Disconnect devices button doesn't disconnect

[beaufortfrancois]

Calling mGattServer.cancelConnection(device); doesn't disconnect device as I've observed in btmon and adb logs when tapping "Disconnect devices" button.
Moreover, onConnectionStateChange is not called which means "Devices connected" text is not updated.

@g-ortuno

[g-ortuno]

Do you have some reproduction steps? What device did you connect with?

[beaufortfrancois]

I'll be more detailed tomorrow.
My device is a Nexus 5X.

[beaufortfrancois]

1. [chromebook] Go to https://googlechrome.github.io/samples/web-bluetooth/battery-level.html
2. [Nexus 5X] Open BLE Peripheral Simulator
3. [Nexus 5X] Select "Battery"
4. [chromebook] Click on "Get Bluetooth Device's Battery Level" button, pick device
5. [chromebook] Battery level is read. It works!
6. [Nexus 5X] Click on "Disconnect"
7. [Nexus 5X] Device is disconnected. It works!
8. [Nexus 5X] Move to background BLE Peripheral Simulator
9. [Nexus 5X] Restore BLE Peripheral Simulator
10. [chromebook] Click on "Get Bluetooth Device's Battery Level" button, pick device
11. [chromebook] Battery level is read. It works!
12. [Nexus 5X] Click on "Disconnect"
13. [Nexus 5X] "Devices connected" count is not decreased. 😭

[beaufortfrancois]

I'm still able to reproduce this sadly and I wish https://googlechrome.github.io/samples/web-bluetooth/device-disconnect.html would work with this app.

Code below isn't actually working as getConnectedDevices don't retrieve my connected BLE peripherals. I'm thinking about monitor connected & disconnected devices so that we can cancel connection manually instead.

  private void disconnectFromDevices() {
    Log.d(TAG, "Disconnecting devices...");
    for (BluetoothDevice device : mBluetoothManager.getConnectedDevices(
        BluetoothGattServer.GATT)) {
      Log.d(TAG, "Devices: " + device.getAddress() + " " + device.getName());
      mGattServer.cancelConnection(device);
    }
  }

• When we open a GATT server we should get an onConnectionStateChanged event in the BluetoothGattServerCallback for each BLE device that is connected to the phone.
• When we're done with the device we'll have to call gattServer.cancelConnection(device) to let the system know that it now may be disconnected.

WDYT @g-ortuno?

[g-ortuno]

That's what we use to do but getConnectedDevices seemed like a better approach. We could work around the android bug but we should also report it.

[beaufortfrancois]

It looks like getConnectedDevices has always been used. See ceadf8d#diff-9dee403cd7eefd5dbe7d5d5fe63816e2.
I'll definitely report this bug.

[beaufortfrancois]

Looking at it more closely, I think that cancelConnection doesn't actually disconnect device. Calling getConnectedDevices() after that still returns the "cancelled connected devices".
This is why updateConnectedDevicesStatus should be updated as well.

[sonalchopra-vvdn]

cancelConnection doesn't really disconnect the device and it saved the connection state if we again go for ble connection. No Callback is received to central on calling above method.

[KrechkoMichael]

I faced with the same problem, cancelConnection() doesn't work. I have the issue when I want to connect with only one Central device, but if there are more devices ready to connect, Android generates few "onConnectionStateChanged" events before Advertising is really stopped. After that it's impossible to disconnect unwanted devices using cancelConnection()