public override void DidUpdateFocus (UIFocusUpdateContext context, UIFocusAnimationCoordinator coordinator)
{
var nextFocusedView = context.NextFocusedView;
if (!nextFocusedView.IsDescendantOfView (TableView))
return;
NSIndexPath indexPath = ((UITableViewFocusUpdateContext)context).NextFocusedIndexPath;
if (indexPath == null)
return;
// Cancel any previously queued segues.
delayedSeguesOperationQueue.CancelAllOperations ();
// Create an `NSBlockOperation` to perform the detail segue after a delay.
var performSegueOperation = new NSBlockOperation ();
var segueIdentifier = SegueIdentifierMap[indexPath.Section][indexPath.Row];
performSegueOperation.AddExecutionBlock (() => {
NSThread.SleepFor (performSegueDelay);
if (performSegueOperation.IsCancelled && segueIdentifier == lastPerformedSegueIdentifier)
return;
NSOperationQueue.MainQueue.AddOperation (() => {
PerformSegue (segueIdentifier, nextFocusedView);
lastPerformedSegueIdentifier = segueIdentifier;
TableView.SelectRow (indexPath, true, UITableViewScrollPosition.None);
});
});
delayedSeguesOperationQueue.AddOperation (performSegueOperation);
}
public void ComposeCell(DataItemCollectionViewCell cell, DataItem dataItem)
{
var operationQueue = OperationQueueForCell(cell);
operationQueue.CancelAllOperations();
cell.RepresentedDataItem = dataItem;
cell.Label.Text = dataItem.Title;
cell.ImageView.Alpha = 1f;
cell.ImageView.Image = (UIImage)processedImageCache.ObjectForKey((NSString)dataItem.Identifier);
if (cell.ImageView.Image != null)
{
return;
}
var processImageOperation = new NSBlockOperation();
processImageOperation.AddExecutionBlock(() => {
if (processImageOperation.IsCancelled)
{
return;
}
UIImage image = null;
DispatchQueue.MainQueue.DispatchSync(() => {
image = ProcessImageNamed(dataItem.ImageName);
});
if (image == null)
{
return;
}
processedImageCache.SetObjectforKey(image, (NSString)dataItem.Identifier);
NSOperationQueue.MainQueue.AddOperation(() => {
if (cell.RepresentedDataItem == null)
{
return;
}
cell.ImageView.Alpha = 0f;
cell.ImageView.Image = image;
UIView.Animate(0.25, () => cell.ImageView.Alpha = 1f);
});
});
operationQueue.AddOperation(processImageOperation);
}
public void ComposeCell (DataItemCollectionViewCell cell, DataItem dataItem)
{
var operationQueue = OperationQueueForCell (cell);
operationQueue.CancelAllOperations ();
cell.RepresentedDataItem = dataItem;
cell.Label.Text = dataItem.Title;
cell.ImageView.Alpha = 1f;
cell.ImageView.Image = (UIImage)processedImageCache.ObjectForKey ((NSString)dataItem.Identifier);
if (cell.ImageView.Image != null)
return;
var processImageOperation = new NSBlockOperation ();
processImageOperation.AddExecutionBlock (() => {
if (processImageOperation.IsCancelled)
return;
UIImage image = null;
DispatchQueue.MainQueue.DispatchSync (() => {
image = ProcessImageNamed (dataItem.ImageName);
});
if (image == null)
return;
processedImageCache.SetObjectforKey (image, (NSString)dataItem.Identifier);
NSOperationQueue.MainQueue.AddOperation (() => {
if (cell.RepresentedDataItem == null)
return;
cell.ImageView.Alpha = 0f;
cell.ImageView.Image = image;
UIView.Animate (0.25, () => cell.ImageView.Alpha = 1f);
});
});
operationQueue.AddOperation (processImageOperation);
}
public override void DidUpdateFocus(UIFocusUpdateContext context, UIFocusAnimationCoordinator coordinator)
{
var nextFocusedView = context.NextFocusedView;
if (!nextFocusedView.IsDescendantOfView(TableView))
{
return;
}
NSIndexPath indexPath = ((UITableViewFocusUpdateContext)context).NextFocusedIndexPath;
if (indexPath == null)
{
return;
}
// Cancel any previously queued segues.
delayedSeguesOperationQueue.CancelAllOperations();
// Create an `NSBlockOperation` to perform the detail segue after a delay.
var performSegueOperation = new NSBlockOperation();
var segueIdentifier = SegueIdentifierMap[indexPath.Section][indexPath.Row];
performSegueOperation.AddExecutionBlock(() => {
NSThread.SleepFor(performSegueDelay);
if (performSegueOperation.IsCancelled && segueIdentifier == lastPerformedSegueIdentifier)
{
return;
}
NSOperationQueue.MainQueue.AddOperation(() => {
PerformSegue(segueIdentifier, nextFocusedView);
lastPerformedSegueIdentifier = segueIdentifier;
TableView.SelectRow(indexPath, true, UITableViewScrollPosition.None);
});
});
delayedSeguesOperationQueue.AddOperation(performSegueOperation);
}
