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WebView
DroidKaigi.onCompletion {
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@Online }
(@mr_mkeeda)
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About me
Twitter: @mr_mkeeda
Github: @mkeeda
Android Engineer at Cybozu, Inc
kintone
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WebView
WebView
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WebView
URL/HTML
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UI
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WebView Fragment
loadUrl( URL)
reload()
WebViewClient
onPageStarted()
onPageFinished()
shouldOverrideUrlLoading()
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WebView Fragment
loadUrl( URL)
reload()
WebViewClient
onPageStarted()
onPageFinished()
shouldOverrideUrlLoading()
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Fragment
500 WebView
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https://developer.android.com/topic/architecture
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UI
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UI
Elements
UI
State
= UI
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: Web
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UI
Elements
UI
State
= UI
WebView URL Web
=
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= URL
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UI elements
WebView
UI state
URL A =
UI
Web
A
UI elements
WebView
UI state
URL B =
UI
Web
B
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WebView
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UI elements
WebView
State holder
ViewModel
UI state
URL
3. URL
2
. URL
(UI event)
1. URL
4. URL
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UI elements
WebView
State holder
ViewModel
UI state
URL
UI state
UI state
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WebView
android.widget UI state
Callback
UI state WebView
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UI state
URL
UI elements
WebView
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URL
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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
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class WebViewModel : ViewModel() {
private val _currentUrl =
MutableStateFlow(Uri.parse("https://www.google.com"))
val url: StateFlow = _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)
}
)
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@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
}
}
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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