CCT - AuthTab Sample Demo

[erikrodriguez-se]

This PR contains a working demo for an implementation of AuthTab for Chrome Custom Tabs for Android. The included project, custom-tabs-authview, uses the existing custom-tabs-oauth demo as a guide for authentication using a website, in this case Github.

Some notes:

• The demo uses the custom redirect scheme. If it is desired to use https scheme instead, I can update the project accordingly.
• Some updates beyond the demo were required for the android-browser-helper project to compile in newer versions of Android Studio. Namely, these changes included namespace additions to gradle files as well as updating the gradle version used in the project.

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[orbital17]

Hi Erik, thanks for the PR!
In general, SDK version, Java version and Gradle version need to be updated, but they need to be kept consistent across the project, and it's better to handle these updates in a separate PR.
Would you like to create a PR for the updates? We are not sure when we’ll be able to handle this ourselves. Alternatively, you can try to implement the demo without updating the versions.

[ukaratkevich]

+1 to make a separate PR with build changes.
I also doubt that we want to use androidx snapshots for demo, I'd wait at least for 1.9.0 alpha.

[erikrodriguez-se]

Hi all, I can split this in to two PRs. I'll make this one specific to AuthTab and will create another for project updates.

[ukaratkevich]

I see that AuthView demo is almost identical to the Oauth demo, the difference are:

1. New callback intent-filter
2. Launcher intents are different
3. Different result handling

I think that we can merge this demo into Oauth, as far as I can see it'd require:

1. Add an AuthView callback intent-filter into the AndroidManifest
2. Demo should provide a way to switch between CCT and AuthView. I think a checkbox and shouldUseAuthView should be enough.
3. In AuthManager launch intents and handle results based on shouldUseAuthView.
4. I'd also add comments why AuthView is preferable in AuthManager or even deprecate CCT flow at all.

This way we get rid of duplication and provide some kind of migration steps from CCT to AuthView.
What do you think?