Performance: Investigate androidx: startUpWebView

[david-allison]

This went stable in 1.16. Determine whether it can be used in AnkiDroidApp to speed up app startup

https://developer.android.com/reference/androidx/webkit/WebViewCompat#startUpWebView(android.content.Context,androidx.webkit.WebViewStartUpConfig,androidx.webkit.WebViewOutcomeReceiver%3Candroidx.webkit.WebViewStartUpResult,androidx.webkit.WebViewStartupException%3E)

WebKit 1.16 is available to test on the dependency-updates branch

[neronguyen]

Does the app do any WebView warn up before WebView features? I'm getting used to Anki and looking for a issue to contribute to

[david-allison]

Thanks!!

All our startup is in AnkiDroidApp.kt

I'm in the process of adding logging to this, and it's where we first initialize the WebView.

I mostly want to know if the API would be suitable for us, and the potential downsides

We need to know the version of the WebView before the user uses the app, as we validate the version

We also put the WebView information into a debug log, but this could be deferred

[neronguyen]

I don't see any WebView informtion in the start up result.

About the implementation, I think we can have a deferred in AnkiApp then other usages can wait for completion of this start up before create their WebView instances to gain benefit as the doc statement "Any APIs in android.webkit and androidx.webkit (including WebViewFeature) MUST only be called after the callback is invoked in order to ensure the maximum benefit"

Do we have any benchmark to meisure the start up speed ?
Should I also implement one ?

[david-allison]

• DebugInfoService -> getWebViewInfo, called from:

Anki-Android/AnkiDroid/src/main/java/com/ichi2/anki/AnkiDroidApp.kt

Lines 176 to 179 in 90bbe81

	applicationScope.launch {
	Timber.i("AnkiDroidApp: listing debug info")
	Timber.i(DebugInfoService.getDebugInfo(this@AnkiDroidApp))
	}

I'm in the process of adding startup times to AnkiDroidApp, please lift what you need from my PR and send it in as a PR. Use the Co-authored-by trailer so GitHub credit is attributed to the both of us.

• improvement(startup): split into methods and add timing #20593 - final pattern I'm hoping for - was likely too large to get reviewed, so I've been in the process of splitting it out.
• refactor(AnkiDroidApp): extract setup code #21156 - sample extraction
• Improve startup process & notifying users of nonfatal component errors #20168 - issue

In terms of WebView:

• Outputting debug info is executed on a coroutine. If you wish, the WebView info can be deferred further
• DeckPicker needs to show a dialog if the WebView is out of date - but this could potentially be deferred if there's a plan
  • I'm in the process of making this functionality generic, so all entry points to the app display this.
  • A loading spinner on the page would be acceptable, as long as there's a timeout
  • On first load, a user needs to go through onboarding before this dialog is shown, so it doesn't need to block AnkiDroidApp

Anki-Android/AnkiDroid/src/main/java/com/ichi2/utils/WebViewUtils.kt

Lines 58 to 61 in a2ad00d

	fun showDialogIfWebViewOutdated(
	minimumWebViewVersion: WebViewVersion = OLDEST_WORKING_WEBVIEW_VERSION,
	onOutdated: () -> Unit = {},
	): Boolean {

Also to note: links to the code are better than screenshots:

[neronguyen]

Hi I just create a pull request. I'm not sure that what you want and how to test it properly. Please kindly review and guide. Thank you so much.