bluetooth.onAdapterStateChanged.listen throws NoSuchMethodError

[ToddG]

Summary

There are two issues here.

First, I cannot seem to use bluetooth + dart + chrome on my ubuntu desktop. I have a working BT adapter, and I can pair to devices using the blueman manager. I can also access the BT stack from Java via the bluecove libs (bluecove-gpl-2.1.0.jar, bluecove-emu-2.1.0.jar, bluecove-2.1.0.jar).

Second, I cannot seem to catch the exception that is being thrown in dart:core-patch/object_patch.dart:45. The stack trace is being printed by somewhere else in the stack, as neither my catch clause nor my onError clause are entered into.

Is bluetooth + dart + chrome even supported on ubuntu?

Code

library foo.bluetooth;

import 'package:logging/logging.dart';
import 'package:chrome/chrome_app.dart' as chrome;

final Logger log = new Logger("FooBluetooth");

class FooBluetoothService {

  static void init() {
    try{
      if(chrome.bluetooth == null){ throw new StateError("Chrome.bluetooth extensions not present");}
      chrome.bluetooth.onAdapterStateChanged.listen((chrome.AdapterState e) {
        log.info("Bluetooth Adapter: ${e}");
      }, onError: (e){
        log.severe("Bluetooth Adapter Error: ${e}");
      });
    }catch(e){
      log.severe("Bluetooth Adapter Error: ${e}");
    }
  }
}

Error

Exception: Uncaught Error: The null object does not have a method '[]'.

NoSuchMethodError: method not found: '[]'
Receiver: null
Arguments: ["onAdapterStateChanged"]
Stack Trace:
#0      Object.noSuchMethod (dart:core-patch/object_patch.dart:45)
#1      _ensureHandlerAdded (package:chrome/src/common.dart:174:25)
#2      _runGuarded (dart:async/stream_controller.dart:664)
#3      _BroadcastStreamController._subscribe (dart:async/broadcast_stream_controller.dart:199)
#4      _ControllerStream._createSubscription (dart:async/stream_controller.dart:682)
#5      _StreamImpl.listen (dart:async/stream_impl.dart:474)
#6      FooBluetoothService.init (package:myapp/foo_bluetooth.dart:14:52)
#7      FooApp.attached (chrome-extension://dpccenibohdmiogacpmcnnnnndgnokpc/elements/foo_app.dart:126:29)
#8      Blink_Utils.register (dart:_blink:31036)
#9      _Utils._register (dart:html:41634)
#10     _Utils.register (dart:html:41630)
#11     HtmlDocument.registerElement (dart:html:17289)
#12     PolymerDeclaration.registerType (package:polymer/src/declaration.dart:180:29)
#13     PolymerDeclaration.register (package:polymer/src/declaration.dart:123:17)
#14     _hookJsPolymer.registerDart.<anonymous closure> (package:polymer/src/loader.dart:122:75)
#15     _rootRun (dart:async/zone.dart:895)
#16     _CustomZone.run (dart:async/zone.dart:796)
#17     _hookJsPolymer.registerDart (package:polymer/src/loader.dart:121:22)

System

Ubuntu 14.x:
Linux green 3.13.0-46-generic #77-Ubuntu SMP Mon Mar 2 18:23:39 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

Adapter

Bus 005 Device 005: ID 0a5c:2148 Broadcom Corp. BCM92046DG-CL1ROM Bluetooth 2.1 Adapter

Bluez Libs

ii bluez 4.101-0ubuntu13.1 amd64 Bluetooth tools and daemons
ii bluez-alsa:amd64 4.101-0ubuntu13.1 amd64 Bluetooth ALSA support
ii bluez-cups 4.101-0ubuntu13.1 amd64 Bluetooth printer driver for CUPS
ii bluez-gstreamer 4.101-0ubuntu13.1 amd64 Bluetooth GStreamer support

[DanielJoyce]

Also, this code works fine on a mac, and doesn't throw an error. Its somewhere in the interplay of broken bluetooth support and stream impls.

https://code.google.com/p/dart/issues/detail?id=3357

This request has been closed, but at least have some support for sniffing dart platform and OS versions would let us gracefully degrade experience. 3357 should definitely be reopened until such time Google can guarantee everything will always work perfectly on every platform. ;)