Removed the need for get/setUndoManager()

This dramatically simplifies undo/redo handling and allows to use
unpatched RSyntaxTextArea library.

Author: cmaglie

app/src/processing/app/Editor.java

@@ -33,20 +33,19 @@
 import jssc.SerialPortException;
 import processing.app.debug.RunnerException;
 import processing.app.forms.PasswordAuthorizationDialog;
+import processing.app.helpers.DocumentTextChangeListener;
 import processing.app.helpers.Keys;
 import processing.app.helpers.OSUtils;
 import processing.app.helpers.PreferencesMapException;
 import processing.app.legacy.PApplet;
 import processing.app.syntax.PdeKeywords;
+import processing.app.syntax.SketchTextArea;
 import processing.app.tools.MenuScroller;
 import processing.app.tools.Tool;
 
 import javax.swing.*;
 import javax.swing.event.*;
 import javax.swing.text.BadLocationException;
-import javax.swing.undo.CannotRedoException;
-import javax.swing.undo.CannotUndoException;
-import javax.swing.undo.UndoManager;
 import java.awt.*;
 import java.awt.datatransfer.DataFlavor;
 import java.awt.datatransfer.Transferable;
@@ -185,8 +184,6 @@ public boolean test(SketchController sketch) {
   // undo fellers
   private JMenuItem undoItem;
   private JMenuItem redoItem;
-  protected UndoAction undoAction;
-  protected RedoAction redoAction;
 
   private FindReplace find;
 
@@ -1273,7 +1270,7 @@ private JMenu buildEditMenu() {
 
     undoItem = newJMenuItem(tr("Undo"), 'Z');
     undoItem.setName("menuEditUndo");
-    undoItem.addActionListener(undoAction = new UndoAction());
+    undoItem.addActionListener(e -> getCurrentTab().handleUndo());
     menu.add(undoItem);
 
     if (!OSUtils.isMacOS()) {
@@ -1282,7 +1279,7 @@ private JMenu buildEditMenu() {
         redoItem = newJMenuItemShift(tr("Redo"), 'Z');
     }
     redoItem.setName("menuEditRedo");
-    redoItem.addActionListener(redoAction = new RedoAction());
+    redoItem.addActionListener(e -> getCurrentTab().handleRedo());
     menu.add(redoItem);
 
     menu.addSeparator();
@@ -1478,68 +1475,10 @@ private static JMenuItem newJMenuItemAlt(String title, int what) {
   // . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
 
 
-  class UndoAction extends AbstractAction {
-    public UndoAction() {
-      super("Undo");
-      this.setEnabled(false);
-    }
-
-    public void actionPerformed(ActionEvent e) {
-      try {
-        getCurrentTab().handleUndo();
-      } catch (CannotUndoException ex) {
-        //System.out.println("Unable to undo: " + ex);
-        //ex.printStackTrace();
-      }
-    }
-
-    protected void updateUndoState() {
-      UndoManager undo = getCurrentTab().getUndoManager();
-
-      if (undo.canUndo()) {
-        this.setEnabled(true);
-        undoItem.setEnabled(true);
-        undoItem.setText(undo.getUndoPresentationName());
-        putValue(Action.NAME, undo.getUndoPresentationName());
-      } else {
-        this.setEnabled(false);
-        undoItem.setEnabled(false);
-        undoItem.setText(tr("Undo"));
-        putValue(Action.NAME, "Undo");
-      }
-    }
-  }
-
-
-  class RedoAction extends AbstractAction {
-    public RedoAction() {
-      super("Redo");
-      this.setEnabled(false);
-    }
-
-    public void actionPerformed(ActionEvent e) {
-      try {
-        getCurrentTab().handleRedo();
-      } catch (CannotRedoException ex) {
-        //System.out.println("Unable to redo: " + ex);
-        //ex.printStackTrace();
-      }
-    }
-
-    protected void updateRedoState() {
-      UndoManager undo = getCurrentTab().getUndoManager();
-
-      if (undo.canRedo()) {
-        redoItem.setEnabled(true);
-        redoItem.setText(undo.getRedoPresentationName());
-        putValue(Action.NAME, undo.getRedoPresentationName());
-      } else {
-        this.setEnabled(false);
-        redoItem.setEnabled(false);
-        redoItem.setText(tr("Redo"));
-        putValue(Action.NAME, "Redo");
-      }
-    }
+  protected void updateUndoRedoState() {
+    SketchTextArea textArea = getCurrentTab().getTextArea();
+    undoItem.setEnabled(textArea.canUndo());
+    redoItem.setEnabled(textArea.canRedo());
   }
 
 
@@ -1610,8 +1549,7 @@ public List<EditorTab> getTabs() {
    */
   public void selectTab(final int index) {
     currentTabIndex = index;
-    undoAction.updateUndoState();
-    redoAction.updateRedoState();
+    updateUndoRedoState();
     updateTitle();
     header.rebuild();
     getCurrentTab().activated();
@@ -1710,6 +1648,9 @@ public void reorderTabs() {
    */
   protected void addTab(SketchFile file, String contents) throws IOException {
     EditorTab tab = new EditorTab(this, file, contents);
+    tab.getTextArea().getDocument()
+        .addDocumentListener(new DocumentTextChangeListener(
+            () -> updateUndoRedoState()));
     tabs.add(tab);
     reorderTabs();
   }

app/src/processing/app/EditorTab.java

@@ -44,7 +44,6 @@
 import javax.swing.text.BadLocationException;
 import javax.swing.text.Element;
 import javax.swing.text.PlainDocument;
-import javax.swing.undo.UndoManager;
 import javax.swing.text.DefaultCaret;
 import javax.swing.text.Document;
 
@@ -53,7 +52,6 @@
 import org.fife.ui.rsyntaxtextarea.RSyntaxUtilities;
 import org.fife.ui.rtextarea.Gutter;
 import org.fife.ui.rtextarea.RTextScrollPane;
-import org.fife.ui.rtextarea.RUndoManager;
 
 import cc.arduino.UpdatableBoardsLibsFakeURLsHandler;
 import processing.app.helpers.DocumentTextChangeListener;
@@ -108,10 +106,6 @@ public EditorTab(Editor editor, SketchFile file, String contents)
     file.setStorage(this);
     applyPreferences();
     add(scrollPane, BorderLayout.CENTER);
-
-    RUndoManager undo = new LastUndoableEditAwareUndoManager(this.textarea, this.editor);
-    document.addUndoableEditListener(undo);
-    textarea.setUndoManager(undo);
   }
 
   private RSyntaxDocument createDocument(String contents) {
@@ -407,14 +401,14 @@ public void setText(String what) {
       int oldLength = doc.getLength();
       // The undo manager already seems to group the insert and remove together
       // automatically, but better be explicit about it.
-      textarea.getUndoManager().beginInternalAtomicEdit();
+      textarea.beginAtomicEdit();
       try {
         doc.insertString(oldLength, what, null);
         doc.remove(0, oldLength);
       } catch (BadLocationException e) {
         System.err.println("Unexpected failure replacing text");
       } finally {
-        textarea.getUndoManager().endInternalAtomicEdit();
+        textarea.endAtomicEdit();
       }
     } finally {
       caret.setUpdatePolicy(policy);
@@ -554,10 +548,6 @@ void handleRedo() {
     textarea.redoLastAction();
   }
 
-  public UndoManager getUndoManager() {
-    return textarea.getUndoManager();
-  }
-  
   public String getCurrentKeyword() {
     String text = "";
     if (textarea.getSelectedText() != null)