WebViewと向き合う

DroidKaigi.onCompletion { 2023@Online } の発表資料です
https://yumemi.connpass.com/event/289949/

サンプルコード
https://github.com/mkeeda/webview-sandbox

Transcript

1. WebView DroidKaigi.onCompletion { 20 23 @Online } (@mr_mkeeda)
2. About me Twitter: @mr_mkeeda Github: @mkeeda Android Engineer at Cybozu, Inc kintone 2
3. WebView WebView 3
4. WebView URL/HTML 4
5. UI 5 WebView Fragment loadUrl( URL) reload() WebViewClient onPageStarted() onPageFinished() shouldOverrideUrlLoading()
6. WebView Fragment loadUrl( URL) reload() WebViewClient onPageStarted() onPageFinished() shouldOverrideUrlLoading() 6 Fragment 500 WebView
7. 7 https://developer.android.com/topic/architecture
8. UI 8 UI Elements UI State = UI
9. : Web 9 UI Elements UI State = UI WebView URL Web =
10. = URL 10 UI elements WebView UI state URL A = UI Web A UI elements WebView UI state URL B = UI Web B
11. WebView 11 UI elements WebView State holder ViewModel UI state URL 3. URL 2 . URL (UI event) 1. URL 4. URL
12. 12 UI elements WebView State holder ViewModel UI state URL UI state UI state
13. WebView android.widget UI state Callback UI state WebView 13 UI state URL UI elements WebView
14. URL 14 WebViewClient shouldOverrideUrlLoading() UI elements WebView UI state URL A State holder ViewModel ❌ return true loadUrl() UI state URL B WebViewClient# 
 shouldOverrideUrlLoading() true URL URL UI state URL B
15. 15 class WebViewModel : ViewModel() { private val _currentUrl = MutableStateFlow(Uri.parse("https://www.google.com")) val url: StateFlow<Uri> = _currentUrl.asStateFlow() fun onPageLoad(newUrl: Uri) { _currentUrl.update { currentUrl -> // ೚ҙͷϩδοΫ // … newUrl } } } // Composeableؔ਺ val url by viewModel.url.collectAsStateWithLifecycle() WebScreen( url = url, onUrlChanged = { newUrl -> viewModel.onPageLoad(newUrl) } )
16. 16 @Composable fun WebScreen( url: Uri, onUrlChanged: (Uri) -> Unit ) { AndroidView( factory = { context -> WebView(context).apply { webViewClient = MyWebViewClient(onUrlChanged) } }, update = { webView -> webView.loadUrl(url.toString()) } ) } class MyWebViewClient( private val onUrlChanged: (Uri) -> Unit ) : WebViewClientCompat() { override fun shouldOverrideUrlLoading( view: WebView, request: WebResourceRequest ): Boolean { onUrlChanged(request.url) return true } }
17. WebView UI state 
 https://github.com/mkeeda/webview-sandbox WebView 17 Do not call WebView#loadUrl(String) with the request's URL and then return true. This unnecessarily cancels the current load and starts a new load with the same URL. https://developer.android.com/reference/android/webkit/WebViewClient