@algorytmus said: ... except when something is dragged from another application but when moving the mouse (preview drop) over a model (sketchup view) none of those mouse events are fired for me in the Tool implementing class. What is something ??? a SKP file ?? an Image file ?? (1) The application drag-and-drop handler is not directly exposed via the SketchUp API. Instead, native SketchUp tools are activated when VALID objects are dropped: Images: The ScaleTool is activated after the image is inserted, and selected.* SKP file: The MoveTool is activated after the skp is added to the DefintionList, and an instance is inserted and selected. So in both cases, dropping those valid objects, SHOULD cause your tool's deactivate() callback to fire, just prior to the native tool becoming active.

(1) It's easy to see why the 2nd op is aborted because you call model.abort_operation instead of committing it. (2) Perhaps some other plugin is also creating ops and "gluing" their's transparently between your 2 ops ?? I always disable all other 3rd party plugins when developing!* (But I leave the OEM Dynamic Components extension ON.) (3) Do yourself and us a big favor.. wrap your operations and trap any errors that cause the ops to abort. See [Code] wrapping operations