Take screen density into account when requesting thumbnails (#1262)

* Take screen density into account when requesting thumbnails

Otherwise, we could be asking for images with N size while we needed images for N@2x or N@3x size i.e.

libraries/matrixui/src/main/kotlin/io/element/android/libraries/matrix/ui/media/CoilMediaFetcher.kt

@@ -16,6 +16,7 @@
 
 package io.element.android.libraries.matrix.ui.media
 
+import android.content.Context
 import coil.ImageLoader
 import coil.decode.DataSource
 import coil.decode.ImageSource
@@ -32,8 +33,10 @@ import okio.Buffer
 import okio.Path.Companion.toOkioPath
 import timber.log.Timber
 import java.nio.ByteBuffer
+import kotlin.math.roundToLong
 
 internal class CoilMediaFetcher(
+    private val scalingFunction: (Float) -> Float,
     private val mediaLoader: MatrixMediaLoader,
     private val mediaData: MediaRequestData?,
     private val options: Options
@@ -80,8 +83,8 @@ internal class CoilMediaFetcher(
     private suspend fun fetchThumbnail(mediaSource: MediaSource, kind: MediaRequestData.Kind.Thumbnail, options: Options): FetchResult? {
         return mediaLoader.loadMediaThumbnail(
             source = mediaSource,
-            width = kind.width,
-            height = kind.height
+            width = scalingFunction(kind.width.toFloat()).roundToLong(),
+            height = scalingFunction(kind.height.toFloat()).roundToLong(),
         ).map { byteArray ->
             byteArray.asSourceResult(options)
         }.getOrNull()
@@ -102,6 +105,7 @@ internal class CoilMediaFetcher(
     }
 
     class MediaRequestDataFactory(
+        private val context: Context,
         private val client: MatrixClient
     ) :
         Fetcher.Factory<MediaRequestData> {
@@ -111,6 +115,7 @@ internal class CoilMediaFetcher(
             imageLoader: ImageLoader
         ): Fetcher {
             return CoilMediaFetcher(
+                scalingFunction = { context.resources.displayMetrics.density * it },
                 mediaLoader = client.mediaLoader,
                 mediaData = data,
                 options = options
@@ -119,6 +124,7 @@ internal class CoilMediaFetcher(
     }
 
     class AvatarFactory(
+        private val context: Context,
         private val client: MatrixClient
     ) :
         Fetcher.Factory<AvatarData> {
@@ -129,6 +135,7 @@ internal class CoilMediaFetcher(
             imageLoader: ImageLoader
         ): Fetcher {
             return CoilMediaFetcher(
+                scalingFunction = { context.resources.displayMetrics.density * it },
                 mediaLoader = client.mediaLoader,
                 mediaData = data.toMediaRequestData(),
                 options = options

libraries/matrixui/src/main/kotlin/io/element/android/libraries/matrix/ui/media/ImageLoaderFactories.kt

@@ -46,8 +46,8 @@ class LoggedInImageLoaderFactory @Inject constructor(
                 }
                 add(AvatarDataKeyer())
                 add(MediaRequestDataKeyer())
-                add(CoilMediaFetcher.AvatarFactory(matrixClient))
-                add(CoilMediaFetcher.MediaRequestDataFactory(matrixClient))
+                add(CoilMediaFetcher.AvatarFactory(context, matrixClient))
+                add(CoilMediaFetcher.MediaRequestDataFactory(context, matrixClient))
             }
             .build()
     }