Enable 'next article'

Author: frearb

app/src/main/java/me/ash/reader/data/dao/ArticleDao.kt

@@ -518,6 +518,18 @@ interface ArticleDao {
     )
     suspend fun queryById(id: String): ArticleWithFeed?
 
+    @Transaction
+    @Query(
+        """
+        SELECT * FROM article
+        WHERE feedId = :feedId
+        AND isUnread = :isUnread
+        AND date <= :date
+        ORDER BY date DESC LIMIT 1
+        """
+    )
+    suspend fun queryNextByDate(feedId: String, date: Date, isUnread: Boolean): ArticleWithFeed?
+
     @Insert
     suspend fun insertList(articles: List<Article>): List<Long>
 

app/src/main/java/me/ash/reader/data/repository/AbstractRssRepository.kt

@@ -127,6 +127,9 @@ abstract class AbstractRssRepository constructor(
 
     suspend fun findArticleById(id: String): ArticleWithFeed? = articleDao.queryById(id)
 
+    suspend fun findNextArticleByDate(feedId: String, date: Date): ArticleWithFeed? =
+        articleDao.queryNextByDate(feedId, date, true)
+
     suspend fun isFeedExist(url: String): Boolean = feedDao.queryByLink(context.currentAccountId, url).isNotEmpty()
 
     suspend fun updateGroup(group: Group) {

app/src/main/java/me/ash/reader/ui/page/home/reading/BottomBar.kt

@@ -33,6 +33,7 @@ fun BottomBar(
     isFullContent: Boolean,
     onUnread: (isUnread: Boolean) -> Unit = {},
     onStarred: (isStarred: Boolean) -> Unit = {},
+    onNextArticle: () -> Unit = {},
     onFullContent: (isFullContent: Boolean) -> Unit = {},
 ) {
     val tonalElevation = LocalReadingPageTonalElevation.current
@@ -95,13 +96,14 @@ fun BottomBar(
                         onStarred(!isStarred)
                     }
                     CanBeDisabledIconButton(
-                        disabled = true,
+                        disabled = false,
                         modifier = Modifier.size(40.dp),
                         imageVector = Icons.Rounded.ExpandMore,
                         contentDescription = "Next Article",
                         tint = MaterialTheme.colorScheme.outline,
                     ) {
                         view.performHapticFeedback(HapticFeedbackConstants.KEYBOARD_TAP)
+                        onNextArticle()
                     }
                     CanBeDisabledIconButton(
                         modifier = Modifier.size(36.dp),

app/src/main/java/me/ash/reader/ui/page/home/reading/ReadingPage.kt

@@ -90,6 +90,9 @@ fun ReadingPage(
                         onStarred = {
                             readingViewModel.markStarred(it)
                         },
+                        onNextArticle = {
+                            readingViewModel.nextArticle(navController)
+                        },
                         onFullContent = {
                             if (it) readingViewModel.renderFullContent()
                             else readingViewModel.renderDescriptionContent()

app/src/main/java/me/ash/reader/ui/page/home/reading/ReadingViewModel.kt

@@ -4,6 +4,7 @@ import android.util.Log
 import androidx.compose.foundation.lazy.LazyListState
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import androidx.navigation.NavController
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -14,6 +15,7 @@ import kotlinx.coroutines.launch
 import me.ash.reader.data.model.article.ArticleWithFeed
 import me.ash.reader.data.repository.RssHelper
 import me.ash.reader.data.repository.RssRepository
+import me.ash.reader.ui.page.common.RouteName
 import javax.inject.Inject
 
 @HiltViewModel
@@ -114,6 +116,19 @@ class ReadingViewModel @Inject constructor(
         }
     }
 
+    fun nextArticle(navController: NavController) {
+        val cur = _readingUiState.value.articleWithFeed?.article
+        if (cur != null) {
+            viewModelScope.launch {
+                val next = rssRepository.get().findNextArticleByDate(cur.feedId, cur.date)
+                navController.popBackStack()
+                if (next != null) {
+                    navController.navigate("${RouteName.READING}/${next.article.id}")
+                }
+            }
+        }
+    }
+
     private fun showLoading() {
         _readingUiState.update {
             it.copy(isLoading = true)