fix(drilldown): don't reset vieport on `makeCollaboration`

closes #1565

lib/features/drilldown/DrilldownCentering.js

@@ -1,3 +1,5 @@
+import { is } from '../../util/ModelUtil';
+
 /**
  * Move collapsed subprocesses into view when drilling down.
  *
@@ -21,7 +23,14 @@ export default function DrilldownCentering(eventBus, canvas) {
     });
 
     var newRoot = event.element;
-    var storedViewbox = positionMap.get(newRoot) || { x: 0, y: 0, zoom: 1 };
+    var storedViewbox = positionMap.get(newRoot);
+
+    // current root was replaced with a collaboration, we don't update the viewbox
+    if (is(newRoot, 'bpmn:Collaboration') && !storedViewbox) {
+      return;
+    }
+
+    storedViewbox = storedViewbox || { x: 0, y: 0, zoom: 1 };
 
     var dx = (currentViewbox.x - storedViewbox.x) * currentViewbox.scale,
         dy = (currentViewbox.y - storedViewbox.y) * currentViewbox.scale;

test/spec/features/drilldown/DrilldownIntegrationSpec.js

@@ -0,0 +1,94 @@
+import {
+  inject
+} from 'test/TestHelper';
+
+import coreModule from 'lib/core';
+import modelingModule from 'lib/features/modeling';
+import DrilldownModule from 'lib/features/drilldown';
+import { bootstrapModeler, getBpmnJS } from '../../../helper';
+
+
+describe('features - drilldown', function() {
+
+  var testModules = [
+    coreModule,
+    modelingModule,
+    DrilldownModule
+  ];
+
+  var multiLayerXML = require('./nested-subprocesses.bpmn');
+
+  beforeEach(bootstrapModeler(multiLayerXML, { modules: testModules }));
+
+  describe('Navigation', function() {
+
+    it('should not reset scroll on create collaboration',
+      inject(function(canvas, modeling) {
+
+        // given
+        canvas.scroll({ dx: 500, dy: 500 });
+        canvas.zoom(0.5);
+        var zoomedAndScrolledViewbox = canvas.viewbox();
+
+        // when
+        modeling.makeCollaboration();
+
+        // then
+        expectViewbox(zoomedAndScrolledViewbox);
+      })
+    );
+
+
+    it('should not reset scroll on create collaboration - undo',
+      inject(function(canvas, modeling, commandStack) {
+
+        // given
+        canvas.scroll({ dx: 500, dy: 500 });
+        canvas.zoom(0.5);
+        var zoomedAndScrolledViewbox = canvas.viewbox();
+
+        // when
+        modeling.makeCollaboration();
+        commandStack.undo();
+
+        // then
+        expectViewbox(zoomedAndScrolledViewbox);
+      })
+    );
+
+
+    it('should not reset scroll on create collaboration - redo',
+      inject(function(canvas, modeling, commandStack) {
+
+        // given
+        canvas.scroll({ dx: 500, dy: 500 });
+        canvas.zoom(0.5);
+        var zoomedAndScrolledViewbox = canvas.viewbox();
+
+        // when
+        modeling.makeCollaboration();
+        commandStack.undo();
+        commandStack.redo();
+
+        // then
+        expectViewbox(zoomedAndScrolledViewbox);
+      })
+    );
+
+  });
+
+});
+
+
+// helpers //////////
+
+function expectViewbox(expectedViewbox) {
+  return getBpmnJS().invoke(function(canvas) {
+
+    var viewbox = canvas.viewbox();
+
+    expect(viewbox.x).to.eql(expectedViewbox.x);
+    expect(viewbox.y).to.eql(expectedViewbox.y);
+    expect(viewbox.scale).to.eql(expectedViewbox.scale);
+  });
+}