improve json serialization

app/src/main/java/de/jrpie/android/launcher/Application.kt

@@ -13,6 +13,8 @@ import de.jrpie.android.launcher.actions.TorchManager
 import de.jrpie.android.launcher.apps.AppInfo
 import de.jrpie.android.launcher.apps.DetailedAppInfo
 import de.jrpie.android.launcher.preferences.LauncherPreferences
+import de.jrpie.android.launcher.preferences.migratePreferencesToNewVersion
+import de.jrpie.android.launcher.preferences.resetPreferences
 
 class Application : android.app.Application() {
     val apps = MutableLiveData<List<DetailedAppInfo>>()
@@ -85,6 +87,19 @@ class Application : android.app.Application() {
         val preferences = PreferenceManager.getDefaultSharedPreferences(this)
         LauncherPreferences.init(preferences, this.resources)
 
+
+        // Try to restore old preferences
+        migratePreferencesToNewVersion(this)
+
+        // First time opening the app: set defaults and start tutorial
+        if (!LauncherPreferences.internal().started()) {
+            resetPreferences(this)
+
+            LauncherPreferences.internal().started(true)
+            openTutorial(this)
+        }
+
+
         LauncherPreferences.getSharedPreferences()
             .registerOnSharedPreferenceChangeListener(listener)
 

app/src/main/java/de/jrpie/android/launcher/Functions.kt

@@ -75,7 +75,9 @@ fun openInBrowser(url: String, context: Context) {
 }
 
 fun openTutorial(context: Context) {
-    context.startActivity(Intent(context, TutorialActivity::class.java))
+    context.startActivity(Intent(context, TutorialActivity::class.java).apply {
+        addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+    })
 }
 
 

app/src/main/java/de/jrpie/android/launcher/actions/LauncherAction.kt

@@ -19,10 +19,13 @@ import kotlinx.serialization.KSerializer
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
 import kotlinx.serialization.SerializationException
+import kotlinx.serialization.builtins.serializer
 import kotlinx.serialization.descriptors.SerialDescriptor
 import kotlinx.serialization.descriptors.buildClassSerialDescriptor
 import kotlinx.serialization.encoding.Decoder
 import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.encoding.decodeStructure
+import kotlinx.serialization.encoding.encodeStructure
 
 @Serializable(with = LauncherActionSerializer::class)
 @SerialName("action:launcher")
@@ -248,30 +251,27 @@ fun openAppsList(context: Context, favorite: Boolean = false, hidden: Boolean =
     context.startActivity(intent)
 }
 
-
+/* A custom serializer is required to store type information,
-/**
+   see https://github.com/Kotlin/kotlinx.serialization/issues/1486
- * LauncherAction can't be serialized directly, since it needs a type annotation.
- * Thus this hack is needed.
  */
-@Serializable
+private class LauncherActionSerializer : KSerializer<LauncherAction> {
-private class LauncherActionWrapper(val id: String)
-
-private class LauncherActionSerializer() : KSerializer<LauncherAction> {
     override val descriptor: SerialDescriptor = buildClassSerialDescriptor(
         "action:launcher",
     ) {
-        element("id", LauncherActionWrapper.serializer().descriptor)
+        element("value", String.serializer().descriptor)
     }
     override fun deserialize(decoder: Decoder): LauncherAction {
-        val wrapper = decoder.decodeSerializableValue(LauncherActionWrapper.serializer())
+        val s = decoder.decodeStructure(descriptor) {
-        return LauncherAction.byId(wrapper.id) ?: throw SerializationException()
+            decodeElementIndex(descriptor)
+            decodeSerializableElement(descriptor, 0, String.serializer())
+        }
+        return LauncherAction.byId(s) ?: throw SerializationException()
     }
 
     override fun serialize(encoder: Encoder, value: LauncherAction) {
-        encoder.encodeSerializableValue(
+        encoder.encodeStructure(descriptor) {
-            LauncherActionWrapper.serializer(),
+            encodeSerializableElement(descriptor, 0, String.serializer(), value.id)
-            LauncherActionWrapper(value.id)
+        }
-        )
     }
 
 }

app/src/main/java/de/jrpie/android/launcher/preferences/LauncherPreferences$Config.java

@@ -1,23 +1,18 @@
 package de.jrpie.android.launcher.preferences;
 
-import org.json.JSONException;
-import org.json.JSONObject;
-
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.Set;
 
 import de.jrpie.android.launcher.R;
 import de.jrpie.android.launcher.actions.lock.LockMethod;
-import de.jrpie.android.launcher.apps.AppInfo;
+import de.jrpie.android.launcher.preferences.serialization.SetAppInfoPreferenceSerializer;
+import de.jrpie.android.launcher.preferences.serialization.MapAppInfoStringPreferenceSerializer;
 import de.jrpie.android.launcher.preferences.theme.Background;
 import de.jrpie.android.launcher.preferences.theme.ColorTheme;
 import de.jrpie.android.launcher.preferences.theme.Font;
 import eu.jonahbauer.android.preference.annotations.Preference;
 import eu.jonahbauer.android.preference.annotations.PreferenceGroup;
 import eu.jonahbauer.android.preference.annotations.Preferences;
-import eu.jonahbauer.android.preference.annotations.serializer.PreferenceSerializationException;
-import eu.jonahbauer.android.preference.annotations.serializer.PreferenceSerializer;
 
 @Preferences(
         name = "de.jrpie.android.launcher.preferences.LauncherPreferences",
@@ -30,9 +25,9 @@ import eu.jonahbauer.android.preference.annotations.serializer.PreferenceSeriali
                         @Preference(name = "version_code", type = int.class, defaultValue = "-1"),
                 }),
                 @PreferenceGroup(name = "apps", prefix = "settings_apps_", suffix = "_key", value = {
-                        @Preference(name = "favorites", type = Set.class, serializer = LauncherPreferences$Config.AppInfoSetSerializer.class),
+                        @Preference(name = "favorites", type = Set.class, serializer = SetAppInfoPreferenceSerializer.class),
-                        @Preference(name = "hidden", type = Set.class, serializer = LauncherPreferences$Config.AppInfoSetSerializer.class),
+                        @Preference(name = "hidden", type = Set.class, serializer = SetAppInfoPreferenceSerializer.class),
-                        @Preference(name = "custom_names", type = HashMap.class, serializer = LauncherPreferences$Config.MapAppInfoStringSerializer.class),
+                        @Preference(name = "custom_names", type = HashMap.class, serializer = MapAppInfoStringPreferenceSerializer.class),
                         @Preference(name = "hide_bound_apps", type = boolean.class, defaultValue = "false"),
                 }),
                 @PreferenceGroup(name = "list", prefix = "settings_list_", suffix = "_key", value = {
@@ -78,74 +73,4 @@ import eu.jonahbauer.android.preference.annotations.serializer.PreferenceSeriali
                         @Preference(name = "lock_method", type = LockMethod.class, defaultValue = "DEVICE_ADMIN"),
                 }),
         })
-public final class LauncherPreferences$Config {
+public final class LauncherPreferences$Config {}
-    public static class AppInfoSetSerializer implements PreferenceSerializer<Set<AppInfo>, Set<String>> {
-
-        @Override
-        public Set<String> serialize(Set<AppInfo> value) throws PreferenceSerializationException {
-            if (value == null) return null;
-
-            var serialized = new HashSet<String>(value.size());
-            for (var app : value) {
-                serialized.add(app.serialize());
-            }
-
-            return serialized;
-        }
-
-        @Override
-        public Set<AppInfo> deserialize(Set<String> value) throws PreferenceSerializationException {
-            if (value == null) return null;
-
-            var deserialized = new HashSet<AppInfo>(value.size());
-
-            for (var s : value) {
-                deserialized.add(AppInfo.Companion.deserialize(s));
-            }
-
-            return deserialized;
-        }
-    }
-
-    // TODO migrate to version 2
-    public static class MapAppInfoStringSerializer implements PreferenceSerializer<HashMap<AppInfo, String>, Set<String>> {
-
-        @Override
-        public Set<String> serialize(HashMap<AppInfo, String> value) throws PreferenceSerializationException {
-            if (value == null) return null;
-
-            var serialized = new HashSet<String>(value.size());
-
-            for (var entry : value.entrySet()) {
-                JSONObject obj = new JSONObject();
-                try {
-                    obj.put("key", entry.getKey().serialize());
-                    obj.put("value", entry.getValue());
-                    serialized.add(obj.toString());
-                } catch (JSONException ignored) {
-                }
-            }
-
-            return serialized;
-        }
-
-        @Override
-        public HashMap<AppInfo, String> deserialize(Set<String> value) throws PreferenceSerializationException {
-            if (value == null) return null;
-
-            var deserialized = new HashMap<AppInfo, String>();
-
-            for (var entry : value) {
-                try {
-                    JSONObject obj = new JSONObject(entry);
-                    AppInfo info = AppInfo.Companion.deserialize(obj.getString("key"));
-                    String s = obj.getString("value");
-                    deserialized.put(info, s);
-                } catch (JSONException ignored) {
-                }
-            }
-
-            return deserialized;
-        }
-    }
-}

app/src/main/java/de/jrpie/android/launcher/preferences/Preferences.kt

@@ -6,8 +6,8 @@ import de.jrpie.android.launcher.BuildConfig
 import de.jrpie.android.launcher.actions.Action
 import de.jrpie.android.launcher.apps.AppInfo
 import de.jrpie.android.launcher.apps.DetailedAppInfo
-import de.jrpie.android.launcher.preferences.legacy.migratePreferencesFromVersionUnknown
 import de.jrpie.android.launcher.preferences.legacy.migratePreferencesFromVersion1
+import de.jrpie.android.launcher.preferences.legacy.migratePreferencesFromVersionUnknown
 import de.jrpie.android.launcher.ui.HomeActivity
 
 /* Current version of the structure of preferences.
@@ -19,8 +19,12 @@ const val UNKNOWN_PREFERENCE_VERSION = -1
 private const val TAG = "Launcher - Preferences"
 
 
-
+/*
+ * Tries to detect preferences written by older versions of the app
+ * and migrate them to the current format.
+ */
 fun migratePreferencesToNewVersion(context: Context) {
+    try {
         when (LauncherPreferences.internal().versionCode()) {
             // Check versions, make sure transitions between versions go well
             PREFERENCE_VERSION -> { /* the version installed and used previously are the same */
@@ -31,6 +35,7 @@ fun migratePreferencesToNewVersion(context: Context) {
 
                 Log.i(TAG, "migration of preferences complete.")
             }
+
             1 -> {
                 migratePreferencesFromVersion1()
                 Log.i(TAG, "migration of preferences complete.")
@@ -45,6 +50,10 @@ fun migratePreferencesToNewVersion(context: Context) {
                 )
             }
         }
+    } catch (e: Exception) {
+        Log.e(TAG, "Unable to restore preferences:\n${e.stackTrace}")
+        resetPreferences(context)
+    }
 }
 
 fun resetPreferences(context: Context) {

app/src/main/java/de/jrpie/android/launcher/preferences/legacy/Version1.kt

@@ -7,8 +7,12 @@ import de.jrpie.android.launcher.actions.LauncherAction
 import de.jrpie.android.launcher.apps.AppInfo
 import de.jrpie.android.launcher.apps.AppInfo.Companion.INVALID_USER
 import de.jrpie.android.launcher.preferences.LauncherPreferences
+import de.jrpie.android.launcher.preferences.PREFERENCE_VERSION
+import de.jrpie.android.launcher.preferences.serialization.MapAppInfoStringPreferenceSerializer
 import kotlinx.serialization.encodeToString
 import kotlinx.serialization.json.Json
+import org.json.JSONException
+import org.json.JSONObject
 
 val oldLauncherActionIds: Map<String, LauncherAction> =
     mapOf(
@@ -44,7 +48,7 @@ private fun AppInfo.Companion.legacyDeserialize(serialized: String): AppInfo {
  *  @param id
  *  @param user a user id, ignored if the action is a [LauncherAction].
  */
-private fun Action.Companion.fromId(id: String, user: Int?): Action? {
+private fun Action.Companion.legacyFromId(id: String, user: Int?): Action? {
     if (id.isEmpty()) {
         return null
     }
@@ -68,7 +72,25 @@ private fun Action.Companion.legacyFromPreference(id: String): Action? {
     )
     u = if (u == AppInfo.INVALID_USER) null else u
 
-    return Action.fromId(actionId, u)
+    return Action.legacyFromId(actionId, u)
+}
+
+private fun migrateAppInfoStringMap(key: String) {
+    val preferences = LauncherPreferences.getSharedPreferences()
+    MapAppInfoStringPreferenceSerializer().serialize(
+        preferences.getStringSet(key, setOf())?.mapNotNull { entry ->
+            try {
+                val obj = JSONObject(entry);
+                val info = AppInfo.legacyDeserialize(obj.getString("key"))
+                val value = obj.getString("value");
+                Pair(info, value)
+            } catch (_: JSONException) {
+                null
+            }
+        }?.toMap(HashMap())
+    )?.let {
+        preferences.edit().putStringSet(key, it as Set<String>).apply()
+    }
 }
 
 private fun migrateAppInfoSet(key: String) {
@@ -82,13 +104,24 @@ private fun migrateAppInfoSet(key: String) {
 private fun migrateAction(key: String) {
     Action.legacyFromPreference(key)?.let { action ->
         LauncherPreferences.getSharedPreferences().edit()
-            .putString(key, Json.encodeToString(action)).apply()
+            .putString(key, Json.encodeToString(action))
+            .remove("$key.app")
+            .remove("$key.user")
+            .apply()
     }
 
 }
 
+/**
+ * Migrate preferences from version 1 (used until version j-0.0.18) to the current format
+ * (see [PREFERENCE_VERSION])
+ */
 fun migratePreferencesFromVersion1() {
+    assert(PREFERENCE_VERSION == 2)
+    assert(LauncherPreferences.internal().versionCode() == 1)
     Gesture.entries.forEach { g -> migrateAction(g.id) }
     migrateAppInfoSet(LauncherPreferences.apps().keys().hidden())
     migrateAppInfoSet(LauncherPreferences.apps().keys().favorites())
+    migrateAppInfoStringMap(LauncherPreferences.apps().keys().customNames())
+    LauncherPreferences.internal().versionCode(2)
 }

app/src/main/java/de/jrpie/android/launcher/preferences/legacy/VersionUnknown.kt

@@ -4,9 +4,12 @@ import android.content.Context
 import android.content.SharedPreferences
 import android.util.Log
 import de.jrpie.android.launcher.preferences.LauncherPreferences
+import de.jrpie.android.launcher.preferences.PREFERENCE_VERSION
 import de.jrpie.android.launcher.preferences.theme.Background
 import de.jrpie.android.launcher.preferences.theme.ColorTheme
 
+
+
 private fun migrateStringPreference(
     oldPrefs: SharedPreferences,
     newPreferences: SharedPreferences.Editor,
@@ -42,7 +45,13 @@ private fun migrateBooleanPreference(
 
 private const val TAG = "Preferences ? -> 1"
 
+/**
+ * Try to migrate from a very old preference version, where no version number was stored
+ * and a different file was used.
+ */
 fun migratePreferencesFromVersionUnknown(context: Context) {
+    assert(PREFERENCE_VERSION == 2)
+
     Log.i(
         TAG,
         "Unknown preference version, trying to restore preferences from old version."

app/src/main/java/de/jrpie/android/launcher/preferences/serialization/PreferenceSerializers.kt

@@ -0,0 +1,49 @@
+@file:Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN")
+
+package de.jrpie.android.launcher.preferences.serialization
+
+import de.jrpie.android.launcher.apps.AppInfo
+import eu.jonahbauer.android.preference.annotations.serializer.PreferenceSerializationException
+import eu.jonahbauer.android.preference.annotations.serializer.PreferenceSerializer
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
+
+
+// Serializers for [LauncherPreference$Config]
+@Suppress("UNCHECKED_CAST")
+class SetAppInfoPreferenceSerializer :
+    PreferenceSerializer<java.util.Set<AppInfo>?, java.util.Set<java.lang.String>?> {
+    @Throws(PreferenceSerializationException::class)
+    override fun serialize(value: java.util.Set<AppInfo>?): java.util.Set<java.lang.String>? {
+        return value?.map(AppInfo::serialize)?.toHashSet() as java.util.Set<java.lang.String>
+    }
+
+    @Throws(PreferenceSerializationException::class)
+    override fun deserialize(value: java.util.Set<java.lang.String>?): java.util.Set<AppInfo>? {
+        return value?.map (java.lang.String::toString)?.map(AppInfo::deserialize)?.toHashSet() as? java.util.Set<AppInfo>
+    }
+}
+
+@Suppress("UNCHECKED_CAST")
+class MapAppInfoStringPreferenceSerializer :
+    PreferenceSerializer<java.util.HashMap<AppInfo, String>?, java.util.Set<java.lang.String>?> {
+
+    @Serializable()
+    private class MapEntry(val key: AppInfo, val value: String)
+
+    @Throws(PreferenceSerializationException::class)
+    override fun serialize(value: java.util.HashMap<AppInfo, String>?): java.util.Set<java.lang.String>? {
+        return value?.map { (key, value) ->
+            Json.encodeToString(MapEntry(key, value))
+        }?.toHashSet() as? java.util.Set<java.lang.String>
+    }
+
+    @Throws(PreferenceSerializationException::class)
+    override fun deserialize(value: java.util.Set<java.lang.String>?): java.util.HashMap<AppInfo, String>? {
+        return value?.associateTo(HashMap()) {
+            val entry = Json.decodeFromString<MapEntry>(it.toString())
+            Pair(entry.key, entry.value)
+        }
+    }
+}

app/src/main/java/de/jrpie/android/launcher/ui/HomeActivity.kt

@@ -76,17 +76,6 @@ class HomeActivity : UIObject, AppCompatActivity(),
         super<AppCompatActivity>.onCreate(savedInstanceState)
         super<UIObject>.onCreate()
 
-        // Try to restore old preferences
-        migratePreferencesToNewVersion(this)
-
-        // First time opening the app: set defaults and start tutorial
-        if (!LauncherPreferences.internal().started()) {
-            resetPreferences(this)
-
-            LauncherPreferences.internal().started(true)
-            openTutorial(this)
-        }
-
         // Initialise layout
         binding = HomeBinding.inflate(layoutInflater)
         setContentView(binding.root)

app/src/main/res/values/defaults.xml

@@ -5,12 +5,12 @@
 
     <!-- Swipe up - Apps list -->
     <string-array name="default_up">
-        <item>{\"type\": \"action:launcher\", \"id\": \"choose\"}</item> <!-- All Apps -->
+        <item>{\"type\": \"action:launcher\", \"value\": \"choose\"}</item> <!-- All Apps -->
     </string-array>
 
     <!-- Swipe up (left edge) - Favorite Apps -->
     <string-array name="default_up_left">
-        <item>{\"type\": \"action:launcher\", \"id\": \"choose_from_favorites\"}</item>
+        <item>{\"type\": \"action:launcher\", \"value\": \"choose_from_favorites\"}</item>
     </string-array>
 
     <!-- Swipe up (right edge) - Maps -->
@@ -106,12 +106,12 @@
 
     <!-- Volume up -->
     <string-array name="default_volume_up">
-        <item>{\"type\": \"action:launcher\", \"id\": \"volume_up\"}</item>
+        <item>{\"type\": \"action:launcher\", \"value\": \"volume_up\"}</item>
     </string-array>
 
     <!-- Volume down -->
     <string-array name="default_volume_down">
-        <item>{\"type\": \"action:launcher\", \"id\": \"volume_down\"}</item>
+        <item>{\"type\": \"action:launcher\", \"value\": \"volume_down\"}</item>
     </string-array>
 
     <!-- Double click - Notes -->
@@ -119,7 +119,7 @@
         <item>{\"type\": \"action:app\", \"app\": {\"packageName\": \"it.niedermann.owncloud.notes\", \"activityName\": null}}</item>
         <item>{\"type\": \"action:app\", \"app\": {\"packageName\": \"com.samsung.android.app.notes\", \"activityName\": null}}</item> <!-- Samsung Notes -->
         <item>{\"type\": \"action:app\", \"app\": {\"packageName\": \"com.sec.android.widgetapp.diotek.smemo\", \"activityName\": null}}</item> <!-- S Memo (older devices) -->
-        <item>{\"type\": \"action:launcher\", \"id\": \"lock_screen\"}</item>
+        <item>{\"type\": \"action:launcher\", \"value\": \"lock_screen\"}</item>
     </string-array>
 
     <!-- Long click - Security -->
@@ -128,7 +128,7 @@
         <item>{\"type\": \"action:app\", \"app\": {\"packageName\": \"org.fedorahosted.freeotp\", \"activityName\": null}}</item>
         <item>{\"type\": \"action:app\", \"app\": {\"packageName\": \"proton.android.pass.fdroid\", \"activityName\": null}}</item> <!-- Proton Pass -->
         <item>{\"type\": \"action:app\", \"app\": {\"packageName\": \"com.kunzisoft.keepass.libre\", \"activityName\": null}}</item> <!-- KeePassDX -->
-        <item>{\"type\": \"action:launcher\", \"id\": \"settings\"}</item> <!-- Launcher Settings -->
+        <item>{\"type\": \"action:launcher\", \"value\": \"settings\"}</item> <!-- Launcher Settings -->
     </string-array>
 
     <!-- Time / Clock -->