fix: 浮动按钮在边界状态下越界崩溃

app/src/main/java/io/legado/app/ui/book/read/ReadBookSearchBar.kt

@@ -29,8 +29,8 @@ fun ReadBookSearchBar(
     val searchVisible = state.isShowingSearchResult &&
             !(state.menuVisible && state.menuState.currentRoute != ReadBookMenuRoute.Main)
     val hasResults = state.searchResultList.isNotEmpty()
-    val currentIndex = state.searchResultIndex
     val totalResults = state.searchResultList.size
+    val currentIndex = state.searchResultIndex.coerceIn(0, (totalResults - 1).coerceAtLeast(0))
 
     Box(Modifier.fillMaxSize()) {
         // Left FAB - previous result
@@ -45,9 +45,11 @@ fun ReadBookSearchBar(
             AppFloatingActionButton(
                 onClick = {
                     val prevIndex = currentIndex - 1
+                    val result = state.searchResultList.getOrNull(prevIndex)
+                        ?: return@AppFloatingActionButton
                     onIntent(
                         ReadBookIntent.NavigateToSearchResult(
-                            state.searchResultList[prevIndex], prevIndex
+                            result, prevIndex
                         )
                     )
                 },
@@ -75,9 +77,11 @@ fun ReadBookSearchBar(
             AppFloatingActionButton(
                 onClick = {
                     val nextIndex = currentIndex + 1
+                    val result = state.searchResultList.getOrNull(nextIndex)
+                        ?: return@AppFloatingActionButton
                     onIntent(
                         ReadBookIntent.NavigateToSearchResult(
-                            state.searchResultList[nextIndex], nextIndex
+                            result, nextIndex
                         )
                     )
                 },

app/src/main/java/io/legado/app/ui/book/read/ReadBookViewModel.kt

@@ -231,9 +231,11 @@ class ReadBookViewModel(
             is ReadBookIntent.HideSearchMenu -> _uiState.update { it.copy(searchMenuVisible = false) }
             is ReadBookIntent.SetSearchResults -> {
                 _uiState.update {
+                    val results = intent.results.toImmutableList()
+                    val index = intent.index.coerceSearchResultIndex(results.size)
                     it.copy(
-                        searchResultList = intent.results.toImmutableList(),
-                        searchResultIndex = intent.index,
+                        searchResultList = results,
+                        searchResultIndex = index,
                         isShowingSearchResult = true,
                         searchMenuVisible = true,
                         menuState = ReadBookMenuState(),
@@ -243,7 +245,13 @@ class ReadBookViewModel(
             }
 
             is ReadBookIntent.SetSearchResultIndex -> {
-                _uiState.update { it.copy(searchResultIndex = intent.index) }
+                _uiState.update {
+                    it.copy(
+                        searchResultIndex = intent.index.coerceSearchResultIndex(
+                            it.searchResultList.size
+                        )
+                    )
+                }
             }
 
             is ReadBookIntent.SetShowingSearchResult -> {
@@ -252,7 +260,13 @@ class ReadBookViewModel(
 
             is ReadBookIntent.NavigateToSearchResult -> {
                 ReadBook.saveCurrentBookProgress()
-                _uiState.update { it.copy(searchResultIndex = intent.index) }
+                _uiState.update {
+                    it.copy(
+                        searchResultIndex = intent.index.coerceSearchResultIndex(
+                            it.searchResultList.size
+                        )
+                    )
+                }
                 navigateToSearchResult(intent.result)
             }
 
@@ -3466,3 +3480,7 @@ private const val TITLE_BAR_ICON_KEY = "icons"
 private const val TOOL_BUTTON_PREFS = "tool_button_config"
 private const val TOOL_BUTTON_KEY = "tool_buttons"
 private const val DEFAULT_ENABLED_BUTTON_COUNT = 5
+
+private fun Int.coerceSearchResultIndex(resultSize: Int): Int {
+    return if (resultSize <= 0) 0 else coerceIn(0, resultSize - 1)
+}