"No internet" banner on main, categories, and updates screen

An alternate implementation of @pserwylo's fdroidclient!724

closes #884

app/src/main/java/org/fdroid/fdroid/views/BannerUpdatingRepos.java

@@ -4,21 +4,40 @@ import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
+import android.net.ConnectivityManager;
 import android.util.AttributeSet;
 import android.view.Gravity;
 import android.view.View;
 
 import org.fdroid.fdroid.R;
 import org.fdroid.fdroid.UpdateService;
+import org.fdroid.fdroid.net.ConnectivityMonitorService;
 
 import androidx.localbroadcastmanager.content.LocalBroadcastManager;
 
 /**
- * Widget which reflects whether or not a repo update is currently in progress or not. If so, shows
+ * Banner widget which reflects current status related to repository updates.
- * some sort of feedback to the user.
+ * It will display whether repositories area actively being updated, or
+ * whether there is no Internet connection, so repositories cannot be updated
+ * from the Internet.
+ * <p>
+ * It shows a "No Internet" message when it identifies the device is not
+ * connected. Will only monitor the wifi state when attached to the window.
+ * Note that this does a pretty poor job of responding to network changes in
+ * real time. It only knows how to respond to the <em>enabling</em> of WiFi
+ * (not disabling of WiFi, nor enabling/disabling of mobile data). However it
+ * will always query the network state when it is shown to the user. This way
+ * if they change between tabs, hide and then open F-Droid, or do other things
+ * which require the view to attach to the window again then it will update the
+ * network state. In practice this works pretty well.
+ *
+ * @see <a href="https://gitlab.com/fdroid/fdroidclient/-/merge_requests/724">"No internet" banner on main, categories, and updates screen</a>
  */
 public class BannerUpdatingRepos extends androidx.appcompat.widget.AppCompatTextView {
 
+    private int updateServiceStatus = UpdateService.STATUS_COMPLETE_WITH_CHANGES;
+    private int networkState = ConnectivityMonitorService.FLAG_NET_NO_LIMIT;
+
     public BannerUpdatingRepos(Context context) {
         this(context, null);
     }
@@ -33,51 +52,65 @@ public class BannerUpdatingRepos extends androidx.appcompat.widget.AppCompatText
         setPadding(padding, padding, padding, padding);
         setBackgroundColor(0xFF4A4A4A);
         setGravity(Gravity.CENTER_VERTICAL | Gravity.CENTER_HORIZONTAL);
-        setText(R.string.banner_updating_repositories);
         setTextColor(0xFFFFFFFF);
     }
 
     @Override
     protected void onAttachedToWindow() {
         super.onAttachedToWindow();
-        monitorRepoUpdates();
+        Context context = getContext();
+        networkState = ConnectivityMonitorService.getNetworkState(context);
+        context.registerReceiver(onNetworkStateChanged,
+                new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));
+
+        if (UpdateService.isUpdating()) {
+            updateServiceStatus = UpdateService.STATUS_INFO;
+        }
+        LocalBroadcastManager.getInstance(context).registerReceiver(onRepoFeedback,
+                new IntentFilter(UpdateService.LOCAL_ACTION_STATUS));
+
+        setBannerTextAndVisibility();
     }
 
     @Override
     protected void onDetachedFromWindow() {
         super.onDetachedFromWindow();
-        stopMonitoringRepoUpdates();
+        Context context = getContext();
+        LocalBroadcastManager.getInstance(context).unregisterReceiver(onRepoFeedback);
+        context.unregisterReceiver(onNetworkStateChanged);
     }
 
-    private void monitorRepoUpdates() {
+    private void setBannerTextAndVisibility() {
-        if (isInEditMode()) {
+        if (updateServiceStatus == UpdateService.STATUS_INFO) {
-            return;
+            setText(R.string.banner_updating_repositories);
-        }
+            setVisibility(View.VISIBLE);
-
+        } else if (networkState == ConnectivityMonitorService.FLAG_NET_UNAVAILABLE
-        LocalBroadcastManager.getInstance(getContext()).registerReceiver(onRepoFeedback,
+                || networkState == ConnectivityMonitorService.FLAG_NET_DEVICE_AP_WITHOUT_INTERNET) {
-                new IntentFilter(UpdateService.LOCAL_ACTION_STATUS));
+            setText(R.string.banner_no_internet);
-        setBannerIsVisible(UpdateService.isUpdating());
-    }
-
-    private void setBannerIsVisible(boolean isUpdating) {
-        if (isUpdating) {
             setVisibility(View.VISIBLE);
         } else {
             setVisibility(View.GONE);
         }
     }
 
-    private void stopMonitoringRepoUpdates() {
+    /**
-        LocalBroadcastManager.getInstance(getContext()).unregisterReceiver(onRepoFeedback);
+     * Anything other than a {@link UpdateService#STATUS_INFO} broadcast
-    }
+     * signifies that it was complete (and out banner should be removed).
-
+     */
     private final BroadcastReceiver onRepoFeedback = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {
-            // Anything other than a STATUS_INFO broadcast signifies that it was complete (and out
+            updateServiceStatus = intent.getIntExtra(UpdateService.EXTRA_STATUS_CODE,
-            // banner should be removed).
+                    UpdateService.STATUS_COMPLETE_WITH_CHANGES);
-            boolean isInfo = intent.getIntExtra(UpdateService.EXTRA_STATUS_CODE, 0) == UpdateService.STATUS_INFO;
+            setBannerTextAndVisibility();
-            setBannerIsVisible(isInfo);
+        }
+    };
+
+    private final BroadcastReceiver onNetworkStateChanged = new BroadcastReceiver() {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            networkState = ConnectivityMonitorService.getNetworkState(context);
+            setBannerTextAndVisibility();
         }
     };
 }

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

@@ -379,6 +379,7 @@ This often occurs with apps installed via Google Play or other sources, if they
     <string name="status_download_unknown_size">Downloading\n%2$s from\n%1$s</string>
     <string name="download_404">The requested file was not found.</string>
     <string name="banner_updating_repositories">Updating repositories</string>
+    <string name="banner_no_internet">No Internet</string>
     <string name="status_processing_xml_percent">Processing %2$s / %3$s (%4$d%%) from %1$s</string>
     <string name="status_connecting_to_repo">Connecting to\n%1$s</string>
     <string name="status_inserting_apps">Saving app details</string>