WComponentPeer.java 文件源码

@Override
public boolean requestFocus(Component lightweightChild, boolean temporary,
                            boolean focusedWindowChangeAllowed, long time,
                            FocusEvent.Cause cause)
{
    if (WKeyboardFocusManagerPeer.
        processSynchronousLightweightTransfer((Component)target, lightweightChild, temporary,
                                              focusedWindowChangeAllowed, time))
    {
        return true;
    }

    int result = WKeyboardFocusManagerPeer
        .shouldNativelyFocusHeavyweight((Component)target, lightweightChild,
                                        temporary, focusedWindowChangeAllowed,
                                        time, cause);

    switch (result) {
      case WKeyboardFocusManagerPeer.SNFH_FAILURE:
          return false;
      case WKeyboardFocusManagerPeer.SNFH_SUCCESS_PROCEED:
          if (focusLog.isLoggable(PlatformLogger.Level.FINER)) {
              focusLog.finer("Proceeding with request to " + lightweightChild + " in " + target);
          }
          Window parentWindow = SunToolkit.getContainingWindow((Component)target);
          if (parentWindow == null) {
              return rejectFocusRequestHelper("WARNING: Parent window is null");
          }
          final WWindowPeer wpeer = AWTAccessor.getComponentAccessor()
                                               .getPeer(parentWindow);
          if (wpeer == null) {
              return rejectFocusRequestHelper("WARNING: Parent window's peer is null");
          }
          boolean res = wpeer.requestWindowFocus(cause);

          if (focusLog.isLoggable(PlatformLogger.Level.FINER)) {
              focusLog.finer("Requested window focus: " + res);
          }
          // If parent window can be made focused and has been made focused(synchronously)
          // then we can proceed with children, otherwise we retreat.
          if (!(res && parentWindow.isFocused())) {
              return rejectFocusRequestHelper("Waiting for asynchronous processing of the request");
          }
          return WKeyboardFocusManagerPeer.deliverFocus(lightweightChild,
                                                        (Component)target,
                                                        temporary,
                                                        focusedWindowChangeAllowed,
                                                        time, cause);

      case WKeyboardFocusManagerPeer.SNFH_SUCCESS_HANDLED:
          // Either lightweight or excessive request - all events are generated.
          return true;
    }
    return false;
}