Squishy ViewState no longer mutates global album art widgetState

Test: Manual
Fixes: 228454172
Fixes: 231398191
Change-Id: I6e8fcfb234a5cd6af467350871852d925aa3c6d6

2 files changed, 24 insertions, 2 deletions

diff --git a/packages/SystemUI/src/com/android/systemui/media/MediaViewController.kt b/packages/SystemUI/src/com/android/systemui/media/MediaViewController.kt
index 1437c965512e..7eccb3b91bb5 100644
--- a/packages/SystemUI/src/com/android/systemui/media/MediaViewController.kt
+++ b/packages/SystemUI/src/com/android/systemui/media/MediaViewController.kt
@@ -278,13 +278,14 @@ class MediaViewController @Inject constructor(
     /**
      * Apply squishFraction to a copy of viewState such that the cached version is untouched.
      */
-    private fun squishViewState(
+    @VisibleForTesting
+    internal fun squishViewState(
         viewState: TransitionViewState,
         squishFraction: Float
     ): TransitionViewState {
         val squishedViewState = viewState.copy()
         squishedViewState.height = (squishedViewState.height * squishFraction).toInt()
-        val albumArtViewState = viewState.widgetStates.get(R.id.album_art)
+        val albumArtViewState = squishedViewState.widgetStates.get(R.id.album_art)
         if (albumArtViewState != null) {
             albumArtViewState.height = squishedViewState.height
         }
@@ -317,6 +318,7 @@ class MediaViewController @Inject constructor(
         if (transitionLayout == null) {
             return null
         }
+
         // Not cached. Let's create a new measurement
         if (state.expansion == 0.0f || state.expansion == 1.0f) {
             result = transitionLayout!!.calculateViewState(
diff --git a/packages/SystemUI/tests/src/com/android/systemui/media/MediaViewControllerTest.kt b/packages/SystemUI/tests/src/com/android/systemui/media/MediaViewControllerTest.kt
index 604e1f3ac9eb..18178097d5e3 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/media/MediaViewControllerTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/media/MediaViewControllerTest.kt
@@ -4,16 +4,22 @@ import android.testing.AndroidTestingRunner
 import android.testing.TestableLooper
 import android.view.View
 import androidx.test.filters.SmallTest
+import com.android.systemui.R
 import com.android.systemui.SysuiTestCase
 import com.android.systemui.util.animation.MeasurementInput
 import com.android.systemui.util.animation.TransitionLayout
 import com.android.systemui.util.animation.TransitionViewState
+import com.android.systemui.util.animation.WidgetState
 import junit.framework.Assert.assertTrue
 import org.junit.Before
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.mockito.Mock
+import org.mockito.Mockito.times
+import org.mockito.Mockito.verify
+import org.mockito.Mockito.verifyNoMoreInteractions
 import org.mockito.MockitoAnnotations
+import org.mockito.Mockito.`when` as whenever
 
 /**
  * Tests for {@link MediaViewController}.
@@ -31,6 +37,9 @@ class MediaViewControllerTest : SysuiTestCase() {
     private lateinit var mediaViewController: MediaViewController
     private val mediaHostStateHolder = MediaHost.MediaHostStateHolder()
     private var transitionLayout = TransitionLayout(context, /* attrs */ null, /* defStyleAttr */ 0)
+    @Mock private lateinit var mockViewState: TransitionViewState
+    @Mock private lateinit var mockCopiedState: TransitionViewState
+    @Mock private lateinit var mockWidgetState: WidgetState
 
     @Before
     fun setUp() {
@@ -63,4 +72,15 @@ class MediaViewControllerTest : SysuiTestCase() {
         mediaHostStateHolder.squishFraction = 0.5f
         assertTrue(mediaViewController.obtainViewState(mediaHostStateHolder)!!.height == 50)
     }
+
+    @Test
+    fun testSquish_DoesNotMutateViewState() {
+        whenever(mockViewState.copy()).thenReturn(mockCopiedState)
+        whenever(mockCopiedState.widgetStates)
+            .thenReturn(mutableMapOf(R.id.album_art to mockWidgetState))
+
+        mediaViewController.squishViewState(mockViewState, 0.5f)
+        verify(mockViewState, times(1)).copy()
+        verifyNoMoreInteractions(mockViewState)
+    }
 }
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