DarkMode: move to shared preferences listener

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

app/src/main/java/com/wireguard/android/Application.java

@@ -23,7 +23,6 @@ import com.wireguard.android.model.TunnelManager;
 import com.wireguard.android.util.AsyncWorker;
 import com.wireguard.android.util.RootShell;
 import com.wireguard.android.util.ToolsInstaller;
-import com.wireguard.android.util.Topic;
 
 import java.io.File;
 import java.util.concurrent.Executor;
@@ -68,8 +67,6 @@ public class Application extends android.app.Application {
         ToolsInstaller getToolsInstaller();
 
         TunnelManager getTunnelManager();
-
-        Topic getThemeChangeTopic();
     }
 
     @Qualifier
@@ -119,13 +116,6 @@ public class Application extends android.app.Application {
             return new FileConfigStore(context);
         }
 
-        @ApplicationScope
-        @Provides
-        public static Topic getThemeChangeTopic() {
-            return new Topic();
-        }
-
-
         @ApplicationScope
         @Provides
         public static Executor getExecutor() {

app/src/main/java/com/wireguard/android/activity/BaseActivity.java

@@ -11,24 +11,19 @@ import android.databinding.CallbackRegistry;
 import android.databinding.CallbackRegistry.NotifierCallback;
 import android.os.Bundle;
 import android.support.v7.app.AppCompatActivity;
-import android.util.Log;
 
 import com.wireguard.android.Application;
 import com.wireguard.android.backend.GoBackend;
 import com.wireguard.android.model.Tunnel;
 import com.wireguard.android.model.TunnelManager;
-import com.wireguard.android.util.Topic;
 
-import java.lang.reflect.Field;
 import java.util.Objects;
 
 /**
  * Base class for activities that need to remember the currently-selected tunnel.
  */
 
-public abstract class BaseActivity extends AppCompatActivity implements Topic.Subscriber {
+public abstract class BaseActivity extends ThemeChangeAwareActivity {
-    private static final String TAG = "WireGuard/" + BaseActivity.class.getSimpleName();
-
     private static final String KEY_SELECTED_TUNNEL = "selected_tunnel";
 
     private final SelectionChangeRegistry selectionChangeRegistry = new SelectionChangeRegistry();
@@ -45,8 +40,6 @@ public abstract class BaseActivity extends AppCompatActivity implements Topic.Su
 
     @Override
     protected void onCreate(final Bundle savedInstanceState) {
-        subscribeTopics();
-
         // Restore the saved tunnel if there is one; otherwise grab it from the arguments.
         String savedTunnelName = null;
         if (savedInstanceState != null)
@@ -69,12 +62,6 @@ public abstract class BaseActivity extends AppCompatActivity implements Topic.Su
         }
     }
 
-    @Override
-    protected void onDestroy() {
-        unsubscribeTopics();
-        super.onDestroy();
-    }
-
     @Override
     protected void onSaveInstanceState(final Bundle outState) {
         if (selectedTunnel != null)
@@ -118,35 +105,4 @@ public abstract class BaseActivity extends AppCompatActivity implements Topic.Su
             super(new SelectionChangeNotifier());
         }
     }
-
-    @Override
-    public void onTopicPublished(final Topic topic) {
-        if (topic == Application.getComponent().getThemeChangeTopic()) {
-            try {
-                Field f;
-                Object o = getResources();
-                try {
-                    f = o.getClass().getDeclaredField("mResourcesImpl");
-                    f.setAccessible(true);
-                    o = f.get(o);
-                } catch (final Exception ignored) { }
-                f = o.getClass().getDeclaredField("mDrawableCache");
-                f.setAccessible(true);
-                o = f.get(o);
-                try {
-                    o.getClass().getMethod("onConfigurationChange", int.class).invoke(o, -1);
-                } catch (final Exception ignored) {
-                    o.getClass().getMethod("clear").invoke(o);
-                }
-            } catch (final Exception e) {
-                Log.e(TAG, "Failed to flush drawable cache", e);
-            }
-            recreate();
-        }
-    }
-
-    @Override
-    public Topic[] getSubscription() {
-        return new Topic[] { Application.getComponent().getThemeChangeTopic() };
-    }
 }

app/src/main/java/com/wireguard/android/activity/SettingsActivity.java

@@ -21,7 +21,6 @@ import android.view.MenuItem;
 import com.wireguard.android.Application;
 import com.wireguard.android.R;
 import com.wireguard.android.backend.WgQuickBackend;
-import com.wireguard.android.util.Topic;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -33,7 +32,7 @@ import java.util.Map;
  * Interface for changing application-global persistent settings.
  */
 
-public class SettingsActivity extends AppCompatActivity implements Topic.Subscriber {
+public class SettingsActivity extends ThemeChangeAwareActivity {
     private final Map<Integer, PermissionRequestCallback> permissionRequestCallbacks = new HashMap<>();
     private int permissionRequestCounter;
 
@@ -59,7 +58,6 @@ public class SettingsActivity extends AppCompatActivity implements Topic.Subscri
     @Override
     protected void onCreate(final Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        subscribeTopics();
         if (getSupportFragmentManager().findFragmentById(android.R.id.content) == null) {
             getSupportFragmentManager().beginTransaction()
                     .add(android.R.id.content, new SettingsFragment())
@@ -67,12 +65,6 @@ public class SettingsActivity extends AppCompatActivity implements Topic.Subscri
         }
     }
 
-    @Override
-    protected void onDestroy() {
-        unsubscribeTopics();
-        super.onDestroy();
-    }
-
     @Override
     public boolean onOptionsItemSelected(final MenuItem item) {
         switch (item.getItemId()) {
@@ -99,18 +91,7 @@ public class SettingsActivity extends AppCompatActivity implements Topic.Subscri
         void done(String[] permissions, int[] grantResults);
     }
 
-    @Override
+    public static class SettingsFragment extends PreferenceFragmentCompat {
-    public void onTopicPublished(final Topic topic) {
-        if (topic == Application.getComponent().getThemeChangeTopic())
-            recreate();
-    }
-
-    @Override
-    public Topic[] getSubscription() {
-        return new Topic[] { Application.getComponent().getThemeChangeTopic() };
-    }
-
-    public static class SettingsFragment extends PreferenceFragmentCompat implements SharedPreferences.OnSharedPreferenceChangeListener {
         @Override
         public void onCreatePreferences(final Bundle savedInstanceState, final String key) {
             addPreferencesFromResource(R.xml.preferences);
@@ -121,26 +102,5 @@ public class SettingsActivity extends AppCompatActivity implements Topic.Subscri
                 getPreferenceScreen().removePreference(pref);
             }
         }
-
-        @Override
-        public void onResume() {
-            super.onResume();
-            getPreferenceManager().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);
-        }
-
-        @Override
-        public void onPause() {
-            getPreferenceManager().getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this);
-            super.onPause();
-        }
-
-        @Override
-        public void onSharedPreferenceChanged(final SharedPreferences sharedPreferences, final String key) {
-            if ("dark_theme".equals(key)) {
-                AppCompatDelegate.setDefaultNightMode(
-                        sharedPreferences.getBoolean(key, false) ? AppCompatDelegate.MODE_NIGHT_YES : AppCompatDelegate.MODE_NIGHT_NO);
-                Application.getComponent().getThemeChangeTopic().publish(false);
-            }
-        }
     }
 }

app/src/main/java/com/wireguard/android/activity/ThemeChangeAwareActivity.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright © 2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+package com.wireguard.android.activity;
+
+import android.content.SharedPreferences;
+import android.content.res.Resources;
+import android.os.Bundle;
+import android.preference.PreferenceManager;
+import android.support.v7.app.AppCompatActivity;
+import android.support.v7.app.AppCompatDelegate;
+import android.util.Log;
+
+import java.lang.reflect.Field;
+
+public abstract class ThemeChangeAwareActivity extends AppCompatActivity implements SharedPreferences.OnSharedPreferenceChangeListener {
+    private static final String TAG = "WireGuard/" + ThemeChangeAwareActivity.class.getSimpleName();
+
+    private static Resources lastResources;
+    private static boolean lastDarkMode;
+    private static synchronized void invalidateDrawableCache(final Resources resources, final boolean darkMode) {
+        if (resources == lastResources && darkMode == lastDarkMode)
+            return;
+
+        try {
+            Field f;
+            Object o = resources;
+            try {
+                f = o.getClass().getDeclaredField("mResourcesImpl");
+                f.setAccessible(true);
+                o = f.get(o);
+            } catch (final Exception ignored) { }
+            f = o.getClass().getDeclaredField("mDrawableCache");
+            f.setAccessible(true);
+            o = f.get(o);
+            try {
+                o.getClass().getMethod("onConfigurationChange", int.class).invoke(o, -1);
+            } catch (final Exception ignored) {
+                o.getClass().getMethod("clear").invoke(o);
+            }
+        } catch (final Exception e) {
+            Log.e(TAG, "Failed to flush drawable cache", e);
+        }
+
+        lastResources = resources;
+        lastDarkMode = darkMode;
+    }
+
+
+    @Override
+    protected void onCreate(final Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        PreferenceManager.getDefaultSharedPreferences(this).registerOnSharedPreferenceChangeListener(this);
+    }
+
+    @Override
+    protected void onDestroy() {
+        PreferenceManager.getDefaultSharedPreferences(this).unregisterOnSharedPreferenceChangeListener(this);
+        super.onDestroy();
+    }
+
+    @Override
+    public void onSharedPreferenceChanged(final SharedPreferences sharedPreferences, final String key) {
+        if ("dark_theme".equals(key)) {
+            final boolean darkMode = sharedPreferences.getBoolean(key, false);
+            AppCompatDelegate.setDefaultNightMode(
+                    sharedPreferences.getBoolean(key, false) ?
+                            AppCompatDelegate.MODE_NIGHT_YES :
+                            AppCompatDelegate.MODE_NIGHT_NO);
+            invalidateDrawableCache(getResources(), darkMode);
+            recreate();
+        }
+    }
+}

app/src/main/java/com/wireguard/android/util/Topic.java

@@ -1,109 +0,0 @@
-/*
- * Copyright © 2017 John Wu <topjohnwu@gmail.com>
- * SPDX-License-Identifier: GPL-2.0-or-later
- */
-
-package com.wireguard.android.util;
-
-import java.lang.ref.WeakReference;
-import java.util.Iterator;
-import java.util.LinkedList;
-import java.util.List;
-
-import java.lang.ref.WeakReference;
-import java.util.ArrayList;
-import java.util.List;
-
-public class Topic {
-
-    private static final int NON_INIT = 0;
-    private static final int PENDING = 1;
-    private static final int PUBLISHED = 2;
-
-    private int state = NON_INIT;
-    private List<WeakReference<Subscriber>> subscribers;
-    private Object[] results;
-
-    public Topic() {
-        subscribers = new SyncArrayList<>();
-    }
-
-    public synchronized void subscribe(final Subscriber sub) {
-        subscribers.add(new WeakReference<>(sub));
-    }
-
-    public synchronized void unsubscribe() {
-        subscribers = new SyncArrayList<>();
-    }
-
-    public synchronized void unsubscribe(final Subscriber sub) {
-        List<WeakReference<Subscriber>> subs = subscribers;
-        subscribers = new ArrayList<>();
-        for (final WeakReference<Subscriber> subscriber : subs) {
-            if (subscriber.get() != null && subscriber.get() != sub)
-                subscribers.add(subscriber);
-        }
-    }
-
-    public void reset() {
-        state = NON_INIT;
-        results = null;
-    }
-
-    public boolean isPublished() {
-        return state == PUBLISHED;
-    }
-
-    public void publish() {
-        publish(true);
-    }
-
-    public void publish(boolean record, Object... results) {
-        if (record)
-            state = PUBLISHED;
-        this.results = results;
-        // Snapshot
-        List<WeakReference<Subscriber>> subs = subscribers;
-        for (final WeakReference<Subscriber> subscriber : subs) {
-            if (subscriber != null && subscriber.get() != null)
-                subscriber.get().onTopicPublished(this);
-        }
-    }
-
-    public Object[] getResults() {
-        return results;
-    }
-
-    public boolean isPending() {
-        return state == PENDING;
-    }
-
-    public void setPending() {
-        state = PENDING;
-    }
-
-    public interface Subscriber {
-        default void subscribeTopics() {
-            for (final Topic topic : getSubscription()) {
-                if (topic.isPublished()) {
-                    onTopicPublished(topic);
-                }
-                topic.subscribe(this);
-            }
-        }
-        default void unsubscribeTopics() {
-            for (final Topic event : getSubscription()) {
-                event.unsubscribe(this);
-            }
-        }
-        void onTopicPublished(Topic topic);
-        Topic[] getSubscription();
-    }
-
-    private static class SyncArrayList<E> extends ArrayList<E> {
-        @Override
-        public synchronized boolean add(final E e) {
-            return super.add(e);
-        }
-    }
-}