buildCaptureActions method

Widget buildCaptureActions({ required BuildContext context, required BoxConstraints constraints, CameraController? controller, })

Capture action's widget. 拍照操作区

This displayed at the top of the screen. 该区域显示在屏幕下方。

Implementation

Widget buildCaptureActions({
  required BuildContext context,
  required BoxConstraints constraints,
  CameraController? controller,
}) {
  const fallbackSize = 150.0;
  final previewSize = controller?.value.previewSize;
  final orientation = controller?.value.deviceOrientation ??
      MediaQuery.orientationOf(context);
  final isPortrait = orientation.toString().contains('portrait');
  double effectiveSize;
  if (controller == null || pickerConfig.enableScaledPreview) {
    effectiveSize = lastCaptureActionsEffectiveHeight ?? fallbackSize;
  } else if (previewSize != null) {
    Size constraintSize = Size(constraints.maxWidth, constraints.maxHeight);
    if (isPortrait && constraintSize.aspectRatio > 1 ||
        !isPortrait && constraintSize.aspectRatio < 1) {
      constraintSize = constraintSize.flipped;
    }
    if (isPortrait) {
      effectiveSize = constraintSize.height -
          constraintSize.width * previewSize.aspectRatio;
    } else {
      effectiveSize = constraintSize.width -
          constraintSize.height * previewSize.aspectRatio;
    }
  } else if (lastCaptureActionsEffectiveHeight != null) {
    effectiveSize = lastCaptureActionsEffectiveHeight!;
  } else {
    // Fallback to a reasonable height.
    effectiveSize = fallbackSize;
  }
  if (effectiveSize <= 0) {
    realDebugPrint(
      'Unexpected layout size calculation: $effectiveSize, '
      'portrait: $isPortrait, '
      'orientation: $orientation',
    );
    effectiveSize = fallbackSize;
  } else if (effectiveSize < fallbackSize) {
    effectiveSize = fallbackSize;
  }
  lastCaptureActionsEffectiveHeight = effectiveSize;
  return Container(
    width: isPortrait ? null : effectiveSize,
    height: isPortrait ? effectiveSize : null,
    padding: EdgeInsets.only(bottom: MediaQuery.paddingOf(context).bottom),
    child: Flex(
      direction: isPortrait ? Axis.horizontal : Axis.vertical,
      verticalDirection: orientation == DeviceOrientation.landscapeLeft
          ? VerticalDirection.up
          : VerticalDirection.down,
      children: <Widget>[
        const Spacer(),
        Expanded(
          child: Center(
            child: buildCaptureButton(context, constraints),
          ),
        ),
        if (controller != null &&
            !controller.value.isRecordingVideo &&
            cameras.length > 1)
          Expanded(
            child: RotatedBox(
              quarterTurns: !enableScaledPreview ? cameraQuarterTurns : 0,
              child: buildCameraSwitch(context),
            ),
          )
        else
          const Spacer(),
      ],
    ),
  );
}