Add a "view licenses" button in settings dialog to view open source licenses.

- Followed the instructions here:
  https://developers.google.com/android/guides/opensource
- The plugin will automatically parse libs.versions.toml and store the licenses
  related data in the app bundle as resources.
- Use the activities in play-services-oss-licenses library to view the licenses.

PiperOrigin-RevId: 780235294

Android/src/app/build.gradle.kts

@@ -23,6 +23,7 @@ plugins {
   alias(libs.plugins.kotlin.serialization)
   alias(libs.plugins.protobuf)
   alias(libs.plugins.hilt.application)
+  alias(libs.plugins.oss.licenses)
   kotlin("kapt")
 }
 
@@ -97,6 +98,7 @@ dependencies {
   implementation(libs.protobuf.javalite)
   implementation(libs.hilt.android)
   implementation(libs.hilt.navigation.compose)
+  implementation(libs.play.services.oss.licenses)
   implementation(platform(libs.firebase.bom))
   implementation(libs.firebase.analytics)
   kapt(libs.hilt.android.compiler)

Android/src/app/src/main/AndroidManifest.xml

@@ -48,12 +48,18 @@
         android:supportsRtl="true"
         android:theme="@style/Theme.Gallery"
         tools:targetApi="31">
+        <!--
+          android:configChanges="uiMode" tells the system don't destroy and
+          recreate the activity when UI mode changes (e.g. setting dark mode).
+          Instead, just recompose the view.
+         -->
         <activity
             android:name="com.google.ai.edge.gallery.MainActivity"
             android:exported="true"
             android:theme="@style/Theme.Gallery.SplashScreen"
             android:screenOrientation="portrait"
             android:windowSoftInputMode="adjustResize"
+            android:configChanges="uiMode"
             tools:ignore="DiscouragedApi,LockedOrientationActivity">
             <!-- This is for putting the app into launcher -->
             <intent-filter>
@@ -72,6 +78,16 @@
             </intent-filter>
         </activity>
 
+        <!-- Set themes for activities that are used for viewing open source licenses -->
+        <activity
+            android:name="com.google.android.gms.oss.licenses.OssLicensesMenuActivity"
+            android:exported="true"
+            android:theme="@style/Theme.Gallery.OssLicenses" />
+        <activity
+            android:name="com.google.android.gms.oss.licenses.OssLicensesActivity"
+            android:exported="true"
+            android:theme="@style/Theme.Gallery.OssLicenses" />
+
         <provider
             android:name="androidx.core.content.FileProvider"
             android:authorities="${applicationId}.provider"

Android/src/app/src/main/java/com/google/ai/edge/gallery/ui/home/SettingsDialog.kt

@@ -16,6 +16,11 @@
 
 package com.google.ai.edge.gallery.ui.home
 
+import com.google.android.gms.oss.licenses.OssLicensesMenuActivity
+import android.app.UiModeManager
+import android.content.Context
+import android.content.Intent
+import android.os.Build
 import androidx.compose.foundation.border
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.interaction.MutableInteractionSource
@@ -36,6 +41,7 @@ import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.rounded.CheckCircle
 import androidx.compose.material3.Button
 import androidx.compose.material3.Card
+import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
@@ -55,6 +61,7 @@ import androidx.compose.ui.focus.FocusRequester
 import androidx.compose.ui.focus.focusRequester
 import androidx.compose.ui.focus.onFocusChanged
 import androidx.compose.ui.graphics.SolidColor
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.LocalFocusManager
 import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.text.font.FontWeight
@@ -73,6 +80,7 @@ import kotlin.math.min
 
 private val THEME_OPTIONS = listOf(Theme.THEME_AUTO, Theme.THEME_LIGHT, Theme.THEME_DARK)
 
+@OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun SettingsDialog(
   curThemeOverride: Theme,
@@ -127,6 +135,7 @@ fun SettingsDialog(
           modifier = Modifier.verticalScroll(rememberScrollState()).weight(1f, fill = false),
           verticalArrangement = Arrangement.spacedBy(16.dp),
         ) {
+          val context = LocalContext.current
           // Theme switcher.
           Column(modifier = Modifier.fillMaxWidth()) {
             Text(
@@ -147,6 +156,23 @@ fun SettingsDialog(
 
                     // Save to data store.
                     modelManagerViewModel.saveThemeOverride(theme)
+
+                    // Update ui mode.
+                    //
+                    // This is necessary to make other Activities launched from MainActivity to have
+                    // the correct theme.
+                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
+                      val uiModeManager =
+                        context.applicationContext.getSystemService(Context.UI_MODE_SERVICE)
+                          as UiModeManager
+                      if (theme == Theme.THEME_AUTO) {
+                        uiModeManager.setApplicationNightMode(UiModeManager.MODE_NIGHT_AUTO)
+                      } else if (theme == Theme.THEME_LIGHT) {
+                        uiModeManager.setApplicationNightMode(UiModeManager.MODE_NIGHT_NO)
+                      } else {
+                        uiModeManager.setApplicationNightMode(UiModeManager.MODE_NIGHT_YES)
+                      }
+                    }
                   },
                   checked = theme == selectedTheme,
                   label = { Text(themeLabel(theme)) },
@@ -166,7 +192,7 @@ fun SettingsDialog(
             )
             // Show the start of the token.
             val curHfToken = hfToken
-            if (curHfToken != null) {
+            if (curHfToken != null && curHfToken.accessToken.isNotEmpty()) {
               Text(
                 curHfToken.accessToken.substring(0, min(16, curHfToken.accessToken.length)) + "...",
                 style = MaterialTheme.typography.bodyMedium,
@@ -254,6 +280,24 @@ fun SettingsDialog(
               }
             }
           }
+
+          // Third party licenses.
+          Column(modifier = Modifier.fillMaxWidth()) {
+            Text(
+              "Third-party libraries",
+              style = MaterialTheme.typography.titleSmall.copy(fontWeight = FontWeight.Bold),
+            )
+            OutlinedButton(
+              onClick = {
+                // Create an Intent to launch a license viewer that displays a list of
+                // third-party library names. Clicking a name will show its license content.
+                val intent = Intent(context, OssLicensesMenuActivity::class.java)
+                context.startActivity(intent)
+              }
+            ) {
+              Text("View licenses")
+            }
+          }
         }
 
         // Button row.

Android/src/app/src/main/res/values-night/themes.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+ Copyright 2025 Google LLC
+
+ 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.
+-->
+
+<resources xmlns:tools="http://schemas.android.com/tools">
+  <style name="Theme.Gallery.OssLicenses" parent="Theme.AppCompat">
+    <item name="android:windowOptOutEdgeToEdgeEnforcement" tools:targetApi="35">true</item>
+  </style>
+</resources>

Android/src/app/src/main/res/values/themes.xml

@@ -15,10 +15,13 @@
  limitations under the License.
 -->
 
-<resources>
+<resources xmlns:tools="http://schemas.android.com/tools">
     <style name="Theme.Gallery" parent="android:Theme.Material.Light.NoActionBar" />
     <style name="Theme.Gallery.SplashScreen" parent="Theme.SplashScreen">
         <item name="windowSplashScreenBackground">#2A2A34</item>
         <item name="postSplashScreenTheme">@style/Theme.Gallery</item>
     </style>
+    <style name="Theme.Gallery.OssLicenses" parent="Theme.AppCompat.Light.DarkActionBar">
+        <item name="android:windowOptOutEdgeToEdgeEnforcement" tools:targetApi="35">true</item>
+    </style>
 </resources>

Android/src/gradle/libs.versions.toml

@@ -31,6 +31,8 @@ netOpenidAppauth = "0.11.1"
 splashscreen = "1.2.0-beta01"
 hilt = "2.56.2"
 hiltNavigation = "1.2.0"
+ossLicenses = "0.10.6"
+playServicesOssLicenses = "17.1.0"
 googleService = "4.4.3"
 firebaseBom = "33.16.0"
 
@@ -75,6 +77,7 @@ hilt-android = { module = "com.google.dagger:hilt-android", version.ref = "hilt"
 hilt-navigation-compose = { module = "androidx.hilt:hilt-navigation-compose", version.ref = "hiltNavigation" }
 hilt-android-testing = { module = "com.google.dagger:hilt-android-testing", version.ref = "hilt" }
 hilt-android-compiler = { module = "com.google.dagger:hilt-android-compiler", version.ref = "hilt" }
+play-services-oss-licenses = { module = "com.google.android.gms:play-services-oss-licenses", version.ref = "playServicesOssLicenses"}
 firebase-bom = { group = "com.google.firebase", name = "firebase-bom", version.ref = "firebaseBom" }
 # When using the Firebase BoM, you don't specify versions in Firebase
 # library dependencies.
@@ -87,4 +90,5 @@ kotlin-compose = { id = "org.jetbrains.kotlin.plugin.compose", version.ref = "ko
 kotlin-serialization = { id = "org.jetbrains.kotlin.plugin.serialization", version.ref = "serializationPlugin" }
 protobuf = {id = "com.google.protobuf", version.ref = "protobuf"}
 hilt-application = { id = "com.google.dagger.hilt.android", version.ref = "hilt" }
+oss-licenses = {id = "com.google.android.gms.oss-licenses-plugin", version.ref = "ossLicenses"}
 google-services = { id = "com.google.gms.google-services", version.ref = "googleService" }

Android/src/settings.gradle.kts

@@ -26,6 +26,13 @@ pluginManagement {
     mavenCentral()
     gradlePluginPortal()
   }
+  resolutionStrategy {
+    eachPlugin {
+      if (requested.id.id == "com.google.android.gms.oss-licenses-plugin") {
+        useModule("com.google.android.gms:oss-licenses-plugin:0.10.6")
+      }
+    }
+  }
 }
 
 dependencyResolutionManagement {