Disable wakelock experimental option on Android 6+ (#77)

app/src/main/java/com/nutomic/syncthingandroid/activities/SettingsActivity.java

@@ -231,6 +231,12 @@ public class SettingsActivity extends SyncthingActivity {
 
             mRunOnMeteredWifi.setEnabled(mRunOnWifi.isChecked());
             mWifiSsidWhitelist.setEnabled(mRunOnWifi.isChecked());
+            /* Experimental options */
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+                /* Wakelocks are only valid on Android 5 or lower. */
+                mUseWakelock.setEnabled(false);
+                mUseWakelock.setChecked(false);
+            }
 
             mCategorySyncthingOptions = findPreference("category_syncthing_options");
             setPreferenceCategoryChangeListener(mCategorySyncthingOptions, this::onSyncthingPreferenceChange);

app/src/main/java/com/nutomic/syncthingandroid/service/SyncthingRunnable.java

@@ -4,6 +4,7 @@ import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
+import android.os.Build;
 import android.os.Environment;
 import android.os.PowerManager;
 import android.os.SystemClock;
@@ -133,13 +134,20 @@ public class SyncthingRunnable implements Runnable {
         } catch (IOException | InterruptedException e) {
             Log.w(TAG, "Failed to chmod Syncthing", e);
         }
-        // Loop Syncthing
+
+        /**
+         * Potential fix for #498, keep the CPU running while native binary is running.
+         * Only valid on Android 5 or lower.
+         */
+        PowerManager pm;
+        PowerManager.WakeLock wakeLock = null;
+        Boolean useWakeLock = mPreferences.getBoolean(Constants.PREF_USE_WAKE_LOCK, false);
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M && useWakeLock) {
+            pm = (PowerManager) mContext.getSystemService(Context.POWER_SERVICE);
+            wakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG);
+        }
+
         Process process = null;
-        // Potential fix for #498, keep the CPU running while native binary is running
-        PowerManager pm = (PowerManager) mContext.getSystemService(Context.POWER_SERVICE);
-        PowerManager.WakeLock wakeLock = useWakeLock()
-                ? pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG)
-                : null;
         try {
             if (wakeLock != null) {
                 wakeLock.acquire();
@@ -263,13 +271,6 @@ public class SyncthingRunnable implements Runnable {
         }
     }
 
-    /**
-     * Returns true if the experimental setting for using wake locks has been enabled in settings.
-     */
-    private boolean useWakeLock() {
-        return mPreferences.getBoolean(Constants.PREF_USE_WAKE_LOCK, false);
-    }
-
     /**
      * Look for running libsyncthing.so processes and return an array
      * containing the PIDs of found instances.

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

@@ -434,7 +434,7 @@ Bitte melden Sie auftretende Probleme via GitHub.</string>
 
     <string name="keep_wakelock_while_binary_running">Prozessor wach halten während Syncthing läuft.</string>
 
-    <string name="keep_wakelock_while_binary_running_summary">Nutze dieses Einstellung, wenn du unerwartete Verbindungsabbrüche hast, während du im Batteriebetrieb arbeitest. Das wird zu einem erhöhten Energieverbrauch führen.</string>
+    <string name="keep_wakelock_while_binary_running_summary">Nur für Android 5 oder niedriger. Nutze diese Einstellung, wenn du unerwartete Verbindungsabbrüche hast, während du im Batteriebetrieb arbeitest. Das wird zu einem erhöhten Energieverbrauch führen.</string>
 
     <string name="use_tor_title">Tor benutzen</string>
 

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

@@ -438,7 +438,7 @@ Please report any problems you encounter via Github.</string>
 
     <string name="keep_wakelock_while_binary_running">Keep the CPU awake while Syncthing is running</string>
 
-    <string name="keep_wakelock_while_binary_running_summary">Use this setting if you experience unexpected disconnects while operating on battery. This will result in increased battery consumption.</string>
+    <string name="keep_wakelock_while_binary_running_summary">Only for Android 5 or lower. Use this setting if you experience unexpected disconnects while operating on battery. This will result in increased battery consumption.</string>
 
     <string name="use_tor_title">Use Tor</string>
 

app/src/main/res/xml/app_settings.xml

@@ -242,12 +242,6 @@
         android:title="@string/category_experimental"
         android:key="category_experimental">
 
-        <CheckBoxPreference
-            android:key="wakelock_while_binary_running"
-            android:title="@string/keep_wakelock_while_binary_running"
-            android:summary="@string/keep_wakelock_while_binary_running_summary"
-            android:defaultValue="false" />
-
         <CheckBoxPreference
             android:key="use_tor"
             android:title="@string/use_tor_title"
@@ -270,6 +264,13 @@
             android:title="@string/use_legacy_hashing_title"
             android:summary="@string/use_legacy_hashing_summary" />
 
+        <!-- Only valid for Android < 6 -->
+        <CheckBoxPreference
+            android:key="wakelock_while_binary_running"
+            android:title="@string/keep_wakelock_while_binary_running"
+            android:summary="@string/keep_wakelock_while_binary_running_summary"
+            android:defaultValue="false" />
+
     </PreferenceScreen>
 
     <PreferenceScreen