feat: add multi-element delete action

lib/features/context-pad/ContextPadProvider.js

@@ -1,7 +1,8 @@
 import {
   assign,
   forEach,
-  isArray
+  isArray,
+  every
 } from 'min-dash';
 
 import {
@@ -86,9 +87,49 @@ ContextPadProvider.$inject = [
   'translate'
 ];
 
+ContextPadProvider.prototype.getMultiElementContextPadEntries = function(elements) {
+  var modeling = this._modeling;
+
+  var actions = {};
+
+  if (this._isDeleteAllowed(elements)) {
+    assign(actions, {
+      'delete': {
+        group: 'edit',
+        className: 'bpmn-icon-trash',
+        title: this._translate('Remove'),
+        action: {
+          click: function(event, elements) {
+            modeling.removeElements(elements.slice());
+          }
+        }
+      }
+    });
+  }
+
+  return actions;
+};
+
+/**
+ * @param {djs.model.Base[]} elements
+ * @return {boolean}
+ */
+ContextPadProvider.prototype._isDeleteAllowed = function(elements) {
+
+  var baseAllowed = this._rules.allowed('elements.delete', {
+    elements: elements
+  });
+
+  if (isArray(baseAllowed)) {
+    return every(baseAllowed, function(element) {
+      return includes(baseAllowed, element);
+    });
+  }
+
+  return baseAllowed;
+};
 
 ContextPadProvider.prototype.getContextPadEntries = function(element) {
-
   var contextPad = this._contextPad,
       modeling = this._modeling,
 
@@ -470,3 +511,7 @@ function isEventType(eventBo, type, definition) {
 
   return isType && isDefinition;
 }
+
+function includes(array, item) {
+  return array.indexOf(item) !== -1;
+}