPosition(
+                    xPos,
+                    yPos,
+                    xScale,
+                    yScale,
+                    totalStringDisplacement,
+                    spaceWidth,
+                    stringResult.toString(),
+                    graphicsState.getTextState().getFont(),
+                    graphicsState.getTextState().getFontSize(),
+                    wordSpacingDisplacement ));
+    }
+    
+    /**
+     * This is used to handle an operation.
+     *
+     * @param operation The operation to perform.
+     * @param arguments The list of arguments.
+     *
+     * @throws IOException If there is an error processing the operation.
+     */
+    public void processOperator( String operation, List arguments ) throws IOException
+    {
+        PDFOperator oper = PDFOperator.getOperator( operation );
+        processOperator( oper, arguments );
+    }
+
+    /**
+     * This is used to handle an operation.
+     *
+     * @param operator The operation to perform.
+     * @param arguments The list of arguments.
+     *
+     * @throws IOException If there is an error processing the operation.
+     */
+    protected void processOperator( PDFOperator operator, List arguments ) throws IOException
+    {
+        String operation = operator.getOperation();
+        if( log.isDebugEnabled() )
+        {
+            log.debug( "processOperator( '" + operation + "' )" );
+        }
+        OperatorProcessor processor = (OperatorProcessor)operators.get( operation );
+        if( processor != null )
+        {
+            processor.process( operator, arguments );
+        }
+    } 
+   
+    /**
+     * @return Returns the colorSpaces.
+     */
+    public Map getColorSpaces() 
+    {
+        return ((StreamResources) streamResourcesStack.peek()).colorSpaces;
+    }
+    
+    /**
+     * @return Returns the colorSpaces.
+     */
+    public Map getXObjects() 
+    {
+        return ((StreamResources) streamResourcesStack.peek()).xobjects;
+    }
+    
+    /**
+     * @param value The colorSpaces to set.
+     */
+    public void setColorSpaces(Map value) 
+    {
+        ((StreamResources) streamResourcesStack.peek()).colorSpaces = value;
+    }
+    /**
+     * @return Returns the fonts.
+     */
+    public Map getFonts() 
+    {
+        return ((StreamResources) streamResourcesStack.peek()).fonts;
+    }
+    /**
+     * @param value The fonts to set.
+     */
+    public void setFonts(Map value) 
+    {
+        ((StreamResources) streamResourcesStack.peek()).fonts = value;
+    }
+    /**
+     * @return Returns the graphicsStack.
+     */
+    public Stack getGraphicsStack() 
+    {
+        return graphicsStack;
+    }
+    /**
+     * @param value The graphicsStack to set.
+     */
+    public void setGraphicsStack(Stack value) 
+    {
+        graphicsStack = value;
+    }
+    /**
+     * @return Returns the graphicsState.
+     */
+    public PDGraphicsState getGraphicsState() 
+    {
+        return graphicsState;
+    }
+    /**
+     * @param value The graphicsState to set.
+     */
+    public void setGraphicsState(PDGraphicsState value) 
+    {
+        graphicsState = value;
+    }
+    /**
+     * @return Returns the graphicsStates.
+     */
+    public Map getGraphicsStates() 
+    {
+        return ((StreamResources) streamResourcesStack.peek()).graphicsStates;
+    }
+    /**
+     * @param value The graphicsStates to set.
+     */
+    public void setGraphicsStates(Map value) 
+    {
+        ((StreamResources) streamResourcesStack.peek()).graphicsStates = value;
+    }
+    /**
+     * @return Returns the textLineMatrix.
+     */
+    public Matrix getTextLineMatrix() 
+    {
+        return textLineMatrix;
+    }
+    /**
+     * @param value The textLineMatrix to set.
+     */
+    public void setTextLineMatrix(Matrix value) 
+    {
+        textLineMatrix = value;
+    }
+    /**
+     * @return Returns the textMatrix.
+     */
+    public Matrix getTextMatrix() 
+    {
+        return textMatrix;
+    }
+    /**
+     * @param value The textMatrix to set.
+     */
+    public void setTextMatrix(Matrix value) 
+    {
+        textMatrix = value;
+    }
+    /**
+     * @return Returns the resources.
+     */
+    public PDResources getResources()
+    {
+        return ((StreamResources) streamResourcesStack.peek()).resources;
+    }
+    
+    /**
+     * Get the current page that is being processed.
+     * 
+     * @return The page being processed.
+     */
+    public PDPage getCurrentPage()
+    {
+        return page;
+    }
+}
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