Seeking Advice on Embedding a Custom WebView Implementation in Android App

[nonameShijian]

Hello everyone,

I'm currently working on an Android app and wish to embed a custom WebView instead of relying on the system WebView. Given that Crosswalk is no longer being updated, I decided to take a different approach. I extracted the dex file from webview.apk, converted it into a jar file, and included it in my project. My intention was to hook into the WebView implementation at runtime by specifying my app as the WebView provider. However, this led to the following error:

"Rejecting class com.android.webview.chromium.WebViewChromiumFactoryProviderForT that attempts to sub-type erroneous class com.android.webview.chromium.WebViewChromiumFactoryProvider in /data/app/xxx/xxx/base.apk"

It seems that the issue might be related to not being able to access internal classes such as WebViewFactory within my app. Is there a recommended or correct approach to embedding a WebView implementation directly within an Android app? Any guidance or suggestions would be greatly appreciated.

Thank you!

[uazo]

wow, what a request! extremely interesting.

give me time to regroup and answer you properly.
I anticipate that I would have the time to help you with your project, although it is something that really interests me.

[nonameShijian]

Thank you very much for your help

[uazo]

I haven't forgotten about you, but your question needed some technical insight from me before I answered it. I was not aware of Crosswalk so I wanted to check what it was. too bad it is based on chromium 53, but I think there may be suggestions in the code on how to proceed.

your goal is something I would like to do in the future, I really like challenges, but I have other priorities first. I can tell you how I would deal with the problem,

Is there a recommended or correct approach to embedding a WebView implementation directly within an Android app? Any guidance or suggestions would be greatly appreciated.

First of all, understand how AwShellActivity.java works, being the one that comes closest to integrating a webview into a project. I would start with that, however you should have basic knowledge of how to compile chromium and especially gn.

or maybe you can ask Soren Stoutner, he was planning to do it https://redmine.stoutner.com/issues/86 although I have never seen any updates on the issue

I extracted the dex file from webview.apk, converted it into a jar file, and included it in my project.

I can't know without seeing what you've done, but it looks to me like a hack and as such it could break easily.
I don't want to waste your time, but I wish I could see what you have done.

[uazo]

ah, I also think you can ask the duckduckgo browser team, they would benefit incredibly if they started such a project.

[nonameShijian]

Extracting the dex file is indeed a makeshift solution and not ideal. Based on current information and knowledge about Android, Chromium, and Android WebView, I now know of three methods to embed a WebView:

1. The Crosswalk Native project, which uses the Chromium 77 kernel.
2. Tencent's X5 Kernel, whose latest version utilizes a Chromium 109 or newer kernel, though using this requires real-name authentication.
3. WebViewUpgrade(https://github.com/JonaNorman/WebViewUpgrade), which involves using hook techniques to make the Android system recognize that the package you've embedded in assets or downloaded online is installed, thus using its WebView implementation. This method only requires calling android.webkit.WebView, which can be particularly useful for some frameworks (like Cordova) as it doesn't necessitate additional code for compatibility.

Among these three methods, the first two require the use of additional classes to implement WebView, whereas the last one simply involves calling the standard Android WebView interface.

In the future, I plan to learn how to compile Chromium and possibly rent a server to support the compilation process. Hopefully, these three approaches provide you with some fresh ideas. Thanks again for your assistance and suggestions.

[uazo]

thanks for the links, very interesting.
I'll let you know if one of those takes little time to integrate into cromite

In the future, I plan to learn how to compile Chromium

If I can help you, you can find me here.

[uazo]

@nonameShijian I found https://github.com/wuruxu/crwebview/tree/main
If you come back to this topic, let me know.

[uazo]

My Android device supports arm64-v8a and has been rooted.

don't you use the emulator during debugging?

I'm not very familiar with webview_instrumentation_apk. Could you please explain in detail what webview_instrumentation_apk

me neither. from the docs:

Android WebView is a system framework component. Since Android KitKat, it is implemented using Chromium code (based off the content module). It is possible to test modifications to WebView using a simple test shell. The WebView shell is a view with a URL bar at the top (see code) and is independent of the WebView implementation in the Android system ( the WebView shell is essentially a standalone unbundled app). As drawback, the shell runs in non-production rendering mode only.

[nonameShijian]

My Android device supports arm64-v8a and has been rooted.

don't you use the emulator during debugging?

I'm not very familiar with webview_instrumentation_apk. Could you please explain in detail what webview_instrumentation_apk

me neither. from the docs:

Android WebView is a system framework component. Since Android KitKat, it is implemented using Chromium code (based off the content module). It is possible to test modifications to WebView using a simple test shell. The WebView shell is a view with a URL bar at the top (see code) and is independent of the WebView implementation in the Android system ( the WebView shell is essentially a standalone unbundled app). As drawback, the shell runs in non-production rendering mode only.

I typically use a physical device for testing, but I can also use the emulator from Android Studio (both x86 and x86_64 architectures are fine).

I don't think this webview_instrumentation_apk is what I need either. For implementing a custom WebView, I likely only need the following four types of files: native libraries (SO files), Java classes (JAR/AAR or source), resource files (XML, etc.), and packaged .pak resource files. These are automatically included when packaging an APK.

Is there a way to obtain these four types of files in a form that can be directly used (e.g., as a library dependency like an AAR) within an Android project, rather than having to extract them from a pre-built APK or build them through complex Chromium compilation processes?

[uazo]

Is there a way to obtain these four types of files in a form that can be directly used (e.g., as a library dependency like an AAR) within an Android project, rather than having to extract them from a pre-built APK or build them through complex Chromium compilation processes?

No, google does not offer this feature by default. The closest thing seems to be that webview_instrumentation_apk

[nonameShijian]

No, google does not offer this feature by default. The closest thing seems to be that webview_instrumentation_apk

Okay, I understand. In that case, could you please try compiling the latest version of Chromium into an AAR file based on the code structure of the crwebview project? For the code part, only retain the underlying components of org.chromium, and exclude the WebView-related code such as com.android.webview.xxx.

[uazo]

could you please try compiling the latest version of Chromium into an AAR file based on the code structure of the crwebview project?

Yes, I'll try, sooner or later.

[fish4terrisa-MSDSM]

Hi is there any new update about this?

[nonameShijian]

There is no new progress yet. I am currently developing using this repository: https://github.com/JonaNorman/WebViewUpgrade