Hints manager: Add a class to manage hints (show once info)

This is much cleaner than what was there before, and enables to easily
add more hints.

app/src/main/java/com/etesync/syncadapter/ui/AppSettingsActivity.java

@@ -24,6 +24,7 @@ import com.etesync.syncadapter.App;
 import com.etesync.syncadapter.R;
 import com.etesync.syncadapter.model.ServiceDB;
 import com.etesync.syncadapter.model.Settings;
+import com.etesync.syncadapter.utils.HintManager;
 
 public class AppSettingsActivity extends AppCompatActivity {
 
@@ -150,7 +151,7 @@ public class AppSettingsActivity extends AppCompatActivity {
         }
 
         private void resetHints() {
-            settings.remove(StartupDialogFragment.HINT_BATTERY_OPTIMIZATIONS);
+            HintManager.resetHints(getContext());
             Snackbar.make(getView(), R.string.app_settings_reset_hints_success, Snackbar.LENGTH_LONG).show();
         }
 

app/src/main/java/com/etesync/syncadapter/ui/StartupDialogFragment.java

@@ -25,18 +25,15 @@ import android.support.v7.app.AlertDialog;
 import com.etesync.syncadapter.BuildConfig;
 import com.etesync.syncadapter.Constants;
 import com.etesync.syncadapter.R;
-import com.etesync.syncadapter.model.ServiceDB;
-import com.etesync.syncadapter.model.Settings;
+import com.etesync.syncadapter.utils.HintManager;
 
 import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
 
-import lombok.Cleanup;
-
 public class StartupDialogFragment extends DialogFragment {
-    public static final String
-            HINT_BATTERY_OPTIMIZATIONS = "hint_BatteryOptimizations";
+    private static final HintManager.Hint
+            HINT_BATTERY_OPTIMIZATIONS = HintManager.registerHint("BatteryOptimizations");
 
     private static final String ARGS_MODE = "mode";
 
@@ -49,14 +46,11 @@ public class StartupDialogFragment extends DialogFragment {
     public static StartupDialogFragment[] getStartupDialogs(Context context) {
         List<StartupDialogFragment> dialogs = new LinkedList<>();
 
-        @Cleanup ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(context);
-        Settings settings  = new Settings(dbHelper.getReadableDatabase());
-
         if (BuildConfig.VERSION_NAME.contains("-alpha") || BuildConfig.VERSION_NAME.contains("-beta") || BuildConfig.VERSION_NAME.contains("-rc"))
             dialogs.add(StartupDialogFragment.instantiate(Mode.DEVELOPMENT_VERSION));
 
         // battery optimization whitelisting
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && settings.getBoolean(HINT_BATTERY_OPTIMIZATIONS, true)) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && !HintManager.getHintSeen(context, HINT_BATTERY_OPTIMIZATIONS)) {
             PowerManager powerManager = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
             if (!powerManager.isIgnoringBatteryOptimizations(BuildConfig.APPLICATION_ID))
                 dialogs.add(StartupDialogFragment.instantiate(Mode.BATTERY_OPTIMIZATIONS));
@@ -104,9 +98,7 @@ public class StartupDialogFragment extends DialogFragment {
                         .setNegativeButton(R.string.startup_dont_show_again, new DialogInterface.OnClickListener() {
                             @Override
                             public void onClick(DialogInterface dialog, int which) {
-                                @Cleanup ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
-                                Settings settings = new Settings(dbHelper.getWritableDatabase());
-                                settings.putBoolean(HINT_BATTERY_OPTIMIZATIONS, false);
+                                HintManager.setHintSeen(getContext(), HINT_BATTERY_OPTIMIZATIONS, true);
                             }
                         })
                         .create();

app/src/main/java/com/etesync/syncadapter/utils/HintManager.java

@@ -0,0 +1,50 @@
+package com.etesync.syncadapter.utils;
+
+
+import android.content.Context;
+import android.content.SharedPreferences;
+
+import java.util.LinkedList;
+import java.util.List;
+
+public class HintManager {
+    private final static String PREF_NAME = "hints";
+    private static List<Hint> hints = new LinkedList<>();
+
+    public static Hint registerHint(String hint) {
+        hint = "hint_" + hint;
+        Hint ret = new Hint(hint);
+        hints.add(ret);
+
+        return ret;
+    }
+
+    private static SharedPreferences getPrefs(Context context) {
+        return context.getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
+    }
+
+    public static void setHintSeen(Context context, Hint hint, boolean seen) {
+        SharedPreferences prefs = getPrefs(context);
+
+        prefs.edit().putBoolean(hint.string, seen).apply();
+    }
+
+    public static boolean getHintSeen(Context context, Hint hint) {
+        SharedPreferences prefs = getPrefs(context);
+
+        return prefs.getBoolean(hint.string, false);
+    }
+
+    public static void resetHints(Context context) {
+        for (Hint hint : hints) {
+            setHintSeen(context, hint, false);
+        }
+    }
+
+    public static class Hint {
+        private String string;
+        private Hint(String hint) {
+            this.string = hint;
+        }
+    }
+}