JBCefClient (@NotNull CefDragHandler handler, @NotNull CefBrowser browser) { return myDragHandler.add(handler, browser, () -> { myCefClient.addDragHandler(new CefDragHandler() { @Override public boolean onDragEnter(CefBrowser browser, CefDragData dragData, int mask) { return myDragHandler.handleBoolean(browser, handler -> { return handler.onDragEnter(browser, dragData, mask); }); } }); }); }