feat: 懒加载

app/src/main/java/com/huanchengfly/tieba/post/ui/page/main/MainPage.kt

@@ -7,7 +7,6 @@ import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxHeight
 import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.pager.HorizontalPager
 import androidx.compose.foundation.pager.rememberPagerState
 import androidx.compose.material.Scaffold
 import androidx.compose.material.icons.Icons
@@ -46,6 +45,7 @@ import com.huanchengfly.tieba.post.ui.page.main.user.UserPage
 import com.huanchengfly.tieba.post.ui.utils.DevicePosture
 import com.huanchengfly.tieba.post.ui.utils.MainNavigationContentPosition
 import com.huanchengfly.tieba.post.ui.utils.MainNavigationType
+import com.huanchengfly.tieba.post.ui.widgets.compose.LazyLoadHorizontalPager
 import com.huanchengfly.tieba.post.utils.appPreferences
 import com.ramcosta.composedestinations.annotation.Destination
 import com.ramcosta.composedestinations.annotation.RootNavGraph
@@ -245,7 +245,7 @@ fun MainPage(
                 }
             }
         ) { paddingValues ->
-            HorizontalPager(
+            LazyLoadHorizontalPager(
                 contentPadding = paddingValues,
                 pageCount = navigationItems.size,
                 state = pagerState,

app/src/main/java/com/huanchengfly/tieba/post/ui/page/main/explore/ExplorePage.kt

@@ -3,7 +3,6 @@ package com.huanchengfly.tieba.post.ui.page.main.explore
 import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.width
-import androidx.compose.foundation.pager.HorizontalPager
 import androidx.compose.foundation.pager.rememberPagerState
 import androidx.compose.material.Scaffold
 import androidx.compose.material.Tab
@@ -30,6 +29,7 @@ import com.huanchengfly.tieba.post.ui.page.main.explore.concern.ConcernPage
 import com.huanchengfly.tieba.post.ui.page.main.explore.hot.HotPage
 import com.huanchengfly.tieba.post.ui.page.main.explore.personalized.PersonalizedPage
 import com.huanchengfly.tieba.post.ui.widgets.compose.ActionItem
+import com.huanchengfly.tieba.post.ui.widgets.compose.LazyLoadHorizontalPager
 import com.huanchengfly.tieba.post.ui.widgets.compose.PagerTabIndicator
 import com.huanchengfly.tieba.post.ui.widgets.compose.Toolbar
 import com.huanchengfly.tieba.post.ui.widgets.compose.accountNavIconIfCompact
@@ -125,7 +125,7 @@ fun ExplorePage(
         },
         modifier = Modifier.fillMaxSize(),
     ) { paddingValues ->
-        HorizontalPager(
+        LazyLoadHorizontalPager(
             contentPadding = paddingValues,
             pageCount = pages.size,
             state = pagerState,

app/src/main/java/com/huanchengfly/tieba/post/ui/page/main/notifications/NotificationsPage.kt

@@ -2,7 +2,6 @@ package com.huanchengfly.tieba.post.ui.page.main.notifications
 
 import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.pager.HorizontalPager
 import androidx.compose.foundation.pager.rememberPagerState
 import androidx.compose.material.Scaffold
 import androidx.compose.material.Tab
@@ -24,6 +23,7 @@ import com.huanchengfly.tieba.post.ui.common.theme.compose.ExtendedTheme
 import com.huanchengfly.tieba.post.ui.page.main.notifications.list.NotificationsListPage
 import com.huanchengfly.tieba.post.ui.page.main.notifications.list.NotificationsType
 import com.huanchengfly.tieba.post.ui.widgets.compose.ActionItem
+import com.huanchengfly.tieba.post.ui.widgets.compose.LazyLoadHorizontalPager
 import com.huanchengfly.tieba.post.ui.widgets.compose.PagerTabIndicator
 import com.huanchengfly.tieba.post.ui.widgets.compose.Toolbar
 import com.huanchengfly.tieba.post.ui.widgets.compose.accountNavIconIfCompact
@@ -86,7 +86,7 @@ fun NotificationsPage() {
         },
         modifier = Modifier.fillMaxSize(),
     ) { paddingValues ->
-        HorizontalPager(
+        LazyLoadHorizontalPager(
             contentPadding = paddingValues,
             pageCount = pages.size,
             state = pagerState,

app/src/main/java/com/huanchengfly/tieba/post/ui/widgets/compose/LazyLoad.kt

@@ -1,14 +1,95 @@
 package com.huanchengfly.tieba.post.ui.widgets.compose
 
+import androidx.compose.foundation.ExperimentalFoundationApi
+import androidx.compose.foundation.gestures.Orientation
+import androidx.compose.foundation.gestures.snapping.SnapFlingBehavior
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.pager.HorizontalPager
+import androidx.compose.foundation.pager.PageSize
+import androidx.compose.foundation.pager.PagerDefaults
+import androidx.compose.foundation.pager.PagerState
+import androidx.compose.foundation.pager.rememberPagerState
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.compositionLocalOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+
+val LocalShouldLoad = compositionLocalOf { true }
 
 @Composable
 fun LazyLoad(
     loaded: Boolean,
     onLoad: () -> Unit,
 ) {
-    LaunchedEffect(key1 = loaded, key2 = onLoad) {
-        if (!loaded) onLoad()
+    val shouldLoad = LocalShouldLoad.current
+    LaunchedEffect(loaded, shouldLoad, onLoad) {
+        if (!loaded && shouldLoad) onLoad()
+    }
+}
+
+@Composable
+fun ProvideShouldLoad(
+    shouldLoad: Boolean,
+    content: @Composable () -> Unit
+) {
+    val currentShouldLoad = LocalShouldLoad.current
+
+    val localShouldLoad = remember(currentShouldLoad, shouldLoad) {
+        currentShouldLoad && shouldLoad
+    }
+
+    CompositionLocalProvider(
+        LocalShouldLoad provides localShouldLoad
+    ) {
+        content()
+    }
+}
+
+@OptIn(ExperimentalFoundationApi::class)
+@Composable
+fun LazyLoadHorizontalPager(
+    pageCount: Int,
+    modifier: Modifier = Modifier,
+    state: PagerState = rememberPagerState(),
+    contentPadding: PaddingValues = PaddingValues(0.dp),
+    pageSize: PageSize = PageSize.Fill,
+    beyondBoundsPageCount: Int = 0,
+    pageSpacing: Dp = 0.dp,
+    verticalAlignment: Alignment.Vertical = Alignment.CenterVertically,
+    flingBehavior: SnapFlingBehavior = PagerDefaults.flingBehavior(state = state),
+    userScrollEnabled: Boolean = true,
+    reverseLayout: Boolean = false,
+    key: ((index: Int) -> Any)? = null,
+    pageNestedScrollConnection: NestedScrollConnection = PagerDefaults.pageNestedScrollConnection(
+        Orientation.Horizontal
+    ),
+    pageContent: @Composable (page: Int) -> Unit
+) {
+    HorizontalPager(
+        pageCount = pageCount,
+        state = state,
+        modifier = modifier,
+        contentPadding = contentPadding,
+        pageSize = pageSize,
+        beyondBoundsPageCount = beyondBoundsPageCount,
+        pageSpacing = pageSpacing,
+        verticalAlignment = verticalAlignment,
+        flingBehavior = flingBehavior,
+        userScrollEnabled = userScrollEnabled,
+        reverseLayout = reverseLayout,
+        key = key,
+        pageNestedScrollConnection = pageNestedScrollConnection
+    ) {
+        ProvideShouldLoad(
+            shouldLoad = it == state.currentPage
+        ) {
+            pageContent(it)
+        }
     }
 }