Introduce rule for changing taskbar pinning preferences.

Test: TaskbarPinningPreferenceRuleTest
Bug: 230027385
Flag: TEST_ONLY
Change-Id: I2b87ab8823b17c364b3797a325c8b0d569a1d39a
diff --git a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarPinningPreferenceRule.kt b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarPinningPreferenceRule.kt
new file mode 100644
index 0000000..60c8dec
--- /dev/null
+++ b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarPinningPreferenceRule.kt
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.launcher3.taskbar.rules
+
+import androidx.test.platform.app.InstrumentationRegistry.getInstrumentation
+import com.android.launcher3.ConstantItem
+import com.android.launcher3.LauncherPrefs
+import com.android.launcher3.LauncherPrefs.Companion.TASKBAR_PINNING
+import com.android.launcher3.LauncherPrefs.Companion.TASKBAR_PINNING_IN_DESKTOP_MODE
+import kotlin.reflect.KProperty
+import org.junit.rules.TestRule
+import org.junit.runner.Description
+import org.junit.runners.model.Statement
+
+/**
+ * Rule that allows modifying the Taskbar pinned preferences.
+ *
+ * The original preference values are restored on teardown.
+ *
+ * If this rule is being used with [TaskbarUnitTestRule], make sure this rule is applied first.
+ *
+ * This rule is overkill if a test does not need to change the mode during Taskbar's lifecycle. If
+ * the mode is static, use [TaskbarModeRule] instead, which forces the mode. A test can class can
+ * declare both this rule and [TaskbarModeRule] but using both for a test method is unsupported.
+ */
+class TaskbarPinningPreferenceRule(context: TaskbarWindowSandboxContext) : TestRule {
+
+    private val prefs = LauncherPrefs.get(context)
+
+    var isPinned by PinningPreference(TASKBAR_PINNING)
+    var isPinnedInDesktopMode by PinningPreference(TASKBAR_PINNING_IN_DESKTOP_MODE)
+
+    override fun apply(base: Statement, description: Description): Statement {
+        return object : Statement() {
+            override fun evaluate() {
+                val wasPinned = isPinned
+                val wasPinnedInDesktopMode = isPinnedInDesktopMode
+                try {
+                    base.evaluate()
+                } finally {
+                    isPinned = wasPinned
+                    isPinnedInDesktopMode = wasPinnedInDesktopMode
+                }
+            }
+        }
+    }
+
+    private inner class PinningPreference(private val constantItem: ConstantItem<Boolean>) {
+        operator fun getValue(thisRef: Any?, property: KProperty<*>): Boolean {
+            return prefs.get(constantItem)
+        }
+
+        operator fun setValue(thisRef: Any?, property: KProperty<*>, value: Boolean) {
+            getInstrumentation().runOnMainSync { prefs.put(constantItem, value) }
+        }
+    }
+}
diff --git a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarPinningPreferenceRuleTest.kt b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarPinningPreferenceRuleTest.kt
new file mode 100644
index 0000000..3f0a238
--- /dev/null
+++ b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarPinningPreferenceRuleTest.kt
@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.launcher3.taskbar.rules
+
+import androidx.test.platform.app.InstrumentationRegistry.getInstrumentation
+import com.android.launcher3.util.DisplayController
+import com.android.launcher3.util.LauncherMultivalentJUnit
+import com.google.common.truth.Truth.assertThat
+import org.junit.Test
+import org.junit.runner.Description
+import org.junit.runner.RunWith
+import org.junit.runners.model.Statement
+
+@RunWith(LauncherMultivalentJUnit::class)
+class TaskbarPinningPreferenceRuleTest {
+    private val context = TaskbarWindowSandboxContext.create(getInstrumentation().targetContext)
+
+    private val preferenceRule = TaskbarPinningPreferenceRule(context)
+
+    @Test
+    fun testEnablePinning_verifyDisplayController() {
+        onSetup {
+            preferenceRule.isPinned = true
+            preferenceRule.isPinnedInDesktopMode = false
+            assertThat(DisplayController.isPinnedTaskbar(context)).isTrue()
+        }
+    }
+
+    @Test
+    fun testDisablePinning_verifyDisplayController() {
+        onSetup {
+            preferenceRule.isPinned = false
+            preferenceRule.isPinnedInDesktopMode = false
+            assertThat(DisplayController.isPinnedTaskbar(context)).isFalse()
+        }
+    }
+
+    @Test
+    fun testEnableDesktopPinning_verifyDisplayController() {
+        onSetup {
+            preferenceRule.isPinned = false
+            preferenceRule.isPinnedInDesktopMode = true
+            assertThat(DisplayController.isPinnedTaskbar(context)).isTrue()
+        }
+    }
+
+    @Test
+    fun testDisableDesktopPinning_verifyDisplayController() {
+        onSetup {
+            preferenceRule.isPinned = false
+            preferenceRule.isPinnedInDesktopMode = false
+            assertThat(DisplayController.isPinnedTaskbar(context)).isFalse()
+        }
+    }
+
+    @Test
+    fun testTearDown_afterTogglingPinnedPreference_preferenceReset() {
+        val wasPinned = preferenceRule.isPinned
+        onSetup { preferenceRule.isPinned = !preferenceRule.isPinned }
+        assertThat(preferenceRule.isPinned).isEqualTo(wasPinned)
+    }
+
+    @Test
+    fun testTearDown_afterTogglingDesktopPreference_preferenceReset() {
+        val wasPinnedInDesktopMode = preferenceRule.isPinnedInDesktopMode
+        onSetup { preferenceRule.isPinnedInDesktopMode = !preferenceRule.isPinnedInDesktopMode }
+        assertThat(preferenceRule.isPinnedInDesktopMode).isEqualTo(wasPinnedInDesktopMode)
+    }
+
+    /** Executes [runTest] after the [preferenceRule] setup phase completes. */
+    private fun onSetup(runTest: () -> Unit) {
+        preferenceRule.apply(
+            object : Statement() {
+                override fun evaluate() = runTest()
+            },
+            DESCRIPTION,
+        )
+    }
+
+    private companion object {
+        private val DESCRIPTION =
+            Description.createSuiteDescription(TaskbarPinningPreferenceRule::class.java)
+    }
+}