build method

@override Widget build(BuildContext context)

Override this method to build widgets that depend on the state of the listenable (e.g., the current value of the animation).

Implementation

@override
Widget build(BuildContext context) {
  final Animation<double> animation = listenable as Animation<double>;
  bool dark = Theme.of(context).brightness == Brightness.dark;

  void _performAction([bool isLong = false]) {
    if (onTap != null && !isLong) {
      onTap!();
    } else if (onLongPress != null && isLong) {
      onLongPress!();
    }
    toggleChildren!();
  }

  Widget buildLabel() {
    if (label == null && labelWidget == null) return Container();

    if (labelWidget != null) {
      return GestureDetector(
        onTap: _performAction,
        onLongPress: () => _performAction(true),
        child: labelWidget,
      );
    }

    return GestureDetector(
      onTap: _performAction,
      onLongPress: () => _performAction(true),
      child: Container(
        alignment: labelLocation == LabelLocation.left ? Alignment.centerRight : Alignment.centerLeft,
        child: Container(
          padding: const EdgeInsets.symmetric(vertical: 5.0, horizontal: 8.0),
          decoration: BoxDecoration(
            color: labelBackgroundColor,
            borderRadius: const BorderRadius.all(Radius.circular(6.0)),
            boxShadow: labelShadow,
          ),
          child: Text(label!, style: labelStyle),
        ),
      ),
    );
  }

  Widget button = ScaleTransition(
      scale: animation,
      child: Padding(
        padding: const EdgeInsets.all(4.0),
        child: FloatingActionButton(
          key: btnKey,
          heroTag: heroTag,
          onPressed: _performAction,
          backgroundColor: backgroundColor ?? Colors.white,
          foregroundColor: foregroundColor ?? (dark ? Colors.white : Colors.black),
          elevation: elevation ?? 0.0,
          child: child,
          shape: shapeBorder,
        ),
      ));

  List<Widget> children = [
    if (label != null || labelWidget != null)
      Expanded(
        child: Container(
          padding: EdgeInsets.symmetric(horizontal: 8),
          key: (child == null) ? btnKey : null,
          child: labelLocation == LabelLocation.left ? buildLabel() : null,
        ),
      ),
    if (child != null)
      Container(
        height: buttonSize.height,
        width: buttonSize.width,
        child: (onLongPress == null)
            ? button
            : FittedBox(
          child: GestureDetector(
            onLongPress: () => _performAction(true),
            child: button,
          ),
        ),
      ),
    Expanded(
        child: Container(
          alignment: Alignment.centerLeft,
          child: labelLocation == LabelLocation.right ? buildLabel() : null,
    ))
  ];

  Widget _buildColumnOrRow(
      {CrossAxisAlignment? crossAxisAlignment,
        MainAxisAlignment? mainAxisAlignment,
        required List<Widget> children,
        MainAxisSize? mainAxisSize}) {
    return Container(
      child: Row(
        mainAxisSize: mainAxisSize ?? MainAxisSize.max,
        mainAxisAlignment: mainAxisAlignment ?? MainAxisAlignment.start,
        crossAxisAlignment:
        crossAxisAlignment ?? CrossAxisAlignment.center,
        children: children,
      ),
    );
  }

  return visible
      ? Container(
    // margin: margin,
    child: _buildColumnOrRow(
      mainAxisAlignment: MainAxisAlignment.center,
      mainAxisSize: MainAxisSize.max,
      children: children,
    ),
  )
      : Container();
}