StateEdit (Java SE 15 & JDK 15) (original) (raw)

All Implemented Interfaces:

[Serializable](../../../../java.base/java/io/Serializable.html "interface in java.io"), [UndoableEdit](UndoableEdit.html "interface in javax.swing.undo")

public class StateEdit extends AbstractUndoableEdit

StateEdit is a general edit for objects that change state. Objects being edited must conform to the StateEditable interface.

This edit class works by asking an object to store it's state in Hashtables before and after editing occurs. Upon undo or redo the object is told to restore it's state from these Hashtables.

A state edit is used as follows:

  // Create the edit during the "before" state of the object
  StateEdit newEdit = new StateEdit(myObject);
  // Modify the object
  myObject.someStateModifyingMethod();
  // "end" the edit when you are done modifying the object
  newEdit.end();

Note that when a StateEdit ends, it removes redundant state from the Hashtables - A state Hashtable is not guaranteed to contain all keys/values placed into it when the state is stored!

See Also:

StateEditable

• Field Summary

• Constructor Summary

Constructors

• Method Summary

• Field Details

  • RCSID

  protected static final String RCSID
  Obsolete RCS version identity.
  See Also:
  Constant Field Values

  • object

  The object being edited

  • preState

  The state information prior to the edit

  • postState

  The state information after the edit

  • undoRedoName

  protected String undoRedoName
  The undo/redo presentation name

• Constructor Details

  • StateEdit

  Create and return a new StateEdit.
  Parameters:
  anObject - The object to watch for changing state
  See Also:
  StateEdit

  • StateEdit

  Create and return a new StateEdit with a presentation name.
  Parameters:
  anObject - The object to watch for changing state
  name - The presentation name to be used for this edit
  See Also:
  StateEdit

• Method Details

  • init

  Initialize the state edit.
  Parameters:
  anObject - The object to watch for changing state
  name - The presentation name to be used for this edit

  • end

  public void end()
  Gets the post-edit state of the StateEditable object and ends the edit.

  • undo

  public void undo()
  Tells the edited object to apply the state prior to the edit
  Specified by:
  [undo](UndoableEdit.html#undo%28%29) in interface [UndoableEdit](UndoableEdit.html "interface in javax.swing.undo")
  Overrides:
  [undo](AbstractUndoableEdit.html#undo%28%29) in class [AbstractUndoableEdit](AbstractUndoableEdit.html "class in javax.swing.undo")
  See Also:
  AbstractUndoableEdit.canUndo()

  • redo

  public void redo()
  Tells the edited object to apply the state after the edit
  Specified by:
  [redo](UndoableEdit.html#redo%28%29) in interface [UndoableEdit](UndoableEdit.html "interface in javax.swing.undo")
  Overrides:
  [redo](AbstractUndoableEdit.html#redo%28%29) in class [AbstractUndoableEdit](AbstractUndoableEdit.html "class in javax.swing.undo")
  See Also:
  AbstractUndoableEdit.canRedo()

  • getPresentationName

  public String getPresentationName()
  Gets the presentation name for this edit
  Specified by:
  [getPresentationName](UndoableEdit.html#getPresentationName%28%29) in interface [UndoableEdit](UndoableEdit.html "interface in javax.swing.undo")
  Overrides:
  [getPresentationName](AbstractUndoableEdit.html#getPresentationName%28%29) in class [AbstractUndoableEdit](AbstractUndoableEdit.html "class in javax.swing.undo")
  Returns:
  the empty string ""
  See Also:
  AbstractUndoableEdit.getUndoPresentationName(), AbstractUndoableEdit.getRedoPresentationName()

  • removeRedundantState

  protected void removeRedundantState()
  Remove redundant key/values in state hashtables.