FloatingActionButtonThemeData disabled color

[Gintasz]

FloatingActionButtonThemeData does not have disabled color. It would be a easy if it had, so dimming the floating action button when data fields are not filled could be done with one line of code.

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[royarg02]

I don't know whether it will be okay to have one, as Material design does not allow FABs to be disabled. It recommends it to be hidden instead.
https://material.io/design/interaction/states.html#disabled

[Levi-Lesches]

Should that be the default behavior then? When onPressed == null, hide the FAB?

[royarg02]

Should that be the default behavior then? When onPressed == null, hide the FAB?

It might be a good change, as onPressed: null makes the FAB non-interactive, but still displays it. I checked for the following version:

Flutter 1.26.0-18.0.pre.187 • channel master • https://github.com/flutter/flutter
Framework • revision e96ce0ecb4 (39 minutes ago) • 2021-02-04 02:46:03 -0500
Engine • revision 5e50f4bad3
Tools • Dart 2.12.0 (build 2.12.0-285.0.dev)

[flutter-triage-bot]

This issue is missing a priority label. Please set a priority label when adding the triaged-design label.

[HansMuller]

If the FAB's foreground and background color properties could be MaterialStateColors, then we could add support for a disabled color without really changing the API. However a much nicer solution would be (still using the same API) to refactor FAB to be a ButtonStyleButton. There's an existing PR that's pretty far along: #53502