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// Copyright (C) 2003 Mooffie <mooffie@typo.co.il>
//
// This program 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 of the License, or
// (at your option) any later version.
//
// This program is distributed 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 this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
#ifndef BDE_UNDO_H
#define BDE_UNDO_H
#include <vector>
#include "types.h"
#include "point.h"
// Class UndoStack records the operations (ops) made to EditBox's buffer.
//
// Strictly speaking, the UndoStack is not really a stack: you move the
// "top" pointer up and down within this stack when you undo and redo
// operations.
//
// UndoStack stores the operations in a vector of UndoOp's. UndoOp contains
// all the information needed to restore one operation.
enum OpType { opInsert, opDelete, opReplace };
struct UndoOp {
OpType type;
Point point; // the point in the buffer where the operation was made
unistring inserted_text;
unistring deleted_text;
size_t calc_size() const {
return
sizeof(UndoOp)
+ inserted_text.len() * sizeof(unichar)
+ deleted_text.len() * sizeof(unichar);
}
bool merge(const UndoOp &op);
};
class UndoStack {
private:
std::vector<UndoOp> stack;
unsigned top;
size_t bytes_size; // size of current stack
size_t bytes_size_limit; // max size
bool merge_small_ops; // merge small ops?
bool truncated; // was the stack already truncated
// to fit bytes_size_limit?
private:
void erase_redo_ops();
void truncate_undo();
bool undo_size_too_big() const { return bytes_size >= bytes_size_limit; }
void update_size_up(int chars_count);
void update_size_up(const UndoOp &op);
void update_size_down(const UndoOp &op);
public:
UndoStack();
void clear();
bool was_truncated() { return truncated; }
bool disabled() const { return bytes_size_limit == 0; }
bool is_undo_available() const { return (top != 0); }
bool is_redo_available() const { return (top != stack.size()); }
void record_op(const UndoOp &op);
UndoOp *get_prev_op();
UndoOp *get_next_op();
void set_size_limit(size_t limit);
void set_merge(bool value) { merge_small_ops = value; }
bool is_merge() const { return merge_small_ops; }
};
#endif
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