Package org.eclipse.swt.custom

Class BusyIndicator

java.lang.Object
org.eclipse.swt.custom.BusyIndicator
public class BusyIndicator extends Object
Support for showing a Busy Cursor during a long running process.
See Also:

  • Constructor Details

    • BusyIndicator

      public BusyIndicator()

  • Method Details

    • showWhile

      public static void showWhile(Display display, Runnable runnable)
      Runs the given Runnable while providing busy feedback using this busy indicator.
      Parameters:
      display - the display on which the busy feedback should be displayed. If the display is null, the Display for the current thread will be used. If there is no Display for the current thread, the runnable code will be executed and no busy feedback will be displayed.
      runnable - the runnable for which busy feedback is to be shown. Must not be null.
      Throws:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the runnable is null

    • showWhile

      public static void showWhile(Future<?> future)
      If called from a Display thread, waits for the given Future to complete and provides busy feedback using the busy indicator. While waiting for completion, pending UI events are processed to prevent UI freeze. If there is no Display for the current thread, the Future.get() will be executed ignoring any ExecutionException and no busy feedback will be displayed.
      Parameters:
      future - the Future for which busy feedback is to be shown.
      Since:
      3.127
      Implementation Note:
      In some cases completion is detected by a regular timed wakeup of the Display thread,for minimal latency pass a CompletableFuture or trigger Display.wake() as an external event.

    • execute

      public static <E extends Exception> CompletableFuture<?> execute(SwtRunnable<E> action)
      If called from a Display thread use the given SwtRunnable to produces a CompletableFuture providing busy feedback using the busy indicator while execution is running. If called from a non Display the execution is performed in place and the result returned as a CompletableFuture. It is therefore safe to call this method from any thread and the SwtCallable is always evaluated outside the UI. The ForkJoinPool.commonPool() is used to execute the computation in case this is called from a Display thread
      Parameters:
      action - the action that should be executed and produces a result of the CompletableFuture
      Since:
      3.123

    • execute

      public static <E extends Exception> CompletableFuture<?> execute(SwtRunnable<E> action, Executor executor)
      If called from a Display thread use the given SwtRunnable to produces a CompletableFuture providing busy feedback using the busy indicator while execution is running. If called from a non Display the execution is performed in place and the result returned as a CompletableFuture. It is therefore safe to call this method from any thread and the SwtCallable is always evaluated outside the UI.
      Parameters:
      action - the action that should be executed and produces a result of the CompletableFuture
      executor - the Executor to perform the computation in case this is called from a Display thread, passing a Display will throw an IllegalArgumentException as this will lead to a blocking UI and violates the contract of this method
      Since:
      3.123

    • compute

      public static <V, E extends Exception> CompletableFuture<V> compute(SwtCallable<V,E> action)
      If called from a Display thread use the given SwtCallable to produces a CompletableFuture providing busy feedback using the busy indicator while computation is running. If called from a non Display the computation is performed in place and the result returned as a CompletableFuture. It is therefore safe to call this method from any thread and the SwtCallable is always evaluated outside the UI. The ForkJoinPool.commonPool() is used to execute the computation in case this is called from a Display thread
      Parameters:
      action - the action that should be executed and produces a result of the CompletableFuture
      Since:
      3.123

    • compute

      public static <V, E extends Exception> CompletableFuture<V> compute(SwtCallable<V,E> action, Executor executor)
      If called from a Display thread use the given SwtCallable to compute a CompletableFuture providing busy feedback using the busy indicator while computation is running. If called from a non Display the computation is performed in place and the result returned as a CompletableFuture. It is therefore safe to call this method from any thread and the SwtCallable is always evaluated outside the UI.
      Parameters:
      action - the action that should be executed and produces a result of the CompletableFuture
      executor - the Executor to perform the computation in case this is called from a Display thread, passing a Display will throw an IllegalArgumentException as this will lead to a blocking UI and violates the contract of this method
      Since:
      3.123