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Diffstat (limited to 'khexedit/lib/kbuffercursor.h')
| -rw-r--r-- | khexedit/lib/kbuffercursor.h | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/khexedit/lib/kbuffercursor.h b/khexedit/lib/kbuffercursor.h new file mode 100644 index 0000000..855b3e8 --- /dev/null +++ b/khexedit/lib/kbuffercursor.h @@ -0,0 +1,172 @@ +/*************************************************************************** + kbuffercursor.h - description + ------------------- + begin : Don Mai 29 2003 + copyright : (C) 2003 by Friedrich W. H. Kossebau + email : Friedrich.W.H@Kossebau.de + ***************************************************************************/ + +/*************************************************************************** + * * + * This library is free software; you can redistribute it and/or * + * modify it under the terms of the GNU Library General Public * + * License version 2 as published by the Free Software Foundation. * + * * + ***************************************************************************/ + + +#ifndef KHE_KBUFFERCURSOR_H +#define KHE_KBUFFERCURSOR_H + +#include "kbuffercoord.h" + + +namespace KHE +{ + +class KBufferLayout; + + +/**@short navigates through the buffer in an abstract way, based on the layout + * + * The cursor is allowed to access every coord that has content as + * described in the layout. It holds the coord of the actual position + * and the according index in the data array. + * + * To enable the cursor to be placed behind the last position in a line + * (e.g, to mark all data in the line without placing the cursor to the + * beginning of the next line) there is a flag Behind that should be read + * as that the real index the cursor is at is the current one + 1 + * (as returned by realIndex()) + * + * For appending new data to the buffer there is also the need to be able + * to place the cursor at a position behind the last byte. This can be + * enabled by calling setAppendPosEnabled(true). If the cursor is placed to + * this position it gets the (real) index of the last byte + 1. As this + * index does not point to an existing byte validIndex() returns -1. + * Check for atAppendPos() to see whether cursor is at this position. + * + * If the buffer is empty there is no navigation possible, of course. + * The cursor will be placed to coord 0/0 with index 1, Behind=false. + * + *@author Friedrich W. H. Kossebau + */ +class KBufferCursor +{ + public: + KBufferCursor( const KBufferLayout *L ); + ~KBufferCursor(); + + + public: + bool operator==( const KBufferCursor &c ) const; + bool operator!=( const KBufferCursor &c ) const { return !(*this == c); } + + public: // modificator + void setAppendPosEnabled( bool APE=true ); + + public: // state value access + /** the index that is drawn at the actual coord */ + int index() const; + /** the pos of the actual coord */ + int pos() const; + /** the line of the actual coord */ + int line() const; + /** the actual coord */ + KBufferCoord coord() const; + /** true if the cursor is located to the right of the actual coord but still shown at the coord */ + bool isBehind() const; + /** returns the real index. That is if the cursor is tagged as "behind" the current index + * it's real index is the next one. + * Attention: this could be outside the data's range if the cursor is behind the last byte! + */ + int realIndex() const; + /** returns the true index if it is valid index that is it is inside the data's range. + * Otherwise -1 is returned + */ + int validIndex() const; + + //bool isValid() const; + bool appendPosEnabled() const; + + public: // index calculation service + /** returns the index at the start of the cursor's line */ + int indexAtLineStart() const; + /** returns the index at the end of the cursor's line */ + int indexAtLineEnd() const; + + public: // navigation commands + void gotoIndex( int I ); + void gotoCoord( const KBufferCoord &C ); + void gotoCIndex( int I ); + void gotoCCoord( const KBufferCoord &C ); + void gotoRealIndex(); + + void gotoPreviousByte(); + void gotoNextByte(); + void gotoPreviousByte( int D ); + void gotoNextByte( int D ); + void gotoNextByteInLine(); + void gotoUp(); + void gotoDown(); + void gotoLineStart(); + void gotoLineEnd(); + void gotoStart(); + void gotoEnd(); + void gotoPageUp(); + void gotoPageDown(); + + /** puts the cursor behind the actual position if it isn't already*/ + void stepBehind(); + void updateCoord(); + + + public: // logical state access + bool atStart() const; + bool atEnd() const; + /** could only be true in InsertMode: Cursor is behind the last byte */ + bool atAppendPos() const; + bool atLineStart() const; + bool atLineEnd() const; + + + protected: + /** if newpos allowed steps at a coord behind the last existing + * or, if that is at a line end, behind the line + * does not check for empty content! + */ + void stepToEnd(); + + private: + /** layout, tells how the column is organized */ + const KBufferLayout *Layout; + + /** Position in buffer */ + int Index; + /** Position and Line */ + KBufferCoord Coord; + + /** tells whether the cursor is actually behind the actual position. + * This is used for selection to the end of a line or of the whole buffer. + */ + bool Behind : 1; + + /** tells whether there could be a position behind the end of the layout */ + bool AppendPosEnabled : 1; +}; + + +inline int KBufferCursor::index() const { return Index; } +inline int KBufferCursor::pos() const { return Coord.pos(); } +inline int KBufferCursor::line() const { return Coord.line(); } +inline KBufferCoord KBufferCursor::coord() const { return Coord; } +inline bool KBufferCursor::isBehind() const { return Behind; } +inline int KBufferCursor::realIndex() const { return Behind ? Index + 1 : Index; } + +inline void KBufferCursor::stepBehind() { Behind = true; } + +//inline bool KBufferCursor::isValid() const { return Index != -1; } + +} + +#endif |