User feedback during long operations

[Eneroth3]

This should be done in the tool layer, not in operations themselves. Operations can be used in other extensions where they are just a tiny part of a longer operation, e.g. drawing a house. In such situations it doesn't make any sense to have the feedback saying "56% done" when perhaps 2 or 86 % is done. Also it falls outside the scope of the operations to give user feedback.

The feedback must also fit into the branding of SU and the platform, e.g. be simple statusbar text.

One implementation could be to have BulKSolidOperations yield count, total, container1 and container2 on each operation, total being number of targets multiplied by number of modifiers. Then the tools could produce statusbar texts such as "52% (Uniting Car and Zeppelin)".

[Eneroth3]

Feedback used in SketchUp Simplify Contours Tool. Seems to be used in Sandbox Tools too.

Eneroth Solid Tools could have an identical progress indicator.