Note that your approach is almost always the wrong way to do things (better to pass the context into the object itself that is using the drawable than keeping a static Context
somewhere).
Given that, if you want to do dynamic drawable loading, you can use getIdentifier:
Resources resources = context.getResources();
final int resourceId = resources.getIdentifier(name, "drawable",
context.getPackageName());
return resources.getDrawable(resourceId);