onShootingButtonMove method

void onShootingButtonMove(
  1. PointerMoveEvent event,
  2. BoxConstraints constraints
)

Update the scale value while the user is shooting. 用户在录制时通过滑动更新缩放

Implementation

void onShootingButtonMove(
  PointerMoveEvent event,
  BoxConstraints constraints,
) {
  lastShootingButtonPressedPosition ??= event.position;
  if (controller.value.isRecordingVideo) {
    // First calculate relative offset.
    final Offset offset = event.position - lastShootingButtonPressedPosition!;
    // Then turn negative,
    // multiply double with 10 * 1.5 - 1 = 14,
    // plus 1 to ensure always scale.
    final double scale = offset.dy / constraints.maxHeight * -14 + 1;
    zoom(scale);
  }
}