/// <summary>
/// Raises the RetrieveVirtualItem event.
/// </summary>
/// <param name="e">A VirtualItemThumbnailEventArgs that contains event data.</param>
protected virtual void OnRetrieveVirtualItemThumbnail(VirtualItemThumbnailEventArgs e)
{
if (RetrieveVirtualItemThumbnail != null)
RetrieveVirtualItemThumbnail(this, e);
}
/// <summary>
/// Used by the worker thread to generate image thumbnails.
/// Once a thumbnail image is generated, the item will be redrawn
/// to replace the placeholder image.
/// </summary>
private void DoWork()
{
System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
while (!Stopping)
{
Guid guid = new Guid();
CacheItem request = null;
bool rendererRequest = false;
lock (lockObject)
{
// Wait until we have items waiting to be cached
if (toCache.Count == 0 && rendererToCache.Count == 0)
Monitor.Wait(lockObject);
}
// Set to true when we exceed the cache memory limit
bool cleanupRequired = false;
// Set to true when we fetch at least one thumbnail
bool thumbnailCreated = false;
// Loop until we exhaust the queue
bool queueFull = true;
while (queueFull && !Stopping)
{
lock (lockObject)
{
sw.Start();
// Get an item from the queue
if (toCache.Count != 0)
{
request = toCache.Pop();
guid = request.Guid;
// Is it already cached?
CacheItem existing = null;
if (thumbCache.TryGetValue(guid, out existing))
{
if (existing.Size == request.Size)
request = null;
else
thumbCache.Remove(guid);
}
}
else if (rendererToCache.Count != 0)
{
request = rendererToCache.Pop();
guid = request.Guid;
rendererToCache.Clear();
rendererRequest = true;
}
}
// Is it outside visible area?
bool isvisible = true;
if (request != null && mCacheMode == CacheMode.OnDemand)
{
try
{
if (mImageListView != null && mImageListView.IsHandleCreated && !mImageListView.IsDisposed)
{
isvisible = (bool)mImageListView.Invoke(new CheckItemVisibleDelegateInternal(
mImageListView.IsItemVisible), guid);
}
}
catch (ObjectDisposedException)
{
if (!Stopping) throw;
}
catch (InvalidOperationException)
{
if (!Stopping) throw;
}
}
lock (lockObject)
{
if (!rendererRequest && !isvisible)
request = null;
}
// Proceed if we have a valid request
CacheItem result = null;
if (request != null)
{
Image thumb = null;
// Is it in the edit cache?
Image editSource = null;
lock (lockObject)
{
if (!editCache.TryGetValue(guid, out editSource))
editSource = null;
}
if (editSource != null)
thumb = Utility.ThumbnailFromImage(editSource,
request.Size, Color.White);
// Read thumbnail image
if (thumb == null)
{
if (request.IsVirtualItem)
{
VirtualItemThumbnailEventArgs e = new VirtualItemThumbnailEventArgs(
request.VirtualItemKey, request.Size);
if (mImageListView != null && mImageListView.IsHandleCreated && !mImageListView.IsDisposed)
mImageListView.RetrieveVirtualItemThumbnailInternal(e);
if (e.ThumbnailImage != null)
thumb = e.ThumbnailImage;
}
else
{
thumb = Utility.ThumbnailFromFile(request.FileName,
request.Size, request.UseEmbeddedThumbnails, Color.White);
}
}
// Create the cache item
if (thumb == null)
{
if (!mRetryOnError)
{
result = new CacheItem(guid, request.FileName,
request.Size, null, CacheState.Error, request.UseEmbeddedThumbnails);
}
else
result = null;
}
else
{
result = new CacheItem(guid, request.FileName,
request.Size, thumb, CacheState.Cached, request.UseEmbeddedThumbnails);
thumbnailCreated = true;
}
if (result != null)
{
if (rendererRequest)
{
lock (lockObject)
{
if (rendererItem != null)
rendererItem.Dispose();
rendererGuid = guid;
rendererItem = result;
rendererRequest = false;
}
}
else
{
lock (lockObject)
{
thumbCache.Remove(guid);
thumbCache.Add(guid, result);
if (thumb != null)
{
// Did we exceed the cache limit?
memoryUsed += thumb.Width * thumb.Height * 24 / 8;
if ((mCacheLimitAsMemory != 0 && memoryUsed > mCacheLimitAsMemory) ||
(mCacheLimitAsItemCount != 0 && thumbCache.Count > mCacheLimitAsItemCount))
cleanupRequired = true;
}
}
}
}
try
{
if (mImageListView != null && mImageListView.IsHandleCreated && !mImageListView.IsDisposed)
{
mImageListView.Invoke(new ThumbnailCachedEventHandlerInternal(
mImageListView.OnThumbnailCachedInternal), guid, (result == null));
}
}
catch (ObjectDisposedException)
{
if (!Stopping) throw;
}
catch (InvalidOperationException)
{
if (!Stopping) throw;
}
}
// Check if the cache is exhausted
lock (lockObject)
{
if (toCache.Count == 0 && rendererToCache.Count == 0)
queueFull = false;
}
// Do we need a refresh?
sw.Stop();
if (sw.ElapsedMilliseconds > 100)
{
try
{
if (mImageListView != null && mImageListView.IsHandleCreated && !mImageListView.IsDisposed)
{
mImageListView.Invoke(new RefreshDelegateInternal(
mImageListView.OnRefreshInternal));
}
sw.Reset();
}
catch (ObjectDisposedException)
{
if (!Stopping) throw;
}
catch (InvalidOperationException)
{
if (!Stopping) throw;
}
}
if (queueFull)
sw.Start();
else
{
sw.Reset();
sw.Stop();
}
}
// Clean up invisible items
if (cleanupRequired)
{
Dictionary<Guid, bool> visible = new Dictionary<Guid, bool>();
try
{
if (mImageListView != null && mImageListView.IsHandleCreated && !mImageListView.IsDisposed)
{
visible = (Dictionary<Guid, bool>)mImageListView.Invoke(
new GetVisibleItemsDelegateInternal(mImageListView.GetVisibleItems));
}
}
catch (ObjectDisposedException)
{
if (!Stopping) throw;
}
catch (InvalidOperationException)
{
if (!Stopping) throw;
}
if (visible.Count != 0)
{
lock (lockObject)
{
foreach (KeyValuePair<Guid, CacheItem> item in thumbCache)
{
if (!visible.ContainsKey(item.Key) && item.Value.State == CacheState.Cached && item.Value.Image != null)
{
removedItems.Add(item.Key);
memoryUsedByRemoved += item.Value.Image.Width * item.Value.Image.Width * 24 / 8;
}
}
foreach (Guid iguid in removedItems)
{
if (thumbCache.ContainsKey(iguid))
{
thumbCache[iguid].Dispose();
thumbCache.Remove(iguid);
}
}
removedItems.Clear();
memoryUsed -= memoryUsedByRemoved;
memoryUsedByRemoved = 0;
}
}
}
if (thumbnailCreated)
{
try
{
if (mImageListView != null && mImageListView.IsHandleCreated && !mImageListView.IsDisposed)
{
mImageListView.Invoke(new RefreshDelegateInternal(mImageListView.OnRefreshInternal));
}
}
catch (ObjectDisposedException)
{
if (!Stopping) throw;
}
catch (InvalidOperationException)
{
if (!Stopping) throw;
}
}
}
lock (lockObject)
{
stopped = true;
}
}
/// <summary>
/// Raises the RetrieveVirtualItem event.
/// This method is invoked from the thumbnail thread.
/// </summary>
/// <param name="e">A VirtualItemThumbnailEventArgs that contains event data.</param>
internal virtual void RetrieveVirtualItemThumbnailInternal(VirtualItemThumbnailEventArgs e)
{
OnRetrieveVirtualItemThumbnail(e);
}
/// <summary>
/// Used by the worker thread to generate image thumbnails.
/// Once a thumbnail image is generated, the item will be redrawn
/// to replace the placeholder image.
/// </summary>
private void DoWork()
{
System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
while (!Stopping)
{
Guid guid = new Guid();
CacheItem request = null;
bool rendererRequest = false;
lock (lockObject)
{
// Wait until we have items waiting to be cached
if (toCache.Count == 0 && rendererToCache.Count == 0)
{
Monitor.Wait(lockObject);
}
}
// Set to true when we exceed the cache memory limit
bool cleanupRequired = false;
// Set to true when we fetch at least one thumbnail
bool thumbnailCreated = false;
// Loop until we exhaust the queue
bool queueFull = true;
while (queueFull && !Stopping)
{
lock (lockObject)
{
sw.Start();
// Get an item from the queue
if (toCache.Count != 0)
{
request = toCache.Pop();
guid = request.Guid;
// Is it already cached?
CacheItem existing = null;
if (thumbCache.TryGetValue(guid, out existing))
{
if (existing.Size == request.Size)
{
request = null;
}
else
{
thumbCache.Remove(guid);
}
}
}
else if (rendererToCache.Count != 0)
{
request = rendererToCache.Pop();
guid = request.Guid;
rendererToCache.Clear();
rendererRequest = true;
}
}
// Is it outside visible area?
bool isvisible = true;
if (request != null && mCacheMode == CacheMode.OnDemand)
{
try
{
if (mImageListView != null && mImageListView.IsHandleCreated && !mImageListView.IsDisposed)
{
isvisible = (bool)mImageListView.Invoke(new CheckItemVisibleDelegateInternal(
mImageListView.IsItemVisible), guid);
}
}
catch (ObjectDisposedException)
{
if (!Stopping)
{
throw;
}
}
catch (InvalidOperationException)
{
if (!Stopping)
{
throw;
}
}
}
lock (lockObject)
{
if (!rendererRequest && !isvisible)
{
request = null;
}
}
// Proceed if we have a valid request
CacheItem result = null;
if (request != null)
{
Image thumb = null;
// Is it in the edit cache?
Image editSource = null;
lock (lockObject)
{
if (!editCache.TryGetValue(guid, out editSource))
{
editSource = null;
}
}
if (editSource != null)
{
thumb = Utility.ThumbnailFromImage(editSource,
request.Size, Color.White);
}
// Read thumbnail image
if (thumb == null)
{
if (request.IsVirtualItem)
{
VirtualItemThumbnailEventArgs e = new VirtualItemThumbnailEventArgs(
request.VirtualItemKey, request.Size);
if (mImageListView != null && mImageListView.IsHandleCreated && !mImageListView.IsDisposed)
{
mImageListView.RetrieveVirtualItemThumbnailInternal(e);
}
if (e.ThumbnailImage != null)
{
thumb = e.ThumbnailImage;
}
}
else
{
thumb = Utility.ThumbnailFromFile(request.FileName,
request.Size, request.UseEmbeddedThumbnails, Color.White);
}
}
// Create the cache item
if (thumb == null)
{
if (!mRetryOnError)
{
result = new CacheItem(guid, request.FileName,
request.Size, null, CacheState.Error, request.UseEmbeddedThumbnails);
}
else
{
result = null;
}
}
else
{
result = new CacheItem(guid, request.FileName,
request.Size, thumb, CacheState.Cached, request.UseEmbeddedThumbnails);
thumbnailCreated = true;
}
if (result != null)
{
if (rendererRequest)
{
lock (lockObject)
{
if (rendererItem != null)
{
rendererItem.Dispose();
}
rendererGuid = guid;
rendererItem = result;
rendererRequest = false;
}
}
else
{
lock (lockObject)
{
thumbCache.Remove(guid);
thumbCache.Add(guid, result);
if (thumb != null)
{
// Did we exceed the cache limit?
memoryUsed += thumb.Width * thumb.Height * 24 / 8;
if ((mCacheLimitAsMemory != 0 && memoryUsed > mCacheLimitAsMemory) ||
(mCacheLimitAsItemCount != 0 && thumbCache.Count > mCacheLimitAsItemCount))
{
cleanupRequired = true;
}
}
}
}
}
try
{
if (mImageListView != null && mImageListView.IsHandleCreated && !mImageListView.IsDisposed)
{
mImageListView.Invoke(new ThumbnailCachedEventHandlerInternal(
mImageListView.OnThumbnailCachedInternal), guid, (result == null));
}
}
catch (ObjectDisposedException)
{
if (!Stopping)
{
throw;
}
}
catch (InvalidOperationException)
{
if (!Stopping)
{
throw;
}
}
}
// Check if the cache is exhausted
lock (lockObject)
{
if (toCache.Count == 0 && rendererToCache.Count == 0)
{
queueFull = false;
}
}
// Do we need a refresh?
sw.Stop();
if (sw.ElapsedMilliseconds > 100)
{
try
{
if (mImageListView != null && mImageListView.IsHandleCreated && !mImageListView.IsDisposed)
{
mImageListView.Invoke(new RefreshDelegateInternal(
mImageListView.OnRefreshInternal));
}
sw.Reset();
}
catch (ObjectDisposedException)
{
if (!Stopping)
{
throw;
}
}
catch (InvalidOperationException)
{
if (!Stopping)
{
throw;
}
}
}
if (queueFull)
{
sw.Start();
}
else
{
sw.Reset();
sw.Stop();
}
}
// Clean up invisible items
if (cleanupRequired)
{
Dictionary <Guid, bool> visible = new Dictionary <Guid, bool>();
try
{
if (mImageListView != null && mImageListView.IsHandleCreated && !mImageListView.IsDisposed)
{
visible = (Dictionary <Guid, bool>)mImageListView.Invoke(
new GetVisibleItemsDelegateInternal(mImageListView.GetVisibleItems));
}
}
catch (ObjectDisposedException)
{
if (!Stopping)
{
throw;
}
}
catch (InvalidOperationException)
{
if (!Stopping)
{
throw;
}
}
if (visible.Count != 0)
{
lock (lockObject)
{
foreach (KeyValuePair <Guid, CacheItem> item in thumbCache)
{
if (!visible.ContainsKey(item.Key) && item.Value.State == CacheState.Cached && item.Value.Image != null)
{
removedItems.Add(item.Key);
memoryUsedByRemoved += item.Value.Image.Width * item.Value.Image.Width * 24 / 8;
}
}
foreach (Guid iguid in removedItems)
{
if (thumbCache.ContainsKey(iguid))
{
thumbCache[iguid].Dispose();
thumbCache.Remove(iguid);
}
}
removedItems.Clear();
memoryUsed -= memoryUsedByRemoved;
memoryUsedByRemoved = 0;
}
}
}
if (thumbnailCreated)
{
try
{
if (mImageListView != null && mImageListView.IsHandleCreated && !mImageListView.IsDisposed)
{
mImageListView.Invoke(new RefreshDelegateInternal(mImageListView.OnRefreshInternal));
}
}
catch (ObjectDisposedException)
{
if (!Stopping)
{
throw;
}
}
catch (InvalidOperationException)
{
if (!Stopping)
{
throw;
}
}
}
}
lock (lockObject)
{
stopped = true;
}
}
