animateIfNeeded method

void animateIfNeeded(Rect rect)

Implementation

void animateIfNeeded(Rect rect) {
  if (_lastRect != null && _lastRect != rect) {
    final bool inAnimation = isAnimating;
    Rect from = Rect.fromLTWH(
      _lastRect!.left - rect.left,
      _lastRect!.top - rect.top,
      _lastRect!.width,
      _lastRect!.height,
    );
    if (inAnimation) {
      // We need to recompute the from.
      final Rect currentRect = _animation!.value!;
      from = Rect.fromLTWH(
        currentRect.left + _lastRect!.left - rect.left,
        currentRect.top + _lastRect!.top - rect.top,
        currentRect.width,
        currentRect.height,
      );
    }
    _isAnimating = true;

    _animation = _controller.drive(CurveTween(curve: curve)).drive(
          createRectTween(
            from,
            Rect.fromLTWH(
              0,
              0,
              rect.width,
              rect.height,
            ),
          ),
        );

    if (!inAnimation) {
      SchedulerBinding.instance!.addPostFrameCallback((_) {
        _controller.forward();
      });
    } else {
      SchedulerBinding.instance!.addPostFrameCallback((_) {
        final Duration duration =
            _controller.duration! * (1 - _controller.value);
        _controller.reset();
        _controller.animateTo(
          1,
          duration: duration,
        );
      });
    }
  }
  _lastRect = rect;
}