Bindings: Merge bugfixes and updates

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

app/src/main/java/com/wireguard/android/ConfigListFragment.java

@@ -89,7 +89,7 @@ public class ConfigListFragment extends BaseConfigFragment {
             @SuppressWarnings("unchecked")
             final ObservableMapAdapter<String, Config> adapter =
                     (ObservableMapAdapter<String, Config>) listView.getAdapter();
-            final int position = adapter.getItemPosition(config.getName());
+            final int position = adapter.getPosition(config.getName());
             if (position >= 0)
                 listView.setItemChecked(position, true);
         } else {

app/src/main/java/com/wireguard/android/bindings/BindingAdapters.java

@@ -28,6 +28,8 @@ public final class BindingAdapters {
         if (listener != null && oldList != null && oldLayoutId != newLayoutId) {
             listener.setList(null);
             listener = null;
+            // Stop tracking the old listener.
+            ListenerUtil.trackListener(view, null, R.id.item_change_listener);
         }
         // Avoid adding a listener when there is no new list or layout.
         if (newList == null || newLayoutId == 0)
@@ -44,49 +46,52 @@ public final class BindingAdapters {
     public static <T> void setItems(final ListView view,
                                     final ObservableList<T> oldList, final int oldLayoutId,
                                     final ObservableList<T> newList, final int newLayoutId) {
-        // Remove any existing binding when there is no new list or layout.
+        if (oldList == newList && oldLayoutId == newLayoutId)
-        if (newList == null || newLayoutId == 0) {
-            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)
+        if (adapter != null && oldList != null && oldLayoutId != newLayoutId) {
+            adapter.setList(null);
             adapter = null;
-        // Add a new binding if there was none, or if it must be replaced due to a layout change.
-        if (adapter == null) {
-            view.setAdapter(new ObservableListAdapter<>(view.getContext(), newLayoutId, newList));
-        } else if (newList != oldList) {
-            // Changing the list only requires modifying the existing adapter.
-            adapter.setList(newList);
         }
+        // Avoid setting an adapter when there is no new list or layout.
+        if (newList == null || newLayoutId == 0)
+            return;
+        if (adapter == null) {
+            adapter = new ObservableListAdapter<>(view.getContext(), newLayoutId, newList);
+            view.setAdapter(adapter);
+        }
+        // Either the list changed, or this is an entirely new listener because the layout changed.
+        adapter.setList(newList);
     }
 
     @BindingAdapter({"items", "layout"})
-    public static <K extends Comparable<K>, V> void setItems(
+    public static <K extends Comparable<K>, V> void setItems(final ListView view,
-            final ListView view,
+                                                             final ObservableSortedMap<K, V> oldMap,
-            final ObservableSortedMap<K, V> oldMap, final int oldLayoutId,
+                                                             final int oldLayoutId,
-            final ObservableSortedMap<K, V> newMap, final int newLayoutId) {
+                                                             final ObservableSortedMap<K, V> newMap,
-        // Remove any existing binding when there is no new map or layout.
+                                                             final int newLayoutId) {
-        if (newMap == null || newLayoutId == 0) {
+        if (oldMap == newMap && oldLayoutId == newLayoutId)
-            view.setAdapter(null);
             return;
-        }
         // The ListAdapter interface is not generic, so this cannot be checked.
         @SuppressWarnings("unchecked")
         ObservableMapAdapter<K, V> adapter = (ObservableMapAdapter<K, V>) view.getAdapter();
         // If the layout changes, any existing adapter must be replaced.
-        if (newLayoutId != oldLayoutId)
+        if (adapter != null && oldMap != null && oldLayoutId != newLayoutId) {
+            adapter.setMap(null);
             adapter = null;
-        // Add a new binding if there was none, or if it must be replaced due to a layout change.
-        if (adapter == null) {
-            view.setAdapter(new ObservableMapAdapter<>(view.getContext(), newLayoutId, newMap));
-        } else if (newMap != oldMap) {
-            // Changing the list only requires modifying the existing adapter.
-            adapter.setMap(newMap);
         }
+        // Avoid setting an adapter when there is no new list or layout.
+        if (newMap == null || newLayoutId == 0)
+            return;
+        if (adapter == null) {
+            adapter = new ObservableMapAdapter<>(view.getContext(), newLayoutId, newMap);
+            view.setAdapter(adapter);
+        }
+        // Either the list changed, or this is an entirely new listener because the layout changed.
+        adapter.setMap(newMap);
     }
 
     @BindingAdapter({"filter"})

app/src/main/java/com/wireguard/android/bindings/ItemChangeListener.java

@@ -37,7 +37,7 @@ class ItemChangeListener<T> {
         return binding.getRoot();
     }
 
-    public void setList(final ObservableList<T> newList) {
+    void setList(final ObservableList<T> newList) {
         if (list != null)
             list.removeOnListChangedCallback(callback);
         list = newList;

app/src/main/java/com/wireguard/android/bindings/ObservableListAdapter.java

@@ -37,12 +37,16 @@ class ObservableListAdapter<T> extends BaseAdapter implements ListAdapter {
 
     @Override
     public T getItem(final int position) {
-        return list != null ? list.get(position) : null;
+        if (list == null || position < 0 || position >= list.size())
+            return null;
+        return list.get(position);
     }
 
     @Override
     public long getItemId(final int position) {
-        return position;
+        if (list == null || position < 0 || position >= list.size())
+            return -1;
+        return list.get(position).hashCode();
     }
 
     @Override
@@ -55,7 +59,12 @@ class ObservableListAdapter<T> extends BaseAdapter implements ListAdapter {
         return binding.getRoot();
     }
 
-    public void setList(final ObservableList<T> newList) {
+    @Override
+    public boolean hasStableIds() {
+        return true;
+    }
+
+    void setList(final ObservableList<T> newList) {
         if (list != null)
             list.removeOnListChangedCallback(callback);
         list = newList;

app/src/main/java/com/wireguard/android/bindings/ObservableMapAdapter.java

@@ -44,20 +44,18 @@ public class ObservableMapAdapter<K extends Comparable<K>, V> extends BaseAdapte
     public V getItem(final int position) {
         if (map == null || position < 0 || position >= map.size())
             return null;
-        return map.get(getKeys().get(position));
+        return map.get(getKey(position));
     }
 
     @Override
     public long getItemId(final int position) {
         if (map == null || position < 0 || position >= map.size())
             return -1;
-        return map.get(getKeys().get(position)).hashCode();
+        return getItem(position).hashCode();
     }
 
-    public int getItemPosition(final K key) {
+    private K getKey(final int position) {
-        if (map == null)
+        return getKeys().get(position);
-            return -1;
-        return Collections.binarySearch(getKeys(), key);
     }
 
     private ArrayList<K> getKeys() {
@@ -66,11 +64,18 @@ public class ObservableMapAdapter<K extends Comparable<K>, V> extends BaseAdapte
         return keys;
     }
 
+    public int getPosition(final K key) {
+        if (map == null || key == null)
+            return -1;
+        return Collections.binarySearch(getKeys(), key);
+    }
+
     @Override
     public View getView(final int position, final View convertView, final ViewGroup parent) {
         ViewDataBinding binding = DataBindingUtil.getBinding(convertView);
         if (binding == null)
             binding = DataBindingUtil.inflate(layoutInflater, layoutId, parent, false);
+        binding.setVariable(BR.key, getKey(position));
         binding.setVariable(BR.item, getItem(position));
         binding.executePendingBindings();
         return binding.getRoot();
@@ -81,7 +86,7 @@ public class ObservableMapAdapter<K extends Comparable<K>, V> extends BaseAdapte
         return true;
     }
 
-    public void setMap(final ObservableSortedMap<K, V> newMap) {
+    void setMap(final ObservableSortedMap<K, V> newMap) {
         if (map != null)
             map.removeOnMapChangedCallback(callback);
         keys = null;

app/src/main/res/layout/config_list_item.xml

@@ -7,6 +7,10 @@
 
         <import type="com.wireguard.android.VpnService" />
 
+        <variable
+            name="key"
+            type="String" />
+
         <variable
             name="item"
             type="com.wireguard.config.Config" />
@@ -27,7 +31,7 @@
             android:layout_toStartOf="@+id/config_switch"
             android:ellipsize="end"
             android:maxLines="1"
-            android:text="@{item.name}"
+            android:text="@{key}"
             android:textStyle="@{item.primary ? Typeface.DEFAULT_BOLD : Typeface.DEFAULT}" />
 
         <TextView