Consider adding a "desktop site" check to the prerequisites section of the web installer

[ethereal26]

I would like to report an issue I've experienced when using the web installer.

I have a Pixel Tablet with GOS already installed on it and tried to use it to install GOS on my new Pixel phone. Unfortunately, the flashing process worked fine at the beginning but after the first reboot of the device to be flashed it got stuck and didn't progress any further.

On the Discord server, I've been kindly advised to check if Vanadium was using the "Desktop site" mode for loading the web installer page. I tried to disable it and then the page showed a new "Reconnect device" button every time the device to be flashed needed to be reconnected.

As far as I know, on Pixel phones the default setting for Vanadium is not to load pages in "Desktop site", so what I've described above doesn't seem like a great issue. However, on the Pixel Tablet the default is to use "Desktop site" to load pages. This could be an issue for every user that wants to install GOS from a Pixel Tablet (and possibly other Android tablets that by default load web pages in "desktop site" mode).

I think it would be a good idea documenting this in the prerequisites section of the web installer. Something like "when running the web installer from an Android device, check you are not loading it in desktop site mode".

[thestinger]

It should still work in the desktop site mode. I'm not sure why it wouldn't work in that mode.

[ethereal26]

Yesterday, when I got a fast answer on the Discord server, I assumed this was a known bug/feature of the web installer. Today, reading you saying it should work fine, I've retried the flashing process, to be sure I hadn't missed anything yesterday.

I've found the same behavior. The "Reconnect device" button is not displayed when using desktop mode. I'm attaching two screenshots to better show it. In one of them desktop site mode is enabled and in the other disabled.

After viewing the code from the fastboot.ts source map included in this repo, I see:

        if (navigator.userAgent.includes("Android")) {
            await this.waitForDisconnect();
            onReconnect();
        }

I have a feeling this is the problem. The desktop mode makes Chrome appear to be Linux and thus "Android" doesn't get matched, so it thinks its a desktop.

I'm not aware of a more robust way to check if desktop mode is in use, but an instruction to turn it off could probably work.

A prerequisite has been added to the install page:

On Android, disable desktop mode for the browser since it currently prevents our web installer from detecting Android and handling needing to request permission to reconnect to the device after each reboot. Desktop mode is enabled by default on large tablets with at least 8GB of RAM such as the Pixel Tablet.

This is currently more of a band-aid solution that I proposed, but it does still help.

[thestinger]

I think the check in fastboot.js used to work but they broke it with Chromium for Android changes to more closely match the desktop browser to avoid getting mobile content at all. It's possible we can still use client hints but those may also be adjusted to act like the desktop browser. The point is that they're trying to closely act as a desktop browser to avoid getting mobile specific content but that is what we need to detect because there's the need for the user to authorize reconnecting on Android. We could potentially make a timer where it always shows the reconnect button after a certain amount of time but it would be awkward, since it would sometimes show when it shouldn't and on Android would need to be delayed past when it should be there. It would make it more confusing for desktop browser usage.