navigate method

void navigate(Offset delta)

Implementation

void navigate(Offset delta) {
  // 1. Capture the current translation
  final Matrix4 startMatrix = value;

  // 2. Calculate the end matrix by adding the delta to the current position
  // Note: We use storage[12] and [13] for x and y translation
  final dx = delta.dx * CeleryvizOptions.config.paneEventOffsetX / 2;
  final dy = delta.dy * CeleryvizOptions.config.paneTimestampOffsetY;
  final double endX = max(min(startMatrix.storage[12] + dx, 0.0), maxX);
  final double endY = max(min(startMatrix.storage[13] + dy, 0.0), maxY);

  final Matrix4 endMatrix = startMatrix.clone()
    ..setTranslationRaw(endX, endY, 0.0);

  // 3. Create and trigger the animation
  final Animation<Matrix4> animation = Matrix4Tween(
    begin: startMatrix,
    end: endMatrix,
  ).animate(CurvedAnimation(
    parent: _animationController,
    curve: _curve,
  ));

  void listener() => value = animation.value;

  animation.addListener(listener);

  _animationController.forward(from: 0).whenCompleteOrCancel(() {
    animation.removeListener(listener);
  });
}