SunClipboard.java 文件源码

public synchronized void addFlavorListener(FlavorListener listener) {
    if (listener == null) {
        return;
    }
    AppContext appContext = AppContext.getAppContext();
    Set<FlavorListener> flavorListeners = getFlavorListeners(appContext);
    if (flavorListeners == null) {
        flavorListeners = new HashSet<>();
        appContext.put(CLIPBOARD_FLAVOR_LISTENER_KEY, flavorListeners);
    }
    flavorListeners.add(listener);

    if (numberOfFlavorListeners++ == 0) {
        long[] currentFormats = null;
        try {
            openClipboard(null);
            currentFormats = getClipboardFormats();
        } catch (final IllegalStateException ignored) {
        } finally {
            closeClipboard();
        }
        this.currentFormats = currentFormats;

        registerClipboardViewerChecked();
    }
}