1 files changed, 38 insertions, 0 deletions
diff --git a/app/src/main/java/com/wireguard/android/BindingAdapters.java b/app/src/main/java/com/wireguard/android/BindingAdapters.java
new file mode 100644
index 00000000..aa5b8c1e
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/BindingAdapters.java
@@ -0,0 +1,38 @@
+package com.wireguard.android;
+
+import android.databinding.BindingAdapter;
+import android.databinding.ObservableList;
+import android.widget.ListView;
+
+/**
+ * Static methods for use by generated code in the Android data binding library.
+ */
+
+public final class BindingAdapters {
+    @BindingAdapter({"items", "layout"})
+    public static <T> void listBinding(ListView view, ObservableList<T> oldList, int oldLayoutId,
+                                       ObservableList<T> newList, int newLayoutId) {
+        // Remove any existing binding when there is no new list.
+        if (newList == null) {
+            view.setAdapter(null);
+            return;
+        }
+        // The ListAdapter interface is not generic, so this cannot be checked.
+        @SuppressWarnings("unchecked")
+        ObservableListAdapter<T> adapter = (ObservableListAdapter<T>) view.getAdapter();
+        // If the layout changes, any existing adapter must be replaced.
+        if (newLayoutId != oldLayoutId)
+            adapter = null;
+        // Add a new binding if there was none, or if it must be replaced due to a layout change.
+        if (adapter == null) {
+            adapter = new ObservableListAdapter<>(view.getContext(), newLayoutId, newList);
+            view.setAdapter(adapter);
+        } else if (newList != oldList) {
+            // Changing the list only requires modifying the existing adapter.
+            adapter.setList(newList);
+        }
+    }
+
+    private BindingAdapters() {
+    }
+}