tdegraphics/kdvi/fontpool.h

// -*- C++ -*-
// fontpool.h
//
// (C) 2001-2004 Stefan Kebekus
// Distributed under the GPL

#ifndef _FONTPOOL_H
#define _FONTPOOL_H

#include "fontEncodingPool.h"
#include "fontMap.h"
#include "fontprogress.h"
#include "TeXFontDefinition.h"

#include <tqptrlist.h>
#include <tqobject.h>

#ifdef HAVE_FREETYPE
#include <ft2build.h>
#include FT_FREETYPE_H
#endif

class KProcess;
class KShellProcess;


/**
 *  A list of fonts and a compilation of utility functions
 *
 * This class holds a list of fonts and is able to perform a number of
 * functions on each of the fonts. The main use of this class is that
 * it is able to control a concurrently running "kpsewhich" programm
 * which is used to locate and load the fonts.
 *
 * @author Stefan Kebekus   <kebekus@kde.org>
 *
 **/

class fontPool : public TQObject {
 Q_OBJECT
  

public:
 // Default constructor. 
 fontPool();

 // Default destructor.
 ~fontPool();
 
 /** Method used to set the MetafontMode for the PK font files. This
     data is used when loading fonts. Currently, a change here will be
     applied only to those font which were not yet loaded ---expect
     funny results when changing the data in the mid-work. */
 void setParameters( bool useFontHints );
 
 /** Sets the DVI file's path. This information is used to set the
     current working directory for the kpsewhich command, so that
     kpsewhich will find fonts that are stored in the DVI file's
     directory. */ 
 void setExtraSearchPath( const TQString &path ) {extraSearchPath = path;}
 
 /** Returns the path that is set as the current working directory
     for the kpsewhich command, so that kpsewhich will find fonts
     that are stored in the DVI file's directory. */ 
 TQString getExtraSearchPath( ) const {return extraSearchPath;}
 
 /** Sets the resolution of the output device. */
 void setDisplayResolution( double _displayResolution_in_dpi );
 
 /** Sets the number of centimeters per DVI unit. */
 void setCMperDVIunit( double CMperDVI );
 double getCMperDVIunit() const {return CMperDVIunit;}
 
 // If return value is true, font hinting should be used if possible
 bool getUseFontHints() const {return useFontHints;}
 
 // This method adds a font to the list. If the font is not currently
 // loaded, it's file will be located and font::load_font will be
 // called. Since this is done using a concurrently running process,
 // there is no guarantee that the loading is already performed when
 // the method returns.
 TeXFontDefinition* appendx(const TQString& fontname, TQ_UINT32 checksum, TQ_UINT32 scale, double enlargement);
 
 // Returns a string in a very basic HTML format which describes the
 // fonts in the pool.
 TQString status();
  
  // This is the list which actually holds pointers to the fonts
  TQPtrList<TeXFontDefinition> fontList;

  // This method marks all fonts in the fontpool as "not in use". The
  // fonts are, however, not removed from memory until the method
  // release_fonts is called. The method is called when the dvi-file
  // is closed. Because the next dvi-file which will be loaded is
  // likely to use most of the fonts again, this method implements a
  // convenient way of re-using fonts without loading them repeatedly.
  void mark_fonts_as_unused();

  /** This methods removes all fonts from the fontpool (and thus from
      memory) which are labeled "not in use". For explanation, see the
      mark_fonts_as_unused method. */
  void release_fonts();

#ifdef HAVE_FREETYPE
  /** A handle to the FreeType library, which is used by TeXFont_PFM
      font objects, if KDVI is compiled with FreeType support.  */
  FT_Library FreeType_library;
  
  /** Simple marker. Set to 'true', if the FreeType library was loaded
      successfully */
  bool FreeType_could_be_loaded;

  /** This maps TeX font names to font file names, full font names and
      encodings. See the file 'fontMap.h' for a detailed
      description. */
  fontMap          fontsByTeXName;

  /** This is a list of known font encodings which can be conveniently
      acessed by name. */
  fontEncodingPool encodingPool;
#endif

  /** This flag is set during the construction of the fontPool
      object. It indicates if the QT library supports the alpha
      channel of pixmaps. Experiments show that --depending of the
      configuration of QT at compile and runtime or the availability
      of the XFt extension, alpha channels are either supported, or
      silently converted to 1-bit masks. The redering routines in the
      TeXFont implementation use this flag to choose the apropriate
      drawing routines for the different setups. */
  bool TQPixmapSupportsAlpha;

signals:
  /** Passed through to the top-level kpart. */
  void setStatusBarText( const TQString& );

public slots:
 // Locates font files on the disk using the kpsewhich program.  If
 // 'locateTFMonly' is true, the method does not look for PFB- or
 // PK-fonts. Instead, only TFM-files are searched. This option can be
 // used as a 'last resort': if a found cannot be found, one can at
 // least use the TFM file to draw filled rectangles for the
 // characters. If not null, the bool pointed at by virtualFontsFound
 // is set to true if one of the fonts found is a virtual font. If no
 // virtual font is found, the variable remains untouched.
 void locateFonts();
 
private:
 // This method goes through the list of fonts, and marks each of them
 // as 'located'. Used, e.g. after a fatal error in the font lookup
 // process to ensure that the problematic kpsewhich is not used again
 void markFontsAsLocated();

 // Checks if all the fonts file names have been located, and returns
 // true if that is so.
 bool areFontsLocated();

 // This flag is used by PFB fonts to determine if the FREETYPE engine
 // should use hinted fonts or not
 bool           useFontHints; 
 
 // Resolution of the output device.
 double         displayResolution_in_dpi;
 
 // Number of centimeters per DVI unit
 double         CMperDVIunit; 


 /** Members used for font location */
 
 // Locates font files on the disk using the kpsewhich program.  If
 // 'locateTFMonly' is true, the method does not look for PFB- or
 // PK-fonts. Instead, only TFM-files are searched. This option can be
 // used as a 'last resort': if a found cannot be found, one can at
 // least use the TFM file to draw filled rectangles for the
 // characters. If not null, the bool pointed at by virtualFontsFound
 // is set to true if one of the fonts found is a virtual font. If no
 // virtual font is found, the variable remains untouched.
 void locateFonts(bool makePK, bool locateTFMonly, bool *virtualFontsFound=0);

 // This TQString is used internally by the mf_output_receiver()
 // method.  This string is set to TQString() in locateFonts(bool,
 // bool, bool *). Values are set and read by the
 // mf_output_receiver(...)  method
 TQString        MetafontOutput;

 // This TQString is used to collect the output of kpsewhich and
 // MetaFont. The string is set to TQString() in the
 // locateFonts()-method, and content is gathered by the
 // mf_output_receiver(). This string is used by locateFonts() and
 // locateFonts(bool, bool, bool *) to display error messages.
 TQString        kpsewhichOutput;
 
 // This string is set to the DVI file's path. It is used to set the
 // current working directory for the kpsewhich command, so that
 // kpsewhich will find fonts that are stored in the DVI file's
 // directory. Used by the locateFonts() and the locateFonts(bool,
 // bool, bool *) method. Values are set by the
 // setExtraSearchPath(...) method
 TQString        extraSearchPath;
 
 // FontProgress; the progress dialog used when generating fonts.
 fontProgressDialog progress;
 
private slots:
  /** Members used for font location */
   
  // For internal purposess only. This slot is called when MetaFont is
  // run via the kpsewhich programm. The MetaFont output is
  // transmitted to the fontpool via this slot. This method calles
  // suitable methods in the fontProgres Dialog, and collects the
  // output of MetaFontt int the "MetafontOutput" member
 void mf_output_receiver(KProcess *, char *, int);
};

#endif //ifndef _FONTPOOL_H