void initClasses () {
String className = "SWTTextAttachmentCell";
if (OS.objc_lookUpClass(className) != 0) return;
textLayoutCallback2 = new Callback(getClass(), "textLayoutProc", 2);
long proc2 = textLayoutCallback2.getAddress();
if (proc2 == 0) SWT.error(SWT.ERROR_NO_MORE_CALLBACKS);
long cellBaselineOffsetProc = OS.CALLBACK_cellBaselineOffset(proc2);
long cellSizeProc = OS.CALLBACK_NSTextAttachmentCell_cellSize(proc2);
byte[] types = {'*','\0'};
int size = C.PTR_SIZEOF, align = C.PTR_SIZEOF == 4 ? 2 : 3;
long cls = OS.objc_allocateClassPair(OS.class_NSCell, className, 0);
OS.class_addIvar(cls, SWT_OBJECT, size, (byte)align, types);
OS.class_addProtocol(cls, OS.protocol_NSTextAttachmentCell);
OS.class_addMethod(cls, OS.sel_cellSize, cellSizeProc, "@:");
OS.class_addMethod(cls, OS.sel_cellBaselineOffset, cellBaselineOffsetProc, "@:");
OS.objc_registerClassPair(cls);
}