Notify users when news are updated

core/notifications/build.gradle.kts

@@ -24,6 +24,7 @@ android {
 }
 
 dependencies {
+    implementation(project(":core:common"))
     implementation(project(":core:model"))
 
     implementation(libs.kotlinx.coroutines.android)

core/notifications/src/main/AndroidManifest.xml

@@ -14,4 +14,6 @@
      See the License for the specific language governing permissions and
      limitations under the License.
 -->
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"/>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
+</manifest>

core/notifications/src/main/java/com/google/samples/apps/nowinandroid/core/notifications/AndroidSystemNotifier.kt

@@ -16,17 +16,126 @@
 
 package com.google.samples.apps.nowinandroid.core.notifications
 
+import android.Manifest.permission
+import android.app.Notification
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.content.Context
+import android.content.pm.PackageManager
+import android.os.Build.VERSION
+import android.os.Build.VERSION_CODES
+import androidx.core.app.ActivityCompat
+import androidx.core.app.NotificationCompat
+import androidx.core.app.NotificationCompat.InboxStyle
+import androidx.core.app.NotificationManagerCompat
 import com.google.samples.apps.nowinandroid.core.model.data.NewsResource
+import dagger.hilt.android.qualifiers.ApplicationContext
 import javax.inject.Inject
 import javax.inject.Singleton
 
+private const val NEWS_NOTIFICATION_SUMMARY_ID = 1
+private const val NEWS_NOTIFICATION_CHANNEL_ID = ""
+private const val NEWS_NOTIFICATION_GROUP = "NEWS_NOTIFICATIONS"
+
 /**
  * Implementation of [Notifier] that displays notifications in the system tray.
  */
 @Singleton
-class AndroidSystemNotifier @Inject constructor() : Notifier {
+class AndroidSystemNotifier @Inject constructor(
+    @ApplicationContext private val context: Context,
+) : Notifier {
+
+    override fun onNewsAdded(
+        newsResources: List<NewsResource>,
+    ) = with(context) {
+        if (ActivityCompat.checkSelfPermission(
+                this,
+                permission.POST_NOTIFICATIONS,
+            ) != PackageManager.PERMISSION_GRANTED
+        ) {
+            return
+        }
+
+        val newsNotifications = newsResources.map { newsResource ->
+            newsNotification {
+                setSmallIcon(
+                    com.google.samples.apps.nowinandroid.core.common.R.drawable.ic_nia_notification,
+                )
+                    .setContentTitle(newsResource.title)
+                    .setContentText(newsResource.content)
+                    .setGroup(NEWS_NOTIFICATION_GROUP)
+            }
+        }
+        val summaryNotification = newsNotification {
+            val title = getString(
+                R.string.news_notification_group_summary,
+                newsNotifications.size,
+            )
+            setContentTitle(title)
+                .setContentText(title)
+                .setSmallIcon(
+                    com.google.samples.apps.nowinandroid.core.common.R.drawable.ic_nia_notification,
+                )
+                // Build summary info into InboxStyle template.
+                .setStyle(newsInboxStyle(newsResources, title))
+                .setGroup(NEWS_NOTIFICATION_GROUP)
+                .setGroupSummary(true)
+                .build()
+        }
+
+        with(NotificationManagerCompat.from(this)) {
+            newsNotifications.forEachIndexed { index, notification ->
+                notify(newsResources[index].id.hashCode(), notification)
+            }
+            notify(NEWS_NOTIFICATION_SUMMARY_ID, summaryNotification)
+        }
+    }
+
+    /**
+     * Creates an inbox style summary notification for news updates
+     */
+    private fun newsInboxStyle(
+        newsResources: List<NewsResource>,
+        title: String,
+    ): InboxStyle = newsResources
+        // Show at most 5 lines
+        .take(5)
+        .fold(InboxStyle()) { inboxStyle, newsResource ->
+            inboxStyle.addLine(newsResource.title)
+        }
+        .setBigContentTitle(title)
+        .setSummaryText(title)
+}
+
+/**
+ * Creates a notification for configured for news updates
+ */
+private fun Context.newsNotification(
+    block: NotificationCompat.Builder.() -> Unit,
+): Notification {
+    ensureNotificationChannel()
+    return NotificationCompat.Builder(
+        this,
+        NEWS_NOTIFICATION_CHANNEL_ID,
+    )
+        .setPriority(NotificationCompat.PRIORITY_DEFAULT)
+        .apply(block)
+        .build()
+}
+
+/**
+ * Ensures the a notification channel is is present if applicable
+ */
+private fun Context.ensureNotificationChannel() {
+    if (VERSION.SDK_INT < VERSION_CODES.O) return
 
-    override fun onNewsAdded(newsResources: List<NewsResource>) {
-        // TODO, create notification and display to the user
+    val channel = NotificationChannel(
+        NEWS_NOTIFICATION_CHANNEL_ID,
+        getString(R.string.news_notification_channel_name),
+        NotificationManager.IMPORTANCE_DEFAULT,
+    ).apply {
+        description = getString(R.string.news_notification_channel_description)
     }
+    // Register the channel with the system
+    NotificationManagerCompat.from(this).createNotificationChannel(channel)
 }

core/notifications/src/main/res/values/strings.xml

@@ -15,8 +15,8 @@
      limitations under the License.
 -->
 <resources>
-    <string name="sync_notification_title">Now in Android</string>
-    <string name="sync_notification_channel_name">Sync</string>
-    <string name="sync_notification_channel_description">Background tasks for Now in Android</string>
-
+    <string name="news_notification_title">Now in Android</string>
+    <string name="news_notification_channel_name">News updates</string>
+    <string name="news_notification_channel_description">The latest updates on what\'s new in Android</string>
+    <string name="news_notification_group_summary">%1$d news updates</string>
 </resources>

feature/foryou/build.gradle.kts

@@ -29,4 +29,5 @@ android {
 dependencies {
     implementation(libs.kotlinx.datetime)
     implementation(libs.androidx.activity.compose)
+    implementation(libs.accompanist.permissions)
 }

feature/foryou/src/main/java/com/google/samples/apps/nowinandroid/feature/foryou/ForYouScreen.kt

@@ -16,6 +16,8 @@
 
 package com.google.samples.apps.nowinandroid.feature.foryou
 
+import android.os.Build.VERSION
+import android.os.Build.VERSION_CODES
 import androidx.activity.compose.ReportDrawnWhen
 import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.animation.fadeIn
@@ -57,6 +59,7 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -73,6 +76,9 @@ import androidx.compose.ui.unit.sp
 import androidx.compose.ui.util.trace
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.google.accompanist.permissions.ExperimentalPermissionsApi
+import com.google.accompanist.permissions.PermissionStatus.Denied
+import com.google.accompanist.permissions.rememberPermissionState
 import com.google.samples.apps.nowinandroid.core.designsystem.component.DynamicAsyncImage
 import com.google.samples.apps.nowinandroid.core.designsystem.component.NiaButton
 import com.google.samples.apps.nowinandroid.core.designsystem.component.NiaIconToggleButton
@@ -199,6 +205,7 @@ internal fun ForYouScreen(
         }
     }
     TrackScreenViewEvent(screenName = "ForYou")
+    requestNotificationsPermission()
 }
 
 /**
@@ -383,6 +390,21 @@ fun TopicIcon(
     )
 }
 
+@Composable
+@OptIn(ExperimentalPermissionsApi::class)
+private fun requestNotificationsPermission() {
+    if (VERSION.SDK_INT < VERSION_CODES.TIRAMISU) return
+    val notificationsPermissionState = rememberPermissionState(
+        android.Manifest.permission.POST_NOTIFICATIONS,
+    )
+    LaunchedEffect(notificationsPermissionState) {
+        val status = notificationsPermissionState.status
+        if (status is Denied && !status.shouldShowRationale) {
+            notificationsPermissionState.launchPermissionRequest()
+        }
+    }
+}
+
 @DevicePreviews
 @Composable
 fun ForYouScreenPopulatedFeed(

gradle/libs.versions.toml

@@ -55,6 +55,7 @@ turbine = "0.12.1"
 [libraries]
 accompanist-systemuicontroller = { group = "com.google.accompanist", name = "accompanist-systemuicontroller", version.ref = "accompanist" }
 accompanist-testharness = { group = "com.google.accompanist", name = "accompanist-testharness", version.ref = "accompanist" }
+accompanist-permissions = { group = "com.google.accompanist", name = "accompanist-permissions", version.ref = "accompanist" }
 android-desugarJdkLibs = { group = "com.android.tools", name = "desugar_jdk_libs", version.ref = "androidDesugarJdkLibs" }
 androidx-activity-compose = { group = "androidx.activity", name = "activity-compose", version.ref = "androidxActivity" }
 androidx-appcompat = { group = "androidx.appcompat", name = "appcompat", version.ref = "androidxAppCompat" }