Exemplo n.º 1
0
  /**
   * Execute applet events. Here is the state transition diagram
   *
   * <pre>{@literal
   *   Note: (XXX) is the action
   *         APPLET_XXX is the state
   *  (applet code loaded) --> APPLET_LOAD -- (applet init called)--> APPLET_INIT --
   *  (applet start called) --> APPLET_START -- (applet stop called) --> APPLET_STOP --
   *  (applet destroyed called) --> APPLET_DESTROY --> (applet gets disposed) -->
   *   APPLET_DISPOSE --> ...
   * }</pre>
   *
   * In the legacy lifecycle model. The applet gets loaded, inited and started. So it stays in the
   * APPLET_START state unless the applet goes away(refresh page or leave the page). So the applet
   * stop method called and the applet enters APPLET_STOP state. Then if the applet is revisited, it
   * will call applet start method and enter the APPLET_START state and stay there.
   *
   * <p>In the modern lifecycle model. When the applet first time visited, it is same as legacy
   * lifecycle model. However, when the applet page goes away. It calls applet stop method and
   * enters APPLET_STOP state and then applet destroyed method gets called and enters APPLET_DESTROY
   * state.
   *
   * <p>This code is also called by AppletViewer. In AppletViewer "Restart" menu, the applet is jump
   * from APPLET_STOP to APPLET_DESTROY and to APPLET_INIT .
   *
   * <p>Also, the applet can jump from APPLET_INIT state to APPLET_DESTROY (in Netscape/Mozilla
   * case). Same as APPLET_LOAD to APPLET_DISPOSE since all of this are triggered by browser.
   */
  @Override
  public void run() {

    Thread curThread = Thread.currentThread();
    if (curThread == loaderThread) {
      // if we are in the loader thread, cause
      // loading to occur.  We may exit this with
      // status being APPLET_DISPOSE, APPLET_ERROR,
      // or APPLET_LOAD
      runLoader();
      return;
    }

    boolean disposed = false;
    while (!disposed && !curThread.isInterrupted()) {
      AppletEvent evt;
      try {
        evt = getNextEvent();
      } catch (InterruptedException e) {
        showAppletStatus("bail");
        return;
      }

      // showAppletStatus("EVENT = " + evt.getID());
      try {
        switch (evt.getID()) {
          case APPLET_LOAD:
            if (!okToLoad()) {
              break;
            }
            // This complexity allows loading of applets to be
            // interruptable.  The actual thread loading runs
            // in a separate thread, so it can be interrupted
            // without harming the applet thread.
            // So that we don't have to worry about
            // concurrency issues, the main applet thread waits
            // until the loader thread terminates.
            // (one way or another).
            if (loaderThread == null) {
              setLoaderThread(new Thread(null, this, "AppletLoader", 0, false));
              loaderThread.start();
              // we get to go to sleep while this runs
              loaderThread.join();
              setLoaderThread(null);
            } else {
              // REMIND: issue an error -- this case should never
              // occur.
            }
            break;

          case APPLET_INIT:
            // AppletViewer "Restart" will jump from destroy method to
            // init, that is why we need to check status w/ APPLET_DESTROY
            if (status != APPLET_LOAD && status != APPLET_DESTROY) {
              showAppletStatus("notloaded");
              break;
            }
            applet.resize(defaultAppletSize);

            if (PerformanceLogger.loggingEnabled()) {
              PerformanceLogger.setTime("Applet Init");
              PerformanceLogger.outputLog();
            }
            applet.init();

            // Need the default(fallback) font to be created in this AppContext
            Font f = getFont();
            if (f == null
                || "dialog".equals(f.getFamily().toLowerCase(Locale.ENGLISH))
                    && f.getSize() == 12
                    && f.getStyle() == Font.PLAIN) {
              setFont(new Font(Font.DIALOG, Font.PLAIN, 12));
            }

            // Validate the applet in event dispatch thread
            // to avoid deadlock.
            try {
              final AppletPanel p = this;
              Runnable r =
                  new Runnable() {
                    @Override
                    public void run() {
                      p.validate();
                    }
                  };
              AWTAccessor.getEventQueueAccessor().invokeAndWait(applet, r);
            } catch (InterruptedException ie) {
            } catch (InvocationTargetException ite) {
            }

            status = APPLET_INIT;
            showAppletStatus("inited");
            break;

          case APPLET_START:
            {
              if (status != APPLET_INIT && status != APPLET_STOP) {
                showAppletStatus("notinited");
                break;
              }
              applet.resize(currentAppletSize);
              applet.start();

              // Validate and show the applet in event dispatch thread
              // to avoid deadlock.
              try {
                final AppletPanel p = this;
                final Applet a = applet;
                Runnable r =
                    new Runnable() {
                      @Override
                      public void run() {
                        p.validate();
                        a.setVisible(true);

                        // Fix for BugTraq ID 4041703.
                        // Set the default focus for an applet.
                        if (hasInitialFocus()) {
                          setDefaultFocus();
                        }
                      }
                    };
                AWTAccessor.getEventQueueAccessor().invokeAndWait(applet, r);
              } catch (InterruptedException ie) {
              } catch (InvocationTargetException ite) {
              }

              status = APPLET_START;
              showAppletStatus("started");
              break;
            }

          case APPLET_STOP:
            if (status != APPLET_START) {
              showAppletStatus("notstarted");
              break;
            }
            status = APPLET_STOP;

            // Hide the applet in event dispatch thread
            // to avoid deadlock.
            try {
              final Applet a = applet;
              Runnable r =
                  new Runnable() {
                    @Override
                    public void run() {
                      a.setVisible(false);
                    }
                  };
              AWTAccessor.getEventQueueAccessor().invokeAndWait(applet, r);
            } catch (InterruptedException ie) {
            } catch (InvocationTargetException ite) {
            }

            // During Applet.stop(), any AccessControlException on an involved Class remains in
            // the "memory" of the AppletClassLoader.  If the same instance of the ClassLoader is
            // reused, the same exception will occur during class loading.  Set the
            // AppletClassLoader's
            // exceptionStatusSet flag to allow recognition of what had happened
            // when reusing AppletClassLoader object.
            try {
              applet.stop();
            } catch (java.security.AccessControlException e) {
              setExceptionStatus(e);
              // rethrow exception to be handled as it normally would be.
              throw e;
            }
            showAppletStatus("stopped");
            break;

          case APPLET_DESTROY:
            if (status != APPLET_STOP && status != APPLET_INIT) {
              showAppletStatus("notstopped");
              break;
            }
            status = APPLET_DESTROY;

            // During Applet.destroy(), any AccessControlException on an involved Class remains in
            // the "memory" of the AppletClassLoader.  If the same instance of the ClassLoader is
            // reused, the same exception will occur during class loading.  Set the
            // AppletClassLoader's
            // exceptionStatusSet flag to allow recognition of what had happened
            // when reusing AppletClassLoader object.
            try {
              applet.destroy();
            } catch (java.security.AccessControlException e) {
              setExceptionStatus(e);
              // rethrow exception to be handled as it normally would be.
              throw e;
            }
            showAppletStatus("destroyed");
            break;

          case APPLET_DISPOSE:
            if (status != APPLET_DESTROY && status != APPLET_LOAD) {
              showAppletStatus("notdestroyed");
              break;
            }
            status = APPLET_DISPOSE;

            try {
              final Applet a = applet;
              Runnable r =
                  new Runnable() {
                    @Override
                    public void run() {
                      remove(a);
                    }
                  };
              AWTAccessor.getEventQueueAccessor().invokeAndWait(applet, r);
            } catch (InterruptedException ie) {
            } catch (InvocationTargetException ite) {
            }
            applet = null;
            showAppletStatus("disposed");
            disposed = true;
            break;

          case APPLET_QUIT:
            return;
        }
      } catch (Exception e) {
        status = APPLET_ERROR;
        if (e.getMessage() != null) {
          showAppletStatus("exception2", e.getClass().getName(), e.getMessage());
        } else {
          showAppletStatus("exception", e.getClass().getName());
        }
        showAppletException(e);
      } catch (ThreadDeath e) {
        showAppletStatus("death");
        return;
      } catch (Error e) {
        status = APPLET_ERROR;
        if (e.getMessage() != null) {
          showAppletStatus("error2", e.getClass().getName(), e.getMessage());
        } else {
          showAppletStatus("error", e.getClass().getName());
        }
        showAppletException(e);
      }
      clearLoadAbortRequest();
    }
  }