// This defines the interface to the QextScintillaLexer class.
//
// Copyright (c) 2006
// 	Riverbank Computing Limited <info@riverbankcomputing.co.uk>
// 
// This file is part of QScintilla.
// 
// This copy of QScintilla is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2, or (at your option) any
// later version.
// 
// QScintilla is supplied in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
// details.
// 
// You should have received a copy of the GNU General Public License along with
// QScintilla; see the file LICENSE.  If not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.


#ifndef QEXTSCINTILLALEXER_H
#define QEXTSCINTILLALEXER_H


#include <qobject.h>
#include <qstring.h>
#include <qcolor.h>
#include <qfont.h>

#include <qextscintillaglobal.h>


class QSettings;


//! \brief The QextScintillaLexer class is an abstract class used as a base for
//! specific language lexers.
//!
//! A Scintilla lexer scans the text breaking it up into separate language
//! objects, e.g. keywords, strings, operators.  The lexer then uses a
//! different style to draw each object.  A style is identified by a style
//! number and has a number of attributes, including colour and font.  A
//! specific language lexer will implement appropriate default styles which can
//! be overriden by an application by further sub-classing the specific
//! language lexer.
//!
//! A specific language lexer may provide one or more sets of words to be
//! recognised as keywords.  Most lexers only provide one set, but some may
//! support languages embedded in other languages and provide several sets.
//!
//! QextScintillaLexer provides convenience methods for saving and restoring
//! user preferences for fonts and colours.
class QEXTSCINTILLA_EXPORT QextScintillaLexer : public QObject
{
    Q_OBJECT

public:
    //! Construct a QextScintillaLexer with parent \a parent and name
    //! \a name.  \a parent is typically the QextScintilla instance.
    QextScintillaLexer(QObject *parent = 0,const char *name = 0);

    //! Destroys the QextScintillaLexer instance.
    virtual ~QextScintillaLexer();

    //! Returns the name of the language.  It must be re-implemented by a
    //! sub-class.
    virtual const char *language() const = 0;

    //! Returns the name of the lexer.  Some lexers support a number of
    //! languages.  It must be re-implemented by a sub-class.
    virtual const char *lexer() const = 0;

    //! \internal Returns the characters that can fill up auto-completion.
    //! These are ignored if QextScintilla::setAutoCompletionFillups() has
    //! been explicitly called.
    virtual const char *autoCompletionFillups() const;

    //! \internal Returns the characters that can start auto-completion.
    virtual const char *autoCompletionStartCharacters() const;

    //! Returns the auto-indentation style.  The default is 0 if the
    //! language is block structured, or QextScintilla::AiMaintain if not.
    //!
    //! \sa setAutoIndentStyle(), QextScintilla::AiMaintain,
    //! QextScintilla::AiOpening, QextScintilla::AiClosing
    int autoIndentStyle();

    //! \internal Returns a space separated list of words or characters in
    //! a particular style that define the end of a block for
    //! auto-indentation.  The style is returned via \a style.
    virtual const char *blockEnd(int *style = 0) const;

    //! \internal Returns the number of lines prior to the current one when
    //! determining the scope of a block when auto-indenting.
    virtual int blockLookback() const;

    //! \internal Returns a space separated list of words or characters in
    //! a particular style that define the start of a block for
    //! auto-indentation.  The style is returned via \a style.
    virtual const char *blockStart(int *style = 0) const;

    //! \internal Returns a space separated list of keywords in a
    //! particular style that define the start of a block for
    //! auto-indentation.  The style is returned via \a style.
    virtual const char *blockStartKeyword(int *style = 0) const;

    //! \internal Returns the style used for braces for brace matching.
    virtual int braceStyle() const;

    //! \internal Returns the string of characters that comprise a word.
    //! The default is 0 which implies the upper and lower case alphabetic
    //! characters and underscore.
    virtual const char *wordCharacters() const;

    //! Returns the foreground colour of the text for style number
    //! \a style.  The default colour is black.
    //!
    //! \sa paper()
    virtual QColor color(int style) const;

    //! Returns the end-of-line for style number \a style.  The default is
    //! FALSE.
    virtual bool eolFill(int style) const;

    //! Returns the font for style number \a style.  The default font is
    //! that returned by defaultFont().
    //!
    //! \sa defaultFont()
    virtual QFont font(int style) const;

    //! Returns the set of keywords for the keyword set \a set recognised
    //! by the lexer as a space separated string.  0 is returned if there
    //! is no such set.
    virtual const char *keywords(int set) const;

    //! \internal Returns the number of the style used for whitespace.  The
    //! default implementation returns 0 which is the convention adopted by
    //! most lexers.
    virtual int defaultStyle() const;

    //! Returns the descriptive name for style number \a style.  If the
    //! style is invalid for this language then QString::null is returned.
    //! This is intended to be used in user preference dialogs.
    virtual QString description(int style) const = 0;

    //! Returns the background colour of the text for style number
    //! \a style.
    //!
    //! \sa defaultPaper(), color()
    virtual QColor paper(int style) const;

    //! Returns the default font for all styles.
    //!
    //! \sa setDefaultFont()
    virtual QFont defaultFont() const;

    //! Returns the default text colour for all styles.
    //!
    //! \sa setDefaultColor()
    virtual QColor defaultColor() const;

    //! Returns the default paper colour for all styles.
    //!
    //! \sa setDefaultPaper()
    virtual QColor defaultPaper() const;

    //! Causes all properties to be refreshed by emitting the
    //! propertyChanged() signal as required.
    virtual void refreshProperties();

    //! The colour, paper, font and end-of-line for each style number, and
    //! all lexer specific properties are read from the settings \a qs.
    //! \a prefix is prepended to the key of each entry.  TRUE is returned
    //! if there was no error.
    //!
    //! \sa writeSettings(), QextScintilla::setLexer()
    bool readSettings(QSettings &qs,const char *prefix = "/Scintilla");

    //! The colour, paper, font and end-of-line for each style number, and
    //! all lexer specific properties are written to the settings \a qs.
    //! \a prefix is prepended to the key of each entry.  TRUE is returned
    //! if there was no error.
    //!
    //! \sa readSettings()
    bool writeSettings(QSettings &qs,
               const char *prefix = "/Scintilla") const;

public slots:
    //! The auto-indentation style is set to \a autoindentstyle.
    //!
    //! \sa autoIndentStyle(), QextScintilla::AiMaintain,
    //! QextScintilla::AiOpening, QextScintilla::AiClosing
    virtual void setAutoIndentStyle(int autoindentstyle);

    //! The foreground colour for style number \a style is set to \a c.  If
    //! \a style is -1 then the colour is set for all styles.
    virtual void setColor(const QColor &c,int style = -1);

    //! The default font for all styles is set to \a f.
    //!
    //! \sa defaultFont()
    virtual void setDefaultFont(const QFont &f);

    //! The default text colour for all styles is set to \a c.
    //!
    //! \sa defaultColor(), color()
    virtual void setDefaultColor(const QColor &c);

    //! The default paper colour for all styles is set to \a c.
    //!
    //! \sa defaultPaper(), paper()
    virtual void setDefaultPaper(const QColor &c);

    //! The end-of-line fill for style number \a style is set to
    //! \a eoffill.  If \a style is -1 then the fill is set for all styles.
    virtual void setEolFill(bool eoffill,int style = -1);

    //! The font for style number \a style is set to \a f.  If \a style is
    //! -1 then the font is set for all styles.
    virtual void setFont(const QFont &f,int style = -1);

    //! The background colour for style number \a style is set to \a c.  If
    //! \a style is -1 then the colour is set for all styles.
    virtual void setPaper(const QColor &c,int style = -1);

signals:
    //! This signal is emitted when the foreground colour of style number
    //! \a style has changed.  The new colour is \a c.
    void colorChanged(const QColor &c,int style);

    //! This signal is emitted when the end-of-file fill of style number
    //! \a style has changed.  The new fill is \a eoffilled.
    void eolFillChanged(bool eoffilled,int style);

    //! This signal is emitted when the font of style number \a style has
    //! changed.  The new font is \a f.
    void fontChanged(const QFont &f,int style);

    //! This signal is emitted when the background colour of style number
    //! \a style has changed.  The new colour is \a c.
    void paperChanged(const QColor &c,int style);

    //! This signal is emitted when the value of the lexer property \a prop
    //! needs to be changed.  The new value is \a val.
    void propertyChanged(const char *prop,const char *val);

protected:
    //! The lexer's properties are read from the settings \a qs.  \a prefix
    //! (which has a trailing '/') should be used as a prefix to the key of
    //! each setting.  TRUE is returned if there is no error.
    //!
    virtual bool readProperties(QSettings &qs,const QString &prefix);

    //! The lexer's properties are written to the settings \a qs.
    //! \a prefix (which has a trailing '/') should be used as a prefix to
    //! the key of each setting.  TRUE is returned if there is no error.
    //!
    virtual bool writeProperties(QSettings &qs,const QString &prefix) const;

private:
    int autoIndStyle;
    QFont defFont;
    QColor defColor;
    QColor defPaper;

#if defined(Q_DISABLE_COPY)
    QextScintillaLexer(const QextScintillaLexer &);
    QextScintillaLexer &operator=(const QextScintillaLexer &);
#endif
};

#endif
