/// <summary>
/// Restores the most recent reversion to the manipulator's transformation
/// </summary>
/// <returns>True if the operation was successful, false otherwise</returns>
public bool Redo()
{
// no redos while we're active or in manipulation mode
if (!Active || mManipulating)
{
return(false);
}
// nothing to redo...
if (mRedoStack.Count == 0)
{
return(false);
}
// push the current transform onto the undo stack
mUndoStack.Push(new TransformState(mTransform));
// pop the topmost transform state from the redo stack
// and apply it to the current transform
TransformState state = mRedoStack.Pop();
state.Apply();
// success
return(true);
}
/// <summary>
/// Reverts the most recent change to the manipulator's transformation
/// </summary>
/// <returns>True if the operation was successful, false otherwise</returns>
public bool Undo()
{
// no undos while we're inactive
if (!Active)
{
return(false);
}
// nothing to undo...
if (mUndoStack.Count == 0)
{
return(false);
}
// user requested an undo while manipulating. we must reset the
// manipulation flag, requiring that the user release and press the
// mouse button again in order to start a new operation. otherwise,
// the mouse position and manipulator position will be out of sync
// after the transform is reverted
if (mManipulating)
{
mRedoStack.Clear();
mManipulating = false;
}
// push the current transform state onto the redo stack
mRedoStack.Push(new TransformState(mTransform));
// pop the top transform state from the undo stack and apply
// it to the current transform
TransformState state = mUndoStack.Pop();
state.Apply();
// success
return(true);
}