ADT Page model (#1655)

* Enable when guards

* ADT Page model

* Refine

* Refine

* Remove type conversion

* Cleanup

---------

Co-authored-by: Dude so hot <djohn@fbi.gov>

app/build.gradle.kts

@@ -273,6 +273,7 @@ kotlin {
             "-progressive",
             "-Xjvm-default=all",
             "-Xcontext-receivers",
+            "-Xwhen-guards",
             "-Xsuppress-warning=CONTEXT_RECEIVERS_DEPRECATED",
 
             "-opt-in=coil3.annotation.ExperimentalCoilApi",

app/src/main/kotlin/com/hippo/ehviewer/gallery/Page.kt

@@ -0,0 +1,43 @@
+package com.hippo.ehviewer.gallery
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import com.hippo.ehviewer.image.Image
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.update
+
+class Page(
+    val index: Int,
+    val statusFlow: MutableStateFlow<PageStatus> = MutableStateFlow(PageStatus.Queued),
+)
+
+fun Page.unblock() = statusFlow.update { status ->
+    when (status) {
+        is PageStatus.Blocked -> PageStatus.Ready(status.ad)
+        else -> error("Call unblock on page not blocked!!!")
+    }
+}
+
+fun Page.reset() = statusFlow.update { PageStatus.Queued }
+
+val Page.status
+    get() = statusFlow.value
+
+val Page.statusObserved
+    @Composable
+    get() = statusFlow.collectAsState().value
+
+val PageStatus.progressObserved
+    @Composable
+    get() = when (this) {
+        is PageStatus.Loading -> progress.collectAsState().value
+        else -> 0f
+    }
+
+sealed interface PageStatus {
+    data object Queued : PageStatus
+    data class Blocked(val ad: Image) : PageStatus
+    data class Ready(val image: Image) : PageStatus
+    data class Error(val message: String?) : PageStatus
+    data class Loading(val progress: MutableStateFlow<Float>) : PageStatus
+}

app/src/main/kotlin/com/hippo/ehviewer/ui/reader/GalleryPager.kt

@@ -20,8 +20,8 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.util.fastFold
 import com.hippo.ehviewer.Settings
 import com.hippo.ehviewer.collectAsState
+import com.hippo.ehviewer.gallery.Page
 import com.hippo.ehviewer.gallery.PageLoader2
-import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
 import eu.kanade.tachiyomi.ui.reader.setting.ReadingModeType
 import eu.kanade.tachiyomi.ui.reader.setting.ReadingModeType.CONTINUOUS_VERTICAL
 import eu.kanade.tachiyomi.ui.reader.setting.ReadingModeType.RIGHT_TO_LEFT
@@ -40,7 +40,7 @@ fun GalleryPager(
     pageLoader: PageLoader2,
     showNavigationOverlay: Boolean,
     onNavigationModeChange: () -> Unit,
-    onSelectPage: (ReaderPage) -> Unit,
+    onSelectPage: (Page) -> Unit,
     onMenuRegionClick: () -> Unit,
     modifier: Modifier = Modifier,
 ) {

app/src/main/kotlin/com/hippo/ehviewer/ui/reader/PageActions.kt

@@ -16,6 +16,7 @@ import com.hippo.ehviewer.BuildConfig.APPLICATION_ID
 import com.hippo.ehviewer.R
 import com.hippo.ehviewer.client.EhUrl
 import com.hippo.ehviewer.client.data.GalleryInfo
+import com.hippo.ehviewer.gallery.Page
 import com.hippo.ehviewer.gallery.PageLoader2
 import com.hippo.ehviewer.util.AppConfig
 import com.hippo.ehviewer.util.FileUtils
@@ -25,7 +26,6 @@ import com.hippo.ehviewer.util.isAtLeastQ
 import com.hippo.ehviewer.util.isAtLeastT
 import com.hippo.ehviewer.util.requestPermission
 import com.hippo.files.toOkioPath
-import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
 import eu.kanade.tachiyomi.util.system.logcat
 import java.io.File
 import kotlinx.datetime.Clock
@@ -42,7 +42,7 @@ private fun Context.provideImage(index: Int): Uri? {
 }
 
 context(SnackbarHostState, Context, PageLoader2)
-suspend fun shareImage(page: ReaderPage, info: GalleryInfo? = null) {
+suspend fun shareImage(page: Page, info: GalleryInfo? = null) {
     val error = getString(R.string.error_cant_save_image)
     val share = getString(R.string.share_image)
     val noActivity = getString(R.string.error_cant_find_activity)
@@ -67,7 +67,7 @@ suspend fun shareImage(page: ReaderPage, info: GalleryInfo? = null) {
 }
 
 context(SnackbarHostState, Context, PageLoader2)
-suspend fun copy(page: ReaderPage) {
+suspend fun copy(page: Page) {
     val error = getString(R.string.error_cant_save_image)
     val copied = getString(R.string.copied_to_clipboard)
     val uri = provideImage(page.index)
@@ -83,7 +83,7 @@ suspend fun copy(page: ReaderPage) {
 }
 
 context(SnackbarHostState, Context, PageLoader2)
-suspend fun save(page: ReaderPage) {
+suspend fun save(page: Page) {
     val granted = isAtLeastQ || requestPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE)
     val cannotSave = getString(R.string.error_cant_save_image)
     if (granted) {
@@ -137,7 +137,7 @@ suspend fun save(page: ReaderPage) {
 }
 
 context(SnackbarHostState, Context, PageLoader2)
-suspend fun saveTo(page: ReaderPage) {
+suspend fun saveTo(page: Page) {
     val filename = getImageFilename(page.index)
     if (filename == null) {
         showSnackbar(getString(R.string.error_cant_save_image))

app/src/main/kotlin/com/hippo/ehviewer/ui/reader/PagerItem.kt

@@ -34,18 +34,20 @@ import com.google.accompanist.drawablepainter.DrawablePainter
 import com.hippo.ehviewer.R
 import com.hippo.ehviewer.Settings
 import com.hippo.ehviewer.collectAsState
+import com.hippo.ehviewer.gallery.Page
+import com.hippo.ehviewer.gallery.PageStatus
+import com.hippo.ehviewer.gallery.progressObserved
+import com.hippo.ehviewer.gallery.statusObserved
 import com.hippo.ehviewer.image.Image
 import com.hippo.ehviewer.ui.settings.AdsPlaceholderFile
-import eu.kanade.tachiyomi.source.model.Page
 import eu.kanade.tachiyomi.ui.reader.loader.PageLoader
-import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
 import eu.kanade.tachiyomi.ui.reader.viewer.CombinedCircularProgressIndicator
 import kotlinx.coroutines.flow.drop
 import moe.tarsin.kt.unreachable
 
 @Composable
 fun PagerItem(
-    page: ReaderPage,
+    page: Page,
     pageLoader: PageLoader,
     contentScale: ContentScale,
     modifier: Modifier = Modifier,
@@ -53,26 +55,24 @@ fun PagerItem(
 ) {
     LaunchedEffect(Unit) {
         pageLoader.request(page.index)
-        page.status.drop(1).collect {
-            if (page.status.value == Page.State.QUEUE) {
+        page.statusFlow.drop(1).collect {
+            if (page.statusFlow.value == PageStatus.Queued) {
                 pageLoader.request(page.index)
             }
         }
     }
     val defaultError = stringResource(id = R.string.decode_image_error)
-    val state by page.status.collectAsState()
-    when (state) {
-        Page.State.QUEUE, Page.State.LOAD_PAGE, Page.State.DOWNLOAD_IMAGE -> {
+    when (val state = page.statusObserved) {
+        is PageStatus.Queued, is PageStatus.Loading -> {
             Box(
                 modifier = modifier.fillMaxWidth().aspectRatio(DEFAULT_ASPECT),
                 contentAlignment = Alignment.Center,
             ) {
-                val progress by page.progressFlow.collectAsState()
-                CombinedCircularProgressIndicator(progress = progress / 100f)
+                CombinedCircularProgressIndicator(progress = state.progressObserved)
             }
         }
-        Page.State.READY -> {
-            val image = page.image!!
+        is PageStatus.Ready -> {
+            val image = state.image
             val painter = remember(image) { image.toPainter() }
             val grayScale by Settings.grayScale.collectAsState()
             val invert by Settings.invertedColors.collectAsState()
@@ -100,7 +100,7 @@ fun PagerItem(
                 },
             )
         }
-        Page.State.BLOCKED -> {
+        is PageStatus.Blocked -> {
             SubcomposeAsyncImage(
                 model = AdsPlaceholderFile,
                 contentDescription = null,
@@ -122,14 +122,14 @@ fun PagerItem(
                 }
             }
         }
-        Page.State.ERROR -> {
+        is PageStatus.Error -> {
             Box(modifier = modifier.fillMaxWidth().aspectRatio(DEFAULT_ASPECT)) {
                 Column(
                     modifier = Modifier.align(Alignment.Center),
                     horizontalAlignment = Alignment.CenterHorizontally,
                 ) {
                     Text(
-                        text = page.errorMsg ?: defaultError,
+                        text = state.message ?: defaultError,
                         modifier = Modifier.padding(8.dp),
                         textAlign = TextAlign.Center,
                         style = MaterialTheme.typography.bodyMedium,

app/src/main/kotlin/com/hippo/ehviewer/ui/reader/PagerViewer.kt

@@ -31,9 +31,10 @@ import androidx.compose.ui.unit.toSize
 import arrow.core.partially1
 import com.hippo.ehviewer.Settings
 import com.hippo.ehviewer.collectAsState
+import com.hippo.ehviewer.gallery.Page
 import com.hippo.ehviewer.gallery.PageLoader2
-import eu.kanade.tachiyomi.source.model.Page
-import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
+import com.hippo.ehviewer.gallery.PageStatus
+import com.hippo.ehviewer.gallery.statusObserved
 import eu.kanade.tachiyomi.ui.reader.viewer.NavigationRegions
 import eu.kanade.tachiyomi.ui.reader.viewer.ViewerNavigation.NavigationRegion
 import eu.kanade.tachiyomi.ui.reader.viewer.getAction
@@ -55,7 +56,7 @@ fun PagerViewer(
     isVertical: Boolean,
     pageLoader: PageLoader2,
     navigator: () -> NavigationRegions,
-    onSelectPage: (ReaderPage) -> Unit,
+    onSelectPage: (Page) -> Unit,
     onMenuRegionClick: () -> Unit,
     modifier: Modifier = Modifier,
 ) {
@@ -121,7 +122,7 @@ fun PagerViewer(
 
 @Composable
 private fun PageContainer(
-    page: ReaderPage,
+    page: Page,
     pageLoader: PageLoader2,
     isRtl: Boolean,
     scaleType: Int,
@@ -130,16 +131,16 @@ private fun PageContainer(
     layoutSize: Size,
     navigator: () -> NavigationRegions,
     pagerState: PagerState,
-    onSelectPage: (ReaderPage) -> Unit,
+    onSelectPage: (Page) -> Unit,
     onMenuRegionClick: () -> Unit,
     scope: CoroutineScope,
 ) {
     @Suppress("NAME_SHADOWING")
     val isRtl by rememberUpdatedState(isRtl)
     val zoomableState = rememberZoomableState(zoomSpec = PagerZoomSpec)
-    val status by page.status.collectAsState()
-    if (status == Page.State.READY && layoutSize != Size.Zero) {
-        val size = page.image!!.intrinsicSize.toSize()
+    val status = page.statusObserved
+    if (status is PageStatus.Ready && layoutSize != Size.Zero) {
+        val size = status.image.intrinsicSize.toSize()
         val contentScale = ContentScale.fromPreferences(scaleType, size, layoutSize)
         zoomableState.contentScale = contentScale
         LaunchedEffect(size, contentScale, alignment) {

app/src/main/kotlin/com/hippo/ehviewer/ui/reader/ReaderScreen.kt

@@ -60,7 +60,11 @@ import com.hippo.ehviewer.download.DownloadManager
 import com.hippo.ehviewer.download.archiveFile
 import com.hippo.ehviewer.gallery.ArchivePageLoader
 import com.hippo.ehviewer.gallery.EhPageLoader
+import com.hippo.ehviewer.gallery.Page
 import com.hippo.ehviewer.gallery.PageLoader2
+import com.hippo.ehviewer.gallery.PageStatus
+import com.hippo.ehviewer.gallery.status
+import com.hippo.ehviewer.gallery.unblock
 import com.hippo.ehviewer.ui.composing
 import com.hippo.ehviewer.ui.theme.EhTheme
 import com.hippo.ehviewer.ui.tools.Await
@@ -71,12 +75,10 @@ import com.hippo.files.toOkioPath
 import com.ramcosta.composedestinations.annotation.Destination
 import com.ramcosta.composedestinations.annotation.RootGraph
 import com.ramcosta.composedestinations.navigation.DestinationsNavigator
-import eu.kanade.tachiyomi.source.model.Page
 import eu.kanade.tachiyomi.ui.reader.PageIndicatorText
 import eu.kanade.tachiyomi.ui.reader.ReaderAppBars
 import eu.kanade.tachiyomi.ui.reader.ReaderContentOverlay
 import eu.kanade.tachiyomi.ui.reader.ReaderPageSheetMeta
-import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
 import eu.kanade.tachiyomi.ui.reader.setting.ReadingModeType
 import eu.kanade.tachiyomi.util.lang.launchIO
 import eu.kanade.tachiyomi.util.lang.withIOContext
@@ -216,10 +218,10 @@ fun AnimatedVisibilityScope.ReaderScreen(pageLoader: PageLoader2, info: BaseGall
             Settings.showNavigationOverlayNewUser.value = false
             mutableStateOf(showOnStart)
         }
-        val onSelectPage = { page: ReaderPage ->
+        val onSelectPage = { page: Page ->
             if (Settings.readerLongTapAction.value) {
                 launch {
-                    val pageBlocked = page.status.value == Page.State.BLOCKED
+                    val blocked = page.status is PageStatus.Blocked
                     dialog { cont ->
                         fun dispose() = cont.resume(Unit)
                         val state = rememberModalBottomSheetState()
@@ -236,7 +238,7 @@ fun AnimatedVisibilityScope.ReaderScreen(pageLoader: PageLoader2, info: BaseGall
                                 copy = { launchIO { with(pageLoader) { copy(page) } } },
                                 save = { launchIO { with(pageLoader) { save(page) } } },
                                 saveTo = { launchIO { with(pageLoader) { saveTo(page) } } },
-                                showAds = { page.status.value = Page.State.READY }.takeIf { pageBlocked },
+                                showAds = { page.unblock() }.takeIf { blocked },
                                 dismiss = { launch { state.hide().also { dispose() } } },
                             )
                         }

app/src/main/kotlin/com/hippo/ehviewer/ui/reader/WebtoonViewer.kt

@@ -17,8 +17,8 @@ import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.unit.dp
 import com.hippo.ehviewer.Settings
 import com.hippo.ehviewer.collectAsState
+import com.hippo.ehviewer.gallery.Page
 import com.hippo.ehviewer.gallery.PageLoader2
-import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
 import eu.kanade.tachiyomi.ui.reader.viewer.NavigationRegions
 import eu.kanade.tachiyomi.ui.reader.viewer.ViewerNavigation.NavigationRegion
 import eu.kanade.tachiyomi.ui.reader.viewer.getAction
@@ -33,7 +33,7 @@ fun WebtoonViewer(
     withGaps: Boolean,
     pageLoader: PageLoader2,
     navigator: () -> NavigationRegions,
-    onSelectPage: (ReaderPage) -> Unit,
+    onSelectPage: (Page) -> Unit,
     onMenuRegionClick: () -> Unit,
     modifier: Modifier = Modifier,
 ) {

app/src/main/kotlin/eu/kanade/tachiyomi/source/model/Page.kt

@@ -1,32 +0,0 @@
-package eu.kanade.tachiyomi.source.model
-
-import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.asStateFlow
-
-open class Page(val index: Int) {
-
-    val number: Int
-        get() = index + 1
-
-    var status = MutableStateFlow(State.QUEUE)
-
-    var errorMsg: String? = null
-
-    private val _progressFlow = MutableStateFlow(0)
-
-    val progressFlow = _progressFlow.asStateFlow()
-    var progress: Int
-        get() = _progressFlow.value
-        set(value) {
-            _progressFlow.value = value
-        }
-
-    enum class State {
-        QUEUE,
-        LOAD_PAGE,
-        DOWNLOAD_IMAGE,
-        READY,
-        BLOCKED,
-        ERROR,
-    }
-}

app/src/main/kotlin/eu/kanade/tachiyomi/ui/reader/loader/PageLoader.kt

@@ -3,12 +3,16 @@ package eu.kanade.tachiyomi.ui.reader.loader
 import androidx.annotation.CallSuper
 import androidx.collection.lruCache
 import com.hippo.ehviewer.Settings
+import com.hippo.ehviewer.gallery.Page
+import com.hippo.ehviewer.gallery.PageStatus
+import com.hippo.ehviewer.gallery.reset
+import com.hippo.ehviewer.gallery.status
 import com.hippo.ehviewer.image.Image
 import com.hippo.ehviewer.util.OSUtils
 import com.hippo.ehviewer.util.isAtLeastO
-import eu.kanade.tachiyomi.source.model.Page
-import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
 import eu.kanade.tachiyomi.util.lang.withIOContext
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.update
 
 private const val MAX_CACHE_SIZE = 512 * 1024 * 1024
 private const val MIN_CACHE_SIZE = 128 * 1024 * 1024
@@ -35,7 +39,7 @@ abstract class PageLoader {
 
     val pages by lazy {
         check(size > 0)
-        (0 until size).map { ReaderPage(it) }
+        (0 until size).map { Page(it) }
     }
 
     private val prefetchPageCount = Settings.preloadImage
@@ -58,7 +62,7 @@ abstract class PageLoader {
 
     fun restart() {
         cache.evictAll()
-        pages.forEach(ReaderPage::reset)
+        pages.forEach(Page::reset)
     }
 
     abstract val size: Int
@@ -80,7 +84,7 @@ abstract class PageLoader {
         } else {
             index - 1 downTo (index - prefetchPageCount).coerceAtLeast(0)
         }
-        val pagesAbsent = prefetchRange.filter { pages[it].status.value == Page.State.QUEUE }
+        val pagesAbsent = prefetchRange.filter { pages[it].status == PageStatus.Queued }
         val start = if (prefetchRange.step > 0) prefetchRange.first else prefetchRange.last
         val end = if (prefetchRange.step > 0) prefetchRange.last else prefetchRange.first
         prefetchPages(pagesAbsent, start - 5 to end + 5)
@@ -110,27 +114,22 @@ abstract class PageLoader {
     }
 
     fun notifyPagePercent(index: Int, percent: Float) {
-        pages[index].progress = (percent * 100).toInt()
-        pages[index].status.compareAndSet(Page.State.QUEUE, Page.State.DOWNLOAD_IMAGE)
+        pages[index].statusFlow.update {
+            when (it) {
+                is PageStatus.Loading -> it.apply { progress.update { percent } }
+                else -> PageStatus.Loading(MutableStateFlow(percent))
+            }
+        }
     }
 
     fun notifyPageSucceed(index: Int, image: Image, replaceCache: Boolean = true) {
         if (replaceCache) {
             cache.put(index, image)
         }
-        pages[index].image = image
-        pages[index].status.value = if (image.hasQrCode) Page.State.BLOCKED else Page.State.READY
+        pages[index].statusFlow.update { if (image.hasQrCode) PageStatus.Blocked(image) else PageStatus.Ready(image) }
     }
 
     fun notifyPageFailed(index: Int, error: String?) {
-        pages[index].errorMsg = error
-        pages[index].status.value = Page.State.ERROR
+        pages[index].statusFlow.update { PageStatus.Error(error) }
     }
 }
-
-private fun ReaderPage.reset() {
-    image = null
-    errorMsg = null
-    progress = 0
-    status.value = Page.State.QUEUE
-}

app/src/main/kotlin/eu/kanade/tachiyomi/ui/reader/model/ReaderPage.kt

@@ -1,8 +0,0 @@
-package eu.kanade.tachiyomi.ui.reader.model
-
-import com.hippo.ehviewer.image.Image
-import eu.kanade.tachiyomi.source.model.Page
-
-class ReaderPage(index: Int) : Page(index) {
-    var image: Image? = null
-}