MapEditorController: Show details for map part operations

[dl3sdo]

When merging or removing a map part the user is not informed about the number of affected objects.
This easy change tells the user how many objects are subject of merging or removing a map part.

[dl3sdo]

Examples:

[pkturner]

I like this, considering the whole.

As for the details, I would prefer not to be questioned about removing an empty map part.

[dl3sdo]

@pkturner: Indeed it's an option to remove the popup window if empty map parts shall be removed or merged.
I added another commit so that there is the option to take both or pick the first one only.
@lpechacek,@dg0yt: what is your preference?

[lpechacek]

@lpechacek,@dg0yt: what is your preference?

Given that the map part operations can be undone, I'm all fine with skipping the confirmation on empty parts.

Code-wise, I'm going to review the second patch soon. I've got a remark right away though. The variable holding the number of map parts (i) appears in more places after the change. It should get a more descriptive name.

[dl3sdo]

@lpechacek,@dg0yt: what is your preference?

Given that the map part operations can be undone, I'm all fine with skipping the confirmation on empty parts.

Code-wise, I'm going to review the second patch soon. I've got a remark right away though. The variable holding the number of map parts (i) appears in more places after the change. It should get a more descriptive name.

I agree and will change i to num_objects once your review is finished.

[lpechacek]

LGTM. The comment about the num_objects change is more a nitpicking than a code issue. Take it and re-rest the change if you like the change, or leave it as is. Thanks!