Constructor Detail

Method Detail

• canUndo

   abstract boolean canUndo()

  Returns whether there are edits that can be undone or not. If this returns false a call to undo will throw an exception.

  Returns:

  true if an undo operation is possible, false otherwise.

• canRedo

   abstract boolean canRedo()

  Returns whether there are edits that can be redone or not. If this returns false a call to redo will throw an exception.

  Returns:

  true if a redo operation is possible, false otherwise.

• undo

   abstract void undo()

  Undoes the last edit or throws an exception if an undo operation is not possible. It's recommended that you check whether an undo operation is available using (canUndo) before calling this method. Undoing may be unavailable if there are no edits on the undo stack or if the latest edit on the undo stack cannot be undone. When undoing an edit, the edit is moved to the internal redo stack.

• redo

   abstract void redo()

  Redoes the next edit or throws an exception if a redo operation is not possible. It's recommended that you check whether a redo operation is available using (canRedo) before calling this method. Redoing may be unavailable if there are no edits on the redo stack or if the latest edit on the redo stack cannot be redone. When redoing an edit, the edit is moved to the internal undo stack.

• clearHistory

   abstract void clearHistory()

  Clears the history of all currently recorded edits. After calling this method, this will have no edits that can be undone or redone.

• addOnUndoHistoryChangeListener

   abstract void addOnUndoHistoryChangeListener(@NonNull() OnUndoHistoryChangeListener listener)

  Adds an OnUndoHistoryChangeListener for being notified of changes to the undo manager's edit history (i.e. its undo and redo stacks). If a listener has already been added previously, this method will be a no-op. Passing null is not allowed and will result in an exception.

  Parameters:

  listener - OnUndoHistoryChangeListener that should be notified.

• removeOnUndoHistoryChangeListener

   abstract void removeOnUndoHistoryChangeListener(@NonNull() OnUndoHistoryChangeListener listener)

  Removes a previously added OnUndoHistoryChangeListener. Upon calling this method, listener will no longer be notified of any changes. If listener has not been added previously, this method will be a no-op. Passing null is not allowed, and will result in an exception.

  Parameters:

  listener - OnUndoHistoryChangeListener that should be removed.