cacheMargins method

void cacheMargins()

Caches the marginLeft and marginTop of avatar.

Call this method again if those margins somehow changed during a drag operation.

Implementation

void cacheMargins() {
  // Calculate margins.
  if (avatar != null) {
    var computedStyles = avatar!.getComputedStyle();
    _marginLeft =
        num.tryParse(computedStyles.marginLeft.replaceFirst('px', '')) ?? 0;
    _marginTop =
        num.tryParse(computedStyles.marginTop.replaceFirst('px', '')) ?? 0;
  }
}