Allow UndoManager to use developer-defined changes (text, view, etc.)

richtextfx/src/main/java/org/fxmisc/richtext/GenericStyledArea.java

@@ -73,14 +73,13 @@
 import org.fxmisc.richtext.model.SegmentOps;
 import org.fxmisc.richtext.model.StyleSpans;
 import org.fxmisc.richtext.model.StyledDocument;
-import org.fxmisc.richtext.model.TextChange;
 import org.fxmisc.richtext.model.TextEditingArea;
 import org.fxmisc.richtext.model.TextOps;
 import org.fxmisc.richtext.model.TwoDimensional;
 import org.fxmisc.richtext.model.TwoLevelNavigator;
 import org.fxmisc.richtext.model.UndoActions;
+import org.fxmisc.richtext.util.UndoUtils;
 import org.fxmisc.undo.UndoManager;
-import org.fxmisc.undo.UndoManagerFactory;
 import org.reactfx.EventStream;
 import org.reactfx.EventStreams;
 import org.reactfx.Guard;
@@ -306,11 +305,9 @@ private static int clamp(int min, int val, int max) {
     // undo manager
     private UndoManager undoManager;
     @Override public UndoManager getUndoManager() { return undoManager; }
-    @Override public void setUndoManager(UndoManagerFactory undoManagerFactory) {
-        undoManager.close();
-        undoManager = preserveStyle
-                ? createRichUndoManager(undoManagerFactory)
-                : createPlainUndoManager(undoManagerFactory);
+    @Override public void setUndoManager(UndoManager undoManager) {
+        this.undoManager.close();
+        this.undoManager = undoManager;
     }
 
     private final ObjectProperty<Duration> mouseOverTextDelay = new SimpleObjectProperty<>(null);
@@ -618,9 +615,7 @@ public GenericStyledArea(
         this.applyParagraphStyle = applyParagraphStyle;
         this.segmentOps = segmentOps;
 
-        undoManager = preserveStyle
-                ? createRichUndoManager(UndoManagerFactory.unlimitedHistoryFactory())
-                : createPlainUndoManager(UndoManagerFactory.unlimitedHistoryFactory());
+        undoManager = UndoUtils.createUndoManager(this);
 
         // allow tab traversal into area
         setFocusTraversable(true);
@@ -1449,18 +1444,6 @@ private PS getParagraphStyleForInsertionAt(int pos) {
         }
     }
 
-    private UndoManager createPlainUndoManager(UndoManagerFactory factory) {
-        Consumer<PlainTextChange> apply = change -> replaceText(change.getPosition(), change.getPosition() + change.getRemoved().length(), change.getInserted());
-        BiFunction<PlainTextChange, PlainTextChange, Optional<PlainTextChange>> merge = PlainTextChange::mergeWith;
-        return factory.create(plainTextChanges(), PlainTextChange::invert, apply, merge, TextChange::isIdentity);
-    }
-
-    private UndoManager createRichUndoManager(UndoManagerFactory factory) {
-        Consumer<RichTextChange<PS, SEG, S>> apply = change -> replace(change.getPosition(), change.getPosition() + change.getRemoved().length(), change.getInserted());
-        BiFunction<RichTextChange<PS, SEG, S>, RichTextChange<PS, SEG, S>, Optional<RichTextChange<PS, SEG, S>>> merge = RichTextChange<PS, SEG, S>::mergeWith;
-        return factory.create(richChanges(), RichTextChange::invert, apply, merge, TextChange::isIdentity);
-    }
-
     private void suspendVisibleParsWhile(Runnable runnable) {
         Suspendable.combine(beingUpdated, visibleParagraphs).suspendWhile(runnable);
     }

richtextfx/src/main/java/org/fxmisc/richtext/model/UndoActions.java

@@ -13,7 +13,7 @@ public interface UndoActions {
      * Undo manager of this text area.
      */
     UndoManager getUndoManager();
-    void setUndoManager(UndoManagerFactory undoManagerFactory);
+    void setUndoManager(UndoManager undoManager);
 
     default void undo() { getUndoManager().undo(); }
 

richtextfx/src/main/java/org/fxmisc/richtext/util/UndoUtils.java

@@ -0,0 +1,43 @@
+package org.fxmisc.richtext.util;
+
+import org.fxmisc.richtext.GenericStyledArea;
+import org.fxmisc.richtext.model.PlainTextChange;
+import org.fxmisc.richtext.model.RichTextChange;
+import org.fxmisc.richtext.model.TextChange;
+import org.fxmisc.undo.UndoManager;
+import org.fxmisc.undo.UndoManagerFactory;
+
+import java.util.function.Consumer;
+
+public final class UndoUtils {
+
+    private UndoUtils() {
+        throw new IllegalStateException("UndoUtils cannot be instantiated");
+    }
+
+    public static <PS, SEG, S> UndoManager createUndoManager(GenericStyledArea<PS, SEG, S> area) {
+        return area.isPreserveStyle()
+                ? richTextUndoManager(area)
+                : plainTextUndoManager(area);
+    }
+
+    public static <PS, SEG, S> UndoManager richTextUndoManager(GenericStyledArea<PS, SEG, S> area) {
+        return richTextUndoManager(area, UndoManagerFactory.unlimitedHistoryFactory());
+    }
+
+    public static <PS, SEG, S> UndoManager richTextUndoManager(GenericStyledArea<PS, SEG, S> area,
+                                                               UndoManagerFactory factory) {
+        Consumer<RichTextChange<PS, SEG, S>> apply = change -> area.replace(change.getPosition(), change.getPosition() + change.getRemoved().length(), change.getInserted());
+        return factory.create(area.richChanges(), RichTextChange::invert, apply, TextChange::mergeWith, TextChange::isIdentity);
+    };
+
+    public static <PS, SEG, S> UndoManager plainTextUndoManager(GenericStyledArea<PS, SEG, S> area) {
+        return plainTextUndoManager(area, UndoManagerFactory.unlimitedHistoryFactory());
+    }
+
+    public static <PS, SEG, S> UndoManager plainTextUndoManager(GenericStyledArea<PS, SEG, S> area,
+                                                                UndoManagerFactory factory) {
+        Consumer<PlainTextChange> apply = change -> area.replaceText(change.getPosition(), change.getPosition() + change.getRemoved().length(), change.getInserted());
+        return factory.create(area.plainTextChanges(), PlainTextChange::invert, apply, TextChange::mergeWith, TextChange::isIdentity);
+    }
+}