App interfaces don't work inside Gadgetbridge

[thyttan]

...I have not tested them all, but this is generally my experience.

Example with Schedulers interface:

1. Open app loader inside Bangle.js Gadgetbridge.
2. Navigate to Scheduler app entry (make sure it's installed on the watch).
3. Click the floppy disk icon of Scheduler app entry to try and access its interface.
4. The interface starts loading and the UI is visible behind a dialog saying "Please wait Loading...".
5. The dialog doesn't go away.
6. Clicking the interface's x-button takes me back to the app loader window.

Logcat that starts on step 3 above is attached:
logcat-clicking-scheduler-floppy-disk-icon-in-app-loader-in-gadgetbridge.txt

I don't know what the approach should be. Maybe it's hard to implement e.g. Recorders interface inside Gadgetbridge. One could imagine the downloaded file being stored in Gadgetbridge's Export/Import directory - but I don't know how hard that would be to implement. But the Scheduler one shouldn't be too hard to get working I'd think - but I know hardly anything about webviews so maybe shouldn't say too much.

[gfwilliams]

Just to be clear, this is the interface.html - not custom.html - those pretty much all work fine I think.

I encountered this before with openstmap and didn't have a chance to look into it fully, but as far as I could see it's some issue with how char code 255 (0xff) is received and pushed to JavaScript. Without it the functions in Comms that end up receiving files/data/etc don't know that the transmission has ended.

[thyttan]

Thanks for clarifying! (Yes - I was under the impression those were the same thing 🙃)

[gfwilliams]

You can debug by connecting your phone with adb, then going to chrome://inspect/#devices in Chrome once the app loader is loaded in Gadgetbridge.

Paste this into the console:

var oldBangleRx = bangleRx; bangleRx = function(d) { console.log("RX",JSON.stringify(d)); oldBangleRx(d); }
Android.bangleTx("\x10Bluetooth.println('Hello')\n")

Then you get "Hello\r\n" - great.

But:

Android.bangleTx("\x10Bluetooth.println('\\xff')\n")

Gives "�\r\n" and "�\r\n".charCodeAt() == 65533

The code is getting there ok though because:

Android.bangleTx("\x10Bluetooth.println('\\xff'.charCodeAt())\n")

gives "255\r\n" - so it's a Gadgetbridge issue about how char code 255 ends up translated to a JS a string. It's probably UTF8 related again :(

I think it's https://codeberg.org/Freeyourgadget/Gadgetbridge/src/branch/master/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/banglejs/AppsManagementActivity.java#L153-L156

The idea was we use the JSON library to create a JS string, but I wonder what Android thinks is in that String - whether it's char code 255 or 65533

[thyttan]

I've had trouble using adb directly. But I can use wireless debugging with Android Studio to build and install to my phone. I'll try and read up on it again.

[gfwilliams]

Ok, just fixed with https://codeberg.org/Freeyourgadget/Gadgetbridge/commit/e18a991b138d9097f053457ef156e48d78130608

[gfwilliams]

I just added some code that should help with downloads too - although for it to work for must stuff I'll need to update the app loader (turns out we can't download Blob, so we have to download with base64 links instead)