added wxDIB(HBITMAP) ctor and corresponding Create(); made GetData() return uchar...

[wxWidgets.git] / samples / richedit / wxllist.h

/*-*- c++ -*-********************************************************
 * wxLayoutList.h - a formatted text rendering engine for wxWidgets *
 *                                                                  *
 * (C) 1999-2000 by Karsten Ballüder (ballueder@gmx.net)            *
 *                                                                  *
 * $Id$
 *******************************************************************/


#ifndef WXLLIST_H
#define WXLLIST_H

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

#include   "kbList.h"

#include   "wx/wx.h"
#include   "wx/print.h"
#include   "wx/printdlg.h"
#include   "wx/generic/printps.h"
#include   "wx/generic/prntdlgg.h"
#include   "wx/dataobj.h"

// skip the following defines if embedded in M application
#ifndef   M_BASEDIR
#   define WXMENU_LAYOUT_LCLICK     1111
#   define WXMENU_LAYOUT_RCLICK     1112
#   define WXMENU_LAYOUT_DBLCLICK   1113
#else // for Mahogany only
#   include "MObject.h"
#endif

// use the wxWidgets caret class instead of home grown cursor whenever possible
#ifdef __WXMSW__
#   undef WXLAYOUT_USE_CARET
#   define WXLAYOUT_USE_CARET 1
#endif // __WXMSW__

// do not enable debug mode within Mahogany unless in debug mode
#if defined(__WXDEBUG__) && (( ! defined(M_BASEDIR) )|| defined(DEBUG))
#   define   WXLAYOUT_DEBUG
#endif

#ifdef WXLAYOUT_DEBUG
#   define WXLO_TRACE(x)   wxLogDebug(x)
// activate profiling: #   define WXLO_PROFILE
#else
#   define WXLO_TRACE(x)
#endif

/* Some profiling code: */
#if defined (WXLO_PROFILE)
#include <sys/time.h>
#include <unistd.h>

#   define WXLO_TIMER_DEFINE(x)    static struct timeval  x
#   define WXLO_TIMER_START(x)     gettimeofday(&x,NULL)
#   define WXLO_TIMER_STOP(x)      { struct timeval y; \
                                gettimeofday(&y,NULL); \
                                x.tv_sec -= y.tv_sec; x.tv_usec -= y.tv_usec; }
#   define   WXLO_TIMER_PRINT(x)   wxLogDebug("Timer " #x " elapsed: %ld", \
                                         (long)(x.tv_sec * -1000 - x.tv_usec));
#else
#   define   WXLO_TIMER_DEFINE(x)
#   define   WXLO_TIMER_START(x)
#   define   WXLO_TIMER_STOP(x)
#   define   WXLO_TIMER_PRINT(x)
#endif


#define WXLO_DEBUG_URECT 0

#ifndef WXLO_DEFAULTFONTSIZE
#   define WXLO_DEFAULTFONTSIZE 12
#endif

#ifdef __WXMSW__
#   define WXLO_BITMAP_FORMAT wxBITMAP_TYPE_BMP
#else
#   define WXLO_BITMAP_FORMAT wxBITMAP_TYPE_PNG
#endif

/// Types of currently supported layout objects.
enum wxLayoutObjectType
{
    /// illegal object type, should never appear
    WXLO_TYPE_INVALID = 0,

    /// text object, containing normal text
    WXLO_TYPE_TEXT,

    /// command object, containing font or colour changes
    WXLO_TYPE_CMD,

    /// icon object, any kind of image
    WXLO_TYPE_ICON,

    /// a linebreak, does not exist as an object
    WXLO_TYPE_LINEBREAK
};

/// Type used for coordinates in drawing. Must be signed.
typedef long CoordType;

// Forward declarations.
class wxLayoutList;
class wxLayoutLine;
class wxLayoutObject;

class WXDLLEXPORT wxCaret;
class WXDLLEXPORT wxColour;
class WXDLLEXPORT wxDC;
class WXDLLEXPORT wxFont;

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

   The wxLayout objects which make up the lines.

 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/** The base class defining the interface to each object which can be
    part of the layout. Each object needs to draw itself and calculate
    its size.
*/
class wxLayoutObject
#ifdef M_BASEDIR
   : public MObject
#endif
{
public:
    /** This structure can be used to contain data associated with the
        object.
        It is refcounted, so the caller has to do a DecRef() on it
        instead of a delete.
    */
    struct UserData
    {
        UserData() { m_refcount = 1; }
        inline void IncRef() { m_refcount++; }
        inline void DecRef() { m_refcount--; if(m_refcount == 0) delete this;}
        inline void SetLabel(const wxString &l) { m_label = l; }
        inline const wxString & GetLabel() const { return m_label; }
    private:
        int m_refcount;
        wxString m_label;
    protected:
        virtual ~UserData() { wxASSERT(m_refcount == 0); }
        /// prevents gcc from generating stupid warnings
        friend class dummy_UserData;
    };

    /// return the type of this object
    virtual wxLayoutObjectType GetType() const { return WXLO_TYPE_INVALID; }
    /** Calculates the size of an object.
        @param dc the wxDC to draw on
        @param llist the wxLayoutList
    */
    virtual void Layout(wxDC &dc, wxLayoutList *llist) = 0;

    /** Draws an object.
        @param dc the wxDC to draw on
        @param coords where to draw the baseline of the object.
        @param wxllist pointer to wxLayoutList
        @param begin if !=-1, from which position on to highlight it
        @param end if begin !=-1, how many positions to highlight it
    */
    virtual void Draw(wxDC & /* dc */,
        wxPoint const & /* coords */,
        wxLayoutList *WXUNUSED(wxllist),
        CoordType WXUNUSED(begin) = -1,
        CoordType WXUNUSED(end) = -1)  { }

    /** Calculates and returns the size of the object.
        @param top where to store height above baseline
        @param bottom where to store height below baseline
        @return the size of the object's box in pixels
    */
    virtual wxPoint GetSize(CoordType * top, CoordType *bottom) const
        { *top = 0; *bottom = 0; return wxPoint(0,0); }

    /// Return just the width of the object on the screen.
    virtual CoordType GetWidth() const { return 0; }

    /// returns the number of cursor positions occupied by this object
    virtual CoordType GetLength() const { return 1; }

    /** Returns the cursor offset relating to the screen x position
        relative to begin of object.
        @param dc the wxDC to use for calculations
        @param xpos relative x position from head of object
        @return cursor coordinate offset
    */
    virtual CoordType GetOffsetScreen( wxDC & WXUNUSED(dc),
        CoordType WXUNUSED(xpos) ) const
    {
        return 0;
    }

    /// constructor
    wxLayoutObject() { m_UserData = NULL; }

    /// delete the user data
    virtual ~wxLayoutObject() { if(m_UserData) m_UserData->DecRef(); }

#ifdef WXLAYOUT_DEBUG
    virtual wxString DebugDump() const;
#endif

    /** Tells the object about some user data. This data is associated
        with the object and will be deleted at destruction time.
        It is reference counted.
    */
    void   SetUserData(UserData *data)
    {
        if(m_UserData)
            m_UserData->DecRef();

        m_UserData = data;

        if(m_UserData)
            m_UserData->IncRef();
    }

    /** Return the user data.
        Increments the object's reference count. When no longer needed,
        caller must call DecRef() on the pointer returned.
    */
    UserData * GetUserData() const { if(m_UserData) m_UserData->IncRef(); return m_UserData; }

    /** Makes a copy of this object.
    */
    virtual wxLayoutObject *Copy() = 0;

    /** Clipboard support function. Read and write objects to
        strings. */
    //@{
    /// Writes the object to the string.
    virtual void Write(wxString &ostr) = 0;

    /** Reads an object.
        @param str stream to read from, will bee changed
        @return true on success
    */
    static wxLayoutObject *Read(wxString &istr);
    //@}

    /// returns true if the object is shown on the screen (i.e. not cmd object)
    bool IsVisibleObject() const { return GetType() != WXLO_TYPE_CMD; }

protected:
    /// optional data for application's use
    UserData *m_UserData;
#if defined (M_BASEDIR) && defined (DEBUG)
    MOBJECT_NAME(wxLayoutObject)
#endif
};

/// Define a list type of wxLayoutObject pointers.
KBLIST_DEFINE(wxLayoutObjectList, wxLayoutObject);

/// An illegal iterator to save typing.
#define NULLIT (wxLayoutObjectList::iterator(NULL))

/// The iterator type.
typedef wxLayoutObjectList::iterator wxLOiterator;

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

   wxLayoutObjectText

 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/** This class implements a wxLayoutObject holding plain text.
 */
class wxLayoutObjectText : public wxLayoutObject
{
public:
    wxLayoutObjectText(const wxString &txt = wxEmptyString);

    virtual wxLayoutObjectType GetType() const { return WXLO_TYPE_TEXT; }
    virtual void Layout(wxDC &dc, wxLayoutList *llist);
    virtual void Draw(wxDC &dc, wxPoint const &coords,
        wxLayoutList *wxllist,
        CoordType begin = -1,
        CoordType end = -1);

    /** Calculates and returns the size of the object.
        @param top where to store height above baseline
        @param bottom where to store height below baseline
        @return the size of the object's box in pixels
    */
    virtual wxPoint GetSize(CoordType * top, CoordType *bottom) const;

    /// Return just the width of the object on the screen.
    virtual CoordType GetWidth() const { return m_Width; }

    /** Returns the cursor offset relating to the screen x position
        relative to begin of object.
        @param dc the wxDC to use for calculations
        @param xpos relative x position from head of object
        @return cursor coordinate offset
    */
    virtual CoordType GetOffsetScreen(wxDC &dc, CoordType xpos) const;

    virtual void Write(wxString &ostr);
    static wxLayoutObjectText *Read(wxString &istr);

#ifdef WXLAYOUT_DEBUG
    virtual wxString DebugDump() const;
#endif

    virtual CoordType GetLength() const { return wxStrlen(m_Text.c_str()); }

    // for editing:
    wxString & GetText() { return m_Text; }

    void SetText(wxString const &text) { m_Text = text; }
    /** Makes a copy of this object.
    */
    virtual wxLayoutObject *Copy();

private:
    wxString m_Text;

    /// size of the box containing text
    long   m_Width, m_Height;

    /// Height above baseline.
    long   m_Top;

    /// Height below baseline.
    long   m_Bottom;
};

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

   wxLayoutObjectIcon

 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/** This class implements a wxLayoutObject holding a graphic.
 */
class wxLayoutObjectIcon : public wxLayoutObject
{
public:
    wxLayoutObjectIcon(wxBitmap *icon = NULL);
    wxLayoutObjectIcon(wxBitmap const &icon);

    ~wxLayoutObjectIcon() { if(m_Icon) delete m_Icon; }

    virtual wxLayoutObjectType GetType() const { return WXLO_TYPE_ICON; }
    virtual void Layout(wxDC &dc, wxLayoutList *llist);
    virtual void Draw(wxDC &dc, wxPoint const &coords,
        wxLayoutList *wxllist,
        CoordType begin = -1,
        CoordType end = -1);

    /** Calculates and returns the size of the object.
        @param top where to store height above baseline
        @param bottom where to store height below baseline
        @return the size of the object's box in pixels
    */
    virtual wxPoint GetSize(CoordType * top, CoordType *bottom) const;

    /// Return just the width of the object on the screen.
    virtual CoordType GetWidth() const { return m_Icon->GetWidth(); }

    // return a pointer to the icon
    wxBitmap *GetIcon() const { return m_Icon; }

    /** Makes a copy of this object.
    */
    virtual wxLayoutObject *Copy();
    virtual void Write(wxString &ostr);
    static wxLayoutObjectIcon *Read(wxString &istr);

private:
    wxBitmap *m_Icon;
};

/** This structure holds all formatting information.
*/
struct wxLayoutStyleInfo
{
    wxLayoutStyleInfo(int ifamily = -1,
        int isize = -1,
        int istyle = -1,
        int iweight = -1,
        int iul = -1,
        wxColour *fg = NULL,
        wxColour *bg = NULL);

    wxLayoutStyleInfo & operator=(const wxLayoutStyleInfo &right);

    wxColour & GetBGColour() { return m_bg; }

    /// Font change parameters.
    int  size, family, style, weight, underline;

    /// Colours
    wxColour m_bg, m_fg;
    int m_fg_valid, m_bg_valid; // bool, but must be int!
};

/// a cached font
class wxFontCacheEntry
{
public:
    wxFontCacheEntry(int family, int size, int style, int weight,
        bool underline)
    {
        m_Family = family; m_Size = size; m_Style = style;
        m_Weight = weight; m_Underline = underline;
        m_Font = new wxFont(m_Size, m_Family,
            m_Style, m_Weight, m_Underline);
    }

    bool Matches(int family, int size, int style, int weight,
        bool underline) const
    {
        return size == m_Size && family == m_Family
            && style == m_Style && weight == m_Weight
            && underline == m_Underline;
    }

    wxFont & GetFont() { return *m_Font; }
    ~wxFontCacheEntry()
    {
        delete m_Font;
    }

private:
    wxFont *m_Font;

    // VZ: I wonder why it doesn't use wxLayoutStyleInfo instead of those?
    int  m_Family, m_Size, m_Style, m_Weight;
    bool m_Underline;
};

KBLIST_DEFINE(wxFCEList, wxFontCacheEntry);

class wxFontCache
{
public:
    wxFont & GetFont(int family, int size, int style, int weight,
        bool underline);

    wxFont & GetFont(wxLayoutStyleInfo const &si)
    {
        return GetFont(si.family, si.size, si.style, si.weight,
            si.underline != 0);
    }

private:
    wxFCEList m_FontList;
};

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

   wxLayoutObjectCmd

 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/** This class implements a wxLayoutObject holding style change commands.
 */
class wxLayoutObjectCmd : public wxLayoutObject
{
public:
    virtual wxLayoutObjectType GetType() const { return WXLO_TYPE_CMD; }
    virtual void Layout(wxDC &dc, wxLayoutList *llist);
    virtual void Draw(wxDC &dc, wxPoint const &coords,
        wxLayoutList *wxllist,
        CoordType begin = -1,
        CoordType end = -1);

    wxLayoutObjectCmd(int family = -1,
        int size = -1,
        int style = -1,
        int weight = -1,
        int underline = -1,
        wxColour *fg = NULL,
        wxColour *bg = NULL);

    wxLayoutObjectCmd(const wxLayoutStyleInfo &si);
    ~wxLayoutObjectCmd();
    /** Stores the current style in the styleinfo structure */
    wxLayoutStyleInfo * GetStyle() const;
    /** Makes a copy of this object.
    */
    virtual wxLayoutObject *Copy();
    virtual void Write(wxString &ostr);
    static wxLayoutObjectCmd *Read(wxString &istr);

private:
    wxLayoutStyleInfo *m_StyleInfo;
};

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

   The wxLayoutLine object

   * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/** This class represents a single line of objects to be displayed.
    It knows its height and total size and whether it needs to be
    redrawn or not.
    It has pointers to its first and next line so it can automatically
    update them as needed.
*/
class wxLayoutLine
{
public:
    /** Constructor.
        @param prev pointer to previous line or NULL
        @param next pointer to following line or NULL
        @param llist pointer to layout list
    */
    wxLayoutLine(wxLayoutLine *prev, wxLayoutList *llist);
    /** This function inserts a new object at cursor position xpos.
        @param xpos where to insert new object
        @param obj  the object to insert
        @return true if that xpos existed and the object was inserted
    */
    bool Insert(CoordType xpos, wxLayoutObject *obj);

    /** This function inserts text at cursor position xpos.
        @param xpos where to insert
        @param text  the text to insert
        @return true if that xpos existed and the object was inserted
    */
    bool Insert(CoordType xpos, const wxString& text);

    /** This function appends an object to the line.
        @param obj  the object to insert
    */
    void Append(wxLayoutObject * obj)
    {
        wxASSERT(obj);
        m_ObjectList.push_back(obj);
        m_Length += obj->GetLength();
    }

    /** This function prepends an object to the line. */
    void Prepend(wxLayoutObject * obj)
    {
        wxASSERT(obj);
        m_ObjectList.push_front(obj);
        m_Length += obj->GetLength();
    }

    /** This function appens the next line to this, i.e. joins the two
        lines into one.
    */
    void MergeNextLine(wxLayoutList *llist);

    /** This function deletes npos cursor positions from position xpos.
        @param xpos where to delete
        @param npos how many positions
        @return number of positions still to be deleted
    */
    CoordType Delete(CoordType xpos, CoordType npos);

    /** This function breaks the line at a given cursor position.
        @param xpos where to break it
        @return pointer to the new line object replacing the old one
    */
    wxLayoutLine *Break(CoordType xpos, wxLayoutList *llist);

    /** This function wraps the line: breaks it at  a suitable point
        and merges it with the next.
        @param wrapmargin
        @return true if broken
    */
    bool Wrap(CoordType wrapmargin, wxLayoutList *llist);

    /** Deletes the next word from this position, including leading
        whitespace.
        This function does not delete over font changes, i.e. a word
        with formatting instructions in the middle of it is treated as
        two (three actually!) words. In fact, if the cursor is on a non-text object, that
        one is treated as a word.
        @param xpos from where to delete
        @return true if a word was deleted
    */
    bool DeleteWord(CoordType npos);

    /** Finds a suitable position left to the given column to break the
        line.
        @param column we want to break the line to the left of this
        @return column for breaking line or -1 if no suitable location found
    */
    CoordType GetWrapPosition(CoordType column);

    /** Finds the object which covers the cursor position xpos in this
        line.
        @param xpos the column number
        @param offset where to store the difference between xpos and
        the object's head
        @return iterator to the object or NULLIT
    */
    wxLayoutObjectList::iterator FindObject(CoordType xpos, CoordType
        *offset) const ;

    /** Finds the object which covers the screen position xpos in this
        line.
        @param dc the wxDC to use for calculations
        @param llist the layout list to which this line belongs
        @param xpos the screen x coordinate
        @param offset where to store the difference between xpos and
        the object's head
        @return iterator to the object or NULLIT
    */
    wxLayoutObjectList::iterator FindObjectScreen(wxDC &dc,
        wxLayoutList *llist,
        CoordType xpos,
        CoordType *offset,
        bool *found = NULL) const ;

    /** Finds text in this line.
        @param needle the text to find
        @param xpos the position where to start the search
        @return the cursoor coord where it was found or -1
    */
    CoordType FindText(const wxString &needle, CoordType xpos = 0) const;

    /** Get the first object in the list. This is used by the wxlparser
        functions to export the list.
        @return iterator to the first object
    */
    wxLayoutObjectList::iterator GetFirstObject() const
    {
        return m_ObjectList.begin();
    }

    /// Get the last object in the list.
    wxLayoutObjectList::iterator GetLastObject() const
    {
        return m_ObjectList.tail();
    }

    /** Deletes this line, returns pointer to next line.
        @param update If true, update all following lines.
    */
    wxLayoutLine *DeleteLine(bool update, wxLayoutList *llist);

    /**@name Cursor Management */
    //@{
    /** Return the line number of this line.
        @return the line number
    */
    inline CoordType GetLineNumber() const { return m_LineNumber; }

    /** Return the length of the line.
        @return line lenght in cursor positions
    */
    inline CoordType GetLength() const { return m_Length; }
    //@}

    /**@name Drawing and Layout */
    //@{
    /** Draws the line on a wxDC.
        @param dc the wxDC to draw on
        @param llist the wxLayoutList
        @param offset an optional offset to shift printout
    */
    void Draw(wxDC &dc,
        wxLayoutList *llist,
        const wxPoint &offset = wxPoint(0,0)) const;

    /** Recalculates the positions of objects and the height of the
        line.
        @param dc the wxDC to draw on
        @param llist th   e wxLayoutList
        @param cursorPos if not NULL, set cursor screen position in there
        @param cursorSize if not cursorPos != NULL, set cursor size in there
        @param cursorStyle if non NULL where to store styleinfo for cursor pos
        @param cx if cursorPos != NULL, the cursor x position
        @param suppressStyleUpdate FALSe normally, only to suppress updating of m_StyleInfo
    */
    void Layout(wxDC &dc,
        wxLayoutList *llist,
        wxPoint *cursorPos = NULL,
        wxPoint *cursorSize = NULL,
        wxLayoutStyleInfo *cursorStyle = NULL,
        int cx = 0,
        bool suppressStyleUpdate = false);

    /** This function finds an object belonging to a given cursor
        position. It assumes that Layout() has been called before.
        @param dc the wxDC to use for calculations
        @param xpos screen x position
        @param found if non-NULL set to false if we return the last
        object before the cursor, to true if we really have an object
        for that position
        @return pointer to the object
    */
    wxLayoutObject * FindObjectScreen(wxDC &dc,
        CoordType xpos,
        bool *found = NULL);

    /** This sets the style info for the beginning of this line.
        @param si styleinfo structure
    */
    void ApplyStyle(const wxLayoutStyleInfo &si)
        { m_StyleInfo = si; }

    //@}

    /**@name List traversal */
    //@{
    /// Returns pointer to next line.
    wxLayoutLine *GetNextLine() const { return m_Next; }

    /// Returns pointer to previous line.
    wxLayoutLine *GetPreviousLine() const { return m_Previous; }

    /// Sets the link to the next line.
    void SetNext(wxLayoutLine *next)
        { m_Next = next; if(next) next->m_Previous = this; }

    /// Sets the link to the previous line.
    void SetPrevious(wxLayoutLine *previous)
        { m_Previous = previous; if(previous) previous->m_Next = this; }
    //@}

    /// Returns the position of this line on the canvas.
    wxPoint GetPosition() const { return m_Position; }

    /// Returns the height of this line.
    CoordType GetHeight() const { return m_Height; }

    /// Returns the width of this line.
    CoordType GetWidth() const { return m_Width; }

    /// Recalculates the position of this line on the canvas.
    wxPoint RecalculatePosition(wxLayoutList *llist);

    /** Copies the contents of this line to another wxLayoutList
        @param llist the wxLayoutList destination
        @param from x cursor coordinate where to start
        @param to x cursor coordinate where to stop, -1 for end of line
    */
    void Copy(wxLayoutList *llist,
        CoordType from = 0,
        CoordType to = -1);

#ifdef WXLAYOUT_DEBUG
    void Debug() const;
#endif
    wxLayoutStyleInfo const & GetStyleInfo() const { return m_StyleInfo; }

    /// Returns dirty state
    bool IsDirty() const { return m_Dirty; }

    /** Marks this line as diry.
        @param left xpos from where it is dirty or -1 for all
    */
    void MarkDirty(CoordType left = -1)
    {
        if ( left != -1 )
        {
            if ( m_updateLeft == -1 || left < m_updateLeft )
                m_updateLeft = left;
        }

        m_Dirty = true;
        if(m_Next) m_Next->MarkDirty();
    }

    /// Reset the dirty flag
    void MarkClean() { m_Dirty = false; m_updateLeft = -1; }

private:
    /// Destructor is private. Use DeleteLine() to remove it.
    ~wxLayoutLine();

    /**@name Functions to let the lines synchronise with each other. */
    //@{
    /** Sets the height of this line. Will mark following lines as
        dirty.
        @param height new height
    */
    void SetHeight( CoordType height, wxLayoutList * WXUNUSED(llist) )
    {
        m_Height = height; MarkDirty();
    }

    /** Updates the line numbers. */
    void ReNumber();
    //@}

private:
    /// The line number.
    CoordType m_LineNumber;

    /// The line length in cursor positions.
    CoordType m_Length;

    /// The total height of the line.
    CoordType m_Height;

    /// The total width of the line on screen.
    CoordType m_Width;

    /// The baseline for drawing objects
    CoordType m_BaseLine;

    /// The position on the canvas.
    wxPoint   m_Position;

    /// The list of objects
    wxLayoutObjectList m_ObjectList;

    /// Have we been changed since the last layout?
    bool m_Dirty;

    /// The coordinate of the left boundary of the update rectangle (if m_Dirty)
    CoordType m_updateLeft;

    /// Pointer to previous line if it exists.
    wxLayoutLine *m_Previous;

    /// Pointer to next line if it exists.
    wxLayoutLine *m_Next;

    /// A StyleInfo structure, holding the current settings.
    wxLayoutStyleInfo m_StyleInfo;

    /// Just to suppress gcc compiler warnings.
    friend class dummy;

private:
    wxLayoutLine(const wxLayoutLine &);
};


/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

   The wxLayoutList object

 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/** The wxLayoutList is a list of wxLayoutLine objects. It provides a
    higher level of abstraction for the text and can generally be considered
    as representing "the text".
 */
class wxLayoutList
{
public:
    /// Constructor.
    wxLayoutList();

    /// Destructor.
    ~wxLayoutList();

#ifdef WXLAYOUT_USE_CARET
    /// give us the pointer to the caret to use
    void SetCaret(wxCaret *caret) { m_caret = caret; }
#endif // WXLAYOUT_USE_CARET

    /// Clear the list.
    void Clear(int family = wxROMAN,
        int size=WXLO_DEFAULTFONTSIZE,
        int style=wxNORMAL,
        int weight=wxNORMAL,
        int underline=0,
        wxColour *fg=NULL,
        wxColour *bg=NULL);

    /// Empty: clear the list but leave font settings.
    void Empty();

    /** Enable or disable auto-formatting. Normally, while editing this
        should be enabled which is the default. While
        inserting/deleting lots of text, it makes sense to temporarily
        disable this.
        @param enable true to enable, false to disable
    */

    void SetAutoFormatting(bool enable = true)
        { m_AutoFormat = enable; }

    /**@name Cursor Management */
    //@{
    /** Set new cursor position.
        @param p new position
        @return bool if it could be set
    */
    bool MoveCursorTo(wxPoint const &p);

    /** Move cursor up or down.
        @param n
        @return bool if it could be moved
    */
    bool MoveCursorVertically(int n);

    /** Move cursor left or right.
        @param n = number of positions to move
        @return bool if it could be moved
    */
    bool MoveCursorHorizontally(int n);

    /** Move cursor to the left or right counting in words
        @param n = number of positions in words
        @param untilNext: puts the cursor at the start of the next word if true,
              leaves it at the end of the current one otherwise
        @return bool if it could be moved
    */
    bool MoveCursorWord(int n, bool untilNext = true);

    /// Move cursor to end of line.
    void MoveCursorToEndOfLine()
    {
        wxASSERT(m_CursorLine);
        MoveCursorHorizontally(m_CursorLine->GetLength()-m_CursorPos.x);
    }

    /// Move cursor to the start of line.
    void MoveCursorToBeginOfLine()
        { MoveCursorHorizontally(-m_CursorPos.x); }

    /// get the number of lines in the list
    size_t GetNumLines() const { return m_numLines; }

    /// Returns current cursor position.
    const wxPoint &GetCursorPos(wxDC & WXUNUSED(dc) ) const
        { return m_CursorPos; }
    const wxPoint &GetCursorPos() const { return m_CursorPos; }
    wxLayoutLine * GetCursorLine() { return m_CursorLine; }

    /// move cursor to the end of text
    void MoveCursorToEnd()
    {
        MoveCursorTo(wxPoint(0, GetNumLines() - 1));
        MoveCursorToEndOfLine();
    }

    //@}

    /**@name Editing functions.
        All of these functions return true on success and false on
        failure. */
    //@{
    /// Insert text at current cursor position.
    bool Insert(wxString const &text);

    /// Insert some other object at current cursor position.
    bool Insert(wxLayoutObject *obj);

    /// Inserts objects at current cursor positions
    bool Insert(wxLayoutList *llist);

    /// Inserts a linebreak at current cursor position.
    bool LineBreak();
    /** Wraps the current line. Searches to the left of the cursor to
        break the line. Does nothing if the cursor position is before
        the break position parameter.
        @param column the break position for the line, maximum length
        @return true if line got broken
    */
    bool WrapLine(CoordType column);

    /** Wraps the complete buffer.
        @param column the break position for the line, maximum length
        @return true if line got broken
    */
    bool WrapAll(CoordType column);
    /** This function deletes npos cursor positions.
        @param npos how many positions
        @return true if everything got deleted
    */
    bool Delete(CoordType npos);

    /** Delete the next n lines.
        @param n how many lines to delete
        @return how many it could not delete
    */
    int DeleteLines(int n);

    /// Delete to end of line.
    void DeleteToEndOfLine()
    {
        wxASSERT(m_CursorLine);
        Delete(m_CursorLine->GetLength()-m_CursorPos.x);
    }

    /// Delete to begin of line.
    void DeleteToBeginOfLine()
    {
        wxASSERT(m_CursorLine);
        CoordType n = m_CursorPos.x;
#ifdef WXLAYOUT_DEBUG
        wxASSERT(MoveCursorHorizontally(-n));
#else
        MoveCursorHorizontally(-n);
#endif
        Delete(n);
    }

    /** Delete the next word.
    */
    void DeleteWord()
    {
        wxASSERT(m_CursorLine);
        m_CursorLine->DeleteWord(m_CursorPos.x);
    }

    //@}

    /** Finds text in this list.
        @param needle the text to find
        @param cpos the position where to start the search
        @return the cursor coord where it was found or (-1,-1)
    */
    wxPoint FindText(const wxString &needle, const wxPoint &cpos = wxPoint(0,0)) const;

    /**@name Formatting options */
    //@{
    /// sets font parameters
    void SetFont(int family, int size, int style,
        int weight, int underline,
        wxColour *fg,
        wxColour *bg);

    /// sets font parameters, colours by name
    void SetFont(int family=-1, int size = -1, int style=-1,
        int weight=-1, int underline = -1,
        wxChar const *fg = NULL,
        wxChar const *bg = NULL);

    /// changes to the next larger font size
    inline void SetFontLarger()
        { SetFont(-1,(12*m_CurrentStyleInfo.size)/10); }

    /// changes to the next smaller font size
    inline void SetFontSmaller()
        { SetFont(-1,(10*m_CurrentStyleInfo.size)/12); }

    /// set font family
    inline void SetFontFamily(int family) { SetFont(family); }

    /// set font size
    inline void SetFontSize(int size) { SetFont(-1,size); }

    /// set font style
    inline void SetFontStyle(int style) { SetFont(-1,-1,style); }

    /// set font weight
    inline void SetFontWeight(int weight) { SetFont(-1,-1,-1,weight); }

    /// toggle underline flag
    inline void SetFontUnderline(bool ul) { SetFont(-1,-1,-1,-1,(int)ul); }

    /// set font colours by name
    inline void SetFontColour(wxChar const *fg, wxChar const *bg = NULL)
        { SetFont(-1,-1,-1,-1,-1,fg,bg); }

    /// set font colours by colour
    inline void SetFontColour(wxColour *fg, wxColour *bg = NULL)
        { SetFont(-1,-1,-1,-1,-1,fg,bg); }

    /**
    Returns a pointer to the default settings.
    This is only valid temporarily and should not be stored
    anywhere.
    @return the default settings of the list
    */
    wxLayoutStyleInfo &GetDefaultStyleInfo() { return m_DefaultStyleInfo ; }
    wxLayoutStyleInfo &GetStyleInfo() { return m_CurrentStyleInfo ; }
    const wxLayoutStyleInfo &GetStyleInfo() const { return m_CurrentStyleInfo ; }
    const wxLayoutStyleInfo &GetCursorStyleInfo() const { return m_CursorStyleInfo ; }

    /// is the current font underlined?
    bool IsFontUnderlined() const { return GetCursorStyleInfo().underline != 0; }

    /// is the current font bold?
    bool IsFontBold() const { return GetCursorStyleInfo().weight == wxBOLD; }

    /// is the current font italic?
    bool IsFontItalic() const { return GetCursorStyleInfo().style == wxITALIC; }

    /// set underline if it was off, turn it off if it was on
    void ToggleFontUnderline()
        { SetFontUnderline(!IsFontUnderlined()); }

    /// make font bold if it was normal or make it normal if it was bold
    void ToggleFontWeight()
        { SetFontWeight(IsFontBold() ? wxNORMAL : wxBOLD); }

    /// make font italic if it was normal or make it normal if it was italic
    void ToggleFontItalics()
        { SetFontStyle(IsFontItalic() ? wxNORMAL : wxITALIC); }

    //@}

    /**@name Drawing */
    //@{
    /** Draws the complete list on a wxDC.
        @param dc the wxDC to draw on
        @param offset an optional offset to shift printout
        @param top optional y coordinate where to start drawing
        @param bottom optional y coordinate where to stop drawing
        @param clipStrictly if set, do not draw objects which reach
        beyond "bottom". Set this when printing.
    */
    void Draw(wxDC &dc,
        const wxPoint &offset = wxPoint(0,0),
        CoordType top = -1, CoordType bottom = -1,
        bool clipStrictly = false);

    /** Calculates new layout for the list, like Draw() but does not
        actually draw it.
        @param dc the wxDC to draw on
        @param bottom optional y coordinate where to stop calculating
        @param forceAll force re-layout of all lines
        @param cpos Can hold a cursorposition, and will be overwritten
        with the corresponding DC position.
        @param csize Will hold the cursor size relating to cpos.
    */
    void Layout(wxDC &dc, CoordType bottom = -1, bool forceAll = false,
        wxPoint *cpos = NULL,
        wxPoint *csize = NULL);

    /** Ensure that the whole list will be recalculate on the next call
        to Layout() or Draw().
        @param redrawAll true or false to reset it
    */
    void ForceTotalLayout(bool redrawAll = true)
        { m_ReLayoutAll = redrawAll; }

    /** Returns the screen coordinates relating to a given cursor
        position and the size of the cursor at that position.
        @param dc for which to calculate it
        @param cpos Cursor position to look for.
        @param csize If non-NULL, will be set to the cursor size.
        @return The cursor position on the DC.
    */
    wxPoint GetScreenPos(wxDC &dc, const wxPoint &cpos, wxPoint *csize = NULL);

    /** Calculates new sizes for everything in the list, like Layout()
        but this is needed after the list got changed.
        @param dc the wxDC to draw on
        @param bottom optional y coordinate where to stop calculating
    */
    void Recalculate(wxDC &dc, CoordType bottom = -1);

    /** Returns the size of the list in screen coordinates.
        The return value only makes sense after the list has been
        drawn.
        @return a wxPoint holding the maximal x/y coordinates used for
        drawing
    */
    wxPoint GetSize() const;

    /** Returns the cursor position on the screen.
    */
    wxPoint GetCursorScreenPos() const;

    /** Draws the cursor.
        @param active If true, draw a bold cursor to mark window as
        active.
        @param translate optional translation of cursor coords on screen
    */
    void DrawCursor(wxDC &dc,
        bool active = true,
        const wxPoint & translate = wxPoint(0,0));

    /** This function finds an object belonging to a given screen
        position. It assumes that Layout() has been called before.
        @param pos screen position
        @param cursorPos if non NULL, store cursor position in there
        @param found if used, set this to true if we really found an
        object, to false if we had to take the object near to it
        @return pointer to the object
    */
    wxLayoutObject * FindObjectScreen(wxDC &dc,
        wxPoint const pos,
        wxPoint *cursorPos = NULL,
        bool *found = NULL);

    /** Called by the objects to update the update rectangle.
        @param x horizontal coordinate to include in rectangle
        @param y vertical coordinate to include in rectangle
    */
    void SetUpdateRect(CoordType x, CoordType y);

    /** Called by the objects to update the update rectangle.
        @param p a point to include in it
    */
    void SetUpdateRect(const wxPoint &p)
        { SetUpdateRect(p.x,p.y); }

    /// adds the cursor position to the update rectangle
    void AddCursorPosToUpdateRect()
    {
#ifndef WXLAYOUT_USE_CARET
        SetUpdateRect(m_CursorScreenPos);
        SetUpdateRect(m_CursorScreenPos+m_CursorSize);
//#else - the caret will take care of refreshing itself
#endif // !WXLAYOUT_USE_CARET
    }

    /// Invalidates the update rectangle.
    void InvalidateUpdateRect() { m_UpdateRectValid = false; }

    /// Returns the update rectangle.
    const wxRect *GetUpdateRect() const { return &m_UpdateRect; }
    //@}

    /// get the current cursor size
    const wxPoint& GetCursorSize() const { return m_CursorSize; }

    /**@name For exporting one object after another. */
    //@{
    /** Returns a pointer to the first line in the list. */
    wxLayoutLine *GetFirstLine()
    {
        wxASSERT(m_FirstLine);
        return m_FirstLine;
    }
    //@}

    /// Begin selecting text
    void StartSelection(const wxPoint& cpos = wxPoint(-1,-1),
        const wxPoint& spos = wxPoint(-1,-1));

    // Continue selecting text
    void ContinueSelection(const wxPoint& cpos = wxPoint(-1,-1),
        const wxPoint& spos = wxPoint(-1,-1));

    /// End selecting text.
    void EndSelection(const wxPoint& cpos = wxPoint(-1,-1),
        const wxPoint& spos = wxPoint(-1,-1));

    /// Discard the current selection
    void DiscardSelection();

    /// Are we still selecting text?
    bool IsSelecting() const;

    /// Is the given point (text coords) selected?
    bool IsSelected(const wxPoint &cursor) const;

    /// Do we have a non null selection?
    bool HasSelection() const
        { return m_Selection.m_valid || m_Selection.m_selecting; }

    /** Return the selection as a wxLayoutList.
        @param invalidate if true, the selection will be invalidated after this and can no longer be used.
        @return Another layout list object holding the selection, must be freed by caller
    */
    wxLayoutList *GetSelection(class wxLayoutDataObject *wxldo = NULL, bool invalidate = true);

    /// Delete selected bit
    void DeleteSelection();

    wxLayoutList *Copy(const wxPoint &from = wxPoint(0,0),
        const wxPoint &to = wxPoint(-1,-1));

    /// starts highlighting of text for selections
    void StartHighlighting(wxDC &dc);

    /// ends highlighting of text for selections
    void EndHighlighting(wxDC &dc);

   /** Tests whether this layout line is selected and needs
        highlighting.
        @param line to test for
        @param from set to first cursorpos to be highlighted (for returncode == -1)
        @param to set to last cursorpos to be highlighted  (for returncode == -1)
        @return 0 = not selected, 1 = fully selected, -1 = partially
        selected
    */
    int IsSelected(const wxLayoutLine *line, CoordType *from, CoordType *to);

    void ApplyStyle(wxLayoutStyleInfo const &si, wxDC &dc);
#ifdef WXLAYOUT_DEBUG
    void Debug();
#endif

    // for wxLayoutLine usage only
    void IncNumLines() { m_numLines++; }
    void DecNumLines() { m_numLines--; }

    /// get the line by number
    wxLayoutLine *GetLine(CoordType index) const;

    /** Reads objects from a string and inserts them. Returns NULL if
        string is empty or a linebreak was  found.
        @param istr stream to read from, will bee changed
    */
    void Read(wxString &istr);

private:
    /// Clear the list.
    void InternalClear();

    /// The list of lines.
    wxLayoutLine *m_FirstLine;

    /// The number of lines in the list (store instead recalculating for speed)
    size_t m_numLines;

    /// The update rectangle which needs to be refreshed:
    wxRect  m_UpdateRect;

    /// Is the update rectangle valid?
    bool    m_UpdateRectValid;

    /// Shall we auto-format?
    bool    m_AutoFormat;

    /// Shall we re-layout everything?
    bool    m_ReLayoutAll;

    /**@name Cursor Management */
    //@{
    /// Where the text cursor (column,line) is.
    wxPoint   m_CursorPos;

    /// Where the cursor should be drawn.
    wxPoint   m_CursorScreenPos;

    /// The line where the cursor is.
    wxLayoutLine *m_CursorLine;

    /// The size of the cursor.
    wxPoint   m_CursorSize;

    /// Has the cursor moved (is m_CursorScreenPos up to date)?
    bool      m_movedCursor;

#ifdef WXLAYOUT_USE_CARET
    /// the caret
    wxCaret  *m_caret;
#endif // WXLAYOUT_USE_CARET
    //@}

    /// selection.state and begin/end coordinates
    struct Selection
    {
        Selection() { m_valid = m_selecting = m_discarded = false; }

        bool m_valid;
        bool m_selecting;
        bool m_discarded; // may be true only until the next redraw

        // returns true if we already have the screen coordinates of the
        // selection start and end
        bool HasValidScreenCoords() const
            { return m_ScreenA.x != -1 && m_ScreenB.x != -1; }

        // the start and end of the selection coordinates in pixels
        wxPoint m_ScreenA, m_ScreenB;

        // these coordinates are in text positions, not in pixels
        wxPoint m_CursorA, m_CursorB;
    } m_Selection;
    /** @name Font parameters. */
    //@{
    /// this object manages the fonts for us
    wxFontCache m_FontCache;

    /// the default setting:
    wxLayoutStyleInfo m_DefaultStyleInfo;

    /// the current setting:
    wxLayoutStyleInfo m_CurrentStyleInfo;

    /// the current setting:
    wxLayoutStyleInfo m_CursorStyleInfo;
    //@}
};

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

   The wxLayoutDataObject for exporting data to the clipboard in our
   own format.

 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
class wxLayoutDataObject : public wxCustomDataObject
{
public:
    wxLayoutDataObject()
    {
        SetFormat(wxT("application/wxlayoutlist"));
    }

    // type safe wrappers
    void SetLayoutData(const wxString& text)
        { SetData(text.length() + 1, text.c_str()); }

    const wxChar *GetLayoutData() const { return (const wxChar *)GetData(); }
};

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

   The wxLayoutPrintout object for printing within the wxWidgets print
   framework.

 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/** This class implements a wxPrintout for printing a wxLayoutList within
    the wxWidgets printing framework.
 */
class wxLayoutPrintout: public wxPrintout
{
public:
    /** Constructor.
        @param llist pointer to the wxLayoutList to be printed
        @param title title for PS file or windows
    */
    wxLayoutPrintout(wxLayoutList *llist,
        wxString const & title =
        _T("wxLayout Printout"));

    /// Destructor.
    ~wxLayoutPrintout();

    /** Function which prints the n-th page.
        @param page the page number to print
        @return bool true if we are not at end of document yet
    */
    bool OnPrintPage(int page);
    /** Checks whether page exists in document.
        @param page number of page
        @return true if page exists
    */
    bool HasPage(int page);

    /** Gets called from wxWidgets to find out which pages are existing.
        I'm not totally sure about the parameters though.
        @param minPage the first page in the document
        @param maxPage the last page in the document
        @param selPageFrom the first page to be printed
        @param selPageTo the last page to be printed
    */
    void GetPageInfo(int *minPage, int *maxPage,
        int *selPageFrom, int *selPageTo);
protected:
    /** This little function scales the DC so that the printout has
        roughly the same size as the output on screen.
        @param dc the wxDC to scale
        @return the scale that was applied
    */
    float ScaleDC(wxDC *dc);

    /* no longer used
    virtual void DrawHeader(wxDC &dc, wxPoint topleft, wxPoint bottomright, int pageno);
    */

private:
    /// The list to print.
    wxLayoutList *m_llist;

    /// Title for PS file or window.
    wxString      m_title;

    /// The real paper size.
    int           m_PageHeight, m_PageWidth;

    /// How much we actually print per page.
    int           m_PrintoutHeight;

    /// How many pages we need to print.
    int           m_NumOfPages;

    /// Top left corner where we start printing.
    wxPoint       m_Offset;
};


#endif // WXLLIST_H