src/java/org/apache/fop/render/pdf/PDFContentGenerator.java - xmlgraphics-fop - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
  * (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.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 /* $Id$ */

 package org.apache.fop.render.pdf;

 import java.awt.Color;
 import java.awt.Rectangle;
 import java.awt.geom.AffineTransform;
 import java.io.IOException;
 import java.io.OutputStream;

 import org.apache.fop.pdf.PDFColor;
 import org.apache.fop.pdf.PDFDocument;
 import org.apache.fop.pdf.PDFFilterList;
 import org.apache.fop.pdf.PDFNumber;
 import org.apache.fop.pdf.PDFPaintingState;
 import org.apache.fop.pdf.PDFResourceContext;
 import org.apache.fop.pdf.PDFStream;
 import org.apache.fop.pdf.PDFTextUtil;
 import org.apache.fop.pdf.PDFXObject;

 /**
  * Generator class encapsulating all object references and state necessary to generate a
  * PDF content stream.
  */
 public class PDFContentGenerator {

     /** Controls whether comments are written to the PDF stream. */
     protected static final boolean WRITE_COMMENTS = true;

     private PDFDocument document;
     private OutputStream outputStream;
     private PDFResourceContext resourceContext;

     /** the current stream to add PDF commands to */
     private PDFStream currentStream;

     /** drawing state */
     protected PDFPaintingState currentState = null;
     /** Text generation utility holding the current font status */
     protected PDFTextUtil textutil;


     /**
      * Main constructor. Creates a new PDF stream and additional helper classes for text painting
      * and state management.
      * @param document the PDF document
      * @param out the output stream the PDF document is generated to
      * @param resourceContext the resource context
      */
     public PDFContentGenerator(PDFDocument document, OutputStream out,
             PDFResourceContext resourceContext) {
         this.document = document;
         this.outputStream = out;
         this.resourceContext = resourceContext;
         this.currentStream = document.getFactory()
                 .makeStream(PDFFilterList.CONTENT_FILTER, false);
         this.textutil = new PDFTextUtil() {
             protected void write(String code) {
                 currentStream.add(code);
             }
         };

         this.currentState = new PDFPaintingState();
     }

     /**
      * Returns the applicable resource context for the generator.
      * @return the resource context
      */
     public PDFDocument getDocument() {
         return this.document;
     }

     /**
      * Returns the output stream the PDF document is written to.
      * @return the output stream
      */
     public OutputStream getOutputStream() {
         return this.outputStream;
     }

     /**
      * Returns the applicable resource context for the generator.
      * @return the resource context
      */
     public PDFResourceContext getResourceContext() {
         return this.resourceContext;
     }

     /**
      * Returns the {@link PDFStream} associated with this instance.
      * @return the PDF stream
      */
     public PDFStream getStream() {
         return this.currentStream;
     }

     /**
      * Returns the {@link PDFState} associated with this instance.
      * @return the PDF state
      */
     public PDFPaintingState getState() {
         return this.currentState;
     }

     /**
      * Returns the {@link PDFTextUtil} associated with this instance.
      * @return the text utility
      */
     public PDFTextUtil getTextUtil() {
         return this.textutil;
     }

     /**
      * Flushes all queued PDF objects ready to be written to the output stream.
      * @throws IOException if an error occurs while flushing the PDF objects
      */
     public void flushPDFDoc() throws IOException {
         this.document.output(this.outputStream);
     }

     /**
      * Writes out a comment.
      * @param text text for the comment
      */
     protected void comment(String text) {
         if (WRITE_COMMENTS) {
             currentStream.add("% " + text + "\n");
         }
     }

     /** {@inheritDoc} */
     protected void saveGraphicsState() {
         endTextObject();
         currentState.save();
         currentStream.add("q\n");
     }

     /**
      * Restored the graphics state valid before the previous {@link #saveGraphicsState()}.
      * @param popState true if the state should also be popped, false if only the PDF command
      *           should be issued
      */
     protected void restoreGraphicsState(boolean popState) {
         endTextObject();
         currentStream.add("Q\n");
         if (popState) {
             currentState.restore();
         }
     }

     /** {@inheritDoc} */
     protected void restoreGraphicsState() {
         restoreGraphicsState(true);
     }

     /** Indicates the beginning of a text object. */
     protected void beginTextObject() {
         if (!textutil.isInTextObject()) {
             textutil.beginTextObject();
         }
     }

     /** Indicates the end of a text object. */
     protected void endTextObject() {
         if (textutil.isInTextObject()) {
             textutil.endTextObject();
         }
     }

     /**
      * Concatenates the given transformation matrix with the current one.
      * @param transform the transformation matrix (in points)
      */
     public void concatenate(AffineTransform transform) {
         if (!transform.isIdentity()) {
             currentState.concatenate(transform);
             currentStream.add(CTMHelper.toPDFString(transform, false) + " cm\n");
         }
     }

     /**
      * Intersects the current clip region with the given rectangle.
      * @param rect the clip rectangle
      */
     public void clipRect(Rectangle rect) {
         StringBuffer sb = new StringBuffer();
         sb.append(format(rect.x / 1000f)).append(' ');
         sb.append(format(rect.y / 1000f)).append(' ');
         sb.append(format(rect.width / 1000f)).append(' ');
         sb.append(format(rect.height / 1000f)).append(" re W n\n");
         add(sb.toString());
     }

     /**
      * Adds content to the stream.
      * @param content the PDF content
      */
     public void add(String content) {
         currentStream.add(content);
     }

     /**
      * Formats a float value (normally coordinates in points) as Strings.
      * @param value the value
      * @return the formatted value
      */
     public static final String format(float value) {
         return PDFNumber.doubleOut(value);
     }

     /**
      * Sets the current line width in points.
      * @param width line width in points
      */
     public void updateLineWidth(float width) {
         if (currentState.setLineWidth(width)) {
             //Only write if value has changed WRT the current line width
             currentStream.add(format(width) + " w\n");
         }
     }

     /**
      * Sets the current character spacing (Tc) value.
      * @param value the Tc value (in unscaled text units)
      */
     public void updateCharacterSpacing(float value) {
         if (getState().setCharacterSpacing(value)) {
             currentStream.add(format(value) + " Tc\n");
         }
     }

     /**
      * Establishes a new foreground or fill color.
      * @param col the color to apply
      * @param fill true to set the fill color, false for the foreground color
      * @param stream the PDFStream to write the PDF code to
      */
     public void setColor(Color col, boolean fill, PDFStream stream) {
         assert stream != null;
         PDFColor color = new PDFColor(this.document, col);
         stream.add(color.getColorSpaceOut(fill));
     }

     /**
      * Establishes a new foreground or fill color.
      * @param col the color to apply
      * @param fill true to set the fill color, false for the foreground color
      */
     public void setColor(Color col, boolean fill) {
         setColor(col, fill, getStream());
     }

     /**
      * Establishes a new foreground or fill color. In contrast to updateColor
      * this method does not check the PDFState for optimization possibilities.
      * @param col the color to apply
      * @param fill true to set the fill color, false for the foreground color
      * @param pdf StringBuffer to write the PDF code to, if null, the code is
      *     written to the current stream.
      */
     protected void setColor(Color col, boolean fill, StringBuffer pdf) {
         if (pdf != null) {
             PDFColor color = new PDFColor(this.document, col);
             pdf.append(color.getColorSpaceOut(fill));
         } else {
             setColor(col, fill, this.currentStream);
         }
     }

     /**
      * Establishes a new foreground or fill color.
      * @param col the color to apply (null skips this operation)
      * @param fill true to set the fill color, false for the foreground color
      * @param pdf StringBuffer to write the PDF code to, if null, the code is
      *     written to the current stream.
      */
     public void updateColor(Color col, boolean fill, StringBuffer pdf) {
         if (col == null) {
             return;
         }
         boolean update = false;
         if (fill) {
             update = getState().setBackColor(col);
         } else {
             update = getState().setColor(col);
         }

         if (update) {
             setColor(col, fill, pdf);
         }
     }

     /**
      * Places a previously registered image at a certain place on the page.
      * @param x X coordinate
      * @param y Y coordinate
      * @param w width for image
      * @param h height for image
      * @param xobj the image XObject
      */
     public void placeImage(float x, float y, float w, float h, PDFXObject xobj) {
         saveGraphicsState();
         add(format(w) + " 0 0 "
                           + format(-h) + " "
                           + format(x) + " "
                           + format(y + h)
                           + " cm\n" + xobj.getName() + " Do\n");
         restoreGraphicsState();
     }


 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (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.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	/* $Id$ */

	package org.apache.fop.render.pdf;

	import java.awt.Color;
	import java.awt.Rectangle;
	import java.awt.geom.AffineTransform;
	import java.io.IOException;
	import java.io.OutputStream;

	import org.apache.fop.pdf.PDFColor;
	import org.apache.fop.pdf.PDFDocument;
	import org.apache.fop.pdf.PDFFilterList;
	import org.apache.fop.pdf.PDFNumber;
	import org.apache.fop.pdf.PDFPaintingState;
	import org.apache.fop.pdf.PDFResourceContext;
	import org.apache.fop.pdf.PDFStream;
	import org.apache.fop.pdf.PDFTextUtil;
	import org.apache.fop.pdf.PDFXObject;

	/**
	* Generator class encapsulating all object references and state necessary to generate a
	* PDF content stream.
	*/
	public class PDFContentGenerator {

	/** Controls whether comments are written to the PDF stream. */
	protected static final boolean WRITE_COMMENTS = true;

	private PDFDocument document;
	private OutputStream outputStream;
	private PDFResourceContext resourceContext;

	/** the current stream to add PDF commands to */
	private PDFStream currentStream;

	/** drawing state */
	protected PDFPaintingState currentState = null;
	/** Text generation utility holding the current font status */
	protected PDFTextUtil textutil;


	/**
	* Main constructor. Creates a new PDF stream and additional helper classes for text painting
	* and state management.
	* @param document the PDF document
	* @param out the output stream the PDF document is generated to
	* @param resourceContext the resource context
	*/
	public PDFContentGenerator(PDFDocument document, OutputStream out,
	PDFResourceContext resourceContext) {
	this.document = document;
	this.outputStream = out;
	this.resourceContext = resourceContext;
	this.currentStream = document.getFactory()
	.makeStream(PDFFilterList.CONTENT_FILTER, false);
	this.textutil = new PDFTextUtil() {
	protected void write(String code) {
	currentStream.add(code);
	}
	};

	this.currentState = new PDFPaintingState();
	}

	/**
	* Returns the applicable resource context for the generator.
	* @return the resource context
	*/
	public PDFDocument getDocument() {
	return this.document;
	}

	/**
	* Returns the output stream the PDF document is written to.
	* @return the output stream
	*/
	public OutputStream getOutputStream() {
	return this.outputStream;
	}

	/**
	* Returns the applicable resource context for the generator.
	* @return the resource context
	*/
	public PDFResourceContext getResourceContext() {
	return this.resourceContext;
	}

	/**
	* Returns the {@link PDFStream} associated with this instance.
	* @return the PDF stream
	*/
	public PDFStream getStream() {
	return this.currentStream;
	}

	/**
	* Returns the {@link PDFState} associated with this instance.
	* @return the PDF state
	*/
	public PDFPaintingState getState() {
	return this.currentState;
	}

	/**
	* Returns the {@link PDFTextUtil} associated with this instance.
	* @return the text utility
	*/
	public PDFTextUtil getTextUtil() {
	return this.textutil;
	}

	/**
	* Flushes all queued PDF objects ready to be written to the output stream.
	* @throws IOException if an error occurs while flushing the PDF objects
	*/
	public void flushPDFDoc() throws IOException {
	this.document.output(this.outputStream);
	}

	/**
	* Writes out a comment.
	* @param text text for the comment
	*/
	protected void comment(String text) {
	if (WRITE_COMMENTS) {
	currentStream.add("% " + text + "\n");
	}
	}

	/** {@inheritDoc} */
	protected void saveGraphicsState() {
	endTextObject();
	currentState.save();
	currentStream.add("q\n");
	}

	/**
	* Restored the graphics state valid before the previous {@link #saveGraphicsState()}.
	* @param popState true if the state should also be popped, false if only the PDF command
	* should be issued
	*/
	protected void restoreGraphicsState(boolean popState) {
	endTextObject();
	currentStream.add("Q\n");
	if (popState) {
	currentState.restore();
	}
	}

	/** {@inheritDoc} */
	protected void restoreGraphicsState() {
	restoreGraphicsState(true);
	}

	/** Indicates the beginning of a text object. */
	protected void beginTextObject() {
	if (!textutil.isInTextObject()) {
	textutil.beginTextObject();
	}
	}

	/** Indicates the end of a text object. */
	protected void endTextObject() {
	if (textutil.isInTextObject()) {
	textutil.endTextObject();
	}
	}

	/**
	* Concatenates the given transformation matrix with the current one.
	* @param transform the transformation matrix (in points)
	*/
	public void concatenate(AffineTransform transform) {
	if (!transform.isIdentity()) {
	currentState.concatenate(transform);
	currentStream.add(CTMHelper.toPDFString(transform, false) + " cm\n");
	}
	}

	/**
	* Intersects the current clip region with the given rectangle.
	* @param rect the clip rectangle
	*/
	public void clipRect(Rectangle rect) {
	StringBuffer sb = new StringBuffer();
	sb.append(format(rect.x / 1000f)).append(' ');
	sb.append(format(rect.y / 1000f)).append(' ');
	sb.append(format(rect.width / 1000f)).append(' ');
	sb.append(format(rect.height / 1000f)).append(" re W n\n");
	add(sb.toString());
	}

	/**
	* Adds content to the stream.
	* @param content the PDF content
	*/
	public void add(String content) {
	currentStream.add(content);
	}

	/**
	* Formats a float value (normally coordinates in points) as Strings.
	* @param value the value
	* @return the formatted value
	*/
	public static final String format(float value) {
	return PDFNumber.doubleOut(value);
	}

	/**
	* Sets the current line width in points.
	* @param width line width in points
	*/
	public void updateLineWidth(float width) {
	if (currentState.setLineWidth(width)) {
	//Only write if value has changed WRT the current line width
	currentStream.add(format(width) + " w\n");
	}
	}

	/**
	* Sets the current character spacing (Tc) value.
	* @param value the Tc value (in unscaled text units)
	*/
	public void updateCharacterSpacing(float value) {
	if (getState().setCharacterSpacing(value)) {
	currentStream.add(format(value) + " Tc\n");
	}
	}

	/**
	* Establishes a new foreground or fill color.
	* @param col the color to apply
	* @param fill true to set the fill color, false for the foreground color
	* @param stream the PDFStream to write the PDF code to
	*/
	public void setColor(Color col, boolean fill, PDFStream stream) {
	assert stream != null;
	PDFColor color = new PDFColor(this.document, col);
	stream.add(color.getColorSpaceOut(fill));
	}

	/**
	* Establishes a new foreground or fill color.
	* @param col the color to apply
	* @param fill true to set the fill color, false for the foreground color
	*/
	public void setColor(Color col, boolean fill) {
	setColor(col, fill, getStream());
	}

	/**
	* Establishes a new foreground or fill color. In contrast to updateColor
	* this method does not check the PDFState for optimization possibilities.
	* @param col the color to apply
	* @param fill true to set the fill color, false for the foreground color
	* @param pdf StringBuffer to write the PDF code to, if null, the code is
	* written to the current stream.
	*/
	protected void setColor(Color col, boolean fill, StringBuffer pdf) {
	if (pdf != null) {
	PDFColor color = new PDFColor(this.document, col);
	pdf.append(color.getColorSpaceOut(fill));
	} else {
	setColor(col, fill, this.currentStream);
	}
	}

	/**
	* Establishes a new foreground or fill color.
	* @param col the color to apply (null skips this operation)
	* @param fill true to set the fill color, false for the foreground color
	* @param pdf StringBuffer to write the PDF code to, if null, the code is
	* written to the current stream.
	*/
	public void updateColor(Color col, boolean fill, StringBuffer pdf) {
	if (col == null) {
	return;
	}
	boolean update = false;
	if (fill) {
	update = getState().setBackColor(col);
	} else {
	update = getState().setColor(col);
	}

	if (update) {
	setColor(col, fill, pdf);
	}
	}

	/**
	* Places a previously registered image at a certain place on the page.
	* @param x X coordinate
	* @param y Y coordinate
	* @param w width for image
	* @param h height for image
	* @param xobj the image XObject
	*/
	public void placeImage(float x, float y, float w, float h, PDFXObject xobj) {
	saveGraphicsState();
	add(format(w) + " 0 0 "
	+ format(-h) + " "
	+ format(x) + " "
	+ format(y + h)
	+ " cm\n" + xobj.getName() + " Do\n");
	restoreGraphicsState();
	}


	}