Issue 6289 - Fix OnSharedPreferenceChangeListener

adblockplussbrowser/src/main/java/org/adblockplus/sbrowser/contentblocker/util/SharedPrefsUtils.java

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 87 matching lines @@
     }
     catch (ClassCastException e)
     {
       return defValues;
     }
   }
 
   public static void registerOnSharedPreferenceChangeListener(Context context,
       OnSharedPreferenceChangeListener listener)
   {
-    getDefaultSharedPreferences(context).registerOnSharedPreferenceChangeListener(
-        new OnSharedPreferenceChangeListenerWrapper(listener)
-    );
+    getDefaultSharedPreferences(context).registerOnSharedPreferenceChangeListener(listener);
   }
 
   public static void unregisterOnSharedPreferenceChangeListener(Context context,
       OnSharedPreferenceChangeListener listener)
   {
-    getDefaultSharedPreferences(context).unregisterOnSharedPreferenceChangeListener(
-        new OnSharedPreferenceChangeListenerWrapper(listener)
-    );
+    getDefaultSharedPreferences(context).unregisterOnSharedPreferenceChangeListener(listener);
   }
 
   private static SharedPreferences getDefaultSharedPreferences(Context context)
   {
     return PreferenceManager.getDefaultSharedPreferences(context.getApplicationContext());
   }
 
-  private static class OnSharedPreferenceChangeListenerWrapper
+  public abstract static class OnSharedPreferenceChangeListener

[anton, 2018/01/22 05:41:13]

are you sure that it's better to use class hierarchy with just 1 method body
definition instead of just interface? i think interface is preferred in this
case.

[diegocarloslima, 2018/01/22 11:09:26]

With an interface, we cannot make onSharedPreferenceChanged(SharedPreferences
sharedPreferences, String key) final. The whole goal for this abstract class is
to hide the SharedPreferences instance through the callback. We want to hide the
SharedPreferences, to better indicate that the SharePreferences should be
modified by using the SharedPrefsUtils methods

       implements SharedPreferences.OnSharedPreferenceChangeListener
   {
 
-    private final OnSharedPreferenceChangeListener listener;
-
-    OnSharedPreferenceChangeListenerWrapper(OnSharedPreferenceChangeListener listener) {
-      this.listener = listener;
+    @Override
+    public final void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key)
+    {
+      this.onSharedPreferenceChanged(key);
     }
 
-    @Override
-    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key)
-    {
-      this.listener.onSharedPreferenceChanged(key);
-    }
-
-    @Override
-    public boolean equals(Object obj)
-    {
-      if (this == obj)
-      {
-        return true;
-      }
-      else if (obj instanceof OnSharedPreferenceChangeListenerWrapper)
-      {
-        return this.listener.equals(((OnSharedPreferenceChangeListenerWrapper) obj).listener);
-      }
-      return false;
-    }
-
-    @Override
-    public int hashCode()
-    {
-      return this.listener.hashCode();
-    }
-  }
-
-  public interface OnSharedPreferenceChangeListener
-  {
-    void onSharedPreferenceChanged(String key);
+    protected abstract void onSharedPreferenceChanged(String key);
   }
 }