Revert "Revert "Migrate IDP_GRID_NAME usage to LauncherPrefs""

This reverts commit df11959779ca08a48308d9e390eb5b3fdb4bbf35.

Bug: 269569568
Test: In follow-up CL, everything works on device and manual and unit tests
verified original bug from this CL is not present.

Change-Id: I125bbbfd6442cd3fa1e88c9109de536b88981dc6
diff --git a/src/com/android/launcher3/InvariantDeviceProfile.java b/src/com/android/launcher3/InvariantDeviceProfile.java
index 604c1b8..2fb0fa6 100644
--- a/src/com/android/launcher3/InvariantDeviceProfile.java
+++ b/src/com/android/launcher3/InvariantDeviceProfile.java
@@ -16,6 +16,7 @@
 
 package com.android.launcher3;
 
+import static com.android.launcher3.LauncherPrefs.GRID_NAME;
 import static com.android.launcher3.Utilities.dpiFromPx;
 import static com.android.launcher3.config.FeatureFlags.ENABLE_DEVICE_PROFILE_LOGGING;
 import static com.android.launcher3.config.FeatureFlags.ENABLE_TWO_PANEL_HOME;
@@ -93,8 +94,6 @@
     public static final int TYPE_MULTI_DISPLAY = 1;
     public static final int TYPE_TABLET = 2;
 
-    private static final String KEY_IDP_GRID_NAME = "idp_grid_name";
-
     private static final float ICON_SIZE_DEFINED_IN_APP_DP = 48;
 
     // Constants that affects the interpolation curve between statically defined device profile
@@ -207,8 +206,7 @@
         String gridName = getCurrentGridName(context);
         String newGridName = initGrid(context, gridName);
         if (!newGridName.equals(gridName)) {
-            LauncherPrefs.getPrefs(context).edit().putString(KEY_IDP_GRID_NAME, newGridName)
-                    .apply();
+            LauncherPrefs.get(context).put(GRID_NAME, newGridName);
         }
         new DeviceGridState(this).writeToPrefs(context);
 
@@ -316,7 +314,7 @@
     }
 
     public static String getCurrentGridName(Context context) {
-        return LauncherPrefs.getPrefs(context).getString(KEY_IDP_GRID_NAME, null);
+        return LauncherPrefs.get(context).get(GRID_NAME);
     }
 
     private String initGrid(Context context, String gridName) {
@@ -458,9 +456,8 @@
 
 
     public void setCurrentGrid(Context context, String gridName) {
-        Context appContext = context.getApplicationContext();
-        LauncherPrefs.getPrefs(appContext).edit().putString(KEY_IDP_GRID_NAME, gridName).apply();
-        MAIN_EXECUTOR.execute(() -> onConfigChanged(appContext));
+        LauncherPrefs.get(context).put(GRID_NAME, gridName);
+        MAIN_EXECUTOR.execute(() -> onConfigChanged(context.getApplicationContext()));
     }
 
     private Object[] toModelState() {
diff --git a/src/com/android/launcher3/LauncherPrefs.kt b/src/com/android/launcher3/LauncherPrefs.kt
index 2e07e30..befaa64 100644
--- a/src/com/android/launcher3/LauncherPrefs.kt
+++ b/src/com/android/launcher3/LauncherPrefs.kt
@@ -4,6 +4,8 @@
 import android.content.SharedPreferences
 import android.content.SharedPreferences.OnSharedPreferenceChangeListener
 import androidx.annotation.VisibleForTesting
+import com.android.launcher3.LauncherFiles.DEVICE_PREFERENCES_KEY
+import com.android.launcher3.LauncherFiles.SHARED_PREFERENCES_KEY
 import com.android.launcher3.allapps.WorkProfileManager
 import com.android.launcher3.model.DeviceGridState
 import com.android.launcher3.pm.InstallSessionHelper
@@ -20,11 +22,10 @@
 class LauncherPrefs(private val context: Context) {
 
     /** Wrapper around `getInner` for a `ContextualItem` */
-    fun <T : Any> get(item: ContextualItem<T>): T =
-        getInner(item, item.defaultValueFromContext(context))
+    fun <T> get(item: ContextualItem<T>): T = getInner(item, item.defaultValueFromContext(context))
 
     /** Wrapper around `getInner` for an `Item` */
-    fun <T : Any> get(item: ConstantItem<T>): T = getInner(item, item.defaultValue)
+    fun <T> get(item: ConstantItem<T>): T = getInner(item, item.defaultValue)
 
     /**
      * Retrieves the value for an [Item] from [SharedPreferences]. It handles method typing via the
@@ -32,11 +33,11 @@
      * `String`, `Boolean`, `Float`, `Int`, `Long`, or `Set<String>`.
      */
     @Suppress("IMPLICIT_CAST_TO_ANY", "UNCHECKED_CAST")
-    private fun <T : Any> getInner(item: Item, default: T): T {
+    private fun <T> getInner(item: Item, default: T): T {
         val sp = context.getSharedPreferences(item.sharedPrefFile, Context.MODE_PRIVATE)
 
-        return when (default::class.java) {
-            String::class.java -> sp.getString(item.sharedPrefKey, default as String)
+        return when (item.type) {
+            String::class.java -> sp.getString(item.sharedPrefKey, default as? String)
             Boolean::class.java,
             java.lang.Boolean::class.java -> sp.getBoolean(item.sharedPrefKey, default as Boolean)
             Int::class.java,
@@ -45,11 +46,10 @@
             java.lang.Float::class.java -> sp.getFloat(item.sharedPrefKey, default as Float)
             Long::class.java,
             java.lang.Long::class.java -> sp.getLong(item.sharedPrefKey, default as Long)
-            Set::class.java -> sp.getStringSet(item.sharedPrefKey, default as Set<String>)
+            Set::class.java -> sp.getStringSet(item.sharedPrefKey, default as? Set<String>)
             else ->
                 throw IllegalArgumentException(
-                    "item type: ${default::class.java}" +
-                        " is not compatible with sharedPref methods"
+                    "item type: ${item.type}" + " is not compatible with sharedPref methods"
                 )
         }
             as T
@@ -224,39 +224,36 @@
             backedUpItem(RestoreDbTask.RESTORED_DEVICE_TYPE, InvariantDeviceProfile.TYPE_PHONE)
         @JvmField val APP_WIDGET_IDS = backedUpItem(RestoreDbTask.APPWIDGET_IDS, "")
         @JvmField val OLD_APP_WIDGET_IDS = backedUpItem(RestoreDbTask.APPWIDGET_OLD_IDS, "")
+        @JvmField val GRID_NAME = ConstantItem("idp_grid_name", true, null, String::class.java)
         @JvmField
         val ALLOW_ROTATION =
-            backedUpItem(RotationHelper.ALLOW_ROTATION_PREFERENCE_KEY) {
+            backedUpItem(RotationHelper.ALLOW_ROTATION_PREFERENCE_KEY, Boolean::class.java) {
                 RotationHelper.getAllowRotationDefaultValue(DisplayController.INSTANCE.get(it).info)
             }
 
         @VisibleForTesting
         @JvmStatic
         fun <T> backedUpItem(sharedPrefKey: String, defaultValue: T): ConstantItem<T> =
-            ConstantItem(sharedPrefKey, LauncherFiles.SHARED_PREFERENCES_KEY, defaultValue)
+            ConstantItem(sharedPrefKey, true, defaultValue)
 
         @JvmStatic
         fun <T> backedUpItem(
             sharedPrefKey: String,
+            type: Class<out T>,
             defaultValueFromContext: (c: Context) -> T
-        ): ContextualItem<T> =
-            ContextualItem(
-                sharedPrefKey,
-                LauncherFiles.SHARED_PREFERENCES_KEY,
-                defaultValueFromContext
-            )
+        ): ContextualItem<T> = ContextualItem(sharedPrefKey, true, defaultValueFromContext, type)
 
         @VisibleForTesting
         @JvmStatic
         fun <T> nonRestorableItem(sharedPrefKey: String, defaultValue: T): ConstantItem<T> =
-            ConstantItem(sharedPrefKey, LauncherFiles.DEVICE_PREFERENCES_KEY, defaultValue)
+            ConstantItem(sharedPrefKey, false, defaultValue)
 
         @Deprecated("Don't use shared preferences directly. Use other LauncherPref methods.")
         @JvmStatic
         fun getPrefs(context: Context): SharedPreferences {
             // Use application context for shared preferences, so we use single cached instance
             return context.applicationContext.getSharedPreferences(
-                LauncherFiles.SHARED_PREFERENCES_KEY,
+                SHARED_PREFERENCES_KEY,
                 Context.MODE_PRIVATE
             )
         }
@@ -266,7 +263,7 @@
         fun getDevicePrefs(context: Context): SharedPreferences {
             // Use application context for shared preferences, so we use a single cached instance
             return context.applicationContext.getSharedPreferences(
-                LauncherFiles.DEVICE_PREFERENCES_KEY,
+                DEVICE_PREFERENCES_KEY,
                 Context.MODE_PRIVATE
             )
         }
@@ -275,21 +272,26 @@
 
 abstract class Item {
     abstract val sharedPrefKey: String
-    abstract val sharedPrefFile: String
+    abstract val isBackedUp: Boolean
+    abstract val type: Class<*>
+    val sharedPrefFile: String = if (isBackedUp) SHARED_PREFERENCES_KEY else DEVICE_PREFERENCES_KEY
 
     fun <T> to(value: T): Pair<Item, T> = Pair(this, value)
 }
 
 data class ConstantItem<T>(
     override val sharedPrefKey: String,
-    override val sharedPrefFile: String,
-    val defaultValue: T
+    override val isBackedUp: Boolean,
+    val defaultValue: T,
+    // The default value can be null. If so, the type needs to be explicitly stated, or else NPE
+    override val type: Class<out T> = defaultValue!!::class.java
 ) : Item()
 
 data class ContextualItem<T>(
     override val sharedPrefKey: String,
-    override val sharedPrefFile: String,
-    private val defaultSupplier: (c: Context) -> T
+    override val isBackedUp: Boolean,
+    private val defaultSupplier: (c: Context) -> T,
+    override val type: Class<out T>
 ) : Item() {
     private var default: T? = null