From e44bb309965e63174b89b9e5e527ad9a60d5184f Mon Sep 17 00:00:00 2001
From: Ivan Iskandar <12537387+ivaniskandar@users.noreply.github.com>
Date: Tue, 28 Jun 2022 05:33:57 +0700
Subject: [PATCH] Improve history screen scrolling perf (#7399)

---
 .../presentation/history/HistoryScreen.kt     | 44 +++++++++----------
 .../history/components/HistoryHeader.kt       | 14 +++---
 .../history/components/HistoryItem.kt         |  6 ++-
 3 files changed, 35 insertions(+), 29 deletions(-)

diff --git a/app/src/main/java/eu/kanade/presentation/history/HistoryScreen.kt b/app/src/main/java/eu/kanade/presentation/history/HistoryScreen.kt
index 40588cdec..69e70a59f 100644
--- a/app/src/main/java/eu/kanade/presentation/history/HistoryScreen.kt
+++ b/app/src/main/java/eu/kanade/presentation/history/HistoryScreen.kt
@@ -99,28 +99,6 @@ fun HistoryContent(
 
     val scrollState = rememberLazyListState()
 
-    val transition = rememberInfiniteTransition()
-
-    val translateAnimation = transition.animateFloat(
-        initialValue = 0f,
-        targetValue = 1000f,
-        animationSpec = infiniteRepeatable(
-            animation = tween(
-                durationMillis = 1000,
-                easing = LinearEasing,
-            ),
-        ),
-    )
-
-    val brush = linearGradient(
-        colors = shimmerGradient,
-        start = Offset(0f, 0f),
-        end = Offset(
-            x = translateAnimation.value,
-            y = 00f,
-        ),
-    )
-
     ScrollbarLazyColumn(
         modifier = Modifier
             .nestedScroll(nestedScroll),
@@ -149,6 +127,28 @@ fun HistoryContent(
                     )
                 }
                 null -> {
+                    val transition = rememberInfiniteTransition()
+                    val translateAnimation = transition.animateFloat(
+                        initialValue = 0f,
+                        targetValue = 1000f,
+                        animationSpec = infiniteRepeatable(
+                            animation = tween(
+                                durationMillis = 1000,
+                                easing = LinearEasing,
+                            ),
+                        ),
+                    )
+
+                    val brush = remember {
+                        linearGradient(
+                            colors = shimmerGradient,
+                            start = Offset(0f, 0f),
+                            end = Offset(
+                                x = translateAnimation.value,
+                                y = 00f,
+                            ),
+                        )
+                    }
                     HistoryItemShimmer(brush = brush)
                 }
             }
diff --git a/app/src/main/java/eu/kanade/presentation/history/components/HistoryHeader.kt b/app/src/main/java/eu/kanade/presentation/history/components/HistoryHeader.kt
index 18f5b5f64..747955fe1 100644
--- a/app/src/main/java/eu/kanade/presentation/history/components/HistoryHeader.kt
+++ b/app/src/main/java/eu/kanade/presentation/history/components/HistoryHeader.kt
@@ -4,6 +4,7 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.text.font.FontWeight
@@ -20,14 +21,17 @@ fun HistoryHeader(
     relativeTime: Int,
     dateFormat: DateFormat,
 ) {
+    val context = LocalContext.current
     Text(
         modifier = modifier
             .padding(horizontal = horizontalPadding, vertical = 8.dp),
-        text = date.toRelativeString(
-            LocalContext.current,
-            relativeTime,
-            dateFormat,
-        ),
+        text = remember {
+            date.toRelativeString(
+                context,
+                relativeTime,
+                dateFormat,
+            )
+        },
         style = MaterialTheme.typography.bodyMedium.copy(
             color = MaterialTheme.colorScheme.onSurfaceVariant,
             fontWeight = FontWeight.SemiBold,
diff --git a/app/src/main/java/eu/kanade/presentation/history/components/HistoryItem.kt b/app/src/main/java/eu/kanade/presentation/history/components/HistoryItem.kt
index 1be3d22d7..e720ce46d 100644
--- a/app/src/main/java/eu/kanade/presentation/history/components/HistoryItem.kt
+++ b/app/src/main/java/eu/kanade/presentation/history/components/HistoryItem.kt
@@ -17,6 +17,7 @@ import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
@@ -68,15 +69,16 @@ fun HistoryItem(
                 overflow = TextOverflow.Ellipsis,
                 style = textStyle.copy(fontWeight = FontWeight.SemiBold),
             )
+            val readAt = remember { history.readAt?.toTimestampString() ?: "" }
             Text(
                 text = if (history.chapterNumber > -1) {
                     stringResource(
                         R.string.recent_manga_time,
                         chapterFormatter.format(history.chapterNumber),
-                        history.readAt?.toTimestampString() ?: "",
+                        readAt,
                     )
                 } else {
-                    history.readAt?.toTimestampString() ?: ""
+                    readAt
                 },
                 modifier = Modifier.padding(top = 4.dp),
                 style = textStyle,