org.eclipse.jface.util.SafeRunnable.java Source code

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Here is the source code for org.eclipse.jface.util.SafeRunnable.java

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/*******************************************************************************
 * Copyright (c) 2000, 2015 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Chris Gross (schtoo@schtoo.com) - support for ISafeRunnableRunner added
 *       (bug 49497 [RCP] JFace dependency on org.eclipse.core.runtime enlarges standalone JFace applications)
 *******************************************************************************/
package org.eclipse.jface.util;

import org.eclipse.core.runtime.ISafeRunnable;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.OperationCanceledException;
import org.eclipse.core.runtime.Status;
import org.eclipse.jface.resource.JFaceResources;

/**
 * Implements a default implementation of ISafeRunnable. The default
 * implementation of <code>handleException</code> opens a dialog to show any
 * errors as they accumulate.
 * <p>
 * This may be executed on any thread.
 */
public abstract class SafeRunnable implements ISafeRunnable {

    private static boolean ignoreErrors = false;

    private static ISafeRunnableRunner runner;

    private String message;

    /**
     * Creates a new instance of SafeRunnable with a default error message.
     */
    public SafeRunnable() {
        // do nothing
    }

    /**
     * Creates a new instance of SafeRunnable with the given error message.
     *
     * @param message
     *            the error message to use
     */
    public SafeRunnable(String message) {
        this.message = message;
    }

    @Override
    public void handleException(Throwable e) {
        // Workaround to avoid interactive error dialogs during
        // automated testing
        if (ignoreErrors)
            return;

        if (message == null)
            message = JFaceResources.getString("SafeRunnable.errorMessage"); //$NON-NLS-1$

        Policy.getStatusHandler().show(new Status(IStatus.ERROR, Policy.JFACE, message, e),
                JFaceResources.getString("SafeRunnable.errorMessage")); //$NON-NLS-1$
    }

    /**
     * Flag to avoid interactive error dialogs during automated testing.
     *
     * @param flag
     * @return true if errors should be ignored
     * @deprecated use getIgnoreErrors()
     */
    @Deprecated
    public static boolean getIgnoreErrors(boolean flag) {
        return ignoreErrors;
    }

    /**
     * Flag to avoid interactive error dialogs during automated testing.
     *
     * @return true if errors should be ignored
     *
     * @since 3.0
     */
    public static boolean getIgnoreErrors() {
        return ignoreErrors;
    }

    /**
     * Flag to avoid interactive error dialogs during automated testing.
     *
     * @param flag
     *            set to true if errors should be ignored
     */
    public static void setIgnoreErrors(boolean flag) {
        ignoreErrors = flag;
    }

    /**
     * Returns the safe runnable runner.
     *
     * @return the safe runnable runner
     *
     * @since 3.1
     */
    public static ISafeRunnableRunner getRunner() {
        if (runner == null) {
            runner = createDefaultRunner();
        }
        return runner;
    }

    /**
     * Creates the default safe runnable runner.
     *
     * @return the default safe runnable runner
     * @since 3.1
     */
    private static ISafeRunnableRunner createDefaultRunner() {
        return new ISafeRunnableRunner() {
            @Override
            public void run(ISafeRunnable code) {
                try {
                    code.run();
                } catch (Exception e) {
                    handleException(code, e);
                } catch (LinkageError e) {
                    handleException(code, e);
                }
            }

            private void handleException(ISafeRunnable code, Throwable e) {
                if (!(e instanceof OperationCanceledException)) {
                    try {
                        Policy.getLog().log(
                                new Status(IStatus.ERROR, Policy.JFACE, IStatus.ERROR, "Exception occurred", e)); //$NON-NLS-1$
                    } catch (Exception ex) {
                        e.printStackTrace();
                    }
                }
                code.handleException(e);
            }
        };
    }

    /**
     * Sets the safe runnable runner.
     *
     * @param runner
     *            the runner to set, or <code>null</code> to reset to the
     *            default runner
     * @since 3.1
     */
    public static void setRunner(ISafeRunnableRunner runner) {
        SafeRunnable.runner = runner;
    }

    /**
     * Runs the given safe runnable using the safe runnable runner. This is a
     * convenience method, equivalent to:
     * <code>SafeRunnable.getRunner().run(runnable)</code>.
     *
     * @param runnable
     *            the runnable to run
     * @since 3.1
     */
    public static void run(ISafeRunnable runnable) {
        getRunner().run(runnable);
    }

}