Connection flow tweaks to deal with unusual cases (#220)

- Wait for gatt.connect promise in order to show micro:bit connecting dialog
- Wait for the micro:bit to be in a good state after disconnecting before reconnecting (Bluetooth connection on Windows only)
- Add code to show a reasonable connection help dialog on an initial connect failure as opposed to a reconnect failure
- Improve error types and use these to show the right connect help dialog
- Add a timeout around bluetooth.requestDevice - this addresses a bug where the browser device selection prompt is not shown. We instead reload the page and show our connection dialog at the appropriate part of the flow.

src/App.svelte

@@ -27,11 +27,22 @@
   import ConnectDialogContainer from './components/connection-prompt/ConnectDialogContainer.svelte';
   import { Paths, currentPath, getTitle, navigate } from './router/paths';
   import HomeIcon from 'virtual:icons/ri/home-2-line';
+  import { btSelectMicrobitDialogOnLoad } from './script/stores/connectionStore';
+  import {
+    ConnectDialogStates,
+    connectionDialogState,
+  } from './script/stores/connectDialogStore';
 
   onMount(() => {
     const { bluetooth, usb } = get(compatibility);
     // Value must switch from false to true after mount to trigger dialog transition
     isCompatibilityWarningDialogOpen.set(!bluetooth && !usb);
+
+    if ($btSelectMicrobitDialogOnLoad) {
+      $connectionDialogState.connectionState =
+        ConnectDialogStates.CONNECT_TUTORIAL_BLUETOOTH;
+      $btSelectMicrobitDialogOnLoad = false;
+    }
   });
 
   let routeAnnouncementEl: HTMLDivElement | undefined;

src/StaticConfiguration.ts

@@ -18,6 +18,7 @@ export enum HexOrigin {
 
 class StaticConfiguration {
   public static readonly connectTimeoutDuration: number = 10000;
+  public static readonly requestDeviceTimeoutDuration: number = 30000;
 
   // After how long should we consider the connection lost if ping was not able to conclude?
   public static readonly connectionLostTimeoutDuration: number = 3000;

src/components/PleaseConnectFirst.svelte

@@ -14,7 +14,7 @@
   import StandardButton from './StandardButton.svelte';
 
   const handleInputConnect = async () => {
-    if ($state.showReconnectHelp || Microbits.getInputMicrobit()) {
+    if ($state.showConnectHelp || Microbits.getInputMicrobit()) {
       reconnect();
     } else {
       startConnectionProcess();
@@ -35,7 +35,7 @@
     disabled={$state.reconnectState.reconnecting}
     onClick={handleInputConnect}
     >{$t(
-      $state.showReconnectHelp || Microbits.getInputMicrobit()
+      $state.showConnectHelp || Microbits.getInputMicrobit()
         ? 'actions.reconnect'
         : 'footer.connectButton',
     )}</StandardButton>

src/components/ReconnectHelp.svelte

@@ -11,7 +11,8 @@
   import { state } from '../script/stores/uiStore';
   import { reconnect } from '../script/utils/reconnect';
   import StandardDialog from './dialogs/StandardDialog.svelte';
-  import { stateOnHideReconnectHelp } from '../script/microbit-interfacing/state-updaters';
+  import { stateOnHideConnectHelp } from '../script/microbit-interfacing/state-updaters';
+  import { startConnectionProcess } from '../script/stores/connectDialogStore';
 
   export let isOpen: boolean = false;
 
@@ -20,13 +21,17 @@
       case 'bluetooth': {
         return {
           heading:
-            $state.showReconnectHelp === 'userTriggered'
-              ? 'reconnectFailed.bluetoothHeading'
-              : 'disconnectedWarning.bluetoothHeading',
+            $state.showConnectHelp === 'connect'
+              ? 'connectFailed.bluetoothHeading'
+              : $state.showConnectHelp === 'userReconnect'
+                ? 'reconnectFailed.bluetoothHeading'
+                : 'disconnectedWarning.bluetoothHeading',
           subtitle:
-            $state.showReconnectHelp === 'userTriggered'
-              ? 'reconnectFailed.bluetooth1'
-              : 'disconnectedWarning.bluetooth1',
+            $state.showConnectHelp === 'connect'
+              ? 'connectFailed.bluetooth1'
+              : $state.showConnectHelp === 'userReconnect'
+                ? 'reconnectFailed.bluetooth1'
+                : 'disconnectedWarning.bluetooth1',
           listHeading: 'disconnectedWarning.bluetooth2',
           bulletOne: 'disconnectedWarning.bluetooth3',
           bulletTwo: 'disconnectedWarning.bluetooth4',
@@ -35,13 +40,17 @@
       case 'bridge': {
         return {
           heading:
-            $state.showReconnectHelp === 'userTriggered'
-              ? 'reconnectFailed.bridgeHeading'
-              : 'disconnectedWarning.bridgeHeading',
+            $state.showConnectHelp === 'connect'
+              ? 'connectFailed.bridgeHeading'
+              : $state.showConnectHelp === 'userReconnect'
+                ? 'reconnectFailed.bridgeHeading'
+                : 'disconnectedWarning.bridgeHeading',
           subtitle:
-            $state.showReconnectHelp === 'userTriggered'
-              ? 'reconnectFailed.bridge1'
-              : 'disconnectedWarning.bridge1',
+            $state.showConnectHelp === 'connect'
+              ? 'connectFailed.bridge1'
+              : $state.showConnectHelp === 'userReconnect'
+                ? 'reconnectFailed.bridge1'
+                : 'disconnectedWarning.bridge1',
           listHeading: 'connectMB.usbTryAgain.replugMicrobit2',
           bulletOne: 'connectMB.usbTryAgain.replugMicrobit3',
           bulletTwo: 'connectMB.usbTryAgain.replugMicrobit4',
@@ -50,13 +59,17 @@
       case 'remote': {
         return {
           heading:
-            $state.showReconnectHelp === 'userTriggered'
-              ? 'reconnectFailed.remoteHeading'
-              : 'disconnectedWarning.remoteHeading',
+            $state.showConnectHelp === 'connect'
+              ? 'connectFailed.remoteHeading'
+              : $state.showConnectHelp === 'userReconnect'
+                ? 'reconnectFailed.remoteHeading'
+                : 'disconnectedWarning.remoteHeading',
           subtitle:
-            $state.showReconnectHelp === 'userTriggered'
-              ? 'reconnectFailed.remote1'
-              : 'disconnectedWarning.remote1',
+            $state.showConnectHelp === 'connect'
+              ? 'connectFailed.remote1'
+              : $state.showConnectHelp === 'userReconnect'
+                ? 'reconnectFailed.remote1'
+                : 'disconnectedWarning.remote1',
           listHeading: 'disconnectedWarning.bluetooth2',
           bulletOne: 'disconnectedWarning.bluetooth3',
           bulletTwo: 'disconnectedWarning.bluetooth4',
@@ -73,10 +86,19 @@
       }
     }
   })();
+
+  const handleReconnect = () => {
+    if ($state.showConnectHelp === 'connect') {
+      stateOnHideConnectHelp();
+      startConnectionProcess();
+    } else {
+      reconnect(true);
+    }
+  };
 </script>
 
 {#if $state.reconnectState.connectionType !== 'none'}
-  <StandardDialog {isOpen} onClose={stateOnHideReconnectHelp} class="w-150 space-y-5">
+  <StandardDialog {isOpen} onClose={stateOnHideConnectHelp} class="w-150 space-y-5">
     <svelte:fragment slot="heading">
       {$t(content.heading)}
     </svelte:fragment>
@@ -100,10 +122,14 @@
           {$t('connectMB.troubleshooting')}
           <ExternalLinkIcon />
         </a>
-        <StandardButton onClick={stateOnHideReconnectHelp}
+        <StandardButton onClick={stateOnHideConnectHelp}
           >{$t('actions.cancel')}</StandardButton>
-        <StandardButton type="primary" onClick={() => reconnect(true)}
-          >{$t('actions.reconnect')}</StandardButton>
+        <StandardButton type="primary" onClick={handleReconnect}
+          >{$t(
+            $state.showConnectHelp === 'connect'
+              ? 'footer.connectButton'
+              : 'actions.reconnect',
+          )}</StandardButton>
       </div>
     </svelte:fragment>
   </StandardDialog>

src/components/bottom/ConnectedLiveGraphButtons.svelte

@@ -23,7 +23,7 @@
   };
 
   const handleInputConnect = async () => {
-    if ($state.showReconnectHelp || Microbits.getInputMicrobit()) {
+    if ($state.showConnectHelp || Microbits.getInputMicrobit()) {
       reconnect();
     } else {
       startConnectionProcess();
@@ -55,7 +55,7 @@
     disabled={$state.reconnectState.reconnecting}
     size="small"
     >{$t(
-      $state.showReconnectHelp || Microbits.getInputMicrobit()
+      $state.showConnectHelp || Microbits.getInputMicrobit()
         ? 'actions.reconnect'
         : 'footer.connectButton',
     )}</StandardButton>

src/components/dialogs/StandardDialog.svelte

@@ -33,8 +33,9 @@
     }
   };
 
-  const onOpenChange: CreateDialogProps['onOpenChange'] = ({ next }) => {
-    if (!next) {
+  const onOpenChange: CreateDialogProps['onOpenChange'] = ({ curr, next }) => {
+    // Use curr so we don't call onCloseDialog() on page load.
+    if (curr && !next) {
       onCloseDialog();
     } else {
       onOpenDialog();
@@ -73,9 +74,13 @@
   const sync = createSync(states);
   $: sync.open(isOpen, v => (isOpen = v));
 
+  let prevOpen: boolean;
   $: if (isOpen) {
     onOpenDialog();
-  } else {
+    prevOpen = isOpen;
+  } else if (prevOpen && !isOpen) {
+    // Use prevOpen so we don't call onCloseDialog() on page load.
+    prevOpen = isOpen;
     onCloseDialog();
   }
 

src/messages/ui.en.json

@@ -208,11 +208,17 @@
   "connectMB.reconnecting": "Reconnecting…",
   "connectMB.bluetooth.invalidPattern": "The pattern you have drawn is invalid.",
 
+  "connectFailed.bluetoothHeading": "Failed to connect to micro:bit",
+  "connectFailed.bluetooth1": "The connection to the micro:bit could not be established.",
   "reconnectFailed.radioHeading": "Failed to reconnect to micro:bits",
   "reconnectFailed.bluetoothHeading": "Failed to reconnect to micro:bit",
   "reconnectFailed.bluetooth1": "The connection to the micro:bit could not be re-established.",
+  "connectFailed.remoteHeading": "Failed to connect to micro:bit 1",
+  "connectFailed.remote1": "The connection to the micro:bit you are wearing could not be established.",
   "reconnectFailed.remoteHeading": "Failed to reconnect to micro:bit 1",
   "reconnectFailed.remote1": "The connection to the micro:bit you are wearing could not be re-established.",
+  "connectFailed.bridgeHeading": "Failed to connect to micro:bit 2",
+  "connectFailed.bridge1": "The connection to the micro:bit connected to your computer could not be established.",
   "reconnectFailed.bridgeHeading": "Failed to reconnect to micro:bit 2",
   "reconnectFailed.bridge1": "The connection to the micro:bit connected to your computer could not be re-established.",
   "reconnectFailed.subtitle": "Follow these instructions to restart the connection process.",

src/script/microbit-interfacing/MicrobitBluetooth.ts

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: MIT
  */
 
+import Bowser from 'bowser';
 import StaticConfiguration from '../../StaticConfiguration';
 import { outputting } from '../stores/uiStore';
 import { logError, logMessage } from '../utils/logging';
@@ -22,6 +23,10 @@ import {
   stateOnReady,
   stateOnReconnectionAttempt,
 } from './state-updaters';
+import { btSelectMicrobitDialogOnLoad } from '../stores/connectionStore';
+
+const browser = Bowser.getParser(window.navigator.userAgent);
+const isWindowsOS = browser.getOSName() === 'Windows';
 
 /**
  * UART data target. For fixing type compatibility issues.
@@ -57,6 +62,8 @@ export class MicrobitBluetooth implements MicrobitConnection {
   private gattConnectPromise: Promise<MBSpecs.MBVersion | undefined> | undefined;
   private disconnectPromise: Promise<unknown> | undefined;
   private connecting = false;
+  private isReconnect = false;
+  private reconnectReadyPromise: Promise<void> | undefined;
 
   private outputWriteQueue: {
     busy: boolean;
@@ -77,6 +84,10 @@ export class MicrobitBluetooth implements MicrobitConnection {
     logMessage('Bluetooth connect', states);
     if (this.duringExplicitConnectDisconnect) {
       logMessage('Skipping connect attempt when one is already in progress');
+      // Wait for the gattConnectPromise while showing a "connecting" dialog.
+      // If the user clicks disconnect while the automatic reconnect is in progress,
+      // then clicks reconnect, we need to wait rather than return immediately.
+      await this.gattConnectPromise;
       return;
     }
     this.duringExplicitConnectDisconnect++;
@@ -188,16 +199,29 @@ export class MicrobitBluetooth implements MicrobitConnection {
     } finally {
       this.duringExplicitConnectDisconnect--;
     }
+    this.reconnectReadyPromise = new Promise(resolve => setTimeout(resolve, 3_500));
     if (updateState) {
       this.inUseAs.forEach(value =>
-        stateOnDisconnected(value, userTriggered, 'bluetooth'),
+        stateOnDisconnected(
+          value,
+          userTriggered ? false : this.isReconnect ? 'autoReconnect' : 'connect',
+          'bluetooth',
+        ),
       );
     }
   }
 
   async reconnect(): Promise<void> {
     logMessage('Bluetooth reconnect');
+    this.isReconnect = true;
     const as = Array.from(this.inUseAs);
+    if (isWindowsOS) {
+      // On Windows, the micro:bit can take around 3 seconds to respond to gatt.disconnect().
+      // Attempting to reconnect before the micro:bit has responded results in another
+      // gattserverdisconnected event being fired. We then fail to get primaryService on a
+      // disconnected GATT server.
+      await this.reconnectReadyPromise;
+    }
     await this.connect(...as);
   }
 
@@ -214,7 +238,7 @@ export class MicrobitBluetooth implements MicrobitConnection {
       }
     } catch (e) {
       logError('Bluetooth connect triggered by disconnect listener failed', e);
-      this.inUseAs.forEach(s => stateOnDisconnected(s, false, 'bluetooth'));
+      this.inUseAs.forEach(s => stateOnDisconnected(s, 'autoReconnect', 'bluetooth'));
     }
   };
 
@@ -486,17 +510,32 @@ export const startBluetoothConnection = async (
 
 const requestDevice = async (name: string): Promise<BluetoothDevice | undefined> => {
   try {
-    return navigator.bluetooth.requestDevice({
-      filters: [{ namePrefix: `BBC micro:bit [${name}]` }],
-      optionalServices: [
-        MBSpecs.Services.UART_SERVICE,
-        MBSpecs.Services.ACCEL_SERVICE,
-        MBSpecs.Services.DEVICE_INFO_SERVICE,
-        MBSpecs.Services.LED_SERVICE,
-        MBSpecs.Services.IO_SERVICE,
-        MBSpecs.Services.BUTTON_SERVICE,
-      ],
-    });
+    // In some situations the Chrome device prompt simply doesn't appear so we time this out after 30 seconds and reload the page
+    const result = await Promise.race([
+      navigator.bluetooth.requestDevice({
+        filters: [{ namePrefix: `BBC micro:bit [${name}]` }],
+        optionalServices: [
+          MBSpecs.Services.UART_SERVICE,
+          MBSpecs.Services.ACCEL_SERVICE,
+          MBSpecs.Services.DEVICE_INFO_SERVICE,
+          MBSpecs.Services.LED_SERVICE,
+          MBSpecs.Services.IO_SERVICE,
+          MBSpecs.Services.BUTTON_SERVICE,
+        ],
+      }),
+      new Promise<'timeout'>(resolve =>
+        setTimeout(
+          () => resolve('timeout'),
+          StaticConfiguration.requestDeviceTimeoutDuration,
+        ),
+      ),
+    ]);
+    if (result === 'timeout') {
+      btSelectMicrobitDialogOnLoad.set(true);
+      window.location.reload();
+      return undefined;
+    }
+    return result;
   } catch (e) {
     logError('Bluetooth request device failed/cancelled', e);
     return undefined;