Tell the user that no Wi-Fi is connected and click to fix it

res/drawable/ic_wifi.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportWidth="24.0"
+        android:viewportHeight="24.0">
+    <path
+        android:fillColor="#FFFFFFFF"
+        android:pathData="M1,9l2,2c4.97,-4.97 13.03,-4.97 18,0l2,-2C16.93,2.93 7.08,2.93 1,9zM9,17l3,3 3,-3c-1.65,-1.66 -4.34,-1.66 -6,0zM5,13l2,2c2.76,-2.76 7.24,-2.76 10,0l2,-2C15.14,9.14 8.87,9.14 5,13z"/>
+</vector>

res/layout/activity_device.xml

@@ -99,15 +99,6 @@
             android:text="@string/unreachable_description"
             android:textAppearance="?android:attr/textAppearanceMedium"
             android:visibility="gone" />
-
-        <TextView
-            android:id="@+id/on_data_message"
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:gravity="center_vertical"
-            android:text="@string/on_data_message"
-            android:textAppearance="?android:attr/textAppearanceMedium"
-            android:visibility="gone"/>
     </LinearLayout>
 
 

res/layout/pairing_explanation_text.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TextView
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:paddingTop="16dp"
+    android:paddingBottom="12dp"
+    android:text="@string/pairing_description"
+    android:clickable="false"
+    android:background="@android:color/transparent"
+    >
+
+</TextView>

res/layout/pairing_explanation_text_no_wifi.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TextView
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:background="?attr/selectableItemBackground"
+    android:drawablePadding="8dp"
+    android:paddingTop="16dp"
+    android:paddingBottom="12dp"
+    android:text="@string/no_wifi"
+    android:drawableLeft="@drawable/ic_wifi"
+    android:drawableTint="?attr/colorControlNormal"
+    android:clickable="true"
+    >
+
+</TextView>

res/values/strings.xml

@@ -256,7 +256,7 @@
     <string name="device_rename_confirm">Rename</string>
     <string name="refresh">Refresh</string>
     <string name="unreachable_description">This paired device is not reachable. Make sure it is connected to your same network.</string>
-    <string name="on_data_message">It looks like you are on a mobile data connection. KDE Connect only works on local networks.</string>
+    <string name="no_wifi">You\'re not connected to a Wi-Fi network, so you may not be able to see any devices. Click here to enable Wi-Fi.</string>
     <string name="no_file_browser">There are no file browsers installed.</string>
     <string name="pref_plugin_telepathy">Send SMS</string>
     <string name="pref_plugin_telepathy_desc">Send text messages from your desktop</string>

src/org/kde/kdeconnect/Backends/LanBackend/LanLinkProvider.java

@@ -31,7 +31,6 @@ import org.kde.kdeconnect.Backends.BaseLinkProvider;
 import org.kde.kdeconnect.BackgroundService;
 import org.kde.kdeconnect.Device;
 import org.kde.kdeconnect.Helpers.DeviceHelper;
-import org.kde.kdeconnect.Helpers.NetworkHelper;
 import org.kde.kdeconnect.Helpers.SecurityHelpers.SslHelper;
 import org.kde.kdeconnect.Helpers.StringsHelper;
 import org.kde.kdeconnect.NetworkPacket;
@@ -356,12 +355,6 @@ public class LanLinkProvider extends BaseLinkProvider implements LanLink.LinkDis
     }
 
     private void broadcastUdpPacket() {
-
-        if (NetworkHelper.isOnMobileNetwork(context)) {
-            Log.w("LanLinkProvider", "On 3G network, not sending broadcast.");
-            return;
-        }
-
         new Thread(() -> {
             ArrayList<String> iplist = CustomDevicesActivity
                     .getCustomDeviceList(PreferenceManager.getDefaultSharedPreferences(context));

src/org/kde/kdeconnect/Helpers/NetworkHelper.java

@@ -1,56 +0,0 @@
-package org.kde.kdeconnect.Helpers;
-
-import android.content.Context;
-
-public class NetworkHelper {
-
-    public static boolean isOnMobileNetwork(Context context) {
-
-        return false;
-
-        /*
-        if (context == null) {
-            return false;
-        }
-        if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.LOLLIPOP) {
-            return false; //No good way to know it
-        }
-        try {
-            boolean mobile = false;
-            final ConnectivityManager connMgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
-            Network[] networks = connMgr.getAllNetworks();
-            for (Network network : networks) {
-                NetworkInfo info = connMgr.getNetworkInfo(network);
-                if (info == null) {
-                    continue;
-                }
-                if (info.getType() == ConnectivityManager.TYPE_MOBILE) {
-                    mobile = info.isConnected();
-                    continue;
-                }
-                //Log.e(info.getTypeName(),""+info.isAvailable());
-                if (info.isAvailable())
-                    return false; //We are connected to at least one non-mobile network
-            }
-            if (mobile) { //We suspect we are on a mobile net
-                try (LineNumberReader is = new LineNumberReader(new FileReader("/proc/net/arp"))) {
-                    //Check the number of network neighbours, on data it should be 0
-                    is.skip(Long.MAX_VALUE);
-                    //Log.e("NetworkHelper", "procnetarp has " + is.getLineNumber() + " lines");
-                    if (is.getLineNumber() > 1) { //The first line are the headers
-                        return false; //I have neighbours, so this doesn't look like a mobile network
-                    }
-                } catch (Exception e) {
-                    Log.e("NetworkHelper", "Exception reading procnetarp", e);
-                }
-            }
-            return mobile;
-        } catch (Exception e) {
-            Log.e("isOnMobileNetwork", "Something went wrong, but this is non-critical.", e);
-        }
-        return false;
-
-        */
-    }
-
-}

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

@@ -41,20 +41,17 @@ import androidx.fragment.app.Fragment;
 
 import org.kde.kdeconnect.BackgroundService;
 import org.kde.kdeconnect.Device;
-import org.kde.kdeconnect.Helpers.NetworkHelper;
 import org.kde.kdeconnect.Helpers.SecurityHelpers.SslHelper;
 import org.kde.kdeconnect.Plugins.Plugin;
 import org.kde.kdeconnect.UserInterface.List.PluginListHeaderItem;
 import org.kde.kdeconnect.UserInterface.List.FailedPluginListItem;
 import org.kde.kdeconnect.UserInterface.List.ListAdapter;
 import org.kde.kdeconnect.UserInterface.List.PluginItem;
-import org.kde.kdeconnect.UserInterface.List.SmallEntryItem;
 import org.kde.kdeconnect_tp.R;
 
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.ConcurrentModificationException;
-import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
 import butterknife.BindView;
@@ -90,7 +87,6 @@ public class DeviceFragment extends Fragment {
     @BindView(R.id.pair_request_buttons) View pairRequestButtons;
     @BindView(R.id.error_message_container) View errorMessageContainer;
     @BindView(R.id.not_reachable_message) TextView notReachableMessage;
-    @BindView(R.id.on_data_message) TextView onDataMessage;
     @BindView(R.id.buttons_list) ListView buttonsList;
 
     private Unbinder unbinder;
@@ -310,12 +306,10 @@ public class DeviceFragment extends Fragment {
 
                     boolean paired = device.isPaired();
                     boolean reachable = device.isReachable();
-                    boolean onData = NetworkHelper.isOnMobileNetwork(DeviceFragment.this.getContext());
 
                     pairingButtons.setVisibility(paired ? View.GONE : View.VISIBLE);
                     errorMessageContainer.setVisibility((paired && !reachable) ? View.VISIBLE : View.GONE);
-                    notReachableMessage.setVisibility((paired && !reachable && !onData) ? View.VISIBLE : View.GONE);
+                    notReachableMessage.setVisibility((paired && !reachable) ? View.VISIBLE : View.GONE);
-                    onDataMessage.setVisibility((paired && !reachable && onData) ? View.VISIBLE : View.GONE);
 
                     try {
                         pluginListItems = new ArrayList<>();

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

@@ -24,7 +24,14 @@ import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
 import android.content.res.Resources;
+import android.net.ConnectivityManager;
+import android.net.LinkProperties;
+import android.net.Network;
+import android.net.NetworkInfo;
+import android.net.NetworkRequest;
+import android.os.Build;
 import android.os.Bundle;
+import android.provider.Settings;
 import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuInflater;
@@ -36,7 +43,6 @@ import android.widget.TextView;
 
 import org.kde.kdeconnect.BackgroundService;
 import org.kde.kdeconnect.Device;
-import org.kde.kdeconnect.Helpers.NetworkHelper;
 import org.kde.kdeconnect.UserInterface.List.ListAdapter;
 import org.kde.kdeconnect.UserInterface.List.PairingDeviceItem;
 import org.kde.kdeconnect.UserInterface.List.SectionItem;
@@ -65,6 +71,8 @@ public class PairingFragment extends Fragment implements PairingDeviceItem.Callb
     private boolean listRefreshCalledThisFrame = false;
 
     private TextView headerText;
+    private TextView noWifiHeader;
+    private Object networkChangeListener;
 
     @Override
     public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
@@ -83,14 +91,49 @@ public class PairingFragment extends Fragment implements PairingDeviceItem.Callb
         mSwipeRefreshLayout.setOnRefreshListener(
                 this::updateComputerListAction
         );
-        headerText = new TextView(inflater.getContext());
+        headerText = (TextView) inflater.inflate(R.layout.pairing_explanation_text, null);
-        headerText.setText(getString(R.string.pairing_description));
+        headerText.setOnClickListener(null);
-        headerText.setPadding(0, (int) (16 * getResources().getDisplayMetrics().density), 0, (int) (12 * getResources().getDisplayMetrics().density));
+        headerText.setOnLongClickListener(null);
+        noWifiHeader = (TextView) inflater.inflate(R.layout.pairing_explanation_text_no_wifi, null);
+        noWifiHeader.setOnClickListener(view -> {
+            startActivity(new Intent(Settings.ACTION_WIFI_SETTINGS));
+        });
         ((ListView) listRootView).addHeaderView(headerText);
 
+        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            networkChangeListener = new ConnectivityManager.NetworkCallback() {
+                @Override
+                public void onAvailable(Network network) {
+                    updateDeviceList();
+                }
+
+                @Override
+                public void onLost(Network network) {
+                    updateDeviceList();
+                }
+
+                @Override
+                public void onLinkPropertiesChanged(Network network, LinkProperties linkProperties) {
+                    updateDeviceList();
+                }
+            };
+            ConnectivityManager connManager = (ConnectivityManager) getContext().getSystemService(Context.CONNECTIVITY_SERVICE);
+            connManager.registerNetworkCallback(new NetworkRequest.Builder().build(), (ConnectivityManager.NetworkCallback) networkChangeListener);
+        }
+
         return rootView;
     }
 
+    @Override
+    public void onDestroyView() {
+        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            ConnectivityManager connManager = (ConnectivityManager) getContext().getSystemService(Context.CONNECTIVITY_SERVICE);
+            connManager.unregisterNetworkCallback((ConnectivityManager.NetworkCallback) networkChangeListener);
+        }
+
+        super.onDestroyView();
+    }
+
     @Override
     public void onAttach(Context context) {
         super.onAttach(context);
@@ -126,13 +169,27 @@ public class PairingFragment extends Fragment implements PairingDeviceItem.Callb
             }
             listRefreshCalledThisFrame = true;
 
-            headerText.setText(getString(NetworkHelper.isOnMobileNetwork(getContext()) ? R.string.on_data_message : R.string.pairing_description));
+            Collection<Device> devices = service.getDevices().values();
-            //Disable tap animation
+            boolean someDevicesReachable = false;
-            headerText.setOnClickListener(null);
+            for (Device device : devices) {
-            headerText.setOnLongClickListener(null);
+                if (device.isReachable()) {
+                    someDevicesReachable = true;
+                }
+            }
+
+            ((ListView) rootView.findViewById(R.id.devices_list)).removeHeaderView(headerText);
+            ((ListView) rootView.findViewById(R.id.devices_list)).removeHeaderView(noWifiHeader);
+
+            ConnectivityManager connManager = (ConnectivityManager) getContext().getSystemService(Context.CONNECTIVITY_SERVICE);
+            NetworkInfo wifi = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
+            //Check if we're on Wi-Fi. If we still see a device, don't do anything special
+            if (someDevicesReachable || wifi.isConnected()) {
+                ((ListView) rootView.findViewById(R.id.devices_list)).addHeaderView(headerText);
+            } else {
+                ((ListView) rootView.findViewById(R.id.devices_list)).addHeaderView(noWifiHeader);
+            }
 
             try {
-                Collection<Device> devices = service.getDevices().values();
                 final ArrayList<ListAdapter.Item> items = new ArrayList<>();
 
                 SectionItem connectedSection;