overlay.py 文件源码

def cairo_context_from_gi(gicr):
    #assert isinstance(gicr, GObject.GBoxed)
    offset = sys.getsizeof(object())  # size of PyObject_HEAD
    # Pull the "boxed" pointer off out and use it as a cairo_t*
    cr_ptr = ctypes.c_void_p.from_address(id(gicr) + offset)
    cr = pycairo_dll.PycairoContext_FromContext(cr_ptr, cairo.Context, None)
    # Add a new ref because the pycairo context will attempt to manage this
    cairo_dll.cairo_reference(cr_ptr)
    return cr