/// <summary>
/// Callback method invoked from worker threads to indicate that another
/// thumbnail has been downloaded
/// </summary>
private void ProcessCompletedDownload(IVideo iVideo, VideoThumbnail thumbnail)
{
try
{
// ensure we don't invoke on 'dead' controls (could happen if a background
// thread completes a download after the parent dialog has been dismisssed)
if (!_workQueue.Terminated && !_owner.IsDisposed)
{
// marshal to the UI thread if necessary
if (_owner.InvokeRequired)
{
_owner.BeginInvoke(new CompletedHandler(ProcessCompletedDownload), new object[] { iVideo, thumbnail });
}
else
{
// cache the thumbnail
_thumbnails[iVideo] = thumbnail;
// notify listeners
if (ThumbnailDownloadCompleted != null)
{
ThumbnailDownloadCompleted(iVideo);
}
}
}
}
catch (Exception ex)
{
Trace.Fail("Unexpected exception in DownloaderCompletedHandler: " + ex);
}
}
/// <summary>
/// Main worker thread logic for thumbnailer
/// </summary>
private void ThumbnailDownloaderMain()
{
try
{
// keep waiting for new work items until the queue is terminated
// via the ThreadSafeQueueTerminatedException
while (true)
{
// get the next video to download
IVideo ivideo = _workQueue.Dequeue() as IVideo;
// attempt to download it
Stream videoStream = SafeDownloadThumbnail(ivideo);
// either get the downloaded thumbnail or if we failed due to a
// timeout or other error then put in a special 'Not Available'
// thumbnail image
VideoThumbnail thumbnail;
if (videoStream != null)
{
thumbnail = new VideoThumbnail(videoStream);
}
else
{
thumbnail = new NoAvailableVideoThumbnail();
}
// notification that the download is completed
ProcessCompletedDownload(ivideo, thumbnail);
}
}
catch (ThreadSafeQueueTerminatedException)
{
}
catch (Exception ex)
{
Trace.Fail("Unexpected exception in ThumbnailDownloader: " + ex);
}
}
/// <summary>
/// Download the thumbnail for the specified video (only if it isn't already in our cache)
/// </summary>
public void DownloadThumbnail(IVideo video)
{
if (!_thumbnails.Contains(video))
{
// if we can get a version of the thumbnail from the cache
// then just save this version
PluginHttpRequest pluginHttpRequest = new PluginHttpRequest(video.ThumbnailUrl, HttpRequestCacheLevel.CacheOnly);
using (Stream cachedStream = pluginHttpRequest.GetResponse())
{
if (cachedStream != null)
{
MemoryStream memoryStream = new MemoryStream();
StreamHelper.Transfer(cachedStream, memoryStream);
_thumbnails[video] = new VideoThumbnail(memoryStream);
}
// otherwise mark it as 'downloading' and enque the download
else
{
_thumbnails[video] = new DownloadingVideoThumbnail();
_workQueue.Enqueue(video);
}
}
}
}
/// <summary>
/// Download the thumbnail for the specified video (only if it isn't already in our cache)
/// </summary>
public void DownloadThumbnail(IVideo video)
{
if (!_thumbnails.Contains(video))
{
// if we can get a version of the thumbnail from the cache
// then just save this version
PluginHttpRequest pluginHttpRequest = new PluginHttpRequest(video.ThumbnailUrl, HttpRequestCacheLevel.CacheOnly);
using (Stream cachedStream = pluginHttpRequest.GetResponse())
{
if (cachedStream != null)
{
MemoryStream memoryStream = new MemoryStream();
StreamHelper.Transfer(cachedStream, memoryStream);
_thumbnails[video] = new VideoThumbnail(memoryStream);
}
// otherwise mark it as 'downloading' and enque the download
else
{
_thumbnails[video] = new DownloadingVideoThumbnail();
_workQueue.Enqueue(video);
}
}
}
}
/// <summary>
/// Callback method invoked from worker threads to indicate that another
/// thumbnail has been downloaded
/// </summary>
private void ProcessCompletedDownload(IVideo iVideo, VideoThumbnail thumbnail)
{
try
{
// ensure we don't invoke on 'dead' controls (could happen if a background
// thread completes a download after the parent dialog has been dismisssed)
if (!_workQueue.Terminated && !_owner.IsDisposed)
{
// marshal to the UI thread if necessary
if (_owner.InvokeRequired)
{
_owner.BeginInvoke(new CompletedHandler(ProcessCompletedDownload), new object[] { iVideo, thumbnail });
}
else
{
// cache the thumbnail
_thumbnails[iVideo] = thumbnail;
// notify listeners
if (ThumbnailDownloadCompleted != null)
ThumbnailDownloadCompleted(iVideo);
}
}
}
catch (Exception ex)
{
Trace.Fail("Unexpected exception in DownloaderCompletedHandler: " + ex);
}
}
/// <summary>
/// Main worker thread logic for thumbnailer
/// </summary>
private void ThumbnailDownloaderMain()
{
try
{
// keep waiting for new work items until the queue is terminated
// via the ThreadSafeQueueTerminatedException
while (true)
{
// get the next video to download
IVideo ivideo = _workQueue.Dequeue() as IVideo;
// attempt to download it
Stream videoStream = SafeDownloadThumbnail(ivideo);
// either get the downloaded thumbnail or if we failed due to a
// timeout or other error then put in a special 'Not Available'
// thumbnail image
VideoThumbnail thumbnail;
if (videoStream != null)
thumbnail = new VideoThumbnail(videoStream);
else
thumbnail = new NoAvailableVideoThumbnail();
// notification that the download is completed
ProcessCompletedDownload(ivideo, thumbnail);
}
}
catch (ThreadSafeQueueTerminatedException)
{
}
catch (Exception ex)
{
Trace.Fail("Unexpected exception in ThumbnailDownloader: " + ex);
}
}
protected override void OnDrawItem(DrawItemEventArgs e)
{
// screen invalid drawing states
if (DesignMode || e.Index == -1)
{
return;
}
// get video we are rendering
IVideo video = Items[e.Index] as IVideo;
// determine state
bool selected = ((e.State & DrawItemState.Selected) > 0) && !_preventSelectionPainting;
// calculate colors
Color textColor;
if (selected)
{
if (Focused)
{
textColor = SystemColors.HighlightText;
}
else
{
textColor = SystemColors.ControlText;
}
}
else
{
textColor = SystemColors.ControlText;
}
Color previewColor = Color.FromArgb(200, textColor);
BidiGraphics g = new BidiGraphics(e.Graphics, e.Bounds);
// setup standard string format
TextFormatFlags ellipsesStringFormat = TextFormatFlags.WordBreak | TextFormatFlags.TextBoxControl | TextFormatFlags.ExpandTabs | TextFormatFlags.WordEllipsis;
// draw background
e.DrawBackground();
//using (SolidBrush solidBrush = new SolidBrush(backColor))
// g.FillRectangle(solidBrush, e.Bounds);
// draw the thumbnail image
Rectangle thumbnailRect = new Rectangle(e.Bounds.Left + ScaleX(HORIZONTAL_INSET), e.Bounds.Top + ScaleY(VERTICAL_INSET), THUMBNAIL_IMAGE_WIDTH, THUMBNAIL_IMAGE_HEIGHT);
VideoThumbnail thumbnail = _thumbnailManager.GetThumbnail(video);
thumbnail.Draw(g, e.Font, thumbnailRect);
// calculate standard text drawing metrics
int leftMargin = ScaleX(HORIZONTAL_INSET) + THUMBNAIL_IMAGE_WIDTH + ScaleX(HORIZONTAL_INSET);
int topMargin = e.Bounds.Top + ScaleY(VERTICAL_INSET);
int fontHeight = g.MeasureText(video.Title, e.Font).Height;
// draw title and duration
int titleWidth;
Rectangle durationRectangle;
using (Font hyperlinkFont = new Font(e.Font, FontStyle.Underline))
{
titleWidth = e.Bounds.Right - ScaleX(HORIZONTAL_INSET) - leftMargin;
Rectangle titleRectangle = new Rectangle(leftMargin, topMargin, titleWidth, fontHeight);
string title = video.Title ?? "";
g.DrawText(title,
hyperlinkFont,
titleRectangle, selected ? textColor : SystemColors.HotTrack, ellipsesStringFormat);
}
using (Font durationFont = new Font(e.Font, FontStyle.Regular)) // was bold
{
durationRectangle = new Rectangle(leftMargin, topMargin + fontHeight + 3, titleWidth, fontHeight);
string duration = String.Format(CultureInfo.InvariantCulture, "{0:00}:{1:00}", video.LengthSeconds / 60, video.LengthSeconds % 60);
g.DrawText(
duration,
durationFont,
durationRectangle, textColor, ellipsesStringFormat);
}
// draw description
// calculate layout rectangle
Rectangle layoutRectangle = new Rectangle(
leftMargin,
durationRectangle.Bottom + ScaleY(VERTICAL_INSET),
e.Bounds.Width - leftMargin - ScaleX(HORIZONTAL_INSET),
e.Bounds.Bottom - ScaleY(VERTICAL_INSET) - durationRectangle.Bottom - ScaleY(VERTICAL_INSET));
// draw description
g.DrawText(
video.Description,
e.Font, layoutRectangle, previewColor, ellipsesStringFormat);
// draw bottom-line if necessary
if (!selected)
{
using (Pen pen = new Pen(SystemColors.ControlLight))
g.DrawLine(pen, e.Bounds.Left, e.Bounds.Bottom - ScaleY(1), e.Bounds.Right, e.Bounds.Bottom - ScaleY(1));
}
// focus rectange if necessary
e.DrawFocusRectangle();
}
