I've found this post about BPMN files designer, I tried to open designer window in every way, but i can only open diagram preview. Did anyone use jBPM plugin and can tell me how can I open designer window?
Edit
For simplicity, i'm using this bpmn file:
<?xml version="1.0" encoding="UTF-8"?>
<definitions id="definitions"
xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
targetNamespace="http://www.activiti.org/bpmn2.0">
<process id="helloWorld">
<startEvent id="start" />
<sequenceFlow id="flow1" sourceRef="start" targetRef="script" />
<scriptTask id="script" name="HelloWorld" scriptFormat="groovy">
<script>
System.out.println("Hello world")
</script>
</scriptTask>
<sequenceFlow id="flow2" sourceRef="script" targetRef="theEnd" />
<endEvent id="theEnd" />
</process>
</definitions>
It's from tutorial