only fire change events if selection/cursor really changes

src/Selection.js

@@ -16,14 +16,6 @@ ace.Selection = function(doc) {
 
     ace.implement(this, ace.MEventEmitter);
 
-    this.updateCursor = function() {
-        this.$dispatchEvent("changeCursor", { data: this.getCursor() });
-    };
-
-    this.updateSelection = function() {
-        this.$dispatchEvent("changeSelection", {});
-    };
-
     this.isEmpty = function() {
         return (this.selectionAnchor == null);
     };
@@ -94,8 +86,10 @@ ace.Selection = function(doc) {
     };
 
     this.clearSelection = function() {
-        this.selectionAnchor = null;
-        this.updateSelection();
+        if (this.selectionAnchor) {
+            this.selectionAnchor = null;
+            this.$dispatchEvent("changeSelection", {});
+        }
     };
 
 
@@ -109,12 +103,22 @@ ace.Selection = function(doc) {
     };
 
     this.$moveSelection = function(mover) {
+        var changed = false;
+
         if (!this.selectionAnchor) {
+            changed = true;
             this.selectionAnchor = this.$clone(this.selectionLead);
         }
 
+        var cursor = this.$clone(this.selectionLead);
         mover.call(this);
-        this.updateSelection();
+
+        if (cursor.row !== this.selectionLead.row || cursor.column !== this.selectionLead.column) {
+            changed = true;
+        }
+
+        if (changed)
+            this.$dispatchEvent("changeSelection", {});
     };
 
     this.selectTo = function(row, column) {
@@ -349,8 +353,12 @@ ace.Selection = function(doc) {
     };
 
     this.moveCursorTo = function(row, column) {
-        this.selectionLead = this.$clipPositionToDocument(row, column);
-        this.updateCursor();
+        var cursor = this.$clipPositionToDocument(row, column);
+
+        if (cursor.row !== this.selectionLead.row || cursor.column !== this.selectionLead.column) {
+            this.selectionLead = cursor;
+            this.$dispatchEvent("changeCursor", { data: this.getCursor() });
+        }
     };
 
     this.moveCursorUp = function() {

test/NavigationTest.js

@@ -21,7 +21,7 @@ var NavigationTest = TestCase("NavigationTest",
         var doc = this.createTextDocument(200, 10);
         var editor = new ace.Editor(new MockRenderer(), doc);
 
-        editor.scrollToRow(editor.getLastVisibleRow() + 20);
+        editor.moveCursorTo(editor.getLastVisibleRow() + 20);
         editor.navigateFileStart();
 
         assertEquals(0, editor.getFirstVisibleRow());

test/SelectionTest.js

@@ -216,5 +216,35 @@ var SelectionTest = TestCase("SelectionTest",
         var range = selection.getRange();
         assertPosition(0, 4, range.start);
         assertPosition(0, 6, range.end);
+    },
+
+    "test: moving cursor should fire a 'changeCursor' event" : function() {
+        var doc = new ace.Document("Juhu  Kinners");
+        var selection = doc.getSelection();
+
+        selection.moveCursorTo(0, 5);
+
+        var called = false;
+        selection.addEventListener("changeCursor", function() {
+           called = true;
+        });
+
+        selection.moveCursorTo(0, 6);
+        assertTrue(called);
+    },
+
+    "test: calling setCursor with the same position should not fire an event": function() {
+        var doc = new ace.Document("Juhu  Kinners");
+        var selection = doc.getSelection();
+
+        selection.moveCursorTo(0, 5);
+
+        var called = false;
+        selection.addEventListener("changeCursor", function() {
+           called = true;
+        });
+
+        selection.moveCursorTo(0, 5);
+        assertFalse(called);
     }
 });