Add support for max_volume

[relvacode]

Description:

Adds a new max_volume option to Onkyo media players to limit the maximum volume set by the volume slider.

Pull request in home-assistant.github.io with documentation (if applicable): home-assistant/home-assistant.io#5153

Example entry for configuration.yaml (if applicable):

media_player:
  - platform: onkyo
    host: 192.168.1.2
    name: receiver
    max_volume: 50
    sources:
      pc: 'HTPC'

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass

I get ERROR: typing: commands failed but no errors relate to onkyo.py

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in home-assistant.github.io

If the code communicates with devices, web services, or third-party tools:

• New dependencies have been added to the REQUIREMENTS variable (example).
• New dependencies are only imported inside functions that use them (example).
• New dependencies have been added to requirements_all.txt by running script/gen_requirements_all.py.
• New files were added to .coveragerc.

If the code does not interact with devices:

• Tests have been added to verify that the new code works.

[homeassistant]

Hi @relvacode,

It seems you haven't yet signed a CLA. Please do so here.

Once you do that we will be able to review and accept this pull request.

Thanks!

[pvizeli]

Logic are not allow on this layer.

[relvacode]

@pvizeli In setup_platform()?

[pvizeli]

Component/Platform they have a device are only interfaces and can only do things they handle by device/library.

[relvacode]

Ah that's a shame, on my device volume level 80 will shake the entire house (as the girlfriend found out when she accidentally pressed the volume slider all the way up in the app!), 40 is about as high as we would ever go.
It also means the volume slider steps in the app are too wide to have fine grain control over the volume.

Is there another layer by which this can be achieved? The nad media player appears to implement this at the component level https://www.home-assistant.io/components/media_player.nad/

If not feel free to close, I'll continue using this as a custom component

[rsmeral]

This change is important for more than just customizability. This Onkyo component supports (as per documentation) also Pioneer receivers. And, for example, the volume on my Pioneer SX-S30DAB only goes to 50.
So, the hardcoded value of 80 is incorrect for some of the supposedly supported devices.

@pvizeli I'm not sure I understand your review – this PR is not introducing any logic (apart from value clamping), it's only enabling user-configurability of one value.

[balloob]

Instead of validating this as int, validate it with a range:

vol.All(vol.Coerce(int), vol.Range(min=0, max=SUPPORTED_MAX_VOLUME))

[balloob]

This can be removed as it will be handled by the config.

[balloob]

Few minor changes, but this is ok to merge.

Although @pvizeli is right that we don't want user config for devices in Home Assistant, I think that this is worth an exception because Onkyo is a pass-through device.

[houndci-bot]

line too long (84 > 79 characters)

[relvacode]

@balloob Requested changes made