fix(modeling/behavior): round label move adjustment

Ensure we don't return floating point numbers for conection label
adjustments calculated on connection changes.

lib/features/modeling/behavior/util/LabelLayoutUtil.js

@@ -1,11 +1,13 @@
 'use strict';
 
-var GeometricUtil = require('./GeometricUtil');
-
-var getDistancePointPoint = require('./GeometricUtil').getDistancePointPoint;
+var getDistancePointPoint = require('./GeometricUtil').getDistancePointPoint,
+    rotateVector = require('./GeometricUtil').rotateVector,
+    getAngle = require('./GeometricUtil').getAngle;
 
 var getAttachment = require('./LineAttachmentUtil').getAttachment;
 
+var roundPoint = require('diagram-js/lib/layout/LayoutUtil').roundPoint;
+
 
 function findNewLabelLineStartIndex(oldWaypoints, newWaypoints, attachment, hints) {
 
@@ -164,7 +166,7 @@ function getLabelAdjustment(label, newWaypoints, oldWaypoints, hints) {
   };
 
   // the rotated vector to label
-  var newLabelVector = GeometricUtil.rotateVector({
+  var newLabelVector = rotateVector({
     x: labelPosition.x - oldFoot.x,
     y: labelPosition.y - oldFoot.y
   }, angleDelta);
@@ -173,7 +175,10 @@ function getLabelAdjustment(label, newWaypoints, oldWaypoints, hints) {
   x = newFoot.x + newLabelVector.x - labelPosition.x;
   y = newFoot.y + newLabelVector.y - labelPosition.y;
 
-  return { x: x, y: y };
+  return roundPoint({
+    x: x,
+    y: y
+  });
 }
 
 module.exports.getLabelAdjustment = getLabelAdjustment;
@@ -200,8 +205,8 @@ function getLabelMid(label) {
 }
 
 function getAngleDelta(l1, l2) {
-  var a1 = GeometricUtil.getAngle(l1),
-      a2 = GeometricUtil.getAngle(l2);
+  var a1 = getAngle(l1),
+      a2 = getAngle(l2);
   return a2 - a1;
 }
 

test/spec/features/modeling/LabelLayoutingSpec.js

@@ -416,8 +416,8 @@ describe('modeling - label layouting', function() {
           dragging.end();
 
           // then
-          expect(Math.round(connection.label.x)).to.be.within(240, 242);
-          expect(Math.round(connection.label.y)).to.be.equal(148);
+          expect(connection.label.x).to.be.within(240, 242);
+          expect(connection.label.y).to.be.within(148, 149);
 
         }
       ));