ObservableMapAdapter: Based on an observable TreeMap

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

1 files changed, 67 insertions, 0 deletions

diff --git a/app/src/main/java/com/wireguard/android/ObservableTreeMap.java b/app/src/main/java/com/wireguard/android/ObservableTreeMap.java
new file mode 100644
index 00000000..b0444d66
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/ObservableTreeMap.java
@@ -0,0 +1,67 @@
+package com.wireguard.android;
+
+import android.databinding.MapChangeRegistry;
+import android.databinding.ObservableMap;
+import android.support.annotation.NonNull;
+
+import java.util.Iterator;
+import java.util.Map;
+import java.util.TreeMap;
+
+/**
+ * Observable version of a TreeMap. Only notifies for changes made through methods, not iterators or
+ * views. This behavior is in line with that of ObservableArrayMap.
+ */
+
+public class ObservableTreeMap<K, V> extends TreeMap<K, V> implements ObservableSortedMap<K, V> {
+    private transient MapChangeRegistry listeners;
+
+    @Override
+    public void clear() {
+        super.clear();
+        notifyChange(null);
+    }
+
+    @Override
+    public void addOnMapChangedCallback(
+            final OnMapChangedCallback<? extends ObservableMap<K, V>, K, V> listener) {
+        if (listeners == null)
+            listeners = new MapChangeRegistry();
+        listeners.add(listener);
+    }
+
+    private void notifyChange(final K key) {
+        if (listeners != null)
+            listeners.notifyChange(this, key);
+    }
+
+    @Override
+    public V put(final K key, final V value) {
+        final V oldValue = super.put(key, value);
+        notifyChange(key);
+        return oldValue;
+    }
+
+    @Override
+    public void putAll(@NonNull final Map<? extends K, ? extends V> map) {
+        super.putAll(map);
+        for (final K key : map.keySet())
+            notifyChange(key);
+    }
+
+    @Override
+    public V remove(final Object key) {
+        final V oldValue = super.remove(key);
+        @SuppressWarnings("unchecked")
+        final K k = (K) key;
+        notifyChange(k);
+        return oldValue;
+    }
+
+    @Override
+    public void removeOnMapChangedCallback(
+            final OnMapChangedCallback<? extends ObservableMap<K, V>, K, V> listener) {
+        if (listeners != null)
+            listeners.remove(listener);
+    }
+}