add snippets on how to request projected permissions from phone activity (#969)

* add snippets on how to request projected permissions from phone activity

* address gemini code review feedback

* addressed Dereck's feedback and renamed classes to Projected instead of Glasses

* remove the unused display category string

---------

Co-authored-by: Dereck Bridie <devbridie@users.noreply.github.com>

Author: trambui09

xr/src/main/AndroidManifest.xml

@@ -24,11 +24,12 @@
         android:label="XR"
         tools:ignore="MissingApplicationIcon">
         <activity
-            android:name="com.example.xr.projected.GlassesMainActivity"
+            android:name="com.example.xr.projected.ProjectedMainActivity"
             android:exported="true"
-            android:requiredDisplayCategory="@string/display_category_xr_projected">
+            android:requiredDisplayCategory="android.hardware.display.category.XR_PROJECTED">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.XR_PROJECTED_LAUNCHER"/>
             </intent-filter>
         </activity>
         <activity

xr/src/main/java/com/example/xr/projected/PermissionsFromPhoneActivity.kt

@@ -0,0 +1,95 @@
+/*
+ * Copyright 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
+ *
+ *     https://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.example.xr.projected
+
+import android.Manifest
+import android.content.pm.PackageManager
+import android.os.Build
+import androidx.activity.ComponentActivity
+import androidx.annotation.RequiresApi
+import androidx.core.content.ContextCompat
+import androidx.xr.projected.ProjectedContext
+import androidx.xr.projected.experimental.ExperimentalProjectedApi
+
+/**
+ * Demonstrates how to request glasses-specific hardware permissions
+ * from an Activity running on the host phone.
+ */
+class PermissionsFromPhoneActivity : ComponentActivity() {
+
+    private var projectedDeviceId: Int = -1
+
+    // [START androidxr_projected_permissions_from_phone_activity_permission_result_callback]
+    private companion object {
+        // REQUEST_CODE_GLASSES_CAMERA is a developer-defined constant.
+        const val REQUEST_CODE_GLASSES_CAMERA = 1001
+    }
+
+    @RequiresApi(Build.VERSION_CODES.VANILLA_ICE_CREAM)
+    override fun onRequestPermissionsResult(
+        requestCode: Int,
+        permissions: Array<out String>,
+        grantResults: IntArray,
+        deviceId: Int
+    ) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults, deviceId)
+
+        // Handle the result of the permission request
+        if (requestCode == REQUEST_CODE_GLASSES_CAMERA && deviceId == projectedDeviceId) {
+            if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
+                // Proceed with glasses camera features
+            } else {
+                // Handle glasses permission denied
+            }
+        }
+    }
+    // [END androidxr_projected_permissions_from_phone_activity_permission_result_callback]
+
+    @OptIn(ExperimentalProjectedApi::class)
+    @RequiresApi(Build.VERSION_CODES.VANILLA_ICE_CREAM)
+    private fun checkAndRequestProjectedCameraPermission() {
+
+        try {
+            val projectedContext = ProjectedContext.createProjectedDeviceContext(this)
+            projectedDeviceId = projectedContext.deviceId
+
+            // [START androidxr_projected_permissions_from_phone_activity_has_permission]
+            // Pass the projected context to check if projected permissions are granted
+            val hasPermission = ContextCompat.checkSelfPermission(
+                projectedContext,
+                Manifest.permission.CAMERA
+            ) == PackageManager.PERMISSION_GRANTED
+            // [END androidxr_projected_permissions_from_phone_activity_has_permission]
+
+            if (hasPermission) {
+                // Proceed with camera features
+            } else {
+                // [START androidxr_projected_permissions_from_phone_activity_request_permission]
+                // Request the projected permission from phone activity
+                requestPermissions(
+                    arrayOf(Manifest.permission.CAMERA),
+                    // REQUEST_CODE_GLASSES_CAMERA is a developer-defined constant
+                    REQUEST_CODE_GLASSES_CAMERA,
+                    projectedDeviceId
+                )
+                // [END androidxr_projected_permissions_from_phone_activity_request_permission]
+            }
+        } catch (e: IllegalStateException) {
+            // Handle the case where the projected device is not found
+        }
+    }
+}

xr/src/main/java/com/example/xr/projected/PhoneMainActivity.kt

@@ -188,7 +188,7 @@ fun ConnectionScreen() {
                     // [START androidxr_projected_start_glasses_activity]
 
                     val options = ProjectedContext.createProjectedActivityOptions(context)
-                    val intent = Intent(context, GlassesMainActivity::class.java)
+                    val intent = Intent(context, ProjectedMainActivity::class.java)
                     context.startActivity(intent, options.toBundle())
 
                     // [END androidxr_projected_start_glasses_activity]

…mple/xr/projected/GlassesMainActivity.kt …le/xr/projected/ProjectedMainActivity.ktxr/src/main/java/com/example/xr/projected/GlassesMainActivity.kt renamed to xr/src/main/java/com/example/xr/projected/ProjectedMainActivity.kt xr/src/main/java/com/example/xr/projected/GlassesMainActivity.kt renamed to xr/src/main/java/com/example/xr/projected/ProjectedMainActivity.kt

@@ -50,7 +50,7 @@ import kotlinx.coroutines.launch
 
 // [START androidxr_projected_ai_glasses_activity]
 @OptIn(ExperimentalProjectedApi::class)
-class GlassesMainActivity : ComponentActivity() {
+class ProjectedMainActivity : ComponentActivity() {
 
     private var displayController: ProjectedDisplayController? = null
     private var isVisualUiSupported by mutableStateOf(false)
@@ -106,14 +106,14 @@ class GlassesMainActivity : ComponentActivity() {
         lifecycleScope.launch {
             // [START androidxr_projected_device_capabilities_check]
             // Check device capabilities
-            val projectedDeviceController = ProjectedDeviceController.create(this@GlassesMainActivity)
+            val projectedDeviceController = ProjectedDeviceController.create(this@ProjectedMainActivity)
             isVisualUiSupported = projectedDeviceController.capabilities.contains(CAPABILITY_VISUAL_UI)
             // [END androidxr_projected_device_capabilities_check]
 
-            val controller = ProjectedDisplayController.create(this@GlassesMainActivity)
+            val controller = ProjectedDisplayController.create(this@ProjectedMainActivity)
             displayController = controller
             val observer = GlassesLifecycleObserver(
-                context = this@GlassesMainActivity,
+                context = this@ProjectedMainActivity,
                 controller = controller,
                 onVisualsChanged = { visualsOn -> areVisualsOn = visualsOn }
             )

xr/src/main/res/values/strings.xml

@@ -15,5 +15,4 @@
      limitations under the License.
 -->
 <resources>
-    <string name="display_category_xr_projected">xr_projected</string>
 </resources>