'Find idle unit' feature doesn't deselect currently selected units if no units are idle

[cpc]

Pressing period (hotkey.selection.idleworker) replaces the current selection with one or all idle units, depending on hotkey.selection.offscreen.

When there are no idle units, however, pressing period does nothing; in particular, it doesn't deselect the currently-selected units.  This makes it hard to know whether idle units were selected or whether the existing selection (containing busy units) was preserved.  The code says // TODO: display a message or play a sound to indicate no more idle units, or something. 

The attached patch resets the current selection regardless of whether there are idle units; this way, if no units are idle, the no units are selected after pressing period. The behavior of period + Shift is unchanged. Is that the right way to go?

[Imarok]

Thank you for the patch, but please upload it to our review platform at code.wildfiregames.com

[cpc]

Will do, thanks for the pointer.

[cpc]

Submitted as ​Phab:D1692

[Vladislav Belov]

I'd prefer to use a sound/UI notification, because the reset is used only as notification in todo case, not as useful function. Example:

1. You have few selected unit, that you're working with.
2. You want to use some idle workers if they exist and you're pressing the hotkey.selection.idleworker.
3. If no idle workers: with that patch, you need to select all units again, with a sound/UI notification, you don't need to do this. In both cases you'll know all workers aren't idle.

[cpc]

Interesting point! I found the current behavior unintuitive, but maybe there's a case to be made that not deselecting is more convenient, and so the slight inconsistency is worth it.

[Stan]

Sounds like what the TODO in that code was for. I can ask Samulis if he'd like to make a sound for that notification, what do you think ?

[cpc]

Sounds great! I would be in favor of using a text notification in addition to the sound, since (especially in multiplayer LAN parties) people sometimes play without sound. I will update the patch accordingly.

[Imarok]

Move tickets to In-game UI as UI & Simulation got some sub components.

[Freagarach]

In 25287:

Play a sound when there are no idle entities.

If there are no idle units and the idle-unit hotkey is pressed there is now a sound played.
Beneficial when there are already units selected since selection doesn't change.

Sound courtesy of @Samualis.

Refs. #5360
Based on a patch by: @cpc
Differential revision: ​https://code.wildfiregames.com/D1692
Comments by: @asterix, @smiley, @Stan, @vladislavbelov