Provide abstraction over storage system

library/src/main/java/de/Maxr1998/modernpreferences/Preferences.kt

@@ -17,7 +17,6 @@
 package de.Maxr1998.modernpreferences
 
 import android.content.Context
-import android.content.SharedPreferences
 import android.graphics.drawable.Drawable
 import android.view.Gravity
 import android.view.ViewGroup
@@ -26,13 +25,13 @@ import androidx.annotation.CallSuper
 import androidx.annotation.DrawableRes
 import androidx.annotation.LayoutRes
 import androidx.annotation.StringRes
-import androidx.core.content.edit
 import androidx.core.view.isVisible
 import de.Maxr1998.modernpreferences.helpers.DependencyManager
 import de.Maxr1998.modernpreferences.helpers.KEY_ROOT_SCREEN
 import de.Maxr1998.modernpreferences.helpers.PreferenceMarker
 import de.Maxr1998.modernpreferences.preferences.CollapsePreference
 import de.Maxr1998.modernpreferences.preferences.SeekBarPreference
+import de.Maxr1998.modernpreferences.storage.Storage
 import java.util.concurrent.atomic.AtomicBoolean
 
 abstract class AbstractPreference internal constructor(val key: String) {
@@ -117,7 +116,7 @@ open class Preference(key: String) : AbstractPreference(key) {
     var screenPosition: Int = 0
         private set
 
-    private var prefs: SharedPreferences? = null
+    private var storage: Storage? = null
 
     /**
      * Whether or not to persist changes to this preference to the attached [SharedPreferences] instance
@@ -137,7 +136,7 @@ open class Preference(key: String) : AbstractPreference(key) {
         check(parent == null) { "Preference was already attached to a screen!" }
         parent = screen
         screenPosition = position
-        prefs = if (persistent) screen.prefs else null
+        storage = if (persistent) screen.storage else null
         DependencyManager.register(this)
         onAttach()
     }
@@ -259,36 +258,30 @@ open class Preference(key: String) : AbstractPreference(key) {
      * Save an int for this [Preference]s' [key] to the [SharedPreferences] of the attached [PreferenceScreen]
      */
     fun commitInt(value: Int) {
-        prefs?.edit {
-            putInt(key, value)
-        }
+        storage?.setInt(key, value)
     }
 
     fun getInt(defaultValue: Int): Int =
-        prefs?.getInt(key, defaultValue) ?: defaultValue
+        storage?.getInt(key, defaultValue) ?: defaultValue
 
     /**
      * Save a boolean for this [Preference]s' [key] to the [SharedPreferences] of the attached [PreferenceScreen]
      */
     fun commitBoolean(value: Boolean) {
-        prefs?.edit {
-            putBoolean(key, value)
-        }
+        storage?.setBoolean(key, value)
     }
 
     fun getBoolean(defaultValue: Boolean): Boolean =
-        prefs?.getBoolean(key, defaultValue) ?: defaultValue
+        storage?.getBoolean(key, defaultValue) ?: defaultValue
 
     /**
      * Save a String for this [Preference]s' [key] to the [SharedPreferences] of the attached [PreferenceScreen]
      */
     fun commitString(value: String) {
-        prefs?.edit {
-            putString(key, value)
-        }
+        storage?.setString(key, value)
     }
 
-    fun getString(): String? = prefs?.getString(key, null)
+    fun getString(): String? = storage?.getString(key, null)
 
     @Deprecated(
         "Passing a default value is not supported anymore, " +
@@ -299,12 +292,10 @@ open class Preference(key: String) : AbstractPreference(key) {
     fun getString(defaultValue: String): String = throw UnsupportedOperationException("Not implemented")
 
     fun commitStringSet(values: Set<String>) {
-        prefs?.edit {
-            putStringSet(key, values)
-        }
+        storage?.setStringSet(key, values)
     }
 
-    fun getStringSet(): Set<String>? = prefs?.getStringSet(key, null)
+    fun getStringSet(): Set<String>? = storage?.getStringSet(key, null)
 
     /**
      * Can be set to [Preference.preBindListener]
@@ -365,7 +356,7 @@ open class Preference(key: String) : AbstractPreference(key) {
  */
 @Suppress("unused", "MemberVisibilityCanBePrivate")
 class PreferenceScreen private constructor(builder: Builder) : Preference(builder.key) {
-    internal val prefs = builder.prefs
+    internal val storage = builder.storage
     private val keyMap: Map<String, Preference> = builder.keyMap
     private val preferences: List<Preference> = builder.preferences
     internal val collapseIcon: Boolean = builder.collapseIcon
@@ -438,21 +429,15 @@ class PreferenceScreen private constructor(builder: Builder) : Preference(builde
     override fun hashCode() = (31 * key.hashCode()) + preferences.hashCode()
 
     @PreferenceMarker
-    class Builder private constructor(private var context: Context?, key: String) : AbstractPreference(key), Appendable {
-        constructor(context: Context?) : this(context, KEY_ROOT_SCREEN)
-        constructor(builder: Builder, key: String = "") : this(builder.context, key)
-        constructor(collapse: CollapsePreference, key: String = "") : this(collapse.screen?.context, key)
+    class Builder private constructor(private var context: Context?, internal val storage: Storage?, key: String) : AbstractPreference(key), Appendable {
+        constructor(context: Context?, storage: Storage?) : this(context, storage, KEY_ROOT_SCREEN)
+        constructor(builder: Builder, key: String = "") : this(builder.context, builder.storage, key)
+        constructor(collapse: CollapsePreference, key: String = "") : this(collapse.screen?.context, collapse.screen?.storage, key)
 
         // Internal structures
-        internal var prefs: SharedPreferences? = null
         internal val keyMap = HashMap<String, Preference>()
         internal val preferences = ArrayList<Preference>()
 
-        /**
-         * The filename to use for the [SharedPreferences] of this [PreferenceScreen]
-         */
-        var preferenceFileName: String = (context?.packageName ?: "package") + "_preferences"
-
         /**
          * If true, the preference items in this screen will have a smaller left padding when they have no icon
          */
@@ -489,7 +474,6 @@ class PreferenceScreen private constructor(builder: Builder) : Preference(builde
         }
 
         fun build(): PreferenceScreen {
-            prefs = context?.getSharedPreferences(preferenceFileName, Context.MODE_PRIVATE)
             context = null
             return PreferenceScreen(this)
         }

library/src/main/java/de/Maxr1998/modernpreferences/helpers/DependencyManager.kt

@@ -1,8 +1,8 @@
 package de.Maxr1998.modernpreferences.helpers
 
-import android.content.SharedPreferences
 import de.Maxr1998.modernpreferences.Preference
 import de.Maxr1998.modernpreferences.preferences.StatefulPreference
+import de.Maxr1998.modernpreferences.storage.Storage
 import java.lang.ref.WeakReference
 import java.util.*
 import kotlin.collections.HashMap
@@ -22,7 +22,7 @@ internal object DependencyManager {
         val screen = preference.parent
         check(screen != null) { "Preference must be attached to a screen first" }
         val dependency = preference.dependency ?: return
-        val key = PreferenceKey(screen.prefs, dependency)
+        val key = PreferenceKey(screen.storage, dependency)
         preferences.getOrPut(key) { LinkedList() }.add(WeakReference(preference))
         stateCache[key]?.let { state -> preference.enabled = state }
     }
@@ -33,11 +33,11 @@ internal object DependencyManager {
     fun publishState(preference: StatefulPreference) {
         val screen = preference.parent
         check(screen != null) { "Preference must be attached to a screen first" }
-        val key = PreferenceKey(screen.prefs, preference.key)
+        val key = PreferenceKey(screen.storage, preference.key)
         val state = preference.state // Cache state so that every dependent gets the same value
         stateCache[key] = state
         preferences[key]?.forEach { it.get()?.enabled = state }
     }
 
-    private data class PreferenceKey(val preferenceStore: SharedPreferences?, val key: String)
+    private data class PreferenceKey(val storage: Storage?, val key: String)
 }

library/src/main/java/de/Maxr1998/modernpreferences/helpers/PreferencesDsl.kt

@@ -26,15 +26,17 @@ import de.Maxr1998.modernpreferences.preferences.*
 import de.Maxr1998.modernpreferences.preferences.choice.MultiChoiceDialogPreference
 import de.Maxr1998.modernpreferences.preferences.choice.SelectionItem
 import de.Maxr1998.modernpreferences.preferences.choice.SingleChoiceDialogPreference
+import de.Maxr1998.modernpreferences.storage.SharedPreferencesStorage
+import de.Maxr1998.modernpreferences.storage.Storage
 
 // DSL marker
 @DslMarker
 @Retention(AnnotationRetention.SOURCE)
 annotation class PreferenceMarker
 
 // PreferenceScreen DSL functions
-inline fun screen(context: Context?, block: PreferenceScreen.Builder.() -> Unit): PreferenceScreen {
-    return PreferenceScreen.Builder(context).apply(block).build()
+inline fun screen(context: Context?, storage: Storage? = context?.let { SharedPreferencesStorage(it) }, block: PreferenceScreen.Builder.() -> Unit): PreferenceScreen {
+    return PreferenceScreen.Builder(context, storage).apply(block).build()
 }
 
 val emptyScreen: PreferenceScreen by lazy { screen(null) {} }

library/src/main/java/de/Maxr1998/modernpreferences/storage/SharedPreferencesStorage.kt

@@ -0,0 +1,62 @@
+package de.Maxr1998.modernpreferences.storage
+
+import android.content.Context
+import android.content.SharedPreferences
+
+class SharedPreferencesStorage(
+    private val prefs: SharedPreferences,
+    private val mode: Mode = Mode.Apply
+) : Storage {
+
+    enum class Mode {
+        Commit,
+        Apply
+    }
+
+    constructor(
+        context: Context,
+        preferenceFileName: String = (context.packageName ?: "package") + "_preferences",
+        mode: Mode = Mode.Apply
+    ) : this(context.getSharedPreferences(preferenceFileName, Context.MODE_PRIVATE), mode)
+
+    override fun setInt(key: String, value: Int) = edit {
+        putInt(key, value)
+    }
+
+    override fun getInt(key: String, defaultValue: Int): Int =
+        prefs.getInt(key, defaultValue)
+
+    override fun setBoolean(key: String, value: Boolean) = edit {
+        putBoolean(key, value)
+    }
+
+    override fun getBoolean(key: String, defaultValue: Boolean): Boolean =
+        prefs.getBoolean(key, defaultValue)
+
+    override fun setString(key: String, value: String) = edit {
+        putString(key, value)
+    }
+
+    override fun getString(key: String, defaultValue: String?): String? =
+        prefs.getString(key, defaultValue)
+
+    override fun setStringSet(key: String, values: Set<String>) = edit {
+        putStringSet(key, values)
+    }
+
+    override fun getStringSet(key: String, defaultValue: Set<String>?): Set<String>? =
+        prefs.getStringSet(key, defaultValue)
+
+    private fun edit(
+        action: SharedPreferences.Editor.() -> Unit
+    ) {
+        val editor = prefs.edit()
+        action(editor)
+        if (mode == Mode.Commit) {
+            editor.commit()
+        } else {
+            editor.apply()
+        }
+    }
+
+}

library/src/main/java/de/Maxr1998/modernpreferences/storage/Storage.kt

@@ -0,0 +1,16 @@
+package de.Maxr1998.modernpreferences.storage
+
+interface Storage {
+
+    fun setInt(key: String, value: Int)
+    fun getInt(key: String, defaultValue: Int): Int
+
+    fun setBoolean(key: String, value: Boolean)
+    fun getBoolean(key: String, defaultValue: Boolean): Boolean
+
+    fun setString(key: String, value: String)
+    fun getString(key: String, defaultValue: String?): String?
+
+    fun setStringSet(key: String, values: Set<String>)
+    fun getStringSet(key: String, defaultValue: Set<String>?): Set<String>?
+}

library/src/test/java/de/Maxr1998/modernpreferences/testing/PreferencesTests.kt

@@ -11,6 +11,8 @@ import de.Maxr1998.modernpreferences.helpers.subScreen
 import de.Maxr1998.modernpreferences.helpers.switch
 import de.Maxr1998.modernpreferences.preferences.SwitchPreference
 import de.Maxr1998.modernpreferences.preferences.TwoStatePreference
+import de.Maxr1998.modernpreferences.storage.SharedPreferencesStorage
+import de.Maxr1998.modernpreferences.storage.Storage
 import io.kotest.assertions.throwables.shouldThrow
 import io.kotest.data.blocking.forAll
 import io.kotest.data.row
@@ -32,11 +34,13 @@ import org.junit.jupiter.api.TestInstance
 class PreferencesTests {
 
     private val contextMock: Context = mockk()
+    private lateinit var storageMock: Storage
 
     @BeforeAll
     fun setup() {
         // Setup mocks for SharedPreferences
         val sharedPreferences = SPMockBuilder().createSharedPreferences()
+        storageMock = SharedPreferencesStorage(sharedPreferences)
         every { contextMock.packageName } returns "package"
         every { contextMock.getSharedPreferences(any(), any()) } returns sharedPreferences
     }
@@ -76,7 +80,7 @@ class PreferencesTests {
                 row(a = true, b = true, c = false)
             ) { checked: Boolean, disableDependents: Boolean, state: Boolean ->
                 lateinit var pref: TwoStatePreference
-                screen(contextMock) {
+                screen(contextMock, storageMock) {
                     pref = switch(uniqueKeySequence.next()) {
                         this.disableDependents = disableDependents
                     }
@@ -105,7 +109,7 @@ class PreferencesTests {
 
         runBlocking {
             checkAll(2, Exhaustive.boolean()) { disableDependents ->
-                screen(contextMock) {
+                screen(contextMock, storageMock) {
                     val dependencyKey = uniqueKeySequence.next()
                     dependent = pref(uniqueKeySequence.next()) {
                         this.dependency = dependencyKey
@@ -117,7 +121,7 @@ class PreferencesTests {
                 check(dependent, dependency)
 
                 // With inverted order of dependent and dependency
-                screen(contextMock) {
+                screen(contextMock, storageMock) {
                     val dependencyKey = uniqueKeySequence.next()
                     dependency = switch(dependencyKey) {
                         this.disableDependents = disableDependents
@@ -129,7 +133,7 @@ class PreferencesTests {
                 check(dependent, dependency)
 
                 // With sub-screens
-                screen(contextMock) {
+                screen(contextMock, storageMock) {
                     val dependencyKey = uniqueKeySequence.next()
                     dependent = pref(uniqueKeySequence.next()) {
                         this.dependency = dependencyKey
@@ -142,7 +146,7 @@ class PreferencesTests {
                 }
                 check(dependent, dependency)
 
-                screen(contextMock) {
+                screen(contextMock, storageMock) {
                     val dependencyKey = uniqueKeySequence.next()
                     subScreen {
                         dependent = pref(uniqueKeySequence.next()) {
@@ -155,7 +159,7 @@ class PreferencesTests {
                 }
                 check(dependent, dependency)
 
-                screen(contextMock) {
+                screen(contextMock, storageMock) {
                     val dependencyKey = uniqueKeySequence.next()
                     dependency = switch(dependencyKey) {
                         this.disableDependents = disableDependents
@@ -168,7 +172,7 @@ class PreferencesTests {
                 }
                 check(dependent, dependency)
 
-                screen(contextMock) {
+                screen(contextMock, storageMock) {
                     val dependencyKey = uniqueKeySequence.next()
                     subScreen {
                         dependency = switch(dependencyKey) {
@@ -190,7 +194,7 @@ class PreferencesTests {
 
         // Setup screens
         lateinit var subScreen: PreferenceScreen
-        val rootScreen = screen(contextMock) {
+        val rootScreen = screen(contextMock, storageMock) {
             subScreen = +PreferenceScreen.Builder(this, "").build()
         }
         adapter.setRootScreen(rootScreen)
@@ -224,7 +228,7 @@ class PreferencesTests {
 
         // Setup screens
         lateinit var subScreen: PreferenceScreen
-        val rootScreen = screen(contextMock) {
+        val rootScreen = screen(contextMock, storageMock) {
             subScreen = +PreferenceScreen.Builder(this, "").build()
         }
         adapter.setRootScreen(rootScreen)
@@ -257,7 +261,7 @@ class PreferencesTests {
     @Test
     fun `Saved state should be empty on root screen`() {
         val adapter = createPreferenceAdapter()
-        adapter.setRootScreen(screen(contextMock) {})
+        adapter.setRootScreen(screen(contextMock, storageMock) {})
         adapter.getSavedState().screenPath.size shouldBe 0
     }
 
@@ -267,7 +271,7 @@ class PreferencesTests {
 
         // Setup screens
         lateinit var subScreen: PreferenceScreen
-        val rootScreen = screen(contextMock) {
+        val rootScreen = screen(contextMock, storageMock) {
             subScreen = +PreferenceScreen.Builder(this, "").build()
         }
         adapter.setRootScreen(rootScreen)