85 lines
2.3 KiB
Go
85 lines
2.3 KiB
Go
package bluetooth
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import (
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"git.tcp.direct/kayos/prototooth/winbt"
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)
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// Address contains a Bluetooth MAC address.
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type Address struct {
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MACAddress
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}
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// Scan starts a BLE scan. It is stopped by a call to StopScan. A common pattern
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// is to cancel the scan when a particular device has been found.
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func (a *Adapter) Scan(callback func(*Adapter, ScanResult)) (err error) {
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if a.watcher != nil {
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// Cannot scan more than once: which one should ScanStop()
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// stop?
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return errScanning
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}
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a.watcher, err = winbt.NewBluetoothLEAdvertisementWatcher()
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if err != nil {
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return
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}
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defer a.watcher.Release()
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// Listen for incoming BLE advertisement packets.
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err = a.watcher.AddReceivedEvent(func(watcher *winbt.IBluetoothLEAdvertisementWatcher, args *winbt.IBluetoothLEAdvertisementReceivedEventArgs) {
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var result ScanResult
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result.RSSI = args.RawSignalStrengthInDBm()
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addr := args.BluetoothAddress()
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adr := result.Address.(Address)
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for i := range adr.MAC {
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adr.MAC[i] = byte(addr)
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addr >>= 8
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}
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// Note: the IsRandom bit is never set.
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advertisement := args.Advertisement()
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result.AdvertisementPayload = &advertisementFields{
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AdvertisementFields{
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LocalName: advertisement.LocalName(),
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},
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}
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callback(a, result)
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})
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if err != nil {
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return
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}
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// Wait for when advertisement has stopped by a call to StopScan().
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// Advertisement doesn't seem to stop right away, there is an
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// intermediate Stopping state.
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stoppingChan := make(chan struct{})
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err = a.watcher.AddStoppedEvent(func(watcher *winbt.IBluetoothLEAdvertisementWatcher, args *winbt.IBluetoothLEAdvertisementWatcherStoppedEventArgs) {
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// Note: the args parameter has an Error property that should
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// probably be checked, but I'm not sure when stopping the
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// advertisement watcher could ever result in an error (except
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// for bugs).
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close(stoppingChan)
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})
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if err != nil {
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return
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}
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err = a.watcher.Start()
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if err != nil {
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return err
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}
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// Wait until advertisement has stopped, and finish.
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<-stoppingChan
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a.watcher = nil
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return nil
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}
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// StopScan stops any in-progress scan. It can be called from within a Scan
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// callback to stop the current scan. If no scan is in progress, an error will
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// be returned.
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func (a *Adapter) StopScan() error {
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if a.watcher == nil {
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return errNotScanning
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}
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return a.watcher.Stop()
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}
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