Changed abstract plugin to receive packages from unpaired device

Now plugin can register to receive network packages from unpaired
devices.

REVIEW: 124819

src/org/kde/kdeconnect/Device.java

@@ -548,12 +548,21 @@ public class Device implements BaseLink.PackageReceiver {
 
         } else {
 
-            Log.e("KDE/onPackageReceived","Device not paired, ignoring package!");
+            Log.e("KDE/onPackageReceived","Device not paired, will pass package to unpairedPackageListeners");
 
             if (pairStatus != PairStatus.Requested) {
                 unpair();
             }
 
+            for (Plugin plugin : unpairedPackageListeners) {
+                try {
+                    plugin.onUnpairedDevicePackageReceived(np);
+                } catch (Exception e) {
+                    e.printStackTrace();
+                    Log.e("KDE/Device", "Exception in "+plugin.getDisplayName()+"'s onPackageReceived() in unPairedPackageListeners");
+                }
+            }
+
         }
 
     }
@@ -716,6 +725,10 @@ public class Device implements BaseLink.PackageReceiver {
             Log.e("KDE/removePlugin","Exception calling onDestroy for plugin "+pluginKey);
         }
 
+        if (unpairedPackageListeners.contains(plugin)) {
+            unpairedPackageListeners.remove(plugin);
+        }
+
         for (PluginsChangedListener listener : pluginsChangedListeners) {
             listener.onPluginsChanged(this);
         }
@@ -782,4 +795,11 @@ public class Device implements BaseLink.PackageReceiver {
         pluginsChangedListeners.remove(listener);
     }
 
+    private final ArrayList<Plugin> unpairedPackageListeners = new ArrayList<>();
+
+    public void registerUnpairedPackageListener(Plugin p) {
+        Log.e("KDE/registerUnpairedPackageListener", p.getPluginKey() + " plugin registered to receive package from unpaired device");
+        unpairedPackageListeners.add(p);
+    }
+
 }

src/org/kde/kdeconnect/Plugins/Plugin.java

@@ -43,6 +43,14 @@ public abstract class Plugin {
         this.context = context;
     }
 
+    /**
+     * To receive the network package from the unpaired device, Register your plugin
+     * using Device::registerUnpairedPackageListener and override this method.
+     */
+    public boolean onUnpairedDevicePackageReceived(NetworkPackage np) {
+        return false;
+    }
+
     /**
      * Return the internal plugin name, that will be used as a
      * unique key to distinguish it. Use the class name as key.