Merge "Adds listener support to FakeFeatureFlags" into tm-qpr-dev am: 34fdbdb544 am: eb40375d6c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19763934

Change-Id: Ief57092ca3366a450850913437587669d56c8977
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/packages/SystemUI/tests/src/com/android/systemui/flags/FakeFeatureFlagsTest.kt b/packages/SystemUI/tests/src/com/android/systemui/flags/FakeFeatureFlagsTest.kt
index ff579a1..318f2bc 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/flags/FakeFeatureFlagsTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/flags/FakeFeatureFlagsTest.kt
@@ -41,7 +41,7 @@
      * specified. If not, an exception is thrown.
      */
     @Test
-    fun throwsIfUnspecifiedFlagIsAccessed() {
+    fun accessingUnspecifiedFlags_throwsException() {
         val flags: FeatureFlags = FakeFeatureFlags()
         try {
             assertThat(flags.isEnabled(Flags.TEAMFOOD)).isFalse()
@@ -88,7 +88,7 @@
     }
 
     @Test
-    fun specifiedFlagsReturnCorrectValues() {
+    fun specifiedFlags_returnCorrectValues() {
         val flags = FakeFeatureFlags()
         flags.set(unreleasedFlag, false)
         flags.set(releasedFlag, false)
@@ -114,4 +114,125 @@
         assertThat(flags.isEnabled(sysPropBooleanFlag)).isTrue()
         assertThat(flags.getString(resourceStringFlag)).isEqualTo("Android")
     }
+
+    @Test
+    fun listenerForBooleanFlag_calledOnlyWhenFlagChanged() {
+        val flags = FakeFeatureFlags()
+        val listener = VerifyingListener()
+        flags.addListener(unreleasedFlag, listener)
+
+        flags.set(unreleasedFlag, true)
+        flags.set(unreleasedFlag, true)
+        flags.set(unreleasedFlag, false)
+        flags.set(unreleasedFlag, false)
+
+        listener.verifyInOrder(unreleasedFlag.id, unreleasedFlag.id)
+    }
+
+    @Test
+    fun listenerForStringFlag_calledOnlyWhenFlagChanged() {
+        val flags = FakeFeatureFlags()
+        val listener = VerifyingListener()
+        flags.addListener(stringFlag, listener)
+
+        flags.set(stringFlag, "Test")
+        flags.set(stringFlag, "Test")
+
+        listener.verifyInOrder(stringFlag.id)
+    }
+
+    @Test
+    fun listenerForBooleanFlag_notCalledAfterRemoved() {
+        val flags = FakeFeatureFlags()
+        val listener = VerifyingListener()
+        flags.addListener(unreleasedFlag, listener)
+        flags.set(unreleasedFlag, true)
+        flags.removeListener(listener)
+        flags.set(unreleasedFlag, false)
+
+        listener.verifyInOrder(unreleasedFlag.id)
+    }
+
+    @Test
+    fun listenerForStringFlag_notCalledAfterRemoved() {
+        val flags = FakeFeatureFlags()
+        val listener = VerifyingListener()
+
+        flags.addListener(stringFlag, listener)
+        flags.set(stringFlag, "Test")
+        flags.removeListener(listener)
+        flags.set(stringFlag, "Other")
+
+        listener.verifyInOrder(stringFlag.id)
+    }
+
+    @Test
+    fun listenerForMultipleFlags_calledWhenFlagsChange() {
+        val flags = FakeFeatureFlags()
+        val listener = VerifyingListener()
+        flags.addListener(unreleasedFlag, listener)
+        flags.addListener(releasedFlag, listener)
+
+        flags.set(releasedFlag, true)
+        flags.set(unreleasedFlag, true)
+
+        listener.verifyInOrder(releasedFlag.id, unreleasedFlag.id)
+    }
+
+    @Test
+    fun listenerForMultipleFlags_notCalledAfterRemoved() {
+        val flags = FakeFeatureFlags()
+        val listener = VerifyingListener()
+
+        flags.addListener(unreleasedFlag, listener)
+        flags.addListener(releasedFlag, listener)
+        flags.set(releasedFlag, true)
+        flags.set(unreleasedFlag, true)
+        flags.removeListener(listener)
+        flags.set(releasedFlag, false)
+        flags.set(unreleasedFlag, false)
+
+        listener.verifyInOrder(releasedFlag.id, unreleasedFlag.id)
+    }
+
+    @Test
+    fun multipleListenersForSingleFlag_allAreCalledWhenChanged() {
+        val flags = FakeFeatureFlags()
+        val listener1 = VerifyingListener()
+        val listener2 = VerifyingListener()
+        flags.addListener(releasedFlag, listener1)
+        flags.addListener(releasedFlag, listener2)
+
+        flags.set(releasedFlag, true)
+
+        listener1.verifyInOrder(releasedFlag.id)
+        listener2.verifyInOrder(releasedFlag.id)
+    }
+
+    @Test
+    fun multipleListenersForSingleFlag_removedListenerNotCalledAfterRemoval() {
+        val flags = FakeFeatureFlags()
+        val listener1 = VerifyingListener()
+        val listener2 = VerifyingListener()
+        flags.addListener(releasedFlag, listener1)
+        flags.addListener(releasedFlag, listener2)
+
+        flags.set(releasedFlag, true)
+        flags.removeListener(listener2)
+        flags.set(releasedFlag, false)
+
+        listener1.verifyInOrder(releasedFlag.id, releasedFlag.id)
+        listener2.verifyInOrder(releasedFlag.id)
+    }
+
+    class VerifyingListener : FlagListenable.Listener {
+        var flagEventIds = mutableListOf<Int>()
+        override fun onFlagChanged(event: FlagListenable.FlagEvent) {
+            flagEventIds.add(event.flagId)
+        }
+
+        fun verifyInOrder(vararg eventIds: Int) {
+            assertThat(flagEventIds).containsExactlyElementsIn(eventIds.asList())
+        }
+    }
 }
diff --git a/packages/SystemUI/tests/utils/src/com/android/systemui/flags/FakeFeatureFlags.kt b/packages/SystemUI/tests/utils/src/com/android/systemui/flags/FakeFeatureFlags.kt
index b53ad0a..c56fdb1 100644
--- a/packages/SystemUI/tests/utils/src/com/android/systemui/flags/FakeFeatureFlags.kt
+++ b/packages/SystemUI/tests/utils/src/com/android/systemui/flags/FakeFeatureFlags.kt
@@ -16,14 +16,12 @@
 
 package com.android.systemui.flags
 
-import android.util.SparseArray
-import android.util.SparseBooleanArray
-import androidx.core.util.containsKey
-
 class FakeFeatureFlags : FeatureFlags {
-    private val booleanFlags = SparseBooleanArray()
-    private val stringFlags = SparseArray<String>()
+    private val booleanFlags = mutableMapOf<Int, Boolean>()
+    private val stringFlags = mutableMapOf<Int, String>()
     private val knownFlagNames = mutableMapOf<Int, String>()
+    private val flagListeners = mutableMapOf<Int, MutableSet<FlagListenable.Listener>>()
+    private val listenerFlagIds = mutableMapOf<FlagListenable.Listener, MutableSet<Int>>()
 
     init {
         Flags.getFlagFields().forEach { field ->
@@ -33,27 +31,52 @@
     }
 
     fun set(flag: BooleanFlag, value: Boolean) {
-        booleanFlags.put(flag.id, value)
+        if (booleanFlags.put(flag.id, value)?.let { value != it } != false) {
+            notifyFlagChanged(flag)
+        }
     }
 
     fun set(flag: DeviceConfigBooleanFlag, value: Boolean) {
-        booleanFlags.put(flag.id, value)
+        if (booleanFlags.put(flag.id, value)?.let { value != it } != false) {
+            notifyFlagChanged(flag)
+        }
     }
 
     fun set(flag: ResourceBooleanFlag, value: Boolean) {
-        booleanFlags.put(flag.id, value)
+        if (booleanFlags.put(flag.id, value)?.let { value != it } != false) {
+            notifyFlagChanged(flag)
+        }
     }
 
     fun set(flag: SysPropBooleanFlag, value: Boolean) {
-        booleanFlags.put(flag.id, value)
+        if (booleanFlags.put(flag.id, value)?.let { value != it } != false) {
+            notifyFlagChanged(flag)
+        }
     }
 
     fun set(flag: StringFlag, value: String) {
-        stringFlags.put(flag.id, value)
+        if (stringFlags.put(flag.id, value)?.let { value != it } == null) {
+            notifyFlagChanged(flag)
+        }
     }
 
     fun set(flag: ResourceStringFlag, value: String) {
-        stringFlags.put(flag.id, value)
+        if (stringFlags.put(flag.id, value)?.let { value != it } == null) {
+            notifyFlagChanged(flag)
+        }
+    }
+
+    private fun notifyFlagChanged(flag: Flag<*>) {
+        flagListeners[flag.id]?.let { listeners ->
+            listeners.forEach { listener ->
+                listener.onFlagChanged(
+                    object : FlagListenable.FlagEvent {
+                        override val flagId = flag.id
+                        override fun requestNoRestart() {}
+                    }
+                )
+            }
+        }
     }
 
     override fun isEnabled(flag: UnreleasedFlag): Boolean = requireBooleanValue(flag.id)
@@ -70,25 +93,30 @@
 
     override fun getString(flag: ResourceStringFlag): String = requireStringValue(flag.id)
 
-    override fun addListener(flag: Flag<*>, listener: FlagListenable.Listener) {}
+    override fun addListener(flag: Flag<*>, listener: FlagListenable.Listener) {
+        flagListeners.getOrPut(flag.id) { mutableSetOf() }.add(listener)
+        listenerFlagIds.getOrPut(listener) { mutableSetOf() }.add(flag.id)
+    }
 
-    override fun removeListener(listener: FlagListenable.Listener) {}
+    override fun removeListener(listener: FlagListenable.Listener) {
+        listenerFlagIds.remove(listener)?.let {
+                flagIds -> flagIds.forEach {
+                        id -> flagListeners[id]?.remove(listener)
+                }
+        }
+    }
 
     private fun flagName(flagId: Int): String {
         return knownFlagNames[flagId] ?: "UNKNOWN(id=$flagId)"
     }
 
     private fun requireBooleanValue(flagId: Int): Boolean {
-        if (!booleanFlags.containsKey(flagId)) {
-            throw IllegalStateException("Flag ${flagName(flagId)} was accessed but not specified.")
-        }
         return booleanFlags[flagId]
+            ?: error("Flag ${flagName(flagId)} was accessed but not specified.")
     }
 
     private fun requireStringValue(flagId: Int): String {
-        if (!stringFlags.containsKey(flagId)) {
-            throw IllegalStateException("Flag ${flagName(flagId)} was accessed but not specified.")
-        }
         return stringFlags[flagId]
+            ?: error("Flag ${flagName(flagId)} was accessed but not specified.")
     }
 }