From 1e995204735e1074b0a42732c9bbfdca7b792b63 Mon Sep 17 00:00:00 2001
From: Pierre-Yves Nicolas <6371790+pynicolas@users.noreply.github.com>
Date: Thu, 2 Apr 2026 17:48:12 +0200
Subject: [PATCH] Thumbnails: avoid loading many Bitmaps, increase cache size

---
 app/src/main/java/org/fairscan/app/MainViewModel.kt    |  2 +-
 .../main/java/org/fairscan/app/data/ImageRepository.kt |  2 +-
 app/src/main/java/org/fairscan/app/ui/PreviewUtils.kt  | 10 +++-------
 .../fairscan/app/ui/screens/document/DocumentScreen.kt |  2 +-
 .../java/org/fairscan/app/ui/state/DocumentUiModel.kt  |  5 +++--
 5 files changed, 9 insertions(+), 12 deletions(-)

diff --git a/app/src/main/java/org/fairscan/app/MainViewModel.kt b/app/src/main/java/org/fairscan/app/MainViewModel.kt
index 2740cd1..db07988 100644
--- a/app/src/main/java/org/fairscan/app/MainViewModel.kt
+++ b/app/src/main/java/org/fairscan/app/MainViewModel.kt
@@ -63,7 +63,7 @@ class MainViewModel(val imageRepository: ImageRepository, launchMode: LaunchMode
         _pages.map { pages ->
             pages.map {
                 val jpeg = imageRepository.getThumbnail(it.key())
-                PageThumbnail(it.key(), jpeg?.toBitmap())
+                PageThumbnail(it.key(), jpeg)
             }.toImmutableList()
         }
         .flowOn(Dispatchers.IO)
diff --git a/app/src/main/java/org/fairscan/app/data/ImageRepository.kt b/app/src/main/java/org/fairscan/app/data/ImageRepository.kt
index 3b45627..ab6bd62 100644
--- a/app/src/main/java/org/fairscan/app/data/ImageRepository.kt
+++ b/app/src/main/java/org/fairscan/app/data/ImageRepository.kt
@@ -67,7 +67,7 @@ class ImageRepository(
 
     private val processingJobs = synchronizedMap(mutableMapOf<PageViewKey, Deferred<Unit>>())
     private val imageCache = createLruCache<PageViewKey, Deferred<Jpeg?>>(maxEntries = 50)
-    private val thumbnailCache = createLruCache<PageViewKey, Deferred<Jpeg?>>(maxEntries = 200)
+    private val thumbnailCache = createLruCache<PageViewKey, Deferred<Jpeg?>>(maxEntries = 1000)
 
     private fun <K, V> createLruCache(maxEntries: Int): MutableMap<K, V> =
         synchronizedMap(object : LinkedHashMap<K, V>(16, 0.75f, true) {
diff --git a/app/src/main/java/org/fairscan/app/ui/PreviewUtils.kt b/app/src/main/java/org/fairscan/app/ui/PreviewUtils.kt
index 0fc6e41..2c6ae74 100644
--- a/app/src/main/java/org/fairscan/app/ui/PreviewUtils.kt
+++ b/app/src/main/java/org/fairscan/app/ui/PreviewUtils.kt
@@ -15,11 +15,10 @@
 package org.fairscan.app.ui
 
 import android.content.Context
-import android.graphics.Bitmap
-import android.graphics.BitmapFactory
 import kotlinx.collections.immutable.ImmutableList
 import kotlinx.collections.immutable.persistentListOf
 import kotlinx.collections.immutable.toImmutableList
+import org.fairscan.app.domain.Jpeg
 import org.fairscan.app.domain.PageViewKey
 import org.fairscan.app.domain.Rotation
 import org.fairscan.app.ui.state.DocumentUiModel
@@ -41,8 +40,5 @@ fun fakeDocument(pageIds: ImmutableList<String>, context: Context): DocumentUiMo
     return DocumentUiModel(pageKeys)
 }
 
-fun fakeImage(id: String, context: Context): Bitmap =
-    context.assets.open("${id}.jpg").use { input ->
-        BitmapFactory.decodeStream(input)
-    }
-
+fun fakeImage(id: String, context: Context): Jpeg =
+    Jpeg(context.assets.open("${id}.jpg").readBytes())
diff --git a/app/src/main/java/org/fairscan/app/ui/screens/document/DocumentScreen.kt b/app/src/main/java/org/fairscan/app/ui/screens/document/DocumentScreen.kt
index 5930fdf..498986e 100644
--- a/app/src/main/java/org/fairscan/app/ui/screens/document/DocumentScreen.kt
+++ b/app/src/main/java/org/fairscan/app/ui/screens/document/DocumentScreen.kt
@@ -339,7 +339,7 @@ private fun BottomBar(
 @Preview(name = "Landscape", showBackground = true, widthDp = 640, heightDp = 320)
 fun DocumentScreenPreview() {
     FairScanTheme {
-        val image = fakeImage("gallica.bnf.fr-bpt6k5530456s-1", LocalContext.current)
+        val image = fakeImage("gallica.bnf.fr-bpt6k5530456s-1", LocalContext.current).toBitmap()
         val document = fakeDocument(
             listOf(1, 2).map { "gallica.bnf.fr-bpt6k5530456s-$it" }.toImmutableList(),
             LocalContext.current
diff --git a/app/src/main/java/org/fairscan/app/ui/state/DocumentUiModel.kt b/app/src/main/java/org/fairscan/app/ui/state/DocumentUiModel.kt
index 1a47814..c0dea9f 100644
--- a/app/src/main/java/org/fairscan/app/ui/state/DocumentUiModel.kt
+++ b/app/src/main/java/org/fairscan/app/ui/state/DocumentUiModel.kt
@@ -17,6 +17,7 @@ package org.fairscan.app.ui.state
 import android.graphics.Bitmap
 import kotlinx.collections.immutable.ImmutableList
 import kotlinx.collections.immutable.persistentListOf
+import org.fairscan.app.domain.Jpeg
 import org.fairscan.app.domain.PageViewKey
 
 data class DocumentUiModel(
@@ -32,11 +33,11 @@ data class DocumentUiModel(
         return pages.lastIndex
     }
     fun thumbnail(index: Int): Bitmap? {
-        return pages[index].thumbnail
+        return pages[index].thumbnail?.toBitmap()
     }
 }
 
 data class PageThumbnail(
     val key: PageViewKey,
-    val thumbnail: Bitmap?,
+    val thumbnail: Jpeg?,
 )