private UIImage ApplyCustomTransformations(List <ITransformation <UIImage> > transformations, UIImage result)
{
if (result == null)
{
throw new ArgumentNullException("result");
}
for (int i = 0; i < transformations.Count; i++)
{
ITransformation <UIImage> transformation = transformations[i];
UIImage newResult = transformation.Transform(result);
if (newResult == null)
{
StringBuilder builder = new StringBuilder()
.Append("Transformation ")
.Append(transformation.Key)
.Append(" returned null after ")
.Append(i)
.Append(" previous transformation(message).\n\nTransformation list:\n");
foreach (ITransformation <UIImage> t in transformations)
{
builder.Append(t.Key).Append('\n');
}
// TODO Need a better way to invoke on main thread
new NSObject().InvokeOnMainThread(() =>
{
throw new NullReferenceException(builder.ToString());
});
return(null);
}
// TODO Check if result is disposed
if (newResult == result)
{
m_Picasso.RunOnPicassoThread(() =>
{
throw new InvalidOperationException("Transformation " +
transformation.Key + " return input Bitmap but recycled it.");
});
return(null);
}
// If the transformation returned a new bitmap ensure they recycled the original.
// TODO Check if result is NOT disposed
if (newResult != result)
{
m_Picasso.RunOnPicassoThread(() =>
{
throw new InvalidOperationException("Transformation "
+ transformation.Key
+ " mutated input Bitmap but failed to recycle the original.");
});
return(null);
}
result = newResult;
}
return(result);
}
