posture-aware Activity orientation and landscape PreviewDisplay framing

app/src/main/AndroidManifest.xml

@@ -70,9 +70,9 @@
         <profileable android:shell="true"/>
         <activity
             android:name=".MainActivity"
+            android:configChanges="orientation|screenSize|smallestScreenSize|screenLayout|keyboardHidden"
             android:exported="true"
             android:label="@string/app_name_short"
-            android:screenOrientation="nosensor"
             android:theme="@style/Theme.JetpackCamera">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

app/src/main/java/com/google/jetpackcamera/MainActivity.kt

@@ -18,6 +18,7 @@ package com.google.jetpackcamera
 import android.app.Activity
 import android.content.Intent
 import android.content.pm.ActivityInfo
+import android.content.res.Configuration
 import android.hardware.Camera
 import android.net.Uri
 import android.os.Build
@@ -31,6 +32,7 @@ import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
 import androidx.activity.viewModels
 import androidx.annotation.RequiresApi
+import androidx.annotation.VisibleForTesting
 import androidx.compose.foundation.background
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.foundation.layout.Arrangement
@@ -81,6 +83,26 @@ import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.launch
 
 private const val TAG = "MainActivity"
+private const val LARGE_SCREEN_MIN_WIDTH_DP = 600
+
+/**
+ * Resolves the Activity's [ActivityInfo] screen orientation policy for the current window posture.
+ *
+ * Full-screen compact handhelds (`!isInMultiWindowMode && smallestScreenWidthDp < 600`) lock the
+ * window to [ActivityInfo.SCREEN_ORIENTATION_NOSENSOR] so the UI counter-rotates via sensor
+ * gravity without triggering a system window rotation. Multi-window panes and large screens
+ * (`smallestScreenWidthDp >= 600`) use [ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED] so the OS
+ * does not apply 1:1 portrait compatibility letterboxing.
+ */
+@VisibleForTesting
+internal fun resolveRequestedOrientation(
+    isInMultiWindowMode: Boolean,
+    smallestScreenWidthDp: Int
+): Int = if (!isInMultiWindowMode && smallestScreenWidthDp < LARGE_SCREEN_MIN_WIDTH_DP) {
+    ActivityInfo.SCREEN_ORIENTATION_NOSENSOR
+} else {
+    ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED
+}
 
 /**
  * Activity for the JetpackCameraApp.
@@ -103,6 +125,10 @@ class MainActivity : ComponentActivity() {
             navigationBarStyle = SystemBarStyle.dark(android.graphics.Color.TRANSPARENT)
         )
         super.onCreate(savedInstanceState)
+        updateRequestedOrientation(resources.configuration)
+        addOnMultiWindowModeChangedListener { info ->
+            updateRequestedOrientation(resources.configuration, info.isInMultiWindowMode)
+        }
         cameraLaunchConfigProvider.setIntent(intent)
         var uiState: MainActivityUiState by mutableStateOf(Loading)
 
@@ -194,6 +220,24 @@ class MainActivity : ComponentActivity() {
         }
     }
 
+    override fun onConfigurationChanged(newConfig: Configuration) {
+        super.onConfigurationChanged(newConfig)
+        updateRequestedOrientation(newConfig)
+    }
+
+    private fun updateRequestedOrientation(
+        configuration: Configuration,
+        multiWindowMode: Boolean = isInMultiWindowMode
+    ) {
+        val targetOrientation = resolveRequestedOrientation(
+            isInMultiWindowMode = multiWindowMode,
+            smallestScreenWidthDp = configuration.smallestScreenWidthDp
+        )
+        if (requestedOrientation != targetOrientation) {
+            requestedOrientation = targetOrientation
+        }
+    }
+
     private val debugSettings: DebugSettings
         get() = cameraLaunchConfigProvider.config.value.debugSettings
 

app/src/test/java/com/google/jetpackcamera/MainActivityOrientationTest.kt

@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2026 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.google.jetpackcamera
+
+import android.content.pm.ActivityInfo
+import com.google.common.truth.Truth.assertThat
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+
+/**
+ * Unit tests for [resolveRequestedOrientation].
+ */
+@RunWith(JUnit4::class)
+class MainActivityOrientationTest {
+
+    @Test
+    fun resolveRequestedOrientation_fullScreenCompactPhone_locksToNoSensor() {
+        assertThat(
+            resolveRequestedOrientation(
+                isInMultiWindowMode = false,
+                smallestScreenWidthDp = 411
+            )
+        ).isEqualTo(ActivityInfo.SCREEN_ORIENTATION_NOSENSOR)
+
+        assertThat(
+            resolveRequestedOrientation(
+                isInMultiWindowMode = false,
+                smallestScreenWidthDp = 599
+            )
+        ).isEqualTo(ActivityInfo.SCREEN_ORIENTATION_NOSENSOR)
+    }
+
+    @Test
+    fun resolveRequestedOrientation_multiWindowCompact_allowsUnspecifiedOrientation() {
+        assertThat(
+            resolveRequestedOrientation(
+                isInMultiWindowMode = true,
+                smallestScreenWidthDp = 411
+            )
+        ).isEqualTo(ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED)
+    }
+
+    @Test
+    fun resolveRequestedOrientation_largeScreenOrFoldable_allowsUnspecifiedOrientation() {
+        assertThat(
+            resolveRequestedOrientation(
+                isInMultiWindowMode = false,
+                smallestScreenWidthDp = 600
+            )
+        ).isEqualTo(ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED)
+
+        assertThat(
+            resolveRequestedOrientation(
+                isInMultiWindowMode = true,
+                smallestScreenWidthDp = 673
+            )
+        ).isEqualTo(ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED)
+    }
+}