/// <summary>
/// Performs requested amount of undo operation and places the transactions on the redo stack.
/// UNDONE: What if there is a currently opened transaction?
/// </summary>
/// <param name="count">The number of undo operations to perform. At the end of the operation, requested number of visible
/// transactions are undone. Hence actual number of transactions undone might be more than this number if there are some
/// hidden transactions adjacent to (on top of or at the bottom of) the visible ones.
/// </param>
/// <remarks>
/// After the last visible transaction is undone, hidden transactions left on top the stack are undone as well until a
/// visible or linked transaction is encountered or stack is emptied totally.
/// </remarks>
public void Undo(int count)
{
if (count <= 0)
{
throw new ArgumentException(String.Format(CultureInfo.CurrentUICulture, "Strings.RedoAndUndoAcceptOnlyPositiveCounts", "Undo", count), "count");
}
if (!IsThereEnoughVisibleTransactions(this.undoStack, count))
{
throw new InvalidOperationException(String.Format(CultureInfo.CurrentUICulture, "Strings.CannotUndoMoreTransactionsThanExist", "undo", count));
}
TextUndoHistoryState originalState = this.state;
this.state = TextUndoHistoryState.Undoing;
using (new AutoEnclose(delegate { this.state = originalState; }))
{
while (count > 0)
{
if (!this.undoStack.Peek().CanUndo)
{
throw new InvalidOperationException("Strings.CannotUndoRequestedPrimitiveFromHistoryUndo");
}
ITextUndoTransaction ut = this.undoStack.Pop();
ut.Undo();
this.redoStack.Push(ut);
RaiseUndoRedoHappened(this.state, ut);
--count;
}
}
}
/// <summary>
/// Performs requested amount of undo operation and places the transactions on the redo stack.
/// UNDONE: What if there is a currently opened transaction?
/// </summary>
/// <param name="count">The number of undo operations to perform. At the end of the operation, requested number of visible
/// transactions are undone. Hence actual number of transactions undone might be more than this number if there are some
/// hidden transactions adjacent to (on top of or at the bottom of) the visible ones.
/// </param>
/// <remarks>
/// After the last visible transaction is undone, hidden transactions left on top the stack are undone as well until a
/// visible or linked transaction is encountered or stack is emptied totally.
/// </remarks>
public void Undo(int count)
{
if (count <= 0)
{
throw new ArgumentException("count must be > 0", nameof(count));
}
if (!IsThereEnoughVisibleTransactions(_undoStack, count))
{
throw new InvalidOperationException("Not enough undos/redos on the stack");
}
TextUndoHistoryState originalState = _state;
_state = TextUndoHistoryState.Undoing;
using (new AutoEnclose(delegate { this._state = originalState; })) {
while (count > 0)
{
if (!_undoStack.Peek().CanUndo)
{
throw new InvalidOperationException("Undo cannot request primitives from stack");
}
ITextUndoTransaction ut = _undoStack.Pop();
ut.Undo();
_redoStack.Push(ut);
RaiseUndoRedoHappened(_state, ut);
--count;
}
}
}
/// <summary>
/// Performs requested amount of undo operation and places the transactions on the redo stack.
/// UNDONE: What if there is a currently opened transaction?
/// </summary>
/// <param name="count">The number of undo operations to perform. At the end of the operation, requested number of visible
/// transactions are undone. Hence actual number of transactions undone might be more than this number if there are some
/// hidden transactions adjacent to (on top of or at the bottom of) the visible ones.
/// </param>
/// <remarks>
/// After the last visible transaction is undone, hidden transactions left on top the stack are undone as well until a
/// visible or linked transaction is encountered or stack is emptied totally.
/// </remarks>
public void Undo(int count)
{
if (count <= 0)
{
throw new ArgumentOutOfRangeException(nameof(count));
}
if (!IsThereEnoughVisibleTransactions(this.undoStack, count))
{
throw new InvalidOperationException("Cannot undo more transactions than exist");
}
TextUndoHistoryState originalState = this.state;
this.state = TextUndoHistoryState.Undoing;
using (new AutoEnclose(delegate { this.state = originalState; }))
{
while (count > 0)
{
if (!this.undoStack.Peek().CanUndo)
{
throw new InvalidOperationException("Strings.CannotUndoRequestedPrimitiveFromHistoryUndo");
}
ITextUndoTransaction ut = this.undoStack.Pop();
ut.Undo();
this.redoStack.Push(ut);
RaiseUndoRedoHappened(this.state, ut);
--count;
}
}
}