Add 'Habit Mode' feature to optionally show app after screen unlock

app/src/main/AndroidManifest.xml

@@ -28,6 +28,9 @@ You should have received a copy of the GNU General Public License along with Sim
     <uses-permission android:name="com.android.launcher.permission.INSTALL_SHORTCUT" />
     <uses-permission android:name="android.permission.READ_CALENDAR" />
     <uses-permission android:name="android.permission.WRITE_CALENDAR" />
+    <uses-permission android:name="android.permission.RECEIVE_USER_PRESENT" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
     <supports-screens
         android:anyDensity="true"
         android:largeScreens="true"
@@ -195,6 +198,19 @@ You should have received a copy of the GNU General Public License along with Sim
                 />
         </receiver>
 
+        <!-- In support of 'habit mode' that launches SimpleTask when the device is unlocked-->   
+        <receiver android:name=".AppLauncherReceiver" android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.USER_PRESENT" />
+            </intent-filter>
+        </receiver>
+
+        <!-- Service to improve reliability of 'habit mode' -->
+        <service
+            android:name=".AppLauncherService"
+            android:enabled="true"
+            android:exported="false" />
+
         <service
             android:name=".AppWidgetService"
             android:exported="false"

app/src/main/java/nl/mpcjanssen/simpletask/AppLauncherReceiver.kt

@@ -0,0 +1,16 @@
+package nl.mpcjanssen.simpletask
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+
+class AppLauncherReceiver : BroadcastReceiver() {
+
+    override fun onReceive(context: Context, intent: Intent) {
+        if (intent.action == Intent.ACTION_USER_PRESENT) {
+            val simpleTaskActivity = Intent(context, Simpletask::class.java)
+            simpleTaskActivity.flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_REORDER_TO_FRONT
+            context.startActivity(simpleTaskActivity)
+        }
+    }
+}

app/src/main/java/nl/mpcjanssen/simpletask/AppLauncherService.kt

@@ -0,0 +1,55 @@
+package nl.mpcjanssen.simpletask
+
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.Service
+import android.content.Intent
+import android.content.IntentFilter
+import android.os.Build
+import android.os.IBinder
+import androidx.core.app.NotificationCompat
+
+class AppLauncherService : Service() {
+
+    private val appLauncherReceiver = AppLauncherReceiver()
+
+    override fun onBind(intent: Intent): IBinder? {
+        return null
+    }
+
+    override fun onCreate() {
+        super.onCreate()
+
+        // Create a notification channel for the foreground service
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            val channel = NotificationChannel(
+                    "simpletask_launcher_service",
+                    "SimpleTask Launcher Service",
+                    NotificationManager.IMPORTANCE_LOW
+            )
+            val notificationManager = getSystemService(NotificationManager::class.java)
+            notificationManager.createNotificationChannel(channel)
+        }
+
+        // Create a notification for the foreground service using NotificationCompat.Builder()
+        val notification = NotificationCompat.Builder(this, "simpletask_launcher_service")
+                .setContentTitle("SimpleTask Habit Mode")
+                .setContentText("Waiting for Screen Unlock")
+                .setSmallIcon(R.drawable.ic_done_white_24dp)
+                .build()
+
+        // Start the foreground service with the notification
+        startForeground(1, notification)
+
+        // Register the BroadcastReceiver for the ACTION_USER_PRESENT broadcast
+        val intentFilter = IntentFilter(Intent.ACTION_USER_PRESENT)
+        registerReceiver(appLauncherReceiver, intentFilter)
+    }
+
+    override fun onDestroy() {
+        // Unregister the BroadcastReceiver when the service is destroyed
+        unregisterReceiver(appLauncherReceiver)
+
+        super.onDestroy()
+    }
+}

app/src/main/java/nl/mpcjanssen/simpletask/Preferences.kt

@@ -30,9 +30,11 @@ package nl.mpcjanssen.simpletask
 import android.Manifest
 import android.content.*
 import android.content.pm.PackageManager
+import android.net.Uri
 import android.os.Build
 import android.os.Bundle
 import android.preference.*
+import android.provider.Settings
 import android.text.TextUtils
 import androidx.core.app.ActivityCompat
 import androidx.core.content.ContextCompat
@@ -89,6 +91,7 @@ class Preferences : ThemedPreferenceActivity(), SharedPreferences.OnSharedPrefer
                 val broadcastIntent = Intent(Constants.BROADCAST_MAIN_FONTSIZE_CHANGED)
                 localBroadcastManager.sendBroadcast(broadcastIntent)
             }
+            getString(R.string.habit_mode_pref_key) -> requestDrawOverlaysPermissionAndStartService()
         }
     }
 
@@ -111,6 +114,24 @@ class Preferences : ThemedPreferenceActivity(), SharedPreferences.OnSharedPrefer
         }
     }
 
+    private fun requestDrawOverlaysPermissionAndStartService() {
+        Log.i(TAG, "requestDrawOverlaysPermissionAndStartService")
+        if (TodoApplication.config.enableHabitMode) {
+            // test to see if we already have permission
+            val canDrawOverlays = Settings.canDrawOverlays(this)
+            if (!canDrawOverlays) {
+
+                val intent = Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION)
+                intent.data = Uri.parse("package:${packageName}")
+                startActivityForResult(intent, 0)
+            }
+
+            startService(Intent(this, AppLauncherService::class.java))
+        } else {
+            stopService(Intent(this, AppLauncherService::class.java))
+        }
+    }
+
     override fun onResume() {
         super.onResume()
         // Set up a listener whenever a key changes

app/src/main/java/nl/mpcjanssen/simpletask/Simpletask.kt

@@ -11,7 +11,7 @@
 
 package nl.mpcjanssen.simpletask
 
-import android.annotation.SuppressLint
+    import android.annotation.SuppressLint
 import android.app.DatePickerDialog
 import android.app.PendingIntent
 import android.app.SearchManager
@@ -42,6 +42,7 @@ import androidx.annotation.RequiresApi
 import androidx.core.content.FileProvider
 import androidx.core.app.NotificationCompat
 import androidx.core.app.NotificationManagerCompat
+import android.provider.Settings
 
 import hirondelle.date4j.DateTime
 import nl.mpcjanssen.simpletask.adapters.DrawerAdapter
@@ -80,9 +81,18 @@ class Simpletask : ThemedNoActionBarActivity() {
 
     private val uiHandler = UiHandler()
 
+
+
     public override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         Log.i(TAG, "onCreate")
+
+        // If Habit Mode is enabled, we start the foreground service that 
+        // catches the screen unlock events reliably. 
+        if(TodoApplication.config.enableHabitMode) {
+            startService(Intent(this, AppLauncherService::class.java))
+        }
+
         m_savedInstanceState = savedInstanceState
         val intentFilter = IntentFilter()
         intentFilter.addAction(Constants.BROADCAST_ACTION_LOGOUT)

app/src/main/java/nl/mpcjanssen/simpletask/util/Config.kt

@@ -177,6 +177,8 @@ class Config(app: TodoApplication) : Preferences(app) {
 
     val showConfirmationDialogs by BooleanPreference(R.string.ui_show_confirmation_dialogs, true)
 
+    val enableHabitMode by BooleanPreference(R.string.habit_mode_pref_key, false)
+
     val defaultSorts: Array<String>
         get() = TodoApplication.app.resources.getStringArray(R.array.sortKeys)
 

app/src/main/res/values/donottranslate.xml

@@ -184,4 +184,5 @@ You should have received a copy of the GNU General Public License along with Tod
     <string name="query_store"                    translatable="false">query_store</string>
     <string name="force_english"                  translatable="false">force_english</string>
     <string name="idle_before_save"               translatable="false">idle_before_save</string>
+    <string name="habit_mode_pref_key"            translatable="false">habit_mode_enable</string>
 </resources>

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

@@ -405,6 +405,8 @@ You should have received a copy of the GNU General Public License along with Tod
     <string name="lua_config_share">Share</string>
     <string name="lua_open_config">Lua config</string>
     <string name="use_uuid_title">Assign a UUID to each task</string>
+    <string name="habit_mode_pref_title">Enable Habit Mode (BETA)</string>
+    <string name="habit_mode_pref_summary">Habit Mode brings this app to the foreground every time the device is unlocked.</string>
     <string name="task_drag_title">Drag tasks to reorder (BETA)</string>
     <string name="nav_drawer_hint">Save the current filter\n
         using the save button</string>

app/src/main/res/xml/interface_preferences.xml

@@ -63,4 +63,10 @@
         android:key="@string/task_drag"
         android:title="@string/task_drag_title"
         />
+    <CheckBoxPreference
+        android:defaultValue="false"
+        android:key="@string/habit_mode_pref_key"
+        android:summary="@string/habit_mode_pref_summary"
+        android:title="@string/habit_mode_pref_title"
+        />
 </PreferenceScreen>