public TweetImageFetchRequest(TweetImageInfo image, UIView view, bool placeholder)
{
var scale = UIScreen.MainScreen.Scale;
tweetImage = image;
targetContentMode = view.ContentMode;
targetDimensions = TIPImageUtils.TIPDimensionsFromView(view);
forcePlaceholder = placeholder;
if (forcePlaceholder)
{
imageUrl = new NSUrl("placeholder://placeholder.com/placeholder.jpg");
}
else
{
if (tweetImage.MediaUrl.StartsWith("https://pbs.twimg.com/media/", StringComparison.OrdinalIgnoreCase))
{
var variantName = DetermineVariant(tweetImage.OriginalDimensions, targetDimensions, targetContentMode);
imageUrl = new NSUrl($"{tweetImage.MediaUrlWithoutExtension}?format={tweetImage.Format}&name={variantName}");
}
else
{
imageUrl = new NSUrl(tweetImage.MediaUrl);
}
}
}
private string DetermineVariant(CGSize aspectRatio, CGSize dimensions, UIViewContentMode contentMode)
{
if (aspectRatio.Height <= 0 || aspectRatio.Width <= 0)
{
aspectRatio = new CGSize(1, 1);
}
var scaleToFit = (UIViewContentMode.ScaleAspectFit == contentMode);
var scaledToTargetDimensions = TIPImageUtils.TIPDimensionsScaledToTargetSizing(aspectRatio, dimensions, (scaleToFit ? UIViewContentMode.ScaleAspectFit : UIViewContentMode.ScaleAspectFill));
string selectedVariantName = null;
foreach (var variant in variantSizeMap)
{
var variantSize = new CGSize(variant.Value, variant.Value);
var scaledToVariantDimensions = TIPImageUtils.TIPDimensionsScaledToTargetSizing(aspectRatio, variantSize, UIViewContentMode.ScaleAspectFit);
if (scaledToVariantDimensions.Width >= scaledToTargetDimensions.Width && scaledToVariantDimensions.Height >= scaledToTargetDimensions.Height)
{
selectedVariantName = variant.Key;
break;
}
}
if (string.IsNullOrEmpty(selectedVariantName))
{
selectedVariantName = variantSizeMap.Keys.LastOrDefault();
}
return(selectedVariantName);
}
public bool FetchHelperShouldContinueLoadingAfterFetching(TIPImageViewFetchHelper helper, ITIPImageFetchResult previewImageResult)
{
if (previewImageResult.ImageIsTreatedAsPlaceholder)
{
return(true);
}
var request = helper.FetchRequest;
if (request.GetOptions().HasFlag(TIPImageFetchOptions.TreatAsPlaceholder))
{
// would be a downgrade, stop
return(false);
}
var originalDimensions = previewImageResult.ImageOriginalDimensions;
var viewDimensions = TIPImageUtils.TIPDimensionsFromView(helper.FetchImageView);
if (originalDimensions.Height >= viewDimensions.Height && originalDimensions.Width >= viewDimensions.Width)
{
return(false);
}
return(true);
}
