Question:
The AWT’s Frame class provides a setCursor method that allows me to set the cursor to one of the standard images (arrow, watch, etc.). The problem is I’m implementing an applet that lives in a browser window, not in a frame. How can I set the cursor in applet code (short of creating an invisible frame and calling its setCursor method)?

Answer:
I recently read somewhere that one can simply search through the ancestors of an applet in its component hierarchy until a frameis encountered, then use the frame’s setCursor() method. I wassurprised. I guess this frame must be the one created by the browseritself. I tried a few experiments and discovered that in Netscape myapplet did indeed have an ancestral container which was an instance ofa class called EmbeddedAppletFrame, which extended the Frame class.

Using Sun’s Applet Viewer, the same experiment produced an ancestorin the AppletViewer class, which apparently extends the Frame class.If it is generally true that all applets in all browsers arecontained in a Java frame, then this seems to open the doorfor all kinds of interesting hacks!

Below is a sample applet that allows users to select a cursor. Itworks in Netscape and Applet Viewer.

*/import java.awt.*;import java.applet.*;public class CursorDemo extends Applet {   private Frame myFrame;  // my frame ancestor   public void init() {      Panel p = new Panel();      p.setLayout(new FlowLayout());      p.add(new Button(“CROSSHAIR”));      p.add(new Button(“HAND”));      p.add(new Button(“WAIT”));      p.add(new Button(“TEXT”));      p.add(new Button(“DEFAULT”));      setLayout(new BorderLayout());      add(“North”, new Label(“Select a cursor:”));      add(“Center”, p);      /* search ancestors in the component hierarchy         until a frame is found      */      Object parent = getParent();      while (! (parent instanceof Frame))          parent = ((Component) parent).getParent ();      myFrame = (Frame) parent; // EmbeddedAppletFrame in Netscape   }   public boolean action(Event e, Object arg) {      if (arg.equals(“CROSSHAIR”))         myFrame.setCursor (Frame.CROSSHAIR_CURSOR);      else if (arg.equals(“HAND”))         myFrame.setCursor(Frame.HAND_CURSOR);      else if (arg.equals(“WAIT”))         myFrame.setCursor(Frame.WAIT_CURSOR);      else if (arg.equals(“TEXT”))         myFrame.setCursor(Frame.TEXT_CURSOR);      else if (arg.equals(“DEFAULT”))         myFrame.setCursor(Frame.DEFAULT_CURSOR);      else         return false;      return true;   }   }