/// <summary>
/// Gets an item from the artwork cache.
/// </summary>
/// <param name="trackID">The item's ID.</param>
/// <returns>A CacheReceipt that indicates the success of the request and the Uri of the image, if possible.</returns>
internal static CacheReceipt <Uri> GetArtworkCacheItem(uint trackID)
{
var x = _local.CreateContainer(ArtContainerGuid.ToString(), Windows.Storage.ApplicationDataCreateDisposition.Always).Values[trackID.ToString()] as string;
if (x == null)
{
return(new CacheReceipt <Uri>(CacheStatus.Uncached, null));
}
else if (x.Length == 0)
{
return(new CacheReceipt <Uri>(CacheStatus.CannotCache, null));
}
else
{
return(new CacheReceipt <Uri>(CacheStatus.Cached, new Uri(x)));
}
}
/// <summary>
/// Deletes any album artwork containers that are not the current one in the local storage.
/// API consumers should periodically call this function during normal app operation.
/// </summary>
public static async void CleanArtworkCache()
{
try
{
string artFolder = ArtContainerGuid.ToString();
var subfolders = await Windows.Storage.ApplicationData.Current.LocalFolder.GetFoldersAsync();
foreach (var folder in subfolders)
{
if (folder.Name != artFolder)
{
await folder.DeleteAsync();
}
}
}
catch (Exception)
{
// Justification: artwork cache cleaning happens automatically, and failure does not harm user
}
}
/// <summary>
/// Sets an item in the artwork cache.
/// </summary>
/// <param name="artGuid">The ArtContainerGuid at the start of the cache operation. If it is different from the current ArtContainerGuid, the cache will be ignored.</param>
/// <param name="status">The status of the cache operation.</param>
/// <param name="trackID">The item's ID.</param>
/// <param name="path">The path to the image, if status is CacheStatus.Cached.</param>
/// <returns>Whether the cache was successful.</returns>
internal static bool SetArtworkCacheItem(Guid artGuid, CacheStatus status, uint trackID, Uri path)
{
if (artGuid == ArtContainerGuid)
{
switch (status)
{
case CacheStatus.Cached:
_local.CreateContainer(ArtContainerGuid.ToString(), Windows.Storage.ApplicationDataCreateDisposition.Always).Values[trackID.ToString()] = path.ToString();
break;
case CacheStatus.CannotCache:
_local.CreateContainer(ArtContainerGuid.ToString(), Windows.Storage.ApplicationDataCreateDisposition.Always).Values[trackID.ToString()] = string.Empty;
break;
case CacheStatus.Uncached:
break;
}
return(true);
}
else
{
return(false);
}
}