Using phet-io to hide a circuit tool icon, then dropping a circuit element of that type, makes the tool icon reappear.

[samreid]

Discovered in https://github.com/phetsims/circuit-construction-kit-common/issues/589#issuecomment-694843412

In this version, dragging out other components or resetting doesn't restore the resistor tool. But dragging the resistor tool to to the toolbox restores it. I'll wait for guidance on how to proceed here, but here are some options:

• instrument the "max number" of resistors. Setting the max to 1 and starting with a resistor in the play area would mean that you can put it back in the toolbox and get it back out.
• Making it impossible to drop in a circuit element that has been disabled. But we would need another "channel" or phetioID for this.

[samreid]

@arouinfar and I discussed this today. We considered a new attribute on the circuit element model, canBeDroppedInToolbox which defaults to true, but can be set to false if the client wants to prevent that.

[samreid]

UPDATE: We have a new plan in https://github.com/phetsims/circuit-construction-kit-common/issues/797 that will affect this issue.

[samreid]

We added CircuitElement.isDisposableProperty in #797, can this issue be closed?

[samreid]

@arouinfar and I discussed, and agreed this is solved by isDisposableProperty, closing.