/*******************************************************************************
 * Copyright (c) 2000, 2007 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 dwtx.core.runtime enlarges standalone JFace applications)
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/
module dwtx.jface.util.SafeRunnable;

import dwtx.jface.util.ISafeRunnableRunner;
import dwtx.jface.util.SafeRunnableDialog;
import dwtx.jface.util.Policy;

import dwt.events.DisposeEvent;
import dwt.events.DisposeListener;
import dwt.widgets.Display;
import dwtx.core.runtime.ISafeRunnable;
import dwtx.core.runtime.IStatus;
import dwtx.core.runtime.OperationCanceledException;
import dwtx.core.runtime.Status;
import dwtx.jface.resource.JFaceResources;

import dwt.dwthelper.utils;
import dwt.dwthelper.Runnable;

/**
 * Implements a default implementation of ISafeRunnable. The default
 * implementation of <code>handleException</code> opens a message dialog.
 * <p>
 * <b>Note:<b> This class can open an error dialog and should not be used
 * outside of the UI Thread.
 * </p>
 */
public abstract class SafeRunnable : ISafeRunnable {

    private static bool ignoreErrors = false;

    private static ISafeRunnableRunner runner;

    private String message;

    private static SafeRunnableDialog dialog;

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

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


    /* (non-Javadoc)
     * @see dwtx.core.runtime.ISafeRunnable#handleException(java.lang.Throwable)
     */
    public void handleException(Exception e) {
        // Workaround to avoid interactive error dialogs during automated
        // testing
        if (!ignoreErrors) {
            if (message is null)
                message = JFaceResources.getString("SafeRunnable.errorMessage"); //$NON-NLS-1$

            Runnable runnable = new class Runnable {
                IStatus status;
                this(){
                    status = new Status(IStatus.ERROR, Policy.JFACE, message,e);
                }
                public void run() {
                    if (dialog is null || dialog.getShell().isDisposed()) {
                        dialog = new SafeRunnableDialog(status);
                        dialog.create();
                        dialog.getShell().addDisposeListener(
                                new class DisposeListener {
                                    public void widgetDisposed(DisposeEvent e) {
                                        dialog = null;
                                    }
                                });
                        dialog.open();
                    } else {
                        dialog.addStatus(status);
                        dialog.refresh();
                    }
                }
            };
            if (Display.getCurrent() !is null) {
                runnable.run();
            } else {
                Display.getDefault().asyncExec(runnable);
            }
        }
    }

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

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

    /**
     * Returns the safe runnable runner.
     *
     * @return the safe runnable runner
     *
     * @since 3.1
     */
    public static ISafeRunnableRunner getRunner() {
        if (runner is 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 class ISafeRunnableRunner {
            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, Exception e) {
                if (!(cast(OperationCanceledException)e )) {
                    try {
                        Policy.getLog().log(
                                new Status(IStatus.ERROR, Policy.JFACE,
                                        IStatus.ERROR, "Exception occurred", e)); //$NON-NLS-1$
                    } catch (Exception ex) {
                        ExceptionPrintStackTrace(e);
                    }
                }
                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);
    }

}