textoutputdev.h

source code: Covert TXT to PDF

//========================================================================
//
// TextOutputDev.h
//
// Copyright 1997-2002 Glyph & Cog, LLC
//
//========================================================================

#ifndef TEXTOUTPUTDEV_H
#define TEXTOUTPUTDEV_H

#include <aconf.h>

#ifdef USE_GCC_PRAGMAS
#pragma interface
#endif

#include <stdio.h>
#include "gtypes.h"
#include "GfxFont.h"
#include "OutputDev.h"

class GString;
class GList;
class GfxFont;
class GfxState;

//------------------------------------------------------------------------

typedef void (*TextOutputFunc)(void *stream, char *text, int len);


//------------------------------------------------------------------------
// TextFontInfo
//------------------------------------------------------------------------

class TextFontInfo {
public:

  TextFontInfo(GfxState *state);
  ~TextFontInfo();

  GBool matches(GfxState *state);

private:

  GfxFont *gfxFont;
  double horizScaling;

  double minSpaceWidth;		// min width for inter-word space, as a
				//   fraction of the font size
  double maxSpaceWidth;		// max width for inter-word space, as a
				//   fraction of the font size


  friend class TextWord;
  friend class TextPage;
};

//------------------------------------------------------------------------
// TextWord
//------------------------------------------------------------------------

class TextWord {
public:

  // Constructor.
  TextWord(GfxState *state, double x0, double y0,
	   TextFontInfo *fontA, double fontSize);


  // Destructor.
  ~TextWord();

  // Add a character to the word.
  void addChar(GfxState *state, double x, double y,
	       double dx, double dy, Unicode u);


private:

  GBool xyBefore(TextWord *word2);
  void merge(TextWord *word2);

  double xMin, xMax;		// bounding box x coordinates
  double yMin, yMax;		// bounding box y coordinates
  double yBase;			// baseline y coordinate
  Unicode *text;		// the text
  double *xRight;		// right-hand x coord of each char
  int len;			// length of text and xRight
  int size;			// size of text and xRight arrays
  TextFontInfo *font;		// font information
  double fontSize;		// font size
  GBool spaceAfter;		// set if there is a space between this
				//   word and the next word on the line
  TextWord *next;		// next word in line (before lines are
				//   assembled: next word in xy order)


  friend class TextLine;
  friend class TextPage;
};

//------------------------------------------------------------------------
// TextLine
//------------------------------------------------------------------------

class TextLine {
public:

  TextLine();
  ~TextLine();

private:

  GBool yxBefore(TextLine *line2);
  void merge(TextLine *line2);

  double xMin, xMax;		// bounding box x coordinates
  double yMin, yMax;		// bounding box y coordinates
  double yBase;			// primary baseline y coordinate
  double xSpaceL, xSpaceR;	// whitespace to left and right of this line
  TextFontInfo *font;		// primary font
  double fontSize;		// primary font size
  TextWord *words;		// words in this line
  Unicode *text;		// Unicode text of the line, including
				//   spaces between words
  double *xRight;		// right-hand x coord of each Unicode char
  int *col;			// starting column number of each Unicode char
  int len;			// number of Unicode chars
  int convertedLen;		// total number of converted characters
  GBool hyphenated;		// set if last char is a hyphen
  TextLine *pageNext;		// next line on page
  TextLine *next;		// next line in block
  TextLine *flowNext;		// next line in flow

  friend class TextBlock;
  friend class TextPage;
};

//------------------------------------------------------------------------
// TextBlock
//------------------------------------------------------------------------

class TextBlock {
public:

  TextBlock();
  ~TextBlock();

private:

  GBool yxBefore(TextBlock *blk2);
  void mergeRight(TextBlock *blk2);
  void mergeBelow(TextBlock *blk2);

  double xMin, xMax;		// bounding box x coordinates
  double yMin, yMax;		// bounding box y coordinates
  double xSpaceL, xSpaceR;	// whitespace to left and right of this block
  double ySpaceT, ySpaceB;	// whitespace above and below this block
  double maxFontSize;		// max primary font size
  TextLine *lines;		// lines in block
  TextBlock *next;		// next block in flow
  TextBlock *stackNext;		// next block on traversal stack

  friend class TextFlow;
  friend class TextPage;
};

//------------------------------------------------------------------------
// TextFlow
//------------------------------------------------------------------------

class TextFlow {
public:

  TextFlow();
  ~TextFlow();

private:

  double yMin, yMax;		// bounding box y coordinates
  double ySpaceT, ySpaceB;	// whitespace above and below this flow
  TextBlock *blocks;		// blocks in flow
  TextLine *lines;		// lines in flow
  TextFlow *next;		// next flow on page

  friend class TextPage;
};


//------------------------------------------------------------------------
// TextPage
//------------------------------------------------------------------------

class TextPage {
public:

  // Constructor.
  TextPage(GBool rawOrder);

  // Destructor.
  ~TextPage();

  // Update the current font.
  void updateFont(GfxState *state);


  // Begin a new word.
  void beginWord(GfxState *state, double x0, double y0);

  // Add a character to the current word.
  void addChar(GfxState *state, double x, double y,
	       double dx, double dy,
	       CharCode c, Unicode *u, int uLen);

  // End the current word, sorting it into the list of words.
  void endWord();

  // Add a word, sorting it into the list of words.
  void addWord(TextWord *word);


  // Coalesce strings that look like parts of the same line.
  void coalesce();

  // Find a string.  If <top> is true, starts looking at top of page;
  // otherwise starts looking at <xMin>,<yMin>.  If <bottom> is true,
  // stops looking at bottom of page; otherwise stops looking at
  // <xMax>,<yMax>.  If found, sets the text bounding rectange and
  // returns true; otherwise returns false.
  GBool findText(Unicode *s, int len,
		 GBool top, GBool bottom,
		 double *xMin, double *yMin,
		 double *xMax, double *yMax);

  // Get the text which is inside the specified rectangle.
  GString *getText(double xMin, double yMin,
		   double xMax, double yMax);

  // Dump contents of page to a file.
  void dump(void *outputStream, TextOutputFunc outputFunc,
	    GBool physLayout);

  // Start a new page.
  void startPage(GfxState *state);


private:

  void clear();
  double lineFit(TextLine *line, TextWord *lastWord, TextWord *word);
  GBool lineFit2(TextLine *line0, TextLine *line1);
  GBool blockFit(TextBlock *blk, TextLine *line);
  GBool blockFit2(TextBlock *blk0, TextBlock *blk1);
  GBool flowFit(TextFlow *flow, TextBlock *blk);

  GBool rawOrder;		// keep text in content stream order

  double pageWidth, pageHeight;	// width and height of current page
  TextWord *curWord;		// currently active string
  TextFontInfo *font;		// current font
  double fontSize;		// current font size
  int nest;			// current nesting level (for Type 3 fonts)
  int nTinyChars;		// number of "tiny" chars seen so far

  TextWord *words;		// words, in xy order (before they're
				//   sorted into lines)
  TextWord *wordPtr;		// cursor for the word list

  TextLine *lines;		// lines, in xy order
  TextFlow *flows;		// flows, in reading order

  GList *fonts;			// all font info objects used on this
				//   page [TextFontInfo]


};

//------------------------------------------------------------------------
// TextOutputDev
//------------------------------------------------------------------------

class TextOutputDev: public OutputDev {
public:

  // Open a text output file.  If <fileName> is NULL, no file is
  // written (this is useful, e.g., for searching text).  If
  // <physLayoutA> is true, the original physical layout of the text
  // is maintained.  If <rawOrder> is true, the text is kept in
  // content stream order.
  TextOutputDev(char *fileName, GBool physLayoutA,
		GBool rawOrderA, GBool append);

  // Create a TextOutputDev which will write to a generic stream.  If
  // <physLayoutA> is true, the original physical layout of the text
  // is maintained.  If <rawOrder> is true, the text is kept in
  // content stream order.
  TextOutputDev(TextOutputFunc func, void *stream,
		GBool physLayoutA, GBool rawOrderA);

  // Destructor.
  virtual ~TextOutputDev();

  // Check if file was successfully created.
  virtual GBool isOk() { return ok; }

  //---- get info about output device

  // Does this device use upside-down coordinates?
  // (Upside-down means (0,0) is the top left corner of the page.)
  virtual GBool upsideDown() { return gTrue; }

  // Does this device use drawChar() or drawString()?
  virtual GBool useDrawChar() { return gTrue; }

  // Does this device use beginType3Char/endType3Char?  Otherwise,
  // text in Type 3 fonts will be drawn with drawChar/drawString.
  virtual GBool interpretType3Chars() { return gFalse; }

  // Does this device need non-text content?
  virtual GBool needNonText() { return gFalse; }

  //----- initialization and control

  // Start a page.
  virtual void startPage(int pageNum, GfxState *state);

  // End a page.
  virtual void endPage();

  //----- update text state
  virtual void updateFont(GfxState *state);

  //----- text drawing
  virtual void beginString(GfxState *state, GString *s);
  virtual void endString(GfxState *state);
  virtual void drawChar(GfxState *state, double x, double y,
			double dx, double dy,
			double originX, double originY,
			CharCode c, Unicode *u, int uLen);

  //----- path painting

  //----- special access

  // Find a string.  If <top> is true, starts looking at top of page;
  // otherwise starts looking at <xMin>,<yMin>.  If <bottom> is true,
  // stops looking at bottom of page; otherwise stops looking at
  // <xMax>,<yMax>.  If found, sets the text bounding rectange and
  // returns true; otherwise returns false.
  GBool findText(Unicode *s, int len,
		 GBool top, GBool bottom,
		 double *xMin, double *yMin,
		 double *xMax, double *yMax);

  // Get the text which is inside the specified rectangle.
  GString *getText(double xMin, double yMin,
		   double xMax, double yMax);


private:

  TextOutputFunc outputFunc;	// output function
  void *outputStream;		// output stream
  GBool needClose;		// need to close the output file?
				//   (only if outputStream is a FILE*)
  TextPage *text;		// text for the current page
  GBool physLayout;		// maintain original physical layout when
				//   dumping text
  GBool rawOrder;		// keep text in content stream order
  GBool ok;			// set up ok?

};

#endif