func newCCCD(c *ble.Characteristic) *ble.Descriptor {
d := ble.NewDescriptor(ble.ClientCharacteristicConfigUUID)
d.HandleRead(ble.ReadHandlerFunc(func(req ble.Request, rsp ble.ResponseWriter) {
cccs := req.Conn().(*conn).cccs
ccc := cccs[c.Handle]
binary.Write(rsp, binary.LittleEndian, ccc)
}))
d.HandleWrite(ble.WriteHandlerFunc(func(req ble.Request, rsp ble.ResponseWriter) {
cn := req.Conn().(*conn)
old := cn.cccs[c.Handle]
ccc := binary.LittleEndian.Uint16(req.Data())
oldNotify := old&cccNotify != 0
oldIndicate := old&cccIndicate != 0
newNotify := ccc&cccNotify != 0
newIndicate := ccc&cccIndicate != 0
if newNotify && !oldNotify {
if c.Property&ble.CharNotify == 0 {
rsp.SetStatus(ble.ErrUnlikely)
return
}
send := func(b []byte) (int, error) { return cn.svr.notify(c.ValueHandle, b) }
cn.nn[c.Handle] = ble.NewNotifier(send)
go c.NotifyHandler.ServeNotify(req, cn.nn[c.Handle])
}
if !newNotify && oldNotify {
cn.nn[c.Handle].Close()
}
if newIndicate && !oldIndicate {
if c.Property&ble.CharIndicate == 0 {
rsp.SetStatus(ble.ErrUnlikely)
return
}
send := func(b []byte) (int, error) { return cn.svr.indicate(c.ValueHandle, b) }
cn.in[c.Handle] = ble.NewNotifier(send)
go c.IndicateHandler.ServeNotify(req, cn.in[c.Handle])
}
if !newIndicate && oldIndicate {
cn.in[c.Handle].Close()
}
cn.cccs[c.Handle] = ccc
}))
return d
}
// server (peripheral)
func (c *conn) subscribed(char *ble.Characteristic) {
h := char.Handle
if _, found := c.notifiers[h]; found {
return
}
send := func(b []byte) (int, error) {
c.dev.sendCmd(c.dev.pm, 15, xpc.Dict{
"kCBMsgArgUUIDs": [][]byte{},
"kCBMsgArgAttributeID": h,
"kCBMsgArgData": b,
})
return len(b), nil
}
n := ble.NewNotifier(send)
c.notifiers[h] = n
req := ble.NewRequest(c, nil, 0) // convey *conn to user handler.
go char.NotifyHandler.ServeNotify(req, n)
}