Hidden entity filter card uses space

[cgtobi]

Entity filter cards apparently use space even when they are hidden (if they are empty). Is that expected behaviour?

[balloob]

Hmmm, that's an unfortunate side effect. The layout engine doesn't know a card is going to decide to show itself yes or no. So it will divide the screen in columns based on that a card config will produce a card.

[jeradM]

@balloob what do you think about allowing cards to define an optional willRender method that can be called while building the columns? If that method exists and returns false, we skip that card. Then if something changes in a card that will cause it to render, it can fire rebuild-view. The downside is that when this happens the whole view is rebuilt, but it would solve the current issue

[Misiu]

@jeradM I think this isn't the best solution.
I'd prefer to have a card with the text No valid entities or similar instead of hiding that card completely.
Imagine you have a couple of filter cards and they change quite often. Your UI will be a total mess.
I think that rebuilding the whole view should be avoided because it is time and resource consuming.
Please correct me if I'm wrong - I'm still new to HA, but I have a C# (WinForms) background - there is one rule when invalidating (repainting) components - smallest region possible. I think the same applies here.

[kg333]

The same effect occurs with conditional cards. I have a number of these for alerts of important or unusual states (security alarm engaged, cameras in full recording mode, part of home network not responding, etc), but they cause my main cards to push to the right even if the conditionals are currently hidden:

[KTibow]

How about setting cardHeight to 0?

[kg333]

@KTibow, somewhat interesting result by setting the conditional Markdown cards with card_size: 0 - they no longer shift other cards to the right, but also don't distribute themselves horizontally when they are visible. This also doesn't work for conditional cards that don't have that property (Alarm Panel in my case).

Are there any other ways to force cardHeight?

[KTibow]

I think you might be able to do it with card-mod, mod-card, or layout-card.

[kg333]

No impact with lovelace-card-mod style:

style: |
  ha-card {
    height: 0%;
  }

Using custom:mod-card with report_size: 0 results in same behavior as setting conditional Markdown cards with card_size: 0. Cards all end up vertically stacked.

[KTibow]

Did you apply the size to the conditional card or the markdown card?

[kg333]

To the conditional card itself, rather than the contained cards.