internal CTRunDelegateCallbacks GetCallbacks()
{
var callbacks = new CTRunDelegateCallbacks()
{
version = CTRunDelegateVersion.Version1,
dealloc = Deallocate,
};
var flags = BindingFlags.Public | BindingFlags.Instance;
MethodInfo m;
if ((m = this.GetType().GetMethod("GetAscent", flags)) != null &&
m.DeclaringType != typeof(CTRunDelegateOperations))
{
callbacks.getAscent = GetAscent;
}
if ((m = this.GetType().GetMethod("GetDescent", flags)) != null &&
m.DeclaringType != typeof(CTRunDelegateOperations))
{
callbacks.getDescent = GetDescent;
}
if ((m = this.GetType().GetMethod("GetWidth", flags)) != null &&
m.DeclaringType != typeof(CTRunDelegateOperations))
{
callbacks.getWidth = GetWidth;
}
return(callbacks);
}
static IntPtr Create(CTRunDelegateOperations operations)
{
if (operations == null)
{
throw new ArgumentNullException(nameof(operations));
}
CTRunDelegateCallbacks callbacks = operations.GetCallbacks();
return(CTRunDelegateCreate(ref callbacks, operations.Handle));
}
internal CTRunDelegateCallbacks GetCallbacks()
{
var callbacks = new CTRunDelegateCallbacks()
{
version = 1, // kCTRunDelegateVersion1
dealloc = Deallocate,
getAscent = GetAscent,
getDescent = GetDescent,
getWidth = GetWidth,
};
return(callbacks);
}
CTRunDelegateCallbacks callbacks; // prevent GC since they are called from native code
public CTRunDelegate(CTRunDelegateOperations operations)
{
if (operations == null)
{
throw ConstructorError.ArgumentNull(this, "operations");
}
callbacks = operations.GetCallbacks();
handle = CTRunDelegateCreate(callbacks, GCHandle.ToIntPtr(operations.handle));
if (handle == IntPtr.Zero)
{
throw ConstructorError.Unknown(this);
}
}
static extern IntPtr CTRunDelegateCreate(ref CTRunDelegateCallbacks callbacks, IntPtr refCon);