Change ContentLoadingErrorView to pass state

cketti · cketti · commit a36e7ef2ad4f · 2024-11-12T12:28:18.000+01:00
diff --git a/app-ui-catalog/src/main/java/app/k9mail/ui/catalog/ui/molecule/items/StateItems.kt b/app-ui-catalog/src/main/java/app/k9mail/ui/catalog/ui/molecule/items/StateItems.kt
@@ -130,7 +130,7 @@ private fun StatefulContentLoadingView() {
 @Composable
 private fun StatefulContentLoadingErrorView() {
     val state = remember {
-        mutableStateOf(ContentLoadingErrorState.Loading)
+        mutableStateOf<ContentLoadingErrorState>(ContentLoadingErrorState.Loading)
     }
 
     ContentLoadingErrorView(
diff --git a/core/ui/compose/designsystem/src/debug/kotlin/app/k9mail/core/ui/compose/designsystem/molecule/ContentLoadingErrorViewPreview.kt b/core/ui/compose/designsystem/src/debug/kotlin/app/k9mail/core/ui/compose/designsystem/molecule/ContentLoadingErrorViewPreview.kt
@@ -45,7 +45,7 @@ internal fun ContentLoadingErrorViewErrorPreview() {
 internal fun ContentLoadingErrorViewInteractivePreview() {
     PreviewWithThemes {
         val state = remember {
-            mutableStateOf(ContentLoadingErrorState.Loading)
+            mutableStateOf<ContentLoadingErrorState>(ContentLoadingErrorState.Loading)
         }
 
         DefaultContentLoadingErrorView(
diff --git a/core/ui/compose/designsystem/src/main/kotlin/app/k9mail/core/ui/compose/designsystem/molecule/ContentLoadingErrorView.kt b/core/ui/compose/designsystem/src/main/kotlin/app/k9mail/core/ui/compose/designsystem/molecule/ContentLoadingErrorView.kt
@@ -6,14 +6,34 @@ import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 
+/**
+ * A container view that can animate between a loading view, an error view, and a content view.
+ *
+ * @param ERROR The type describing the error.
+ * @param STATE The type of the state being passed to this view.
+ *
+ * @param state The state relevant for displaying the content inside this view.
+ * @param loading When `state.isLoading` is `true`, this composable function is displayed.
+ * @param error When `state.isLoading` is `false` and `state.error` is not `null`, this composable function is displayed
+ *   with `state.error` being passed as the argument.
+ * @param content When `state.isLoading` is `false` and `state.error` is `null`, this composable function is displayed
+ *   with [state] being passed as the argument.
+ *
+ * **IMPORTANT**: This is a delicate API whose usage should be carefully reviewed. It is using [AnimatedContent] and
+ * inherits its caveats.
+ *
+ * The [loading], [error] and [content] composable functions should only use the state being passed to them (if any).
+ * If you disregard this advice, make sure to read the documentation of [AnimatedContent] to learn when the composable
+ * functions are invoked and what that means for the external state a function fetches.
+ */
 @Composable
-fun ContentLoadingErrorView(
-    state: ContentLoadingErrorState,
+fun <ERROR, STATE : LoadingErrorState<ERROR>> ContentLoadingErrorView(
+    state: STATE,
     loading: @Composable () -> Unit,
-    error: @Composable () -> Unit,
+    error: @Composable (ERROR) -> Unit,
     modifier: Modifier = Modifier,
     contentAlignment: Alignment = Alignment.Center,
-    content: @Composable () -> Unit,
+    content: @Composable (STATE) -> Unit,
 ) {
     Box(
         modifier = modifier,
@@ -22,18 +42,42 @@ fun ContentLoadingErrorView(
         AnimatedContent(
             targetState = state,
             label = "ContentLoadingErrorView",
+            contentKey = { targetState ->
+                ContentKey(isLoading = targetState.isLoading, error = targetState.error)
+            },
         ) { targetState ->
-            when (targetState) {
-                ContentLoadingErrorState.Loading -> loading()
-                ContentLoadingErrorState.Content -> content()
-                ContentLoadingErrorState.Error -> error()
+            val errorValue = targetState.error
+            when {
+                targetState.isLoading -> loading()
+                errorValue != null -> error(errorValue)
+                else -> content(targetState)
             }
         }
     }
 }
 
-enum class ContentLoadingErrorState {
-    Loading,
-    Content,
-    Error,
+/**
+ * Signals [ContentLoadingErrorView] which of its composable function parameters to execute/display.
+ */
+interface LoadingErrorState<ERROR> {
+    val isLoading: Boolean
+    val error: ERROR?
+}
+
+private data class ContentKey<ERROR>(
+    override val isLoading: Boolean,
+    override val error: ERROR?,
+) : LoadingErrorState<ERROR>
+
+/**
+ * Helper that can be use as `state` argument for [ContentLoadingErrorView] when none of the composable function
+ * parameters need access to any state.
+ */
+sealed class ContentLoadingErrorState private constructor(
+    override val isLoading: Boolean,
+    override val error: Unit?,
+) : LoadingErrorState<Unit> {
+    data object Loading : ContentLoadingErrorState(isLoading = true, error = null)
+    data object Content : ContentLoadingErrorState(isLoading = false, error = null)
+    data object Error : ContentLoadingErrorState(isLoading = false, error = Unit)
 }
diff --git a/feature/account/common/src/main/kotlin/app/k9mail/feature/account/common/ui/loadingerror/LoadingErrorState.kt b/feature/account/common/src/main/kotlin/app/k9mail/feature/account/common/ui/loadingerror/LoadingErrorState.kt
diff --git a/feature/account/edit/src/main/kotlin/app/k9mail/feature/account/edit/ui/server/settings/save/SaveServerSettingsContent.kt b/feature/account/edit/src/main/kotlin/app/k9mail/feature/account/edit/ui/server/settings/save/SaveServerSettingsContent.kt
@@ -11,7 +11,6 @@ import app.k9mail.core.ui.compose.designsystem.molecule.ContentLoadingErrorView
 import app.k9mail.core.ui.compose.designsystem.molecule.ErrorView
 import app.k9mail.core.ui.compose.designsystem.molecule.LoadingView
 import app.k9mail.core.ui.compose.designsystem.template.ResponsiveWidthContainer
-import app.k9mail.feature.account.common.ui.loadingerror.rememberContentLoadingErrorViewState
 import app.k9mail.feature.account.edit.R
 
 @Composable
@@ -27,7 +26,7 @@ fun SaveServerSettingsContent(
             .then(modifier),
     ) {
         ContentLoadingErrorView(
-            state = rememberContentLoadingErrorViewState(state),
+            state = state,
             loading = {
                 LoadingView(
                     message = stringResource(id = R.string.account_edit_save_server_settings_loading_message),
diff --git a/feature/account/edit/src/main/kotlin/app/k9mail/feature/account/edit/ui/server/settings/save/SaveServerSettingsContract.kt b/feature/account/edit/src/main/kotlin/app/k9mail/feature/account/edit/ui/server/settings/save/SaveServerSettingsContract.kt
@@ -1,7 +1,7 @@
 package app.k9mail.feature.account.edit.ui.server.settings.save
 
 import app.k9mail.core.ui.compose.common.mvi.UnidirectionalViewModel
-import app.k9mail.feature.account.common.ui.loadingerror.LoadingErrorState
+import app.k9mail.core.ui.compose.designsystem.molecule.LoadingErrorState
 
 interface SaveServerSettingsContract {
 
diff --git a/feature/account/setup/src/main/kotlin/app/k9mail/feature/account/setup/ui/autodiscovery/AccountAutoDiscoveryContent.kt b/feature/account/setup/src/main/kotlin/app/k9mail/feature/account/setup/ui/autodiscovery/AccountAutoDiscoveryContent.kt
@@ -25,7 +25,6 @@ import app.k9mail.core.ui.compose.theme2.MainTheme
 import app.k9mail.feature.account.common.ui.AppTitleTopHeader
 import app.k9mail.feature.account.common.ui.WizardNavigationBar
 import app.k9mail.feature.account.common.ui.WizardNavigationBarState
-import app.k9mail.feature.account.common.ui.loadingerror.rememberContentLoadingErrorViewState
 import app.k9mail.feature.account.oauth.ui.AccountOAuthContract
 import app.k9mail.feature.account.oauth.ui.AccountOAuthView
 import app.k9mail.feature.account.setup.R
@@ -90,24 +89,25 @@ internal fun AutoDiscoveryContent(
     val resources = LocalContext.current.resources
 
     ContentLoadingErrorView(
-        state = rememberContentLoadingErrorViewState(state),
+        state = state,
         loading = {
             LoadingView(
                 message = stringResource(id = R.string.account_setup_auto_discovery_loading_message),
                 modifier = Modifier.fillMaxSize(),
             )
         },
-        error = {
+        error = { error ->
             ErrorView(
                 title = stringResource(id = R.string.account_setup_auto_discovery_loading_error),
-                message = state.error?.toAutoDiscoveryErrorString(resources),
+                message = error.toAutoDiscoveryErrorString(resources),
                 onRetry = { onEvent(Event.OnRetryClicked) },
                 modifier = Modifier.fillMaxSize(),
             )
         },
-        content = {
+        content = { contentState ->
+            @Suppress("ViewModelForwarding")
             ContentView(
-                state = state,
+                state = contentState,
                 onEvent = onEvent,
                 oAuthViewModel = oAuthViewModel,
                 resources = resources,
diff --git a/feature/account/setup/src/main/kotlin/app/k9mail/feature/account/setup/ui/autodiscovery/AccountAutoDiscoveryContract.kt b/feature/account/setup/src/main/kotlin/app/k9mail/feature/account/setup/ui/autodiscovery/AccountAutoDiscoveryContract.kt
@@ -3,11 +3,11 @@ package app.k9mail.feature.account.setup.ui.autodiscovery
 import app.k9mail.autodiscovery.api.AutoDiscoveryResult
 import app.k9mail.core.common.domain.usecase.validation.ValidationResult
 import app.k9mail.core.ui.compose.common.mvi.UnidirectionalViewModel
+import app.k9mail.core.ui.compose.designsystem.molecule.LoadingErrorState
 import app.k9mail.feature.account.common.domain.entity.AuthorizationState
 import app.k9mail.feature.account.common.domain.entity.IncomingProtocolType
 import app.k9mail.feature.account.common.domain.input.BooleanInputField
 import app.k9mail.feature.account.common.domain.input.StringInputField
-import app.k9mail.feature.account.common.ui.loadingerror.LoadingErrorState
 import app.k9mail.feature.account.oauth.domain.entity.OAuthResult
 import app.k9mail.feature.account.oauth.ui.AccountOAuthContract
 
diff --git a/feature/account/setup/src/main/kotlin/app/k9mail/feature/account/setup/ui/createaccount/CreateAccountContent.kt b/feature/account/setup/src/main/kotlin/app/k9mail/feature/account/setup/ui/createaccount/CreateAccountContent.kt
@@ -11,7 +11,6 @@ import app.k9mail.core.ui.compose.designsystem.molecule.ContentLoadingErrorView
 import app.k9mail.core.ui.compose.designsystem.molecule.ErrorView
 import app.k9mail.core.ui.compose.designsystem.molecule.LoadingView
 import app.k9mail.core.ui.compose.designsystem.template.ResponsiveWidthContainer
-import app.k9mail.feature.account.common.ui.loadingerror.rememberContentLoadingErrorViewState
 import app.k9mail.feature.account.setup.R
 
 @Composable
@@ -27,7 +26,7 @@ internal fun CreateAccountContent(
             .then(modifier),
     ) {
         ContentLoadingErrorView(
-            state = rememberContentLoadingErrorViewState(state),
+            state = state,
             loading = {
                 LoadingView(
                     message = stringResource(R.string.account_setup_create_account_creating),
diff --git a/feature/account/setup/src/main/kotlin/app/k9mail/feature/account/setup/ui/createaccount/CreateAccountContract.kt b/feature/account/setup/src/main/kotlin/app/k9mail/feature/account/setup/ui/createaccount/CreateAccountContract.kt
@@ -1,7 +1,7 @@
 package app.k9mail.feature.account.setup.ui.createaccount
 
 import app.k9mail.core.ui.compose.common.mvi.UnidirectionalViewModel
-import app.k9mail.feature.account.common.ui.loadingerror.LoadingErrorState
+import app.k9mail.core.ui.compose.designsystem.molecule.LoadingErrorState
 import app.k9mail.feature.account.setup.AccountSetupExternalContract.AccountCreator.AccountCreatorResult.Error
 import app.k9mail.feature.account.setup.domain.entity.AccountUuid
 
diff --git a/feature/account/setup/src/main/kotlin/app/k9mail/feature/account/setup/ui/specialfolders/SpecialFoldersContent.kt b/feature/account/setup/src/main/kotlin/app/k9mail/feature/account/setup/ui/specialfolders/SpecialFoldersContent.kt
@@ -15,7 +15,6 @@ import app.k9mail.core.ui.compose.designsystem.molecule.LoadingView
 import app.k9mail.core.ui.compose.designsystem.template.ResponsiveWidthContainer
 import app.k9mail.core.ui.compose.theme2.MainTheme
 import app.k9mail.feature.account.common.ui.AppTitleTopHeader
-import app.k9mail.feature.account.common.ui.loadingerror.rememberContentLoadingErrorViewState
 import app.k9mail.feature.account.setup.R
 import app.k9mail.feature.account.setup.ui.specialfolders.SpecialFoldersContract.Event
 import app.k9mail.feature.account.setup.ui.specialfolders.SpecialFoldersContract.State
@@ -41,21 +40,21 @@ fun SpecialFoldersContent(
             )
 
             ContentLoadingErrorView(
-                state = rememberContentLoadingErrorViewState(state = state),
+                state = state,
                 loading = {
                     LoadingView(
                         message = stringResource(id = R.string.account_setup_special_folders_loading_message),
                         modifier = Modifier.fillMaxWidth(),
                     )
                 },
-                error = {
+                error = { error ->
                     SpecialFoldersErrorView(
-                        failure = state.error!!,
+                        failure = error,
                         onRetry = { onEvent(Event.OnRetryClicked) },
                     )
                 },
                 modifier = Modifier.fillMaxSize(),
-            ) {
+            ) { state ->
                 if (state.isSuccess) {
                     LoadingView(
                         message = stringResource(id = R.string.account_setup_special_folders_success_message),
diff --git a/feature/account/setup/src/main/kotlin/app/k9mail/feature/account/setup/ui/specialfolders/SpecialFoldersContract.kt b/feature/account/setup/src/main/kotlin/app/k9mail/feature/account/setup/ui/specialfolders/SpecialFoldersContract.kt
@@ -1,8 +1,8 @@
 package app.k9mail.feature.account.setup.ui.specialfolders
 
 import app.k9mail.core.ui.compose.common.mvi.UnidirectionalViewModel
+import app.k9mail.core.ui.compose.designsystem.molecule.LoadingErrorState
 import app.k9mail.feature.account.common.domain.entity.SpecialFolderOption
-import app.k9mail.feature.account.common.ui.loadingerror.LoadingErrorState
 
 interface SpecialFoldersContract {
 
diff --git a/feature/funding/googleplay/src/main/kotlin/app/k9mail/feature/funding/googleplay/ui/contribution/ContributionContract.kt b/feature/funding/googleplay/src/main/kotlin/app/k9mail/feature/funding/googleplay/ui/contribution/ContributionContract.kt
@@ -3,6 +3,7 @@ package app.k9mail.feature.funding.googleplay.ui.contribution
 import android.app.Activity
 import androidx.compose.runtime.Stable
 import app.k9mail.core.ui.compose.common.mvi.UnidirectionalViewModel
+import app.k9mail.core.ui.compose.designsystem.molecule.LoadingErrorState
 import app.k9mail.feature.funding.googleplay.domain.DomainContract.BillingError
 import app.k9mail.feature.funding.googleplay.domain.entity.Contribution
 import app.k9mail.feature.funding.googleplay.domain.entity.OneTimeContribution
@@ -32,9 +33,9 @@ internal class ContributionContract {
         val selectedContribution: Contribution? = null,
         val isRecurringContributionSelected: Boolean = false,
 
-        val error: BillingError? = null,
-        val isLoading: Boolean = true,
-    )
+        override val error: BillingError? = null,
+        override val isLoading: Boolean = true,
+    ) : LoadingErrorState<BillingError>
 
     sealed interface Event {
         data object OnOneTimeContributionSelected : Event
diff --git a/feature/funding/googleplay/src/main/kotlin/app/k9mail/feature/funding/googleplay/ui/contribution/ContributionList.kt b/feature/funding/googleplay/src/main/kotlin/app/k9mail/feature/funding/googleplay/ui/contribution/ContributionList.kt
@@ -23,7 +23,6 @@ import app.k9mail.core.ui.compose.designsystem.atom.text.TextBodyLarge
 import app.k9mail.core.ui.compose.designsystem.atom.text.TextBodyMedium
 import app.k9mail.core.ui.compose.designsystem.atom.text.TextBodySmall
 import app.k9mail.core.ui.compose.designsystem.atom.text.TextLabelLarge
-import app.k9mail.core.ui.compose.designsystem.molecule.ContentLoadingErrorState
 import app.k9mail.core.ui.compose.designsystem.molecule.ContentLoadingErrorView
 import app.k9mail.core.ui.compose.designsystem.molecule.LoadingView
 import app.k9mail.core.ui.compose.theme2.MainTheme
@@ -44,14 +43,6 @@ internal fun ContributionList(
     onRetryClick: () -> Unit,
     modifier: Modifier = Modifier,
 ) {
-    val contentState = remember(key1 = state.isLoading, key2 = state.error) {
-        when {
-            state.isLoading -> ContentLoadingErrorState.Loading
-            state.error != null -> ContentLoadingErrorState.Error
-            else -> ContentLoadingErrorState.Content
-        }
-    }
-
     Surface(
         color = MainTheme.colors.surfaceContainerLowest,
         shape = MainTheme.shapes.small,
@@ -67,17 +58,17 @@ internal fun ContributionList(
             )
 
             ContentLoadingErrorView(
-                state = contentState,
+                state = state,
                 loading = {
                     LoadingView()
                 },
-                error = {
+                error = { error ->
                     ListErrorView(
-                        error = state.error!!,
+                        error = error,
                         onRetryClick = onRetryClick,
                     )
                 },
-                content = {
+                content = { state ->
                     if (state.oneTimeContributions.isEmpty() && state.recurringContributions.isEmpty()) {
                         ListEmptyView()
                     } else {

Original file line number	Diff line number	Diff line change
`@@ -130,7 +130,7 @@ private fun StatefulContentLoadingView() {`
`130`	`130`	`@Composable`
`131`	`131`	`private fun StatefulContentLoadingErrorView() {`
`132`	`132`	`val state = remember {`
`133`		`- mutableStateOf(ContentLoadingErrorState.Loading)`
	`133`	`+ mutableStateOf<ContentLoadingErrorState>(ContentLoadingErrorState.Loading)`
`134`	`134`	`}`
`135`	`135`
`136`	`136`	`ContentLoadingErrorView(`
Original file line number	Diff line number	Diff line change
`@@ -45,7 +45,7 @@ internal fun ContentLoadingErrorViewErrorPreview() {`
`45`	`45`	`internal fun ContentLoadingErrorViewInteractivePreview() {`
`46`	`46`	`PreviewWithThemes {`
`47`	`47`	`val state = remember {`
`48`		`- mutableStateOf(ContentLoadingErrorState.Loading)`
	`48`	`+ mutableStateOf<ContentLoadingErrorState>(ContentLoadingErrorState.Loading)`
`49`	`49`	`}`
`50`	`50`
`51`	`51`	`DefaultContentLoadingErrorView(`