feat(gap): add Device.Connected()

It is currently not possible to know wether we are connected or not.

This allow the user to know if the device is connected.

Author: acouvreur

gap_darwin.go

@@ -176,6 +176,11 @@ func (d Device) Disconnect() error {
 	return nil
 }
 
+// Connected returns whether the device is currently connected.
+func (d Device) Connected() (bool, error) {
+	return d.prph.State() == cbgo.PeripheralStateConnected, nil
+}
+
 // RequestConnectionParams requests a different connection latency and timeout
 // of the given device connection. Fields that are unset will be left alone.
 // Whether or not the device will actually honor this, depends on the device and

gap_linux.go

@@ -538,6 +538,15 @@ func (d Device) Disconnect() error {
 	return d.device.Call("org.bluez.Device1.Disconnect", 0).Err
 }
 
+// Connected returns whether the device is currently connected.
+func (d Device) Connected() (bool, error) {
+	val, err := d.device.GetProperty("org.bluez.Device1.Connected")
+	if err != nil {
+		return false, err
+	}
+	return val.Value().(bool), nil
+}
+
 // RequestConnectionParams requests a different connection latency and timeout
 // of the given device connection. Fields that are unset will be left alone.
 // Whether or not the device will actually honor this, depends on the device and

gap_windows.go

@@ -428,6 +428,18 @@ func (d Device) Disconnect() error {
 	return nil
 }
 
+// Connected returns whether the device is currently connected.
+func (d Device) Connected() (bool, error) {
+	if d.device == nil {
+		return false, nil
+	}
+	status, err := d.device.GetConnectionStatus()
+	if err != nil {
+		return false, err
+	}
+	return status == bluetooth.BluetoothConnectionStatusConnected, nil
+}
+
 // RequestConnectionParams requests a different connection latency and timeout
 // of the given device connection. Fields that are unset will be left alone.
 // Whether or not the device will actually honor this, depends on the device and