Encode icons in PNG, because JPEG doesn't support transparency

This caused black squares around icons.

app/src/androidTest/java/com/stevesoltys/seedvault/worker/IconManagerTest.kt

@@ -5,10 +5,14 @@
 
 package com.stevesoltys.seedvault.worker
 
+import android.content.pm.PackageInfo
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import androidx.test.filters.MediumTest
 import androidx.test.platform.app.InstrumentationRegistry
+import com.github.luben.zstd.ZstdOutputStream
 import com.google.protobuf.ByteString
+import com.stevesoltys.seedvault.MAGIC_PACKAGE_MANAGER
+import com.stevesoltys.seedvault.metadata.BackupType
 import com.stevesoltys.seedvault.proto.SnapshotKt.blob
 import com.stevesoltys.seedvault.repo.AppBackupManager
 import com.stevesoltys.seedvault.repo.BackupData
@@ -32,6 +36,7 @@ import org.junit.runner.RunWith
 import org.koin.core.component.KoinComponent
 import org.koin.core.component.inject
 import java.io.ByteArrayInputStream
+import java.io.ByteArrayOutputStream
 import kotlin.random.Random
 
 @RunWith(AndroidJUnit4::class)
@@ -76,6 +81,11 @@ class IconManagerTest : KoinComponent {
         iconManager.uploadIcons()
         assertTrue(output.captured.isNotEmpty())
 
+        // @pm@ is needed
+        val pmPackageInfo = PackageInfo().apply { packageName = MAGIC_PACKAGE_MANAGER }
+        val backupData = BackupData(emptyList(), emptyMap())
+        snapshotCreator.onPackageBackedUp(pmPackageInfo, BackupType.KV, backupData)
+
         // get snapshot and assert it has icon chunks
         val snapshot = snapshotCreator.finalizeSnapshot()
         assertTrue(snapshot.iconChunkIdsCount > 0)
@@ -106,6 +116,13 @@ class IconManagerTest : KoinComponent {
         assertTrue(output2.captured.isNotEmpty())
 
         assertArrayEquals(output1.captured, output2.captured)
+
+        // print compressed and uncompressed size
+        val size = output1.captured.size.toFloat() / 1024 / 1024
+        val outputStream = ByteArrayOutputStream()
+        ZstdOutputStream(outputStream).use { it.write(output1.captured) }
+        val compressedSize = outputStream.size().toFloat() / 1024 / 1024
+        println("Icon size: $size MB, compressed $compressedSize MB")
     }
 
 }

app/src/main/java/com/stevesoltys/seedvault/worker/IconManager.kt

@@ -6,7 +6,7 @@
 package com.stevesoltys.seedvault.worker
 
 import android.content.Context
-import android.graphics.Bitmap.CompressFormat.JPEG
+import android.graphics.Bitmap.CompressFormat.PNG
 import android.graphics.BitmapFactory
 import android.graphics.drawable.Drawable
 import android.util.Log
@@ -40,8 +40,7 @@ import java.util.zip.ZipEntry
 import java.util.zip.ZipInputStream
 import java.util.zip.ZipOutputStream
 
-private const val ICON_SIZE = 128
+private const val ICON_SIZE = 64
-private const val ICON_QUALITY = 75
 private const val CACHE_FOLDER = "restore-icons"
 private val TAG = IconManager::class.simpleName
 
@@ -75,8 +74,10 @@ internal class IconManager(
                     setLastModifiedTime(FileTime.fromMillis(0))
                 }
                 zip.putNextEntry(entry)
-                // WEBP_LOSSY compression wasn't deterministic in our tests, so use JPEG
+                // WEBP_LOSSY compression wasn't deterministic in our tests,
-                drawable.toBitmap(ICON_SIZE, ICON_SIZE).compress(JPEG, ICON_QUALITY, zip)
+                // and JPEG doesn't support transparency (causing black squares),
+                // so use PNG
+                drawable.toBitmap(ICON_SIZE, ICON_SIZE).compress(PNG, 0, zip)
                 entries.add(it.packageName)
                 zip.closeEntry()
             }
@@ -91,8 +92,8 @@ internal class IconManager(
                     setLastModifiedTime(FileTime.fromMillis(0))
                 }
                 zip.putNextEntry(entry)
-                // WEBP_LOSSY compression wasn't deterministic in our tests, so use JPEG
+                // For PNG choice see comment above
-                drawable.toBitmap(ICON_SIZE, ICON_SIZE).compress(JPEG, ICON_QUALITY, zip)
+                drawable.toBitmap(ICON_SIZE, ICON_SIZE).compress(PNG, 0, zip)
                 zip.closeEntry()
             }
         }