Submitted by matthiaskrgr
The original post got lost somehow, so I'll try to recover my idea here.
\u2193\u2191\u2192\u2190 represent arrow keys

I think it would nice to have the shop accessible via keyboard.
Here are my suggestions for keys and their functions:

\u2193 and \u2191 to switch between the upper and lower line where items can be selected
\u2190 and \u2192 to choose between specific items
b to buy an item
s to sell an item
f to fix an item
i and/or ? to identify an item
x and/or Esc to get out of the shop window

or (wasn't mentioned in the original post as far as I know)

\u2190\u2192 to switch between items in the lower and upper boxes
\u2193 and \u2191 to switch horizontally between upper item-select box, buy, sell, fix, identify/?, x and the lower box


Buying/selling some items (ammo for example), a quantity can be selected.
\u2192 and \u2191 to increase it
\u2190 and \u2193 to decrease it
[enter] to press the "OK" button
[Esc] to get to the normal shopping screen (where you can select items) without selecting a quantity/buying something

Thank you for your fine work!
Matthias Kr\u00fcger

Posted by lordtim
Here's a solution I hope works:

http://pastebin.org/130655

Instead of using b/s, I set the enter key to just buy or sell depending on which row is selected. Fixing and Identifying still has to be done manually unless buy/sell is inactive.

Posted by syl1
Another idea :  the possibility to use the number's keyboard for item quantity (when we sell stacking items).

Posted by ahuillet
Lordtime: I am afraid you are adding too much code here, this is going to be a maintenance nightmare.

Posted by stedevil
Tagging [P-] meaning it has a patch that needs modification before getting an ACK

Posted by salimiles
 I have created a patch that does this: http://rb.freedroid.org/r/905/

This patch requires the gamepad support (rb 908) and if you want to actually use the keyboard, you need to also add the keyboard emulator (rb 876).

Please note, at this time, there is a known bug in that patch (items bought don't show up in inventory) that needs to be worked out.