TL;DR
I want to be able to middle click on a train, or other container with filterable inventory slots, and set the filter to the current contents.What ?
Middle click can currently be used to set filter slots, but doing it for a whole container is slow and repetitive. This gets even worse on trains where you might want to set on multiple carriages.Mixed supply trains (eg base building, outpost defence) need filters to help ensure a correct mix (unless you want to go with convoluted circuit networks reading contents and inserters working on current contents of course, which would be interesting to see).
Setting all these slot filters is a ball ache, particularly if you're changing your mind on numbers etc as you go, it is however relatively easy to place items in containers as you see fit. If I could lay out my inventory with normal item placement, come out of the contents screen, and then just middle click the container to set every slot to filter to its current contents it would take out a lot of needless extra clicks and time.
Bonus is for single item trains, one stop at the loading station and then a middle click to protect it from accidentally adding the wrong stop and filling your copper smelting line with iron.
Why ?
- It's a relatively simple addition to the game''s controls
- It builds on existing user interaction models without conflicting with existing uses
- Reduces needless interactions for a simple task