From 66801df1118f44e47c87e2342919d770c96ed305 Mon Sep 17 00:00:00 2001
From: jdotzki <joerg.dotzki@zalando.de>
Date: Tue, 24 Feb 2015 16:21:12 +0100
Subject: [PATCH] feature(rules): add modeling rules for event based gateways

closes #193
---
 .../context-pad/ContextPadProvider.js         | 18 ++++++++-
 lib/features/modeling/rules/ModelingRules.js  | 37 ++++++++++++++++---
 2 files changed, 49 insertions(+), 6 deletions(-)

diff --git a/lib/features/context-pad/ContextPadProvider.js b/lib/features/context-pad/ContextPadProvider.js
index c4da417b..263f7b2f 100644
--- a/lib/features/context-pad/ContextPadProvider.js
+++ b/lib/features/context-pad/ContextPadProvider.js
@@ -251,7 +251,8 @@ ContextPadProvider.prototype.getContextPadEntries = function(element) {
 
   if (bpmnElement.$instanceOf('bpmn:FlowNode')) {
 
-    if (!bpmnElement.$instanceOf('bpmn:EndEvent')) {
+    if (!bpmnElement.$instanceOf('bpmn:EndEvent') &&
+        !bpmnElement.$instanceOf('bpmn:EventBasedGateway')) {
 
       assign(actions, {
         'append.end-event': appendAction('bpmn:EndEvent', 'icon-end-event'),
@@ -269,6 +270,21 @@ ContextPadProvider.prototype.getContextPadEntries = function(element) {
       });
     }
 
+    if (bpmnElement.$instanceOf('bpmn:EventBasedGateway')) {
+      // TODO Add Receiving Events
+      assign(actions, {
+        'append.receive-task': appendAction('bpmn:ReceiveTask', 'icon-receive'),
+        'connect': {
+          group: 'connect',
+          className: 'icon-connection',
+          action: {
+            click: startConnect,
+            dragstart: startConnect
+          }
+        }
+      });
+    }
+
     assign(actions, {
       'append.text-annotation': appendAction('bpmn:TextAnnotation', 'icon-text-annotation')
     });
diff --git a/lib/features/modeling/rules/ModelingRules.js b/lib/features/modeling/rules/ModelingRules.js
index b3bf7731..c9ba9f9f 100644
--- a/lib/features/modeling/rules/ModelingRules.js
+++ b/lib/features/modeling/rules/ModelingRules.js
@@ -27,13 +27,40 @@ ModelingRules.prototype.init = function() {
     return a === b;
   }
 
-  function isEventConnectionValid(sourceBo, targetBo) {
-    return targetBo.$instanceOf('bpmn:StartEvent') ||
-            sourceBo.$instanceOf('bpmn:EndEvent');
+  function isEventConnectionInvalid(source, target) {
+
+    var sourceBo = source.businessObject,
+        targetBo = target.businessObject;
+
+    var startEventCheck = targetBo.$instanceOf('bpmn:StartEvent') ||
+                            sourceBo.$instanceOf('bpmn:EndEvent');
+
+    var eventBasedGatewayCheck = false;
+
+    // Ensure target of event based gateway is one of:
+    // receive task, receiving message, timer, signal, condition event
+    if (sourceBo.$instanceOf('bpmn:EventBasedGateway')) {
+
+      eventBasedGatewayCheck = true;
+
+      if (targetBo.$instanceOf('bpmn:ReceiveTask')) {
+        eventBasedGatewayCheck = false;
+      } else if (targetBo.$instanceOf('bpmn:ReceiveMessageEvent')) { // ReceiveMessageEvent check name
+        // TODO waiting for https://github.com/bpmn-io/bpmn-js/issues/192
+      } else if (targetBo.$instanceOf('bpmn:ReceiveTimerEvent')) { // TimerEvent check name
+        // TODO waiting for https://github.com/bpmn-io/bpmn-js/issues/192
+      } else if (targetBo.$instanceOf('bpmn:ReceiveSignalEvent')) { // TimerEvent check name
+        // TODO waiting for https://github.com/bpmn-io/bpmn-js/issues/192
+      } else if (targetBo.$instanceOf('bpmn:ReceiveConditionEvent')) { // TimerEvent check name
+        // TODO waiting for https://github.com/bpmn-io/bpmn-js/issues/192
+      }
+    }
+
+    return startEventCheck || eventBasedGatewayCheck;
   }
 
-  // rules
 
+  // rules
   function canConnect(source, target, connection) {
 
     if (nonExistantOrLabel(source) || nonExistantOrLabel(target)) {
@@ -70,7 +97,7 @@ ModelingRules.prototype.init = function() {
 
     // Do not allow incoming connections on StartEvents
     // and outgoing connections on EndEvents
-    if (isEventConnectionValid(sourceBo, targetBo)) {
+    if (isEventConnectionInvalid(source, target)) {
 
       return false;
     }