macOS CALayer approach in jre7

Hi all,

I have a java application which opens upa window calls functions in a native library to draw using OpenGL.
I have done this by getting the NSView of the window using:

JAWT_MacOSXDrawingSurfaceInfo* ads_macsfinfo = (JAWT_MacOSXDrawingSurfaceInfo*)ads_sfinfo->platformInfo;
//gets the object responsible for drawing associated with the view obtained from the Java AWT surface
parent_view = (ads_macsfinfo->cocoaViewRef);

Then a customized NSview is added as subview to this view using:
[parent_view addSubview: customview]
Drawing is done offscreen in an FBO and then drawing is displayed by copying the texture to onscreen in drawrect. (drawrect being forced using setNeedsDisplay]
This all was functioning perfectly until JRE 7, the NSView approach is no longer possible and instead the CALayer must be used.

I am thus trying to create the same customised NSView as before (now withouthout having parent view and window) and setting this as layer backed using:
[customview setWantsLayer:YES]
The layer which has now been added to the nsview (view.layer), is then set as the layer property of JAWT_SurfaceLayers using

id<JAWT_SurfaceLayers> surfaceLayers = (id <JAWT_SurfaceLayers>)macosx_dsi->platformInfo;
if(surfaceLayers.layer == NULL) {
surfaceLayers.layer = viewlayer;
}

However the function drawrect is only called once eventhough I am calling [customview setNeedsDisplay:YES]
as well as no events are being received on the nsview.

Is this the proper way of setting the connection between the layer and view?

Thanks for any help