Class ModalContext

  • public class ModalContext
    extends Object
    Utility class for supporting modal operations. The runnable passed to the run method is executed in a separate thread, depending on the value of the passed fork argument. If the runnable is executed in a separate thread then the current thread either waits until the new thread ends or, if the current thread is the UI thread, it polls the SWT event queue and dispatches each event.

    This class is not intended to be subclassed.

    This class is not intended to be subclassed by clients.
    This class is not intended to be instantiated by clients.
    • Constructor Detail

      • ModalContext

        public ModalContext()
    • Method Detail

      • canProgressMonitorBeUsed

        public static boolean canProgressMonitorBeUsed​(IProgressMonitor monitor1,
                                                       IProgressMonitor monitor2)
        Returns whether the first progress monitor is the same as, or a wrapper around, the second progress monitor.
        monitor1 - the first progress monitor
        monitor2 - the second progress monitor
        true if the first is the same as, or a wrapper around, the second
        See Also:
      • checkCanceled

        public static void checkCanceled​(IProgressMonitor monitor)
                                  throws InterruptedException
        Checks with the given progress monitor and throws InterruptedException if it has been canceled.

        Code in a long-running operation should call this method regularly so that a request to cancel will be honored.

        Convenience for:

         if (monitor.isCanceled())
                throw new InterruptedException();
        monitor - the progress monitor
        InterruptedException - if canceling the operation has been requested
        See Also:
      • getModalLevel

        public static int getModalLevel()
        Returns the modal nesting level.

        The modal nesting level increases by one each time the method is called within the dynamic scope of another call to

        the modal nesting level, or 0 if this method is called outside the dynamic scope of any invocation of
      • isModalContextThread

        public static boolean isModalContextThread​(Thread thread)
        Returns whether the given thread is running a modal context.
        thread - The thread to be checked
        true if the given thread is running a modal context, false if not
      • run

        public static void run​(IRunnableWithProgress operation,
                               boolean fork,
                               IProgressMonitor monitor,
                               Display display)
                        throws InvocationTargetException,
        Runs the given runnable in a modal context, passing it a progress monitor.

        The modal nesting level is increased by one from the perspective of the given runnable.

        If the supplied operation implements IThreadListener, it will be notified of any thread changes required to execute the operation. Specifically, the operation will be notified of the thread that will call its run method before it is called, and will be notified of the change of control back to the thread calling this method when the operation completes. These thread change notifications give the operation an opportunity to transfer any thread-local state to the execution thread before control is transferred to the new thread.

        operation - the runnable to run
        fork - true if the runnable should run in a separate thread, and false if in the same thread
        monitor - the progress monitor to use to display progress and receive requests for cancellation
        display - the display to be used to read and dispatch events
        InvocationTargetException - if the run method must propagate a checked exception, it should wrap it inside an InvocationTargetException; runtime exceptions and errors are automatically wrapped in an InvocationTargetException by this method
        InterruptedException - if the operation detects a request to cancel, using IProgressMonitor.isCanceled(), it should exit by throwing InterruptedException; this method propagates the exception
      • setDebugMode

        public static void setDebugMode​(boolean debugMode)
        Sets whether ModalContext is running in debug mode.
        debugMode - true for debug mode, and false for normal mode (the default)
      • setAllowReadAndDispatch

        public static void setAllowReadAndDispatch​(boolean allowReadAndDispatch)
        Sets whether ModalContext may process events (by calling Display.readAndDispatch()) while running operations. By default, ModalContext will process events while running operations. Use this method to disallow event processing temporarily.
        allowReadAndDispatch - true (the default) if events may be processed while running an operation, false if Display.readAndDispatch() should not be called from ModalContext.