Tooltips for selected mark are not evaluated

This comes from the “Interactive Average” sample with tooltips enabled in the config:

{
  "$schema": "https://vega.github.io/schema/vega-lite/v4.11.0.json",
  "data": {"url": "data/seattle-weather.csv"},
  "config": {
    "mark": { 
      "tooltip": { "content": "encoding" }
    }
  },
  "layer": [{
    "selection": {
      "brush": {
        "type": "interval",
        "encodings": ["x"]
      }
    },
    "mark": "bar",
    "encoding": {
      "x": {
        "timeUnit": "month",
        "field": "date",
        "type": "ordinal"
      },
      "y": {
        "aggregate": "mean",
        "field": "precipitation",
        "type": "quantitative"
      },
      "opacity": {
        "condition": {
          "selection": "brush", "value": 1
        },
        "value": 0.7
      }
    }
  }, {
    "transform": [{
      "filter": {"selection": "brush"}
    }],
    "mark": "rule",
    "encoding": {
      "y": {
        "aggregate": "mean",
        "field": "precipitation",
        "type": "quantitative"
      },
      "color": {"value": "firebrick"},
      "size": {"value": 3}
    }
  }]
}

The tooltips over unselected marks show the correct values for the tooltip field, but any selected marks will show the unprocessed value of the tooltip config setting, regardless of the value (e.g., true, false, { "content": "data" }).

If, instead, tooltip is specified in the mark def rather than in the config, then the tooltip isn’t shown at all for any marks that are selected (but they are still displayed properly for unselected marks). I.e.:

    "mark": {
      "type": "bar",
      "tooltip": { "content": "encoding" }
    }

FTR, I’ve noticed this behavior with vegaEmbed when passing "tooltip": true in the options.config parameter (in other to enable default tooltips), but I don’t know if that is a bug with vega-embed, vega-lite, or vega.

[jheer]

Re-opening and transferring to Vega-Lite per @marcprux’s request.

[hk7math]

After implementing the touch selection #4208 (comment) , the tooltips are gone on mobile

It turns out the hidden tooltips can be manually turned on simply by setting this in config

"events": {
  "defaults": {
    "allow": true
  }
}