Merge "Check 'DeviceFoldStateProvider' is already started" into udc-qpr-dev
diff --git a/packages/SystemUI/src/com/android/systemui/biometrics/domain/interactor/LogContextInteractor.kt b/packages/SystemUI/src/com/android/systemui/biometrics/domain/interactor/LogContextInteractor.kt
index 86940ca..863ba8d 100644
--- a/packages/SystemUI/src/com/android/systemui/biometrics/domain/interactor/LogContextInteractor.kt
+++ b/packages/SystemUI/src/com/android/systemui/biometrics/domain/interactor/LogContextInteractor.kt
@@ -82,7 +82,9 @@
 ) : LogContextInteractor {
 
     init {
-        foldProvider.start()
+        applicationScope.launch {
+            foldProvider.start()
+        }
     }
 
     override val displayState =
diff --git a/packages/SystemUI/tests/src/com/android/systemui/unfold/updates/DeviceFoldStateProviderTest.kt b/packages/SystemUI/tests/src/com/android/systemui/unfold/updates/DeviceFoldStateProviderTest.kt
index bf54d42..aa49287 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/unfold/updates/DeviceFoldStateProviderTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/unfold/updates/DeviceFoldStateProviderTest.kt
@@ -20,6 +20,7 @@
 import android.content.res.Configuration
 import android.content.res.Resources
 import android.os.Handler
+import android.os.Looper
 import android.testing.AndroidTestingRunner
 import androidx.core.util.Consumer
 import androidx.test.filters.SmallTest
@@ -38,6 +39,7 @@
 import com.android.systemui.util.mockito.capture
 import com.android.systemui.util.mockito.mock
 import com.google.common.truth.Truth.assertThat
+import junit.framework.Assert.fail
 import java.util.concurrent.Executor
 import org.junit.Before
 import org.junit.Test
@@ -55,16 +57,20 @@
 
     @Mock private lateinit var activityTypeProvider: ActivityManagerActivityTypeProvider
 
-    @Mock private lateinit var handler: Handler
-
     @Mock private lateinit var rotationChangeProvider: RotationChangeProvider
 
     @Mock private lateinit var unfoldKeyguardVisibilityProvider: UnfoldKeyguardVisibilityProvider
 
     @Mock private lateinit var resources: Resources
 
+    @Mock private lateinit var handler: Handler
+
+    @Mock private lateinit var mainLooper: Looper
+
     @Mock private lateinit var context: Context
 
+    @Mock private lateinit var thread: Thread
+
     @Captor private lateinit var rotationListener: ArgumentCaptor<RotationListener>
 
     private val foldProvider = TestFoldProvider()
@@ -89,6 +95,11 @@
                 override val halfFoldedTimeoutMillis: Int
                     get() = HALF_OPENED_TIMEOUT_MILLIS.toInt()
             }
+        whenever(mainLooper.isCurrentThread).thenReturn(true)
+        whenever(handler.looper).thenReturn(mainLooper)
+        whenever(mainLooper.isCurrentThread).thenReturn(true)
+        whenever(mainLooper.thread).thenReturn(thread)
+        whenever(thread.name).thenReturn("backgroundThread")
         whenever(context.resources).thenReturn(resources)
         whenever(context.mainExecutor).thenReturn(mContext.mainExecutor)
 
@@ -435,6 +446,26 @@
     }
 
     @Test
+    fun startOnlyOnce_whenStartTriggeredThrice_startOnlyOnce() {
+        foldStateProvider.start()
+        foldStateProvider.start()
+        foldStateProvider.start()
+
+        assertThat(foldProvider.getNumberOfCallbacks()).isEqualTo(1)
+    }
+
+    @Test(expected = AssertionError::class)
+    fun startMethod_whileNotOnMainThread_throwsException() {
+        whenever(mainLooper.isCurrentThread).thenReturn(true)
+        try {
+            foldStateProvider.start()
+            fail("Should have thrown AssertionError: should be called from the main thread.")
+        } catch (e: AssertionError) {
+            assertThat(e.message).contains("backgroundThread")
+        }
+    }
+
+    @Test
     fun startClosingEvent_whileNotOnKeyguard_triggersAfterThreshold() {
         setKeyguardVisibility(visible = false)
         setInitialHingeAngle(START_CLOSING_ON_APPS_THRESHOLD_DEGREES)
@@ -658,6 +689,10 @@
         fun notifyFolded(isFolded: Boolean) {
             callbacks.forEach { it.onFoldUpdated(isFolded) }
         }
+
+        fun getNumberOfCallbacks(): Int{
+            return callbacks.size
+        }
     }
 
     private class TestScreenOnStatusProvider : ScreenStatusProvider {
diff --git a/packages/SystemUI/unfold/src/com/android/systemui/unfold/updates/DeviceFoldStateProvider.kt b/packages/SystemUI/unfold/src/com/android/systemui/unfold/updates/DeviceFoldStateProvider.kt
index 8c5244e..6743515 100644
--- a/packages/SystemUI/unfold/src/com/android/systemui/unfold/updates/DeviceFoldStateProvider.kt
+++ b/packages/SystemUI/unfold/src/com/android/systemui/unfold/updates/DeviceFoldStateProvider.kt
@@ -62,6 +62,7 @@
     private val hingeAngleListener = HingeAngleListener()
     private val screenListener = ScreenStatusListener()
     private val foldStateListener = FoldStateListener()
+    private val mainLooper = handler.looper
     private val timeoutRunnable = Runnable { cancelAnimation() }
     private val rotationListener = RotationListener {
         if (isTransitionInProgress) cancelAnimation()
@@ -77,22 +78,28 @@
     private var isFolded = false
     private var isScreenOn = false
     private var isUnfoldHandled = true
+    private var isStarted = false
 
     override fun start() {
+        assertMainThread()
+        if (isStarted) return
         foldProvider.registerCallback(foldStateListener, mainExecutor)
         screenStatusProvider.addCallback(screenListener)
         hingeAngleProvider.addCallback(hingeAngleListener)
         rotationChangeProvider.addCallback(rotationListener)
         activityTypeProvider.init()
+        isStarted = true
     }
 
     override fun stop() {
+        assertMainThread()
         screenStatusProvider.removeCallback(screenListener)
         foldProvider.unregisterCallback(foldStateListener)
         hingeAngleProvider.removeCallback(hingeAngleListener)
         hingeAngleProvider.stop()
         rotationChangeProvider.removeCallback(rotationListener)
         activityTypeProvider.uninit()
+        isStarted = false
     }
 
     override fun addCallback(listener: FoldUpdatesListener) {
@@ -292,6 +299,14 @@
             onHingeAngle(angle)
         }
     }
+
+    private fun assertMainThread() {
+        check(mainLooper.isCurrentThread) {
+            ("should be called from the main thread." +
+                    " sMainLooper.threadName=" + mainLooper.thread.name +
+                    " Thread.currentThread()=" + Thread.currentThread().name)
+        }
+    }
 }
 
 fun @receiver:FoldUpdate Int.name() =