src/java/org/apache/fop/pdf/PDFTextUtil.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.pdf;

 import java.awt.geom.AffineTransform;

 /**
  * Utility class for generating PDF text objects. It needs to be subclassed to add writing
  * functionality (see {@link #write(String)}).
  */
 public abstract class PDFTextUtil {

     /** The number of decimal places. */
     private static final int DEC = 8;

     /** PDF text rendering mode: Fill text */
     public static final int TR_FILL = 0;
     /** PDF text rendering mode: Stroke text */
     public static final int TR_STROKE = 1;
     /** PDF text rendering mode: Fill, then stroke text */
     public static final int TR_FILL_STROKE = 2;
     /** PDF text rendering mode: Neither fill nor stroke text (invisible) */
     public static final int TR_INVISIBLE = 3;
     /** PDF text rendering mode: Fill text and add to path for clipping */
     public static final int TR_FILL_CLIP = 4;
     /** PDF text rendering mode: Stroke text and add to path for clipping */
     public static final int TR_STROKE_CLIP = 5;
     /** PDF text rendering mode: Fill, then stroke text and add to path for clipping */
     public static final int TR_FILL_STROKE_CLIP = 6;
     /** PDF text rendering mode: Add text to path for clipping */
     public static final int TR_CLIP = 7;

     private boolean inTextObject = false;
     private String startText;
     private String endText;
     private boolean useMultiByte;
     private StringBuffer bufTJ;
     private int textRenderingMode = TR_FILL;

     private String currentFontName;
     private double currentFontSize;

     /**
      * Main constructor.
      */
     public PDFTextUtil() {
         //nop
     }

     /**
      * Writes PDF code.
      * @param code the PDF code to write
      */
     protected abstract void write(String code);

     private void writeAffineTransform(AffineTransform at, StringBuffer sb) {
         double[] lt = new double[6];
         at.getMatrix(lt);
         sb.append(PDFNumber.doubleOut(lt[0], DEC)).append(" ");
         sb.append(PDFNumber.doubleOut(lt[1], DEC)).append(" ");
         sb.append(PDFNumber.doubleOut(lt[2], DEC)).append(" ");
         sb.append(PDFNumber.doubleOut(lt[3], DEC)).append(" ");
         sb.append(PDFNumber.doubleOut(lt[4], DEC)).append(" ");
         sb.append(PDFNumber.doubleOut(lt[5], DEC));
     }

     private void writeChar(char ch, StringBuffer sb) {
         if (!useMultiByte) {
             if (ch < 32 || ch > 127) {
                 sb.append("\\").append(Integer.toOctalString((int)ch));
             } else {
                 switch (ch) {
                 case '(':
                 case ')':
                 case '\\':
                     sb.append("\\");
                     break;
                 default:
                 }
                 sb.append(ch);
             }
         } else {
             sb.append(PDFText.toUnicodeHex(ch));
         }
     }

     private void checkInTextObject() {
         if (!inTextObject) {
             throw new IllegalStateException("Not in text object");
         }
     }

     /**
      * Indicates whether we are in a text object or not.
      * @return true if we are in a text object
      */
     public boolean isInTextObject() {
         return inTextObject;
     }

     /**
      * Called when a new text object should be started. Be sure to call setFont() before
      * issuing any text painting commands.
      */
     public void beginTextObject() {
         if (inTextObject) {
             throw new IllegalStateException("Already in text object");
         }
         write("BT\n");
         this.inTextObject = true;
     }

     /**
      * Called when a text object should be ended.
      */
     public void endTextObject() {
         checkInTextObject();
         write("ET\n");
         this.inTextObject = false;
         initValues();
     }

     /**
      * Resets the state fields.
      */
     protected void initValues() {
         this.currentFontName = null;
         this.currentFontSize = 0.0;
         this.textRenderingMode = TR_FILL;
     }

     /**
      * Creates a "q" command, pushing a copy of the entire graphics state onto the stack.
      */
     public void saveGraphicsState() {
         write("q\n");
     }

     /**
      * Creates a "Q" command, restoring the entire graphics state to its former value by popping
      * it from the stack.
      */
     public void restoreGraphicsState() {
         write("Q\n");
     }

     /**
      * Creates a "cm" command.
      * @param at the transformation matrix
      */
     public void concatMatrix(AffineTransform at) {
         if (!at.isIdentity()) {
             writeTJ();
             StringBuffer sb = new StringBuffer();
             writeAffineTransform(at, sb);
             sb.append(" cm\n");
             write(sb.toString());
         }
     }

     /**
      * Writes a "Tf" command, setting a new current font.
      * @param fontName the name of the font to select
      * @param fontSize the font size (in points)
      */
     public void writeTf(String fontName, double fontSize) {
         checkInTextObject();
         write("/" + fontName + " " + PDFNumber.doubleOut(fontSize) + " Tf\n");

         this.startText = useMultiByte ? "<" : "(";
         this.endText = useMultiByte ? ">" : ")";
     }

     /**
      * Updates the current font. This method only writes a "Tf" if the current font changes.
      * @param fontName the name of the font to select
      * @param fontSize the font size (in points)
      * @param multiByte true indicates the font is a multi-byte font, false means single-byte
      */
     public void updateTf(String fontName, double fontSize, boolean multiByte) {
         checkInTextObject();
         if (!fontName.equals(this.currentFontName) || (fontSize != this.currentFontSize)) {
             writeTJ();
             this.currentFontName = fontName;
             this.currentFontSize = fontSize;
             this.useMultiByte = multiByte;
             writeTf(fontName, fontSize);
         }
     }

     /**
      * Sets the text rendering mode.
      * @param mode the rendering mode (value 0 to 7, see PDF Spec, constants: TR_*)
      */
     public void setTextRenderingMode(int mode) {
         if (mode < 0 || mode > 7) {
             throw new IllegalArgumentException(
                     "Illegal value for text rendering mode. Expected: 0-7");
         }
         if (mode != this.textRenderingMode) {
             writeTJ();
             this.textRenderingMode = mode;
             write(this.textRenderingMode + " Tr\n");
         }
     }

     /**
      * Sets the text rendering mode.
      * @param fill true if the text should be filled
      * @param stroke true if the text should be stroked
      * @param addToClip true if the path should be added for clipping
      */
     public void setTextRenderingMode(boolean fill, boolean stroke, boolean addToClip) {
         int mode;
         if (fill) {
             mode = (stroke ? 2 : 0);
         } else {
             mode = (stroke ? 1 : 3);
         }
         if (addToClip) {
             mode += 4;
         }
         setTextRenderingMode(mode);
     }

     /**
      * Writes a "Tm" command, setting a new text transformation matrix.
      * @param localTransform the new text transformation matrix
      */
     public void writeTextMatrix(AffineTransform localTransform) {
         StringBuffer sb = new StringBuffer();
         writeAffineTransform(localTransform, sb);
         sb.append(" Tm ");
         write(sb.toString());
     }

     /**
      * Writes a char to the "TJ-Buffer".
      * @param codepoint the mapped character (code point/character code)
      */
     public void writeTJMappedChar(char codepoint) {
         if (bufTJ == null) {
             bufTJ = new StringBuffer();
         }
         if (bufTJ.length() == 0) {
             bufTJ.append("[").append(startText);
         }
         writeChar(codepoint, bufTJ);
     }

     /**
      * Writes a glyph adjust value to the "TJ-Buffer".
      * @param adjust the glyph adjust value in thousands of text unit space.
      */
     public void adjustGlyphTJ(double adjust) {
         if (bufTJ == null) {
             bufTJ = new StringBuffer();
         }
         if (bufTJ.length() > 0) {
             bufTJ.append(endText).append(" ");
         }
         if (bufTJ.length() == 0) {
             bufTJ.append("[");
         }
         bufTJ.append(PDFNumber.doubleOut(adjust, DEC - 4));
         bufTJ.append(" ");
         bufTJ.append(startText);
     }

     /**
      * Writes a "TJ" command, writing out the accumulated buffer with the characters and glyph
      * positioning values. The buffer is reset afterwards.
      */
     public void writeTJ() {
         if (isInString()) {
             bufTJ.append(endText).append("] TJ\n");
             write(bufTJ.toString());
             bufTJ.setLength(0);
         }
     }

     private boolean isInString() {
         return bufTJ != null && bufTJ.length() > 0;
     }

 }
	/*
	* 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.pdf;

	import java.awt.geom.AffineTransform;

	/**
	* Utility class for generating PDF text objects. It needs to be subclassed to add writing
	* functionality (see {@link #write(String)}).
	*/
	public abstract class PDFTextUtil {

	/** The number of decimal places. */
	private static final int DEC = 8;

	/** PDF text rendering mode: Fill text */
	public static final int TR_FILL = 0;
	/** PDF text rendering mode: Stroke text */
	public static final int TR_STROKE = 1;
	/** PDF text rendering mode: Fill, then stroke text */
	public static final int TR_FILL_STROKE = 2;
	/** PDF text rendering mode: Neither fill nor stroke text (invisible) */
	public static final int TR_INVISIBLE = 3;
	/** PDF text rendering mode: Fill text and add to path for clipping */
	public static final int TR_FILL_CLIP = 4;
	/** PDF text rendering mode: Stroke text and add to path for clipping */
	public static final int TR_STROKE_CLIP = 5;
	/** PDF text rendering mode: Fill, then stroke text and add to path for clipping */
	public static final int TR_FILL_STROKE_CLIP = 6;
	/** PDF text rendering mode: Add text to path for clipping */
	public static final int TR_CLIP = 7;

	private boolean inTextObject = false;
	private String startText;
	private String endText;
	private boolean useMultiByte;
	private StringBuffer bufTJ;
	private int textRenderingMode = TR_FILL;

	private String currentFontName;
	private double currentFontSize;

	/**
	* Main constructor.
	*/
	public PDFTextUtil() {
	//nop
	}

	/**
	* Writes PDF code.
	* @param code the PDF code to write
	*/
	protected abstract void write(String code);

	private void writeAffineTransform(AffineTransform at, StringBuffer sb) {
	double[] lt = new double[6];
	at.getMatrix(lt);
	sb.append(PDFNumber.doubleOut(lt[0], DEC)).append(" ");
	sb.append(PDFNumber.doubleOut(lt[1], DEC)).append(" ");
	sb.append(PDFNumber.doubleOut(lt[2], DEC)).append(" ");
	sb.append(PDFNumber.doubleOut(lt[3], DEC)).append(" ");
	sb.append(PDFNumber.doubleOut(lt[4], DEC)).append(" ");
	sb.append(PDFNumber.doubleOut(lt[5], DEC));
	}

	private void writeChar(char ch, StringBuffer sb) {
	if (!useMultiByte) {
	if (ch < 32 \|\| ch > 127) {
	sb.append("\\").append(Integer.toOctalString((int)ch));
	} else {
	switch (ch) {
	case '(':
	case ')':
	case '\\':
	sb.append("\\");
	break;
	default:
	}
	sb.append(ch);
	}
	} else {
	sb.append(PDFText.toUnicodeHex(ch));
	}
	}

	private void checkInTextObject() {
	if (!inTextObject) {
	throw new IllegalStateException("Not in text object");
	}
	}

	/**
	* Indicates whether we are in a text object or not.
	* @return true if we are in a text object
	*/
	public boolean isInTextObject() {
	return inTextObject;
	}

	/**
	* Called when a new text object should be started. Be sure to call setFont() before
	* issuing any text painting commands.
	*/
	public void beginTextObject() {
	if (inTextObject) {
	throw new IllegalStateException("Already in text object");
	}
	write("BT\n");
	this.inTextObject = true;
	}

	/**
	* Called when a text object should be ended.
	*/
	public void endTextObject() {
	checkInTextObject();
	write("ET\n");
	this.inTextObject = false;
	initValues();
	}

	/**
	* Resets the state fields.
	*/
	protected void initValues() {
	this.currentFontName = null;
	this.currentFontSize = 0.0;
	this.textRenderingMode = TR_FILL;
	}

	/**
	* Creates a "q" command, pushing a copy of the entire graphics state onto the stack.
	*/
	public void saveGraphicsState() {
	write("q\n");
	}

	/**
	* Creates a "Q" command, restoring the entire graphics state to its former value by popping
	* it from the stack.
	*/
	public void restoreGraphicsState() {
	write("Q\n");
	}

	/**
	* Creates a "cm" command.
	* @param at the transformation matrix
	*/
	public void concatMatrix(AffineTransform at) {
	if (!at.isIdentity()) {
	writeTJ();
	StringBuffer sb = new StringBuffer();
	writeAffineTransform(at, sb);
	sb.append(" cm\n");
	write(sb.toString());
	}
	}

	/**
	* Writes a "Tf" command, setting a new current font.
	* @param fontName the name of the font to select
	* @param fontSize the font size (in points)
	*/
	public void writeTf(String fontName, double fontSize) {
	checkInTextObject();
	write("/" + fontName + " " + PDFNumber.doubleOut(fontSize) + " Tf\n");

	this.startText = useMultiByte ? "<" : "(";
	this.endText = useMultiByte ? ">" : ")";
	}

	/**
	* Updates the current font. This method only writes a "Tf" if the current font changes.
	* @param fontName the name of the font to select
	* @param fontSize the font size (in points)
	* @param multiByte true indicates the font is a multi-byte font, false means single-byte
	*/
	public void updateTf(String fontName, double fontSize, boolean multiByte) {
	checkInTextObject();
	if (!fontName.equals(this.currentFontName) \|\| (fontSize != this.currentFontSize)) {
	writeTJ();
	this.currentFontName = fontName;
	this.currentFontSize = fontSize;
	this.useMultiByte = multiByte;
	writeTf(fontName, fontSize);
	}
	}

	/**
	* Sets the text rendering mode.
	* @param mode the rendering mode (value 0 to 7, see PDF Spec, constants: TR_*)
	*/
	public void setTextRenderingMode(int mode) {
	if (mode < 0 \|\| mode > 7) {
	throw new IllegalArgumentException(
	"Illegal value for text rendering mode. Expected: 0-7");
	}
	if (mode != this.textRenderingMode) {
	writeTJ();
	this.textRenderingMode = mode;
	write(this.textRenderingMode + " Tr\n");
	}
	}

	/**
	* Sets the text rendering mode.
	* @param fill true if the text should be filled
	* @param stroke true if the text should be stroked
	* @param addToClip true if the path should be added for clipping
	*/
	public void setTextRenderingMode(boolean fill, boolean stroke, boolean addToClip) {
	int mode;
	if (fill) {
	mode = (stroke ? 2 : 0);
	} else {
	mode = (stroke ? 1 : 3);
	}
	if (addToClip) {
	mode += 4;
	}
	setTextRenderingMode(mode);
	}

	/**
	* Writes a "Tm" command, setting a new text transformation matrix.
	* @param localTransform the new text transformation matrix
	*/
	public void writeTextMatrix(AffineTransform localTransform) {
	StringBuffer sb = new StringBuffer();
	writeAffineTransform(localTransform, sb);
	sb.append(" Tm ");
	write(sb.toString());
	}

	/**
	* Writes a char to the "TJ-Buffer".
	* @param codepoint the mapped character (code point/character code)
	*/
	public void writeTJMappedChar(char codepoint) {
	if (bufTJ == null) {
	bufTJ = new StringBuffer();
	}
	if (bufTJ.length() == 0) {
	bufTJ.append("[").append(startText);
	}
	writeChar(codepoint, bufTJ);
	}

	/**
	* Writes a glyph adjust value to the "TJ-Buffer".
	* @param adjust the glyph adjust value in thousands of text unit space.
	*/
	public void adjustGlyphTJ(double adjust) {
	if (bufTJ == null) {
	bufTJ = new StringBuffer();
	}
	if (bufTJ.length() > 0) {
	bufTJ.append(endText).append(" ");
	}
	if (bufTJ.length() == 0) {
	bufTJ.append("[");
	}
	bufTJ.append(PDFNumber.doubleOut(adjust, DEC - 4));
	bufTJ.append(" ");
	bufTJ.append(startText);
	}

	/**
	* Writes a "TJ" command, writing out the accumulated buffer with the characters and glyph
	* positioning values. The buffer is reset afterwards.
	*/
	public void writeTJ() {
	if (isInString()) {
	bufTJ.append(endText).append("] TJ\n");
	write(bufTJ.toString());
	bufTJ.setLength(0);
	}
	}

	private boolean isInString() {
	return bufTJ != null && bufTJ.length() > 0;
	}

	}