The discovery now should be enabled while navigating the app UI

src/org/kde/kdeconnect/BackgroundService.java

@@ -20,6 +20,7 @@
 
 package org.kde.kdeconnect;
 
+import android.app.Activity;
 import android.app.Service;
 import android.content.Context;
 import android.content.Intent;
@@ -40,6 +41,7 @@ import java.security.KeyPair;
 import java.security.KeyPairGenerator;
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.locks.Lock;
@@ -57,23 +59,40 @@ public class BackgroundService extends Service {
 
     private final ConcurrentHashMap<String, Device> devices = new ConcurrentHashMap<>();
 
-    private boolean discoveryEnabled = false;
+    private final HashSet<Object> discoveryModeAcquisitions = new HashSet<>();
 
-    public void setDiscoveryEnabled(boolean b) {
+    public void acquireDiscoveryMode(Object key) {
-        if (discoveryEnabled == b)
+        boolean wasEmpty = discoveryModeAcquisitions.isEmpty();
-            return;
+        discoveryModeAcquisitions.add(key);
-
+        if (wasEmpty) {
-        discoveryEnabled = b;
-
-        if (b) {
             onNetworkChange();
-        } else {
+        }
+    }
+
+    public void releaseDiscoveryMode(Object key) {
+        boolean removed = discoveryModeAcquisitions.remove(key);
+        if (removed && discoveryModeAcquisitions.isEmpty()) {
             cleanDevices();
         }
     }
 
-    public boolean isDiscoveryEnabled() {
+    public static void addGuiInUseCounter(final Activity activity) {
-        return discoveryEnabled;
+        BackgroundService.RunCommand(activity, new BackgroundService.InstanceCallback() {
+            @Override
+            public void onServiceStart(BackgroundService service) {
+                service.acquireDiscoveryMode(activity);
+            }
+        });
+    }
+
+    public static void removeGuiInUseCounter(final Activity activity) {
+        BackgroundService.RunCommand(activity, new BackgroundService.InstanceCallback() {
+            @Override
+            public void onServiceStart(BackgroundService service) {
+                //If no user interface is open, close the connections open to other devices
+                service.releaseDiscoveryMode(activity);
+            }
+        });
     }
 
     private final Device.PairingCallback devicePairingCallback = new Device.PairingCallback() {
@@ -157,7 +176,7 @@ public class BackgroundService extends Service {
             } else {
                 Log.i("KDE/BackgroundService", "addLink,unknown device: " + deviceId);
                 device = new Device(BackgroundService.this, identityPackage, link);
-                if (isDiscoveryEnabled() || device.isPaired()) {
+                if (device.isPaired() || !discoveryModeAcquisitions.isEmpty()) {
                     devices.put(deviceId, device);
                     device.addPairingCallback(devicePairingCallback);
                 }

src/org/kde/kdeconnect/Plugins/MousePadPlugin/MousePadActivity.java

@@ -362,5 +362,17 @@ public class MousePadActivity extends ActionBarActivity implements GestureDetect
         imm.toggleSoftInputFromWindow(keyListenerView.getWindowToken(), 0, 0);
     }
 
+    @Override
+    protected void onStart() {
+        super.onStart();
+        BackgroundService.addGuiInUseCounter(this);
+    }
+
+    @Override
+    protected void onStop() {
+        super.onStop();
+        BackgroundService.removeGuiInUseCounter(this);
+    }
+
 }
 

src/org/kde/kdeconnect/Plugins/MprisPlugin/MprisActivity.java

@@ -453,9 +453,15 @@ public class MprisActivity extends ActionBarActivity {
     }
 
     @Override
-    protected void onPause() {
+    protected void onStart() {
-        super.onPause();
+        super.onStart();
-        positionSeekUpdateHandler.removeCallbacks(positionSeekUpdateRunnable);
+        BackgroundService.addGuiInUseCounter(this);
+    }
+
+    @Override
+    protected void onStop() {
+        super.onStop();
+        BackgroundService.removeGuiInUseCounter(this);
     }
 
 }

src/org/kde/kdeconnect/Plugins/NotificationsPlugin/NotificationFilterActivity.java

@@ -30,6 +30,7 @@ import android.widget.AdapterView;
 import android.widget.ArrayAdapter;
 import android.widget.ListView;
 
+import org.kde.kdeconnect.BackgroundService;
 import org.kde.kdeconnect_tp.R;
 
 import java.util.List;
@@ -157,4 +158,16 @@ public class NotificationFilterActivity extends ActionBarActivity {
         return true;
     }
 
+    @Override
+    protected void onStart() {
+        super.onStart();
+        BackgroundService.addGuiInUseCounter(this);
+    }
+
+    @Override
+    protected void onStop() {
+        super.onStop();
+        BackgroundService.removeGuiInUseCounter(this);
+    }
+
 }

src/org/kde/kdeconnect/Plugins/SharePlugin/ShareActivity.java

@@ -205,6 +205,7 @@ public class ShareActivity extends ActionBarActivity {
     @Override
     protected void onStart() {
         super.onStart();
+        BackgroundService.addGuiInUseCounter(this);
         BackgroundService.RunCommand(this, new BackgroundService.InstanceCallback() {
             @Override
             public void onServiceStart(BackgroundService service) {
@@ -217,6 +218,7 @@ public class ShareActivity extends ActionBarActivity {
                 });
             }
         });
+        updateComputerList();
     }
 
     @Override
@@ -227,13 +229,8 @@ public class ShareActivity extends ActionBarActivity {
                 service.removeDeviceListChangedCallback("ShareActivity");
             }
         });
+        BackgroundService.removeGuiInUseCounter(this);
         super.onStop();
     }
 
-    @Override
-    protected void onResume() {
-        super.onResume();
-        updateComputerList();
-    }
-
 }

src/org/kde/kdeconnect/UserInterface/AppCompatPreferenceActivity.java

@@ -28,6 +28,8 @@ import android.view.MenuInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
+import org.kde.kdeconnect.BackgroundService;
+
 /**
  * A {@link android.preference.PreferenceActivity} which implements and proxies the necessary calls
  * to be used with AppCompat.
@@ -104,11 +106,6 @@ public abstract class AppCompatPreferenceActivity extends PreferenceActivity {
         getDelegate().onConfigurationChanged(newConfig);
     }
 
-    @Override
-    protected void onStop() {
-        super.onStop();
-        getDelegate().onStop();
-    }
     @Override
     protected void onDestroy() {
         super.onDestroy();
@@ -126,4 +123,19 @@ public abstract class AppCompatPreferenceActivity extends PreferenceActivity {
         }
         return mDelegate;
     }
+
+    @Override
+    protected void onStart() {
+        super.onStart();
+        BackgroundService.addGuiInUseCounter(this);
+    }
+
+    @Override
+    protected void onStop() {
+        super.onStop();
+        BackgroundService.removeGuiInUseCounter(this);
+        getDelegate().onStop();
+    }
+
+
 }

src/org/kde/kdeconnect/UserInterface/CustomDevicesActivity.java

@@ -37,6 +37,7 @@ import android.widget.EditText;
 import android.widget.ListView;
 import android.widget.TextView;
 
+import org.kde.kdeconnect.BackgroundService;
 import org.kde.kdeconnect_tp.R;
 
 import java.util.ArrayList;
@@ -176,4 +177,17 @@ public class CustomDevicesActivity extends ActionBarActivity {
             ipAddressList = deserializeIpList(deviceListPrefs);
         }
     }
+
+    @Override
+    protected void onStart() {
+        super.onStart();
+        BackgroundService.addGuiInUseCounter(this);
+    }
+
+    @Override
+    protected void onStop() {
+        super.onStop();
+        BackgroundService.removeGuiInUseCounter(this);
+    }
+
 }

src/org/kde/kdeconnect/UserInterface/MaterialActivity.java

@@ -159,56 +159,21 @@ public class MaterialActivity extends AppCompatActivity {
     @Override
     protected void onStart() {
         super.onStart();
-        BackgroundService.RunCommand(MaterialActivity.this, new BackgroundService.InstanceCallback() {
+        BackgroundService.addGuiInUseCounter(this);
-            @Override
-            public void onServiceStart(BackgroundService service) {
-                service.onNetworkChange();
-                service.addDeviceListChangedCallback("MaterialActivity", new BackgroundService.DeviceListChangedCallback() {
-                    @Override
-                    public void onDeviceListChanged() {
-                        updateComputerList();
-                    }
-                });
-            }
-        });
     }
 
     @Override
     protected void onStop() {
-        BackgroundService.RunCommand(MaterialActivity.this, new BackgroundService.InstanceCallback() {
+        BackgroundService.removeGuiInUseCounter(this);
-            @Override
-            public void onServiceStart(BackgroundService service) {
-                service.removeDeviceListChangedCallback("MaterialActivity");
-            }
-        });
         super.onStop();
     }
 
     @Override
     protected void onResume() {
         super.onResume();
-
-        BackgroundService.RunCommand(this, new BackgroundService.InstanceCallback() {
-            @Override
-            public void onServiceStart(BackgroundService service) {
-                service.setDiscoveryEnabled(true);
-            }
-        });
-
         updateComputerList();
     }
 
-    @Override
-    public void onPause() {
-        super.onPause();
-        BackgroundService.RunCommand(this, new BackgroundService.InstanceCallback() {
-            @Override
-            public void onServiceStart(BackgroundService service) {
-                service.setDiscoveryEnabled(false);
-            }
-        });
-    }
-
     //TODO: Make it accept two parameters, a constant with the type of screen and the device id in
     //case the screen is for a device, or even three parameters and the third one be the plugin id?
     //This way we can keep adding more options with null plugin id (eg: about)

src/org/kde/kdeconnect/UserInterface/PluginSettingsActivity.java

@@ -23,6 +23,7 @@ package org.kde.kdeconnect.UserInterface;
 import android.os.Bundle;
 import android.view.MenuItem;
 
+import org.kde.kdeconnect.BackgroundService;
 import org.kde.kdeconnect_tp.R;
 
 import java.util.Locale;
@@ -52,4 +53,16 @@ public class PluginSettingsActivity extends AppCompatPreferenceActivity {
         }
     }
 
+    @Override
+    protected void onStart() {
+        super.onStart();
+        BackgroundService.addGuiInUseCounter(this);
+    }
+
+    @Override
+    protected void onStop() {
+        super.onStop();
+        BackgroundService.removeGuiInUseCounter(this);
+    }
+
 }

src/org/kde/kdeconnect/UserInterface/SettingsActivity.java

@@ -22,6 +22,7 @@ package org.kde.kdeconnect.UserInterface;
 
 import android.os.Bundle;
 import android.preference.PreferenceScreen;
+import android.util.Log;
 import android.view.MenuItem;
 
 import org.kde.kdeconnect.BackgroundService;
@@ -68,4 +69,17 @@ public class SettingsActivity extends AppCompatPreferenceActivity {
             return super.onOptionsItemSelected(item);
         }
     }
+
+    @Override
+    protected void onStart() {
+        super.onStart();
+        BackgroundService.addGuiInUseCounter(this);
+    }
+
+    @Override
+    protected void onStop() {
+        super.onStop();
+        BackgroundService.removeGuiInUseCounter(this);
+    }
+
 }