// PlayNextImage
// Called when a new image is displayed due to a timeout.
// Removes the current image object and queues a new next image.
// Sets the next image index as the new current image, and increases the size
// of the new current image. Then sets the timeout to display the next image.
private async void PlayNextImage(int num)
{
// Stop the timer to avoid repeating.
if (timer != null)
{
timer.Stop();
}
await dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
async() =>
{
SlideShowPanel.Children.Remove((UIElement)(SlideShowPanel.FindName("image" + num)));
var i = await QueueImage(num + 2, false);
currentImage = num + 1;
((Image)SlideShowPanel.FindName("image" + currentImage)).Width = imageSize;
});
timer = new Windows.UI.Xaml.DispatcherTimer();
timer.Interval = new TimeSpan(0, 0, timeLapse);
timer.Tick += delegate(object sender, object e)
{
PlayNextImage(num + 1);
};
timer.Start();
}
// QueueImage
// Called to create an image object for the displayed images.
private async System.Threading.Tasks.Task <Image> QueueImage(int num, bool isFirstImage)
{
// Create the image element for the specified image index and add to the
// slide show div.
Image image = new Image();
image.Width = isFirstImage ? imageSize : thumbnailSize;
image.Name = "image" + num;
image.VerticalAlignment = VerticalAlignment.Bottom;
var fileContents = await imageList[num % imageList.Count].OpenReadAsync();
var imageBitmap = new Windows.UI.Xaml.Media.Imaging.BitmapImage();
imageBitmap.SetSource(fileContents);
image.Source = imageBitmap;
await dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
() =>
{
SlideShowPanel.Children.Add(image);
});
// If this is the first image of the slide show, queue the next image. Do
// not queue if streaming as images are already queued before
// streaming using Play To.
if (isFirstImage && !streaming)
{
var i = await QueueImage(num + 1, false);
timer = new Windows.UI.Xaml.DispatcherTimer();
timer.Interval = new TimeSpan(0, 0, timeLapse);
timer.Tick += delegate(object sender, object e)
{
PlayNextImage(num);
};
timer.Start();
}
// Use the transferred event of the Play To connection for the current image object
// to "move" to the next image in the slide show. The transferred event occurs
// when the PlayToSource.playNext() method is called, or when the Play To
// Receiver selects the next image.
image.PlayToSource.Connection.Transferred +=
async delegate(Windows.Media.PlayTo.PlayToConnection sender,
Windows.Media.PlayTo.PlayToConnectionTransferredEventArgs e)
{
currentImage = num + 1;
await dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
() =>
{
((Image)SlideShowPanel.FindName("image" + currentImage)).Width = imageSize;
});
};
// Use the statechanged event to determine which action to take or to respond
// if the Play To Receiver is disconnected.
image.PlayToSource.Connection.StateChanged +=
async delegate(Windows.Media.PlayTo.PlayToConnection sender,
Windows.Media.PlayTo.PlayToConnectionStateChangedEventArgs e)
{
switch (e.CurrentState)
{
case Windows.Media.PlayTo.PlayToConnectionState.Disconnected:
// If the state is disconnected and the current image index equals the
// num value passed to queueImage, then the image element is not connected
// to the Play To Receiver any more. Restart the slide show.
// Otherwise, the current image has been discarded and the slide show
// has moved to the next image. Clear the current image object and
// remove it from the slide show div.
if (currentImage == num)
{
await dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
async() =>
{
MessageBlock.Text = "Slideshow disconnected";
// Cancel any existing timeout
if (timer != null)
{
timer.Stop();
}
// Clear all image objects from the slide show div
SlideShowPanel.Children.Clear();
// Reset the slide show objects and values to their beginning state
streaming = false;
DisconnectButton.Visibility = Visibility.Collapsed;
InstructionsBlock.Visibility = Visibility.Visible;
DisconnectButton.Click -= DisconnectButtonClick;
// Restart the slide show from the current image index
var i = await QueueImage(currentImage, true);
});
}
else
{
await dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
() =>
{
image.PlayToSource.Next = null;
if (streaming)
{
SlideShowPanel.Children.Remove(image);
}
});
}
break;
case Windows.Media.PlayTo.PlayToConnectionState.Connected:
// If the state is connected and the previous state is disconnected,
// then the image element is newly connected. Queue up the next image so
// that it is loaded while the current image is being displayed.
// If the previous state is rendering, then the user has paused the slideshow
// on the Play To Receiver. Clear the current timeout until the user restarts
// the slide show.
await dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
async() =>
{
if (e.PreviousState == Windows.Media.PlayTo.PlayToConnectionState.Disconnected)
{
var imageNext = await QueueImage(num + 1, false);
image.PlayToSource.Next = imageNext.PlayToSource;
}
else if (e.PreviousState == Windows.Media.PlayTo.PlayToConnectionState.Rendering)
{
if (timer != null)
{
timer.Stop();
}
}
if (currentImage == num)
{
MessageBlock.Text = "Slideshow connected";
}
});
break;
case Windows.Media.PlayTo.PlayToConnectionState.Rendering:
// If the state is rendering and the previous state is
// connected, then the Play To Receiver has restarted
// the slide show.
await dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
() =>
{
if (e.PreviousState == Windows.Media.PlayTo.PlayToConnectionState.Connected)
{
// Clear any existing timeout.
if (timer != null)
{
timer.Stop();
}
// Restart the slide show.
timer = new Windows.UI.Xaml.DispatcherTimer();
timer.Interval = new TimeSpan(0, 0, timeLapse);
timer.Tick += delegate(object s, object args)
{
image.PlayToSource.PlayNext();
};
timer.Start();
}
if (currentImage == num)
{
MessageBlock.Text = "Slideshow rendering";
}
});
break;
}
};
return(image);
}