Update order of checkmark buttons automatically upon exiting settings

app/src/main/java/org/isoron/uhabits/activities/habits/list/views/CheckmarkPanelView.java

@@ -33,7 +33,7 @@ import org.isoron.uhabits.utils.*;
 
 import static android.view.View.MeasureSpec.*;
 
-public class CheckmarkPanelView extends LinearLayout
+public class CheckmarkPanelView extends LinearLayout implements Preferences.Listener
 {
     private static final int CHECKMARK_LEFT_TO_RIGHT = 0;
 
@@ -178,6 +178,26 @@ public class CheckmarkPanelView extends LinearLayout
         }
     }
 
+    @Override
+    protected void onAttachedToWindow()
+    {
+        super.onAttachedToWindow();
+        prefs.addListener(this);
+    }
+
+    @Override
+    protected void onDetachedFromWindow()
+    {
+        prefs.removeListener(this);
+        super.onDetachedFromWindow();
+    }
+
+    @Override
+    public void onCheckmarkOrderChanged()
+    {
+        setupCheckmarkButtons();
+    }
+
     public interface Controller extends CheckmarkButtonController.Listener
     {
 

app/src/main/java/org/isoron/uhabits/preferences/Preferences.java

@@ -25,6 +25,8 @@ import android.preference.*;
 import org.isoron.uhabits.*;
 import org.isoron.uhabits.activities.*;
 
+import java.util.*;
+
 import javax.inject.*;
 
 @AppScope
@@ -37,15 +39,23 @@ public class Preferences
 
     private Boolean shouldReverseCheckmarks = null;
 
+    private LinkedList<Listener> listeners;
+
     @Inject
     public Preferences(@AppContext Context context)
     {
         this.context = context;
+        listeners = new LinkedList<>();
 
         prefs = PreferenceManager.getDefaultSharedPreferences(context);
         prefs.registerOnSharedPreferenceChangeListener(this);
     }
 
+    public void addListener(Listener listener)
+    {
+        listeners.add(listener);
+    }
+
     public Integer getDefaultHabitColor(int fallbackColor)
     {
         return prefs.getInt("pref_default_habit_palette_color", fallbackColor);
@@ -59,11 +69,6 @@ public class Preferences
         return defaultScoreInterval;
     }
 
-    public long getSnoozeInterval()
-    {
-        return Long.parseLong(prefs.getString("pref_snooze_interval", "15"));
-    }
-
     public void setDefaultScoreSpinnerPosition(int position)
     {
         prefs.edit().putInt("pref_score_view_interval", position).apply();
@@ -109,6 +114,11 @@ public class Preferences
         prefs.edit().putBoolean("pref_show_completed", showCompleted).apply();
     }
 
+    public long getSnoozeInterval()
+    {
+        return Long.parseLong(prefs.getString("pref_snooze_interval", "15"));
+    }
+
     public int getTheme()
     {
         return prefs.getInt("pref_theme", ThemeSwitcher.THEME_LIGHT);
@@ -155,7 +165,15 @@ public class Preferences
                                           String key)
     {
         if (key.equals("pref_checkmark_reverse_order"))
+        {
             shouldReverseCheckmarks = null;
+            for(Listener l : listeners) l.onCheckmarkOrderChanged();
+        }
+    }
+
+    public void removeListener(Listener listener)
+    {
+        listeners.remove(listener);
     }
 
     public void setDefaultHabitColor(int color)
@@ -170,6 +188,8 @@ public class Preferences
             .edit()
             .putBoolean("pref_checkmark_reverse_order", reverse)
             .apply();
+
+        for(Listener l : listeners) l.onCheckmarkOrderChanged();
     }
 
     public boolean shouldReverseCheckmarks()
@@ -199,4 +219,9 @@ public class Preferences
             .putLong("last_hint_timestamp", timestamp)
             .apply();
     }
+
+    public interface Listener
+    {
+        default void onCheckmarkOrderChanged() {}
+    }
 }