fixed undo/redo functionality

Author: miho

Diff for: gradle/project-info.gradle

@@ -3,7 +3,7 @@
 // -----------------------------------------------------------------------------
 ext.publishing.artifactId =  project.name.toLowerCase()
 ext.publishing.groupId    =  'eu.mihosoft.monacofx'
-ext.publishing.versionId  =  '0.0.5'
+ext.publishing.versionId  =  '0.0.6'
 
 ext.publishing.developerName         = 'Michael Hoffer'
 ext.publishing.developerAlias        = 'miho'

Diff for: src/main/java/eu/mihosoft/monacofx/Document.java

@@ -34,6 +34,8 @@ public class Document {
     private JSObject editorGlobal;
     private JSObject window;
 
+    private boolean updatingText;
+
     private final StringProperty textProperty = new SimpleStringProperty();
     private final StringProperty languageProperty = new SimpleStringProperty();
     private final IntegerProperty numberOfLinesProperty = new SimpleIntegerProperty();
@@ -50,14 +52,19 @@ void setEditor(WebEngine engine, JSObject window, JSObject editor) {
 
         // text changes -> js
         textProperty.addListener((ov) -> {
-            editor.call("setValue", getText());
+            if(!updatingText) editor.call("setValue", getText());
         });
 
         // keep a global reference because it's garbage collected otherwise
         jsfListener = new JFunction( args -> {
             String text = (String) editor.call("getValue");
             if(text!=null) {
-                setText(text);
+                try {
+                    updatingText = true;
+                    setText(text);
+                }finally {
+                    updatingText=false;
+                }
                 numberOfLinesProperty.setValue(text.split("\\R").length);
             }
             return null;

Diff for: src/main/java/eu/mihosoft/monacofx/ViewController.java

@@ -30,27 +30,40 @@
 public final class ViewController {
 
     private final Editor editor;
+    private JSObject window;
 
     //private final ObjectProperty<Position> cursorPositionProperty = new SimpleObjectProperty<>();
     private final IntegerProperty scrollPositionProperty = new SimpleIntegerProperty();
 
+    private JFunction scrollChangeListener;
+
     public ViewController(Editor editor) {
         this.editor = editor;
     }
 
     void setEditor(JSObject window, JSObject editor) {
+        this.window = window;
          // initial scroll
         editor.call("setScrollPosition", getScrollPosition());
         // scroll changes -> js
         scrollPositionProperty().addListener((ov) -> {
             editor.call("setScrollPosition", getScrollPosition());
         });
          // scroll changes <- js
-        window.setMember("scrollChangeListener", new JFunction( args -> {
+        scrollChangeListener = new JFunction( args -> {
             int pos = (int) editor.call("getScrollTop");
             setScrollPosition(pos);
             return null;
-        }));
+        });
+        window.setMember("scrollChangeListener", scrollChangeListener);
+    }
+
+    public void undo() {
+        window.call("undo");
+    }
+
+    public void redo() {
+        window.call("redo");
     }
 
     public void setScrollPosition(int posIdx) {

Diff for: src/main/resources/eu/mihosoft/monacofx/monaco-editor-0.20.0/index.html

@@ -126,8 +126,55 @@
             }
         });
 
+		// UNDO-/REDO functionality
+        const initialVersion = editorView.getModel().getAlternativeVersionId();
+        let currentVersion = initialVersion;
+        let lastVersion = initialVersion;
+        editorView.onDidChangeModelContent(e => {
+            const versionId = editorView.getModel().getAlternativeVersionId();
+            // undoing
+            if (versionId < currentVersion) {
+                // REDO AVAILABLE
+                // enableRedoButton();
+
+                // no more undo possible
+                if (versionId === initialVersion) {
+                    // UNDO NOT AVAILABLE
+                    // disableUndoButton();
+                }
+            } else {
+                // redoing
+                if (versionId <= lastVersion) {
+                    // redoing the last change
+                    if (versionId == lastVersion) {
+                        // REDO NOT AVAILABLE
+                        // disableRedoButton();
+                    }
+                } else { // adding new change, disable redo when adding new changes
+                    // REDO NOT AVAILABLE
+                    // disableRedoButton();
+                    if (currentVersion > lastVersion) {
+                        lastVersion = currentVersion;
+                    }
+                }
+
+                // UNDO AVAILABLE
+                // enableUndoButton();
+            }
+            currentVersion = versionId;
+        });
+
 	});
 
+    function undo() {
+        editorView.trigger('aaaa', 'undo', 'aaaa');
+        editorView.focus();
+    }
+
+    function redo() {
+        editorView.trigger('aaaa', 'redo', 'aaaa');
+        editorView.focus();
+    }
 
 	function getCode() {