Merge pull request #1016 from opf/feature/ui-component-table-widgets-merged-timeline-chart-group-expansion-fixes

Fix timeline chart redrawing when group element expansions are toggled

app/assets/javascripts/angular/models/timelines/mixins/ui.js

@@ -437,6 +437,7 @@ angular.module('openproject.timelines.models')
 
       $timeout(function() {
         // rebuild content
+        timeline.bustVerticalOffsetCache(tree);
         timeline.rebuildBackground(tree, width, height);
         chart.css({'display': 'block'});
         timeline.rebuildForeground(tree);
@@ -603,6 +604,13 @@ angular.module('openproject.timelines.models')
       this.previousRelativeVerticalBottomOffsetParameter = offset;
       return result;
     },
+    bustVerticalOffsetCache: function(tree) {
+      tree.iterateWithChildren(function(node) {
+        var currentElement = node.getDOMElement();
+        currentElement.removeAttr("data-vertical-offset");
+        currentElement.removeAttr("data-vertical-bottom-offset");
+      });
+    },
     rebuildForeground: function(tree) {
       var timeline = this;
       var previousGrouping = -1;