Class: UndoSupport

• Inheritance
• Description
• Class protocol
  • cleanup
  • instance creation
• Instance protocol
  • accessing
  • initialization
  • queries
  • undo & again
• Private classes
• Examples

Inheritance:

   Object
   |
   +--UndoSupport

Package:

stx:libbasic2

Category:

Views-Text

Version:

rev: 1.16 date: 2024/02/16 18:57:48

user: stefan

file: UndoSupport.st directory: libbasic2

module: stx stc-classLibrary: libbasic2

Description:

Framework for undo & redo.
See concrete usage in EditTextView.


[instance variables:]

[class variables:]

copyright
COPYRIGHT (c) 2004 by eXept Software AG
             All Rights Reserved

This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice.   This software may not
be provided or otherwise made available to, or used by, any
other person.  No title to or ownership of the software is
hereby transferred.

Class protocol:

 lowSpaceCleanup

(comment from inherited method)
ignored here - redefined in some classes to
cleanup in low-memory situations

 for: anActionPerformer

 new

(comment from inherited method)
return an instance of myself without indexed variables

Instance protocol:

 actionInfo: aString

 undoLimit

 undoLimit: something

 actionPerformer: something

 initialize

undoLimit := 1000.

 resetHistories

 isInTransaction

 transactionNotEmpty

 addUndo: action

 addUndoFirst: action

 closeTransactionAndAddTo: anUndoList

at the end of an operation, check the individual undo actions
and add them to the given undoList.
(either individually or as a compound undo action).
Check if the new action(s) can be combined with the previous undo action into one
(this is done for individual keystrokes and character-deletions)

 executeActionFrom: doList addUndoTo: unDoList

 hasRedoAction

 hasUndoAction

 lastRedoAction

 lastUndoAction

 nonUndoableDo: aBlock

 redo

 redoActionInfo

 undo

 undoActionInfo

 undoableDo: aBlock

 undoableDo: aBlock info: aString

Private classes:

    CompoundAction

Examples:

See usage in EditTextView