When an applet is launched and focused in a browser and then another TAB is selected in the browser
the EmbeddedFrame doesn't receive WM_ACTIVATE(WA_INACTIVE) native message. On returning back to
the applet and clicking, say, some textfield in the applet the textfield will not be able to
receive key events. The latter is reproducible with JavaFX applets (see Comments), but is not
reproducible with Java applets.