add useListenableSelector

[ronnieeeeee]

Hi, Remi!

useListenable is easy to use, but I think it tends to cause unnecessary rebuilds In such a case, I think the useListenableSelector added this time is convenient.

This is an example where the button is disabled when nothing is entered in TextField.

Example using useListenable.

Widget build(BuildContext context) {
    var ctrl = useTextEditingController();
    useListenable(ctrl);
    return Column(
      children: [
        TextField(
          controller: ctrl,
        ),
        ElevatedButton(
            onPressed: ctrl.text.isNotEmpty ? () => print("Pressed!") : null,
            child: Text("Button")),
      ],
    );
  }

Example using useListenableSelector. This is the better performance.

 Widget build(BuildContext context) {
    final ctrl = useTextEditingController();
    final bool isNotEmpty =
        useListenableSelector(ctrl, () => ctrl.text.isNotEmpty);
    return Column(
      children: [
        TextField(controller: ctrl),
        ElevatedButton(
            // If no text is entered, the button cannot be pressed
            onPressed: isNotEmpty ? () => print("Pressed!") : null,
            child: Text("Button")),
      ],
    );
  }

[codecov[bot]]

Codecov Report

Merging #308 (911aff4) into master (8c68676) will increase coverage by 0.07%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #308      +/-   ##
==========================================
+ Coverage   98.17%   98.25%   +0.07%     
==========================================
  Files          13       14       +1     
  Lines         659      689      +30     
==========================================
+ Hits          647      677      +30     
  Misses         12       12              

Impacted Files	Coverage Δ
...ges/flutter_hooks/lib/src/listenable_selector.dart	100.00% <100.00%> (ø)

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[rrousselGit]

Thanks!