crop method
Implementation
void crop(int top, int left, int bottom, int right) {
if (top < 0) {
throw ArgumentError('Top must be greater or equal to zero');
}
if (left < 0) {
throw ArgumentError('Left must be greater or equal to zero');
}
if (bottom < 0) {
throw ArgumentError('Bottom must be greater or equal to zero');
}
if (right < 0) {
throw ArgumentError('Right must be greater or equal to zero');
}
_hasCrop = true;
_cropTop = top;
_cropLeft = left;
_cropBottom = bottom;
_cropRight = right;
}