protected T CachedComputation <T>(Func <T> computation, string[] dependentOn, [CallerMemberName] string propertyName = null)
{
if (m_cachedComputationProperties == null)
{
m_cachedComputationProperties = new Dictionary <string, CachedComputationProperty>();
}
CachedComputationProperty prop;
if (!m_cachedComputationProperties.TryGetValue(propertyName, out prop))
{
prop = new CachedComputationProperty(this, propertyName, delegate { return(computation()); });
m_cachedComputationProperties[propertyName] = prop;
foreach (var dependentOnProperty in dependentOn)
{
ListenToProperty(dependentOnProperty, prop.NotifyDependentOnValueChanged);
}
}
object val = prop.GetValue();
if (val == null)
{
return(default(T));
}
return((T)val);
}
protected T CachedComputation <T>(Func <T> computation, string[] dependentOn, [CallerMemberName] string propertyName = null)
{
// Have to initialize this here since this method gets called before any class initializers are performed (not sure why exactly, probably because it's used in property values in parent class)
// But there shouldn't be any cross-threading concerns since that's part of the overall initialization anyways too
if (m_cachedComputationPropertiesLock == null)
{
m_cachedComputationPropertiesLock = new object();
}
if (propertyName == null)
{
// This should theoretically never be null, but seems like Android, when running in the widget at least, it ends up being null?
// Adding this check to confirm.
throw new ArgumentNullException(nameof(propertyName));
}
CachedComputationProperty prop;
lock (m_cachedComputationPropertiesLock)
{
if (m_cachedComputationProperties == null)
{
m_cachedComputationProperties = new Dictionary <string, CachedComputationProperty>();
}
if (!m_cachedComputationProperties.TryGetValue(propertyName, out prop))
{
prop = new CachedComputationProperty(this, propertyName, delegate { return(computation()); });
m_cachedComputationProperties[propertyName] = prop;
ListenToProperties(dependentOn, prop.NotifyDependentOnValueChanged);
}
}
object val = prop.GetValue();
if (val == null)
{
return(default(T));
}
return((T)val);
}
