private void removeDropTransfer(Transfer transfer){
	if (dropTypes.length == 1) {
		dropTypes = new Transfer[0];
	} else {
		int index = -1;
		for(int i = 0; i < dropTypes.length; i++) {
			if (dropTypes[i] == transfer) {
				index = i;
				break;
			}
		}
		if (index == -1) return;
		Transfer[] newTypes = new Transfer[dropTypes.length - 1];
		System.arraycopy(dropTypes, 0, newTypes, 0, index);
		System.arraycopy(dropTypes, index + 1, newTypes, index, dropTypes.length - index - 1);
		dropTypes = newTypes;
	}
	if (dropTarget != null) {
		dropTarget.setTransfer(dropTypes);
	}
}