Multiselect list: Tool menu for asymmetric multiselect operations.

[slhh]

Each item of the multiselect list should have a tool icon opening a radial menu containig asymmetric tools working on multiple selection; 1 to 1, 1 to many, or many to 1 operations could be supported this way.
Example operations:

• Copy tags to others and delete this (current point-area merge)
• Split this (area, MP) along others (lines)
• Add others as member to this (MP, other relation)

Instead of a tools submenu the tools could be placed directly, but this would have a performance disadvantage because checking for availability of the specific tool needs to be done for every selection click, and not only when opening the tools menu. Complex operations could require time-consuming structure checks for testing of availability.

A prerequisite for this enhancement is #2949 .

[bhousel]

There are some good ideas in here.. are you proposing an icon that just pops open the radial menu? Clicking on any of the selected features already does pop up the radial menu.

And the radial menu already does check for availability of all the tools every time it is shown, and it does handle multiselection scenerios.

[homersimpsons]

This would be great, I often see houses that are not part of relation or with street tags, and to avoid confusion thoose ones need to be tagged or part of a relation, but, when there are 150+ buildings it's really long to add all manually (in this case I prefer relation) and sett all to 'house' role.

[slhh]

@homersimpsons
Meanwhile I prefer #3028 for adding tags, because it seems to be less error-prone due to making the user more aware what will happen. This can avoid common errors of tagging multiple objects like tagging vertices unintentionally together with the way.

For adding multiple members to a relation an operation to paste CTRL-C copied features as members into the all members section of an relation would likely be easier to use in the gereral case.

But there is a usecase where adding members based on a asymmetric multiselect operation would be very useful. This is identifying and adding missing members of a hiking route, a multipolygon, a site, etc. graphically. Provided that members of a selected relation are highlighted (using a different style than selected as already agreed on #3140), the full highlighting of the multiselection would be a preview of the resulting relation. This would make identifying and adding the missing objects quite easy.

In addition removing the other selected objects from the member list of the selected relation would be very useful two. This operation needs to be available in a very specific context only, which could minimize the impact on the UI.

Unfortunately, setting up the multiselection in order to add/remove members to/from a relation needs some strategic planing of the operation in general, because the relation needs to be the first element to be selected, otherwise the selected elements are unselected when selecting the relation. This isn't the case if the relation is a multipolygon, and it isn't an issue in case of the above usecase, because it seems to be the natural workflow. For the remaining cases the requirement of strategic planing can by avoided by implementing #2964 , which doesn't have any impact on the UI except of the rare case of selecting an item from the multiselection list. Selecting an item from the multiselection list doesn't seem to have any significant usecase without #2964 due to destroying the multiselection.