fix(ring): open the ring screen when an alarm or timer goes off in the app

A full-screen intent opens its activity only on a locked phone or a dark
display. While the user is in Clockula, SystemUI shows it as a heads-up
and the ring screen never comes up. Both ring services now start their
screen directly when the app has a visible window, which Android allows
from the background. Anywhere else the full-screen intent still decides.

CHANGELOG.md

@@ -47,7 +47,8 @@ The first release of Clockula: alarms, timers, a stopwatch and a world clock.
   default sound instead.
 - A ring screen over the lock screen with snooze and dismiss. The dismiss
   challenge always gives you a way out, works with a screen reader, and Back
-  can't silence an alarm.
+  can't silence an alarm. It also opens when the alarm or a timer goes off
+  while you're using Clockula.
 - Choose what the volume buttons do while an alarm rings: change the volume
   (as before), snooze, dismiss or nothing. Dismiss still respects the dismiss
   challenge by snoozing instead, and a snooze press with no snoozes left

app/src/main/java/de/jeanlucmakiola/clockula/alarm/ring/AlarmRingService.kt

@@ -18,8 +18,10 @@ import de.jeanlucmakiola.clockula.domain.alarm.RingPresentationPolicy
 import de.jeanlucmakiola.clockula.domain.alarm.RingSession
 import de.jeanlucmakiola.clockula.domain.ring.RingFallbackPolicy
 import de.jeanlucmakiola.clockula.domain.ring.SilenceAfter
+import de.jeanlucmakiola.clockula.ring.ForegroundRingScreen
 import de.jeanlucmakiola.clockula.ring.RingAudioPlayer
 import de.jeanlucmakiola.clockula.ring.RingVibrator
+import de.jeanlucmakiola.clockula.ui.ring.AlarmRingActivity
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
@@ -128,10 +130,12 @@ class AlarmRingService : Service() {
      * replaces it with the alarm's own notification as soon as the session is
      * read. Same channel and same id, so the user sees one notification — and
      * the placeholder is the first post, so it is the one that opens the ring
-     * screen.
+     * screen. Inside the app the full-screen intent only shows a heads-up,
+     * so the screen is opened directly there.
      */
     private fun startForegroundPreparing() {
         startForeground(RingNotifications.preparing(this, presentation(), repostPendingIntent()))
+        ForegroundRingScreen.launchIfVisible(this, AlarmRingActivity::class.java)
     }
 
     private fun startForeground(session: RingSession) {

app/src/main/java/de/jeanlucmakiola/clockula/ring/ForegroundRingScreen.kt

@@ -0,0 +1,38 @@
+package de.jeanlucmakiola.clockula.ring
+
+import android.app.Activity
+import android.app.ActivityManager
+import android.content.Context
+import android.content.Intent
+
+/**
+ * Opens a ring screen directly while one of Clockula's own windows is on
+ * screen.
+ *
+ * A full-screen intent opens its activity only when the phone is locked or the
+ * display is off. On a phone in use, and so always while the user is inside
+ * Clockula, SystemUI shows it as a heads-up and the ring screen never comes up.
+ * An app with a visible window may start activities from the background, so
+ * the ring services start the screen themselves in that one case. Everywhere
+ * else the full-screen intent stays in charge, and a heads-up over another app
+ * is what the platform asks for.
+ */
+object ForegroundRingScreen {
+
+    fun launchIfVisible(context: Context, screen: Class<out Activity>) {
+        if (!appIsVisible()) return
+        // A refused start costs nothing: the notification is up either way.
+        runCatching {
+            context.startActivity(
+                Intent(context, screen).addFlags(Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK),
+            )
+        }
+    }
+
+    /** The process holds a visible activity, not only a foreground service. */
+    private fun appIsVisible(): Boolean {
+        val process = ActivityManager.RunningAppProcessInfo()
+        ActivityManager.getMyMemoryState(process)
+        return process.importance <= ActivityManager.RunningAppProcessInfo.IMPORTANCE_VISIBLE
+    }
+}

app/src/main/java/de/jeanlucmakiola/clockula/timer/service/TimerService.kt

@@ -20,12 +20,14 @@ import de.jeanlucmakiola.clockula.domain.timer.TimerMode
 import de.jeanlucmakiola.clockula.domain.timer.TimerRing
 import de.jeanlucmakiola.clockula.domain.timer.TimerRingDecision
 import de.jeanlucmakiola.clockula.domain.timer.TimerSettings
+import de.jeanlucmakiola.clockula.ring.ForegroundRingScreen
 import de.jeanlucmakiola.clockula.ring.RingAudioPlayer
 import de.jeanlucmakiola.clockula.ring.RingVibrator
 import de.jeanlucmakiola.clockula.timer.AlarmRingStatus
 import de.jeanlucmakiola.clockula.timer.TimerEngine
 import de.jeanlucmakiola.clockula.timer.TimerIntents
 import de.jeanlucmakiola.clockula.timer.TimerServiceState
+import de.jeanlucmakiola.clockula.ui.ring.TimerRingActivity
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
@@ -286,6 +288,8 @@ class TimerService : Service() {
             fullScreen = sounding && capabilities.snapshot().canUseFullScreenIntent
         }
         startForeground(TimerNotifications.timer(this, state, fullScreen))
+        // Inside the app the full-screen intent only shows a heads-up.
+        if (!state.alertOnce && sounding) ForegroundRingScreen.launchIfVisible(this, TimerRingActivity::class.java)
     }
 
     /**