RectangularSelectionTransferHandler.java 文件源码

@Override
public synchronized DataFlavor[] getTransferDataFlavors() {
    if (transferDataFlavorsCache != null) {
        return transferDataFlavorsCache;
    }
    DataFlavor[] flavors = delegate.getTransferDataFlavors();
    DataFlavor[] result = Arrays.copyOf(flavors, flavors.length + 1);
    result[flavors.length] = RECTANGULAR_SELECTION_FLAVOR;

    return transferDataFlavorsCache = result;
}