Changeset 12181 in josm for trunk/src/org/openstreetmap/josm/data/preferences/AbstractProperty.java

Timestamp:

2017-05-15T19:28:35+02:00 (7 years ago)

Author:

michael2402

Message:

Add a new ListenableWeakReference. Use it to not lose references to weak preference listeners too early.

File:

• trunk/src/org/openstreetmap/josm/data/preferences/AbstractProperty.java (modified) (2 diffs)

trunk/src/org/openstreetmap/josm/data/preferences/AbstractProperty.java

@@ -6 +6 @@
 import org.openstreetmap.josm.data.Preferences.PreferenceChangeEvent;
 import org.openstreetmap.josm.data.Preferences.PreferenceChangedListener;
+import org.openstreetmap.josm.tools.ListenableWeakReference;
 
 /**
@@ -250 +251 @@
      */
     public void addWeakListener(ValueChangeListener<? super T> listener) {
-        addWeakListenerImpl(new PreferenceChangedListenerAdapter(listener));
-    }
-
-    protected void addWeakListenerImpl(PreferenceChangedListener adapter) {
-        getPreferences().addWeakKeyPreferenceChangeListener(getKey(), adapter);
+        ValueChangeListener<T> weakListener = new WeakPreferenceAdapter(listener);
+        PreferenceChangedListenerAdapter adapter = new PreferenceChangedListenerAdapter(weakListener);
+        addListenerImpl(adapter);
+    }
+
+    private class WeakPreferenceAdapter extends ListenableWeakReference<ValueChangeListener<? super T>>
+            implements ValueChangeListener<T> {
+        public WeakPreferenceAdapter(ValueChangeListener<? super T> referent) {
+            super(referent);
+        }
+
+        @Override
+        public void valueChanged(ValueChangeEvent<? extends T> e) {
+            ValueChangeListener<? super T> r = this.get();
+            r.valueChanged(e);
+        }
+
+        @Override
+        protected void onDereference() {
+            removeListenerImpl(new PreferenceChangedListenerAdapter(this));
+        }
+
     }