Replace WebView login with Chrome Custom Tabs

[bhatganeshdarshan]

Description

This PR replaces the previous WebView-based login flow with Chrome Custom Tabs, improving reliability and UX across browsers

Fixes #6688

Why change from webview to custom tabs

• WebView login can break or feel inconsistent when the flow opens external pages (email verification) and then returns to the app.
• Custom Tabs uses the system browser context (cookies/session), which is generally more reliable

What changed

• Replaced the in-app WebView login with Chrome Custom Tabs.
• Updated manifest queries to detect Custom Tabs providers via CustomTabsService

[westnordost]

Hmm, that's the big issue with this PR. This library is not multi platform. I cannot merge a PR that replaces functionality that already works with multiplatform (i.e. with iOS) with an implementation that doesn't.

Looking at the source code, it is also completely written in Java and also depends on a couple of Java and Android stuff ( https://android.googlesource.com/platform/frameworks/support/+/androidx-main/browser/browser/build.gradle#39 ), so it doesn't look like it would be trivial to migrate for them. I don't think it is on their agenda.

In short, we can't use that library.

[westnordost]

The only multiplatform way to open an URL in the browser via compose that I know is LocalUriHandler. This doesn't however, allow to pass any (launch) parameters to the browser.

[bhatganeshdarshan]

Perfect got it !! So if we dont want to use implementation("androidx.browser:browser:1.9.0") ,
we can open it in a browser without custom tabs ,

currently in my approach if chrome custom tabs are available , i m using that else it opens it in browser

so if we remove custom tabs and only open in browser like this :

fun launchUrl(context: Context, url: String): Boolean {
        return try {
            val browserIntent = Intent(Intent.ACTION_VIEW, url.toUri())
            context.startActivity(browserIntent)
            true
        } catch (e: Exception) {
            false
        }
    }

it'll work ig :

WhatsApp.Video.2026-01-17.at.19.03.36.mp4

[westnordost]

but Context is Android only and hence that will not even compile on platforms other than Android

[bhatganeshdarshan]

As you said, the only way would be to use val uriHandler = LocalUriHandler.current right?

[westnordost]

In a nutshell, yes.

[westnordost]

That I know of, that is.

[westnordost]

I haven't had a closer look at the code, it looks odd though that it is so much more code than with the WebView. Did you forget to delete code you copied or something? I'd think it should be less code when just calling the external browser + handling the URL callback because there's no fiddling around with the WebView.

Also, the WebView dependency can be removed.

I also spotted some things that seem to be residue from testing, such as delay, unrelated changes and the like.

Also, isn't there an entry in the manifest missing that declares that this app handles URLs with a certain scheme?

[bhatganeshdarshan]

I haven't had a closer look at the code, it looks odd though that it is so much more code than with the WebView. Did you forget to delete code you copied or something? I'd think it should be less code when just calling the external browser + handling the URL callback because there's no fiddling around with the WebView.

Also, the WebView dependency can be removed.

I also spotted some things that seem to be residue from testing, such as delay, unrelated changes and the like.

Also, isn't there an entry in the manifest missing that declares that this app handles URLs with a certain scheme?

with webview we had the in-app control , errors ,redirects etc , also things like if user has presesed back and exited out of webview . But when launch external browser need to handle many cases like prevent reopening the browser , oauth callback and handling cancellation ..

so the ui code has reduced but the code related to the flow has become more explicit because we no longer control the browser like webview

and for entry in manifest , looks like everything working fine .. i removed the <query> which i was using to find the browsers that support custom tabs , since we no longer using custom tabs , its of no use so i removed it ..

also delay need to be removed , rename markCustomTabLaunched to a more relevent name like markAuthUrlLaunched and some Logs .. sorry i forgot to remove ..
lmk if any other changes need to be done
thank you