Reduce Simplify way and Join areas dialogs

[bilbo]

If Simplify way and Join areas actions are invoked and the some of the simplified or joined ways lies at least partially outside of download area, annoying dialog "Do you want to delete nodes outside of download area" appears.

This patch adds "Do not ask again" checkbox to that dialog, allowing user to get rid of these dialog for good. The settings is shared with other "Do you want to delete nodes outside of download area" dialogs.

Technically, one of the dialogs is turned from HelpAware dialog (which does not support "Do not ask again") to ordinary dialog, but as the associated help is not helpful to the problem of deleting outside nodes, I don't think this would be an issue.

Also, this check for nodes outside of donwload area is done before analyzing the result. Often the result is that after join or simplification, only nodes inside the data area are deleted. These dialogs could be further improved by asking once the action is prepared and once is is clear that the action actually contains at least one node deletion outside the data areas (though I have not done that in my patch).

[bilbo]

The patch

[stoecker]

This check is there for a reason. It should prevent issues with OSM data (which we had a lot) and not make your life easier. Simply load larger areas when doing such operations.

[bilbo]

Replying to stoecker:

This check is there for a reason. It should prevent issues with OSM data (which we had a lot) and not make your life easier. Simply load larger areas when doing such operations.

Simply loading larger area is often not an option due to 50000 nodes limit.

Also, I don't think this would cause any issues with the data, because if you manage to delete a node that is actually used, it will result in failed upload and conflict resolution. So I think this warning is safe to ignore, as any possible conflict is always detected at uploading.

In attached file join_areas.osm.bz2 there is example of case, where if you join the two wetland areas, no nodes are deleted at all. In other similar cases, where the line where the two areas touch each other is inside downloaded area, but some part is outside, some nodes may be deleted, but not any nodes outside of downloaded area. Actually, I have never encountered any data where joining areas would cause some node that should be left there to be deleted (though I've encountered some cases, where simplifying ways partially outside resulted in deletions of used nodes, but those could be handled in conflict resolution without any bad result on the data)

What if I change the patch so that the warning only for "join areas" would be togglable off and in both cases the warning will show only if actually any nodes outside of downloaded area are to be deleted?

[bilbo]

example where this question does not make much sense

[stoecker]

You don't need to load a "larger" area. You simply can load additional areas. As said this warning is based on trouble we already had, so any way to remove the warning even partial is a wontfix. We simply wont encourage users to do such dangerous things when there are enough way to do it properly.

[bilbo]

Replying to stoecker:

You don't need to load a "larger" area. You simply can load additional areas. As said this warning is based on trouble we already had, so any way to remove the warning even partial is a wontfix. We simply wont encourage users to do such dangerous things when there are enough way to do it properly.

What trouble exactly it was?

IMHO changing the warning so that it will warn only in cases where actually some nodes are deleted outside of downloaded area will cause users to draw more attention to such cases (basically suppress the warning for cases where nothing can go wrong, like if the simplify way will remove only nodes inside downloaded area) and maybe examine the situation (or perhaps download the surroundings before trying again). If these warnings appear too often, users will just start pressing enter after seeing it for tenth or so time and theswe warning boxes will become quite useless anyway.
(Like me, I started to ignore the boxes, then I solved it for me by writing this patch)

[stoecker]

Fixing it in a way, that it does not warn in case no outside nodes are deleted or changed is an acceptable solution.