Bug 512054

Summary: Investigate how to support accessing a single transaction policy from multiple handlers
Product: [Tools] GEF Reporter: Matthias Wienand <matthias.wienand>
Component: GEF MVCAssignee: gef-inbox <gef-inbox>
Status: NEW --- QA Contact:
Severity: normal    
Priority: P3    
Version: 1.1.0   
Target Milestone: ---   
Hardware: All   
OS: All   
Whiteboard:

Description Matthias Wienand CLA 2017-02-10 12:04:41 EST
Currently, when multiple interaction policies access the same transaction policy to perform their actions, the transaction policy is initialized more than once, which leads to an IllegalStateException ("already initialized").

This unfortunate constellation can be observed within the MVC Logo Example when interleaving touch gestures for panning and zooming (PanOrZoomOnScrollPolicy, ZoomOnPinchSpreadPolicy).

A workaround is to combine the multiple interaction policies to a single interaction policy that implements the individual interaction interfaces. This combined policy can then ensure that an underlying transaction policy is only once initialized.

We need to investigate how to simplify the combination of interaction policies that use the same transaction policy.