From 385a16448cee06db272792db1239e9a6eae12d32 Mon Sep 17 00:00:00 2001
From: Peter Serwylo <peter@serwylo.com>
Date: Tue, 14 Mar 2017 17:42:20 +1100
Subject: [PATCH] Stop listening for broadcasts when view not shown.

---
 .../fdroid/views/main/MainViewAdapter.java       | 16 ++++++++++++++++
 .../fdroid/views/main/MainViewController.java    | 16 +++++++++++++++-
 .../fdroid/views/updates/UpdatesAdapter.java     |  4 ++++
 .../fdroid/views/updates/UpdatesViewBinder.java  | 15 +++++++++++----
 4 files changed, 46 insertions(+), 5 deletions(-)

diff --git a/app/src/main/java/org/fdroid/fdroid/views/main/MainViewAdapter.java b/app/src/main/java/org/fdroid/fdroid/views/main/MainViewAdapter.java
index 98c30d726..7731c89c3 100644
--- a/app/src/main/java/org/fdroid/fdroid/views/main/MainViewAdapter.java
+++ b/app/src/main/java/org/fdroid/fdroid/views/main/MainViewAdapter.java
@@ -39,6 +39,22 @@ class MainViewAdapter extends RecyclerView.Adapter<MainViewController> {
         positionToId.put(4, R.id.settings);
     }
 
+    @Override
+    public void onViewDetachedFromWindow(MainViewController holder) {
+        long viewType = getItemId(holder.getAdapterPosition());
+        if (viewType == R.id.updates) {
+            holder.unbindUpdates();
+        }
+    }
+
+    @Override
+    public void onViewAttachedToWindow(MainViewController holder) {
+        long viewType = getItemId(holder.getAdapterPosition());
+        if (viewType == R.id.updates) {
+            holder.bindUpdates();
+        }
+    }
+
     @Override
     public MainViewController onCreateViewHolder(ViewGroup parent, int viewType) {
         MainViewController holder = createEmptyView();
diff --git a/app/src/main/java/org/fdroid/fdroid/views/main/MainViewController.java b/app/src/main/java/org/fdroid/fdroid/views/main/MainViewController.java
index b0a674ac3..e5e804c3b 100644
--- a/app/src/main/java/org/fdroid/fdroid/views/main/MainViewController.java
+++ b/app/src/main/java/org/fdroid/fdroid/views/main/MainViewController.java
@@ -1,6 +1,7 @@
 package org.fdroid.fdroid.views.main;
 
 import android.content.Intent;
+import android.support.annotation.Nullable;
 import android.support.v4.app.Fragment;
 import android.support.v7.app.AppCompatActivity;
 import android.support.v7.widget.RecyclerView;
@@ -24,6 +25,9 @@ class MainViewController extends RecyclerView.ViewHolder {
     private final AppCompatActivity activity;
     private final FrameLayout frame;
 
+    @Nullable
+    private UpdatesViewBinder updatesView = null;
+
     MainViewController(AppCompatActivity activity, FrameLayout frame) {
         super(frame);
         this.activity = activity;
@@ -41,7 +45,17 @@ class MainViewController extends RecyclerView.ViewHolder {
      * @see UpdatesViewBinder
      */
     public void bindUpdates() {
-        new UpdatesViewBinder(activity, frame);
+        if (updatesView == null) {
+            updatesView = new UpdatesViewBinder(activity, frame);
+        }
+
+        updatesView.bind();
+    }
+
+    public void unbindUpdates() {
+        if (updatesView != null) {
+            updatesView.unbind();
+        }
     }
 
     /**
diff --git a/app/src/main/java/org/fdroid/fdroid/views/updates/UpdatesAdapter.java b/app/src/main/java/org/fdroid/fdroid/views/updates/UpdatesAdapter.java
index e9cb56ab0..b144b957f 100644
--- a/app/src/main/java/org/fdroid/fdroid/views/updates/UpdatesAdapter.java
+++ b/app/src/main/java/org/fdroid/fdroid/views/updates/UpdatesAdapter.java
@@ -258,6 +258,10 @@ public class UpdatesAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder
         LocalBroadcastManager.getInstance(activity).registerReceiver(receiverAppStatusChanges, filter);
     }
 
+    public void stopListeningForStatusUpdates() {
+        LocalBroadcastManager.getInstance(activity).unregisterReceiver(receiverAppStatusChanges);
+    }
+
     private void onManyAppStatusesChanged(String reasonForChange) {
         switch (reasonForChange) {
             case AppUpdateStatusManager.REASON_UPDATES_AVAILABLE:
diff --git a/app/src/main/java/org/fdroid/fdroid/views/updates/UpdatesViewBinder.java b/app/src/main/java/org/fdroid/fdroid/views/updates/UpdatesViewBinder.java
index 9157099a7..c48f802dd 100644
--- a/app/src/main/java/org/fdroid/fdroid/views/updates/UpdatesViewBinder.java
+++ b/app/src/main/java/org/fdroid/fdroid/views/updates/UpdatesViewBinder.java
@@ -10,17 +10,24 @@ import org.fdroid.fdroid.R;
 
 public class UpdatesViewBinder {
 
+    private final UpdatesAdapter adapter;
+
     public UpdatesViewBinder(AppCompatActivity activity, FrameLayout parent) {
         View view = activity.getLayoutInflater().inflate(R.layout.main_tab_updates, parent, true);
 
-        UpdatesAdapter adapter = new UpdatesAdapter(activity);
-
-        // TODO: Find the right time to stop listening for status updates.
-        adapter.listenForStatusUpdates();
+        adapter = new UpdatesAdapter(activity);
 
         RecyclerView list = (RecyclerView) view.findViewById(R.id.list);
         list.setHasFixedSize(true);
         list.setLayoutManager(new LinearLayoutManager(activity));
         list.setAdapter(adapter);
     }
+
+    public void bind() {
+        adapter.listenForStatusUpdates();
+    }
+
+    public void unbind() {
+        adapter.stopListeningForStatusUpdates();
+    }
 }