/// <summary>
/// Perform the redo operation. If an undo handler is specified, it
/// will be used to perform the actual operation. Otherwise, the command
/// instance is asked to perform the redo.
/// </summary>
public void Redo()
{
if (!CanRedo())
{
return;
}
// Remove newest entry from the redo stack.
UndoInfo info = (UndoInfo)m_redoStack.Pop();
// Perform the redo.
Debug.Assert(info.m_undoCommand != null);
if (info.m_undoHandler != null)
{
info.m_undoHandler.Redo(info.m_undoCommand);
info.m_undoHandler.refreshHistory(m_undoList);
}
else
{
info.m_undoCommand.Redo();
}
// Now the command is available for undo again. Put it back
// into the undo list.
m_undoList.Add(info);
}
/// <summary>
/// Perform the undo operation. If an undo handler is specified, it
/// will be used to perform the actual operation. Otherwise, the command
/// instance is asked to perform the undo.
/// </summary>
public void Undo()
{
if (!CanUndo())
{
return;
}
// Remove newest entry from the undo list.
UndoInfo info = (UndoInfo)m_undoList[m_undoList.Count - 1];
m_undoList.RemoveAt(m_undoList.Count - 1);
// Perform the undo.
Debug.Assert(info.m_undoCommand != null);
if (info.m_undoHandler != null)
{
info.m_undoHandler.Undo(info.m_undoCommand);
info.m_undoHandler.refreshHistory(m_undoList);
}
else
{
info.m_undoCommand.Undo();
}
// Now the command is available for redo. Push it onto
// the redo stack.
m_redoStack.Push(info);
}
/// <summary>
/// Register a new undo command. Use this method after your
/// application has performed an operation/command that is
/// undoable.
/// </summary>
/// <param name="cmd">New command to add to the manager.</param>
public void AddUndoCommand(UndoCommand cmd)
{
Debug.Assert(cmd != null);
Debug.Assert(m_undoList.Count <= m_maxUndoLevel);
if (m_maxUndoLevel == 0)
{
return;
}
UndoInfo info = null;
if (m_undoList.Count == m_maxUndoLevel)
{
// Remove the oldest entry from the undo list to make room.
info = (UndoInfo)m_undoList[0];
m_undoList.RemoveAt(0);
}
// Insert the new undoable command into the undo list.
if (info == null)
{
info = new UndoInfo();
}
info.m_undoCommand = cmd;
info.m_undoHandler = null;
m_undoList.Add(info);
// Clear the redo stack.
ClearRedo();
}
/// <summary>
/// Clear the contents of the redo stack.
/// </summary>
private void ClearRedo()
{
while (m_redoStack.Count > 0)
{
UndoInfo info = (UndoInfo)m_redoStack.Pop();
info.m_undoCommand = null;
info.m_undoHandler = null;
}
}
/// <summary>
/// Clear the contents of the undo list.
/// </summary>
private void ClearUndo()
{
while (m_undoList.Count > 0)
{
UndoInfo info = (UndoInfo)m_undoList[m_undoList.Count - 1];
m_undoList.RemoveAt(m_undoList.Count - 1);
info.m_undoCommand = null;
info.m_undoHandler = null;
}
}
/// <summary>
/// Get the next redo command. This is like a "Peek"
/// method. It does not remove the command from the redo stack.
/// </summary>
/// <returns>The next redo command.</returns>
public UndoCommand GetNextRedoCommand()
{
if (m_redoStack.Count == 0)
{
return(null);
}
UndoInfo info = (UndoInfo)m_redoStack.Peek();
return(info.m_undoCommand);
}
/// <summary>
/// Get the next (or newest) undo command. This is like a "Peek"
/// method. It does not remove the command from the undo list.
/// </summary>
/// <returns>The next undo command.</returns>
public UndoCommand GetNextUndoCommand()
{
if (m_undoList.Count == 0)
{
return(null);
}
UndoInfo info = (UndoInfo)m_undoList[m_undoList.Count - 1];
return(info.m_undoCommand);
}
/// <summary>
/// Register a new undo command along with an undo handler. The
/// undo handler is used to perform the actual undo or redo
/// operation later when requested.
/// </summary>
/// <param name="cmd">New command to add to the manager.</param>
/// <param name="undoHandler">Undo handler to perform the actual undo/redo operation.</param>
public void AddUndoCommand(UndoCommand cmd, IUndoHandler undoHandler)
{
AddUndoCommand(cmd);
if (m_undoList.Count > 0)
{
UndoInfo info = (UndoInfo)m_undoList[m_undoList.Count - 1];
Debug.Assert(info != null);
info.m_undoHandler = undoHandler;
undoHandler.refreshHistory(m_undoList);
}
}
/// <summary>
/// Retrieve all of the redo commands. Useful for debugging,
/// to analyze the contents of the redo stack.
/// </summary>
/// <returns>Array of commands for redo.</returns>
public UndoCommand[] GetRedoCommands()
{
if (m_redoStack.Count == 0)
{
return(null);
}
UndoCommand[] cmdList = new UndoCommand[m_redoStack.Count];
object[] objList = m_redoStack.ToArray();
for (int i = 0; i < objList.Length; i++)
{
UndoInfo info = (UndoInfo)objList[i];
cmdList[i] = info.m_undoCommand;
}
return(cmdList);
}
/// <summary>
/// Register a new undo command. Use this method after your
/// application has performed an operation/command that is
/// undoable.
/// </summary>
/// <param name="cmd">New command to add to the manager.</param>
public void AddUndoCommand(UndoCommand cmd)
{
Debug.Assert(cmd != null);
Debug.Assert(m_undoList.Count <= m_maxUndoLevel);
if (m_maxUndoLevel == 0)
return;
UndoInfo info = null;
if (m_undoList.Count == m_maxUndoLevel)
{
// Remove the oldest entry from the undo list to make room.
info = (UndoInfo)m_undoList[0];
m_undoList.RemoveAt(0);
}
// Insert the new undoable command into the undo list.
if (info == null)
info = new UndoInfo();
info.m_undoCommand = cmd;
info.m_undoHandler = null;
m_undoList.Add(info);
// Clear the redo stack.
ClearRedo();
}
