/// <summary>
/// The <see cref="BackgroundWorker.DoWork"/> event handler here waits on a semaphore if there
/// are not status text items yet to process. If the semaphore has a non-zero value and we haven't
/// been asked to close yet and there are pending status text items to be displayed, then we safely
/// dequeue one and use the <see cref="BackgroundWorker.ReportProgress"/> event to notify the UI
/// thread for this instance of the status text to display. We then wait for the minimum display
/// timespan specified for the status text item before iterating.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
while (true)
{
// Wait on the semaphore, which will return if/as soon as there are status text items in
// the queue or we've been allowed to close, otherwise will block indefinitely (no timeout).
splashItemsSemaphore.WaitOne();
SplashStatusTextItem statusTextItem = null;
// Safely attempt to retrieve an item from the queue.
lock (this.synchronisationObject)
{
// If we're now allowed to close and there's nothing left in the queue then it's time to break.
if (this.allowToClose && this.splashTextQueue.Count == 0)
{
break;
}
statusTextItem = this.splashTextQueue.Dequeue();
}
// Use the report progress facility to communicate to this control's UI thread with the new status
// text item to display.
this.backgroundWorker.ReportProgress(0, statusTextItem);
// If there's a non-zero timespan to keep the text displayed then sleep for that duration before continuing.
if (statusTextItem.MinimumTimeSpanDisplayed > TimeSpan.Zero)
{
Thread.Sleep(statusTextItem.MinimumTimeSpanDisplayed);
}
}
}
/// <summary>
/// <see cref="BackgroundWorker.ProgressChanged"/> event handler which updates the status text label
/// with the supplied status text as provided from the background worker thread.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void backgroundWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
SplashStatusTextItem statusTextItem = (SplashStatusTextItem)e.UserState;
this.labelStatus.Text = statusTextItem.Text;
}