feat(layout): filter redundant connection waypoints

lib/features/modeling/BpmnLayouter.js

@@ -9,6 +9,8 @@ var BaseLayouter = require('diagram-js/lib/layout/BaseLayouter'),
 
 var LayoutUtil = require('diagram-js/lib/layout/LayoutUtil');
 
+var pointsOnLine = require('diagram-js/lib/util/Geometry').pointsOnLine;
+
 var isExpanded = require('../../util/DiUtil').isExpanded;
 
 var getMid = LayoutUtil.getMid,
@@ -157,6 +159,20 @@ BpmnLayouter.prototype.layoutConnection = function(connection, hints) {
         start, end,
         waypoints,
         manhattanOptions);
+
+    // filter un-needed waypoints that may be the result of
+    // bundle collapsing
+    updatedWaypoints = updatedWaypoints && updatedWaypoints.reduce(function(points, p, idx) {
+
+      var previous = points[points.length - 1],
+          next = updatedWaypoints[idx + 1];
+
+      if (!pointsOnLine(previous, next, p, 0)) {
+        points.push(p);
+      }
+
+      return points;
+    }, []);
   }
 
   return updatedWaypoints || [ start, end ];

test/spec/features/modeling/layout/LayoutConnectionSpec.js

@@ -13,14 +13,17 @@ describe('features/modeling - layout connection', function() {
 
   var diagramXML = require('../../../../fixtures/bpmn/sequence-flows.bpmn');
 
-  var testModules = [ coreModule, modelingModule ];
-
-  beforeEach(bootstrapModeler(diagramXML, { modules: testModules }));
+  beforeEach(bootstrapModeler(diagramXML, {
+    modules: [
+      coreModule,
+      modelingModule
+    ]
+  }));
 
 
-  describe('connection handling', function() {
+  describe('should not touch already layouted', function() {
 
-    it('should execute', inject(function(elementRegistry, modeling, bpmnFactory) {
+    it('execute', inject(function(elementRegistry, modeling, bpmnFactory) {
 
       // given
       var sequenceFlowConnection = elementRegistry.get('SequenceFlow_1'),
@@ -44,12 +47,8 @@ describe('features/modeling - layout connection', function() {
       expect(sequenceFlow.di.waypoint).eql(diWaypoints);
     }));
 
-  });
 
-
-  describe('undo support', function() {
-
-    it('should undo', inject(function(elementRegistry, commandStack, modeling) {
+    it('undo', inject(function(elementRegistry, commandStack, modeling) {
 
       // given
       var sequenceFlowConnection = elementRegistry.get('SequenceFlow_1'),
@@ -68,12 +67,8 @@ describe('features/modeling - layout connection', function() {
       expect(sequenceFlow.di.waypoint).eql(oldDiWaypoints);
     }));
 
-  });
 
-
-  describe('redo support', function() {
-
-    it('should redo', inject(function(elementRegistry, commandStack, modeling) {
+    it('redo', inject(function(elementRegistry, commandStack, modeling) {
 
       // given
       var sequenceFlowConnection = elementRegistry.get('SequenceFlow_1'),
@@ -95,4 +90,35 @@ describe('features/modeling - layout connection', function() {
 
   });
 
+
+  it('should remove un-needed waypoints', inject(function(elementRegistry, modeling) {
+
+    // given
+    var taskShape = elementRegistry.get('Task_2'),
+        sequenceFlowConnection = elementRegistry.get('SequenceFlow_1');
+
+    // when
+    // moving task
+    modeling.moveElements([ taskShape ], { x: 250, y: -95 });
+
+    // then
+    var newWaypoints = sequenceFlowConnection.waypoints;
+
+    expect(newWaypoints.map(toPoint)).to.eql([
+      { x: 578, y: 341 },
+      { x: 982, y: 341 }
+    ]);
+  }));
+
 });
+
+
+
+///////// helpers ///////////////////////////
+
+function toPoint(p) {
+  return {
+    x: p.x,
+    y: p.y
+  };
+}