wxWidgets/include/wx/fontmap.h

/////////////////////////////////////////////////////////////////////////////
// Name:        wx/fontmap.h
// Purpose:     wxFontMapper class
// Author:      Vadim Zeitlin
// Modified by:
// Created:     04.11.99
// RCS-ID:      $Id$
// Copyright:   (c) Vadim Zeitlin
// Licence:     wxWindows license
/////////////////////////////////////////////////////////////////////////////

#ifndef _WX_FONTMAPPER_H_
#define _WX_FONTMAPPER_H_

#ifdef __GNUG__
    #pragma interface "fontmap.h"
#endif

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

#if wxUSE_FONTMAP

#include "wx/fontenc.h"         // for wxFontEncoding

#if wxUSE_GUI
    #include "wx/fontutil.h"    // for wxNativeEncodingInfo
#endif // wxUSE_GUI

#if wxUSE_CONFIG
    class WXDLLEXPORT wxConfigBase;
#endif // wxUSE_CONFIG

#if wxUSE_GUI
    class WXDLLEXPORT wxWindow;
#endif // wxUSE_GUI

// ----------------------------------------------------------------------------
// wxFontMapper manages user-definable correspondence between logical font
// names and the fonts present on the machine.
//
// The default implementations of all functions will ask the user if they are
// not capable of finding the answer themselves and store the answer in a
// config file (configurable via SetConfigXXX functions). This behaviour may
// be disabled by giving the value of FALSE to "interactive" parameter.
// However, the functions will always consult the config file to allow the
// user-defined values override the default logic and there is no way to
// disable this - which shouldn't be ever needed because if "interactive" was
// never TRUE, the config file is never created anyhow.
// ----------------------------------------------------------------------------

class WXDLLEXPORT wxFontMapper
{
public:
    // default ctor
    wxFontMapper();

    // virtual dtor for a base class
    virtual ~wxFontMapper();

    // return instance of the wxFontMapper singleton
    static wxFontMapper *Get();
    // set the sigleton to 'mapper' instance and return previous one
    static wxFontMapper *Set(wxFontMapper *mapper);

#if wxUSE_GUI
    // find an alternative for the given encoding (which is supposed to not be
    // available on this system). If successful, return TRUE and fill info
    // structure with the parameters required to create the font, otherwise
    // return FALSE
    virtual bool GetAltForEncoding(wxFontEncoding encoding,
                                   wxNativeEncodingInfo *info,
                                   const wxString& facename = wxEmptyString,
                                   bool interactive = TRUE);

    // version better suitable for 'public' use. Returns wxFontEcoding
    // that can be used it wxFont ctor
    bool GetAltForEncoding(wxFontEncoding encoding,
                           wxFontEncoding *alt_encoding,
                           const wxString& facename = wxEmptyString,
                           bool interactive = TRUE);

    // checks whether given encoding is available in given face or not.
    // If no facename is given, 
    virtual bool IsEncodingAvailable(wxFontEncoding encoding,
                                     const wxString& facename = wxEmptyString);
#endif // wxUSE_GUI

    // returns the encoding for the given charset (in the form of RFC 2046) or
    // wxFONTENCODING_SYSTEM if couldn't decode it
    virtual wxFontEncoding CharsetToEncoding(const wxString& charset,
                                             bool interactive = TRUE);

    // encoding names
    // --------------

    // return internal string identifier for the encoding (see also
    // GetEncodingDescription())
    static wxString GetEncodingName(wxFontEncoding encoding);

    // return user-readable string describing the given encoding
    //
    // NB: hard-coded now, but might change later (read it from config?)
    static wxString GetEncodingDescription(wxFontEncoding encoding);

    // configure the appearance of the dialogs we may popup
    // ----------------------------------------------------

#if wxUSE_GUI
    // the parent window for modal dialogs
    void SetDialogParent(wxWindow *parent) { m_windowParent = parent; }

    // the title for the dialogs (note that default is quite reasonable)
    void SetDialogTitle(const wxString& title) { m_titleDialog = title; }
#endif // wxUSE_GUI

    // functions which allow to configure the config object used: by default,
    // the global one (from wxConfigBase::Get() will be used) and the default
    // root path for the config settings is the string returned by
    // GetDefaultConfigPath()
    // ----------------------------------------------------------------------

#if wxUSE_CONFIG
    // set the config object to use (may be NULL to use default)
    void SetConfig(wxConfigBase *config) { m_config = config; }

    // set the root config path to use (should be an absolute path)
    void SetConfigPath(const wxString& prefix);

    // return default config path
    static const wxChar *GetDefaultConfigPath();
#endif

protected:

#if wxUSE_CONFIG
    // get the config object we're using - if it wasn't set explicitly, this
    // function will use wxConfig::Get() to get the global one
    wxConfigBase *GetConfig();

    // gets the root path for our settings - if itwasn't set explicitly, use
    // GetDefaultConfigPath()
    const wxString& GetConfigPath();
#endif

    // change to the given (relative) path in the config, return TRUE if ok
    // (then GetConfig() will return something !NULL), FALSE if no config
    // object
    //
    // caller should provide a pointer to the string variable which should be
    // later passed to RestorePath()
    bool ChangePath(const wxString& pathNew, wxString *pathOld);

    // restore the config path after use
    void RestorePath(const wxString& pathOld);

#if wxUSE_GUI
    // GetAltForEncoding() helper: tests for the existence of the given
    // encoding and saves the result in config if ok - this results in the
    // following (desired) behaviour: when an unknown/unavailable encoding is
    // requested for the first time, the user is asked about a replacement,
    // but if he doesn't choose any and the default logic finds one, it will
    // be saved in the config so that the user won't be asked about it any
    // more
    bool TestAltEncoding(const wxString& configEntry,
                         wxFontEncoding encReplacement,
                         wxNativeEncodingInfo *info);
#endif // wxUSE_GUI

#if wxUSE_CONFIG
    // config object and path (in it) to use
    wxConfigBase *m_config;
    bool m_configIsDummy;
#endif

    wxString  m_configRootPath;

#if wxUSE_GUI
    // the title for our dialogs
    wxString m_titleDialog;

    // the parent window for our dialogs
    wxWindow *m_windowParent;
#endif // wxUSE_GUI

    friend class wxFontMapperPathChanger;
    
private:
    static wxFontMapper *sm_instance;
};

// ----------------------------------------------------------------------------
// global variables
// ----------------------------------------------------------------------------

// the default font mapper for wxWindows programs
// do NOT use! This is for backward compatibility, use wxFontMapper::Get() instead
#define wxTheFontMapper (wxFontMapper::Get())

#endif // wxUSE_FONTMAP

#endif // _WX_FONTMAPPER_H_