package bluej.editor.moe;

import bluej.utility.javafx.FXPlatformRunnable;
import javafx.beans.binding.BooleanExpression;
import javafx.beans.property.BooleanProperty;
import javafx.beans.property.SimpleBooleanProperty;
import org.fxmisc.richtext.util.UndoUtils;
import org.fxmisc.undo.UndoManager;




| An undo/redo manager for the editor. A stack of compound edits is maintained;
| the "beginCompoundEdit()" and "endCompoundEdit()" methods can be used to 
|* create a compound edit (which is treated as a single edit for undo/redo purposes).
* 
* @author Davin McCall
 
*/
public class MoeUndoManager{    
   private UndoManager undoManager;
|
|private BooleanProperty canUndo;
|
|private BooleanProperty canRedo;
|
|public MoeUndoManager(MoeEditorPane editorPane)
|
|{
|
|// We uses a plain text undo manager instead of a rich text one.
|
|// This is to avoid making the undo manager to record the automatic
|
|// styling that MoeEditor performs.
|
|undoManager = UndoUtils.plainTextUndoManager(editorPane);
|
|}
|
|public UndoManager getUndoManager()
|
|{
|
|return undoManager;
|
|}
|
|/**
| Runs the given edit action.  See comment within.
|
public void compoundEdit(FXPlatformRunnable edit)
   {
      breakEdit();
       
      
      
      

       
      
      
      
      
      
      
      
      

      
         edit.run();         
         }
      breakEdit();     
      }
    
   
   public BooleanExpression canUndo()
   {
      if (canUndo == null)
       {            
         canUndo = new SimpleBooleanProperty();
         canUndo.bind(undoManager.undoAvailableProperty());         
         }
       
      return canUndo;     
      }
    
   
   public BooleanExpression canRedo()
   {
      if (canRedo == null)
       {            
         canRedo = new SimpleBooleanProperty();
         canRedo.bind(undoManager.redoAvailableProperty());         
         }
       
      return canRedo;     
      }
    
   
   public void undo()
   {
      undoManager.undo();     
      }
    
   
   public void redo()
   {
      undoManager.redo();     
      }

   
   public void forgetHistory()
   {
      undoManager.forgetHistory();     
      }

   
   


| Stops edits before this point merging with later edits into one single undoable item
| (which is what happens by default).
|
public void breakEdit()
   {
      undoManager.preventMerge();     
      } 
   }