diff --git a/app/src/main/java/com/wireguard/android/BindingAdapters.java b/app/src/main/java/com/wireguard/android/BindingAdapters.java index aa5b8c1e..77c6f657 100644 --- a/app/src/main/java/com/wireguard/android/BindingAdapters.java +++ b/app/src/main/java/com/wireguard/android/BindingAdapters.java @@ -1,6 +1,7 @@ package com.wireguard.android; import android.databinding.BindingAdapter; +import android.databinding.ObservableArrayMap; import android.databinding.ObservableList; import android.widget.ListView; @@ -9,6 +10,32 @@ import android.widget.ListView; */ public final class BindingAdapters { + @BindingAdapter({"items", "layout"}) + public static void arrayMapBinding(ListView view, ObservableArrayMap oldMap, + int oldLayoutId, ObservableArrayMap newMap, + int newLayoutId) { + // Remove any existing binding when there is no new map. + if (newMap == null) { + view.setAdapter(null); + return; + } + // The ListAdapter interface is not generic, so this cannot be checked. + @SuppressWarnings("unchecked") + ObservableArrayMapAdapter adapter = + (ObservableArrayMapAdapter) 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 ObservableArrayMapAdapter<>(view.getContext(), newLayoutId, newMap); + view.setAdapter(adapter); + } else if (newMap != oldMap) { + // Changing the list only requires modifying the existing adapter. + adapter.setMap(newMap); + } + } + @BindingAdapter({"items", "layout"}) public static void listBinding(ListView view, ObservableList oldList, int oldLayoutId, ObservableList newList, int newLayoutId) { diff --git a/app/src/main/java/com/wireguard/android/ObservableArrayMapAdapter.java b/app/src/main/java/com/wireguard/android/ObservableArrayMapAdapter.java new file mode 100644 index 00000000..d2a5a4cc --- /dev/null +++ b/app/src/main/java/com/wireguard/android/ObservableArrayMapAdapter.java @@ -0,0 +1,84 @@ +package com.wireguard.android; + +import android.content.Context; +import android.databinding.DataBindingUtil; +import android.databinding.ObservableArrayMap; +import android.databinding.ObservableMap; +import android.databinding.ViewDataBinding; +import android.view.LayoutInflater; +import android.view.View; +import android.view.ViewGroup; +import android.widget.BaseAdapter; +import android.widget.ListAdapter; + +import java.lang.ref.WeakReference; + +/** + * A generic ListAdapter backed by an ObservableMap. + */ + +class ObservableArrayMapAdapter extends BaseAdapter implements ListAdapter { + private final int layoutId; + private final LayoutInflater layoutInflater; + private ObservableArrayMap map; + private final OnMapChangedCallback callback = new OnMapChangedCallback<>(this); + + ObservableArrayMapAdapter(Context context, int layoutId, ObservableArrayMap map) { + this.layoutInflater = LayoutInflater.from(context); + this.layoutId = layoutId; + setMap(map); + } + + @Override + public int getCount() { + return map != null ? map.size() : 0; + } + + @Override + public V getItem(int position) { + return map != null ? map.get(map.keyAt(position)) : null; + } + + @Override + public long getItemId(int position) { + return position; + } + + @Override + public View getView(int position, View convertView, ViewGroup parent) { + ViewDataBinding binding = DataBindingUtil.getBinding(convertView); + if (binding == null) + binding = DataBindingUtil.inflate(layoutInflater, layoutId, parent, false); + binding.setVariable(BR.item, getItem(position)); + binding.executePendingBindings(); + return binding.getRoot(); + } + + public void setMap(ObservableArrayMap newMap) { + if (map != null) + map.removeOnMapChangedCallback(callback); + map = newMap; + if (map != null) { + map.addOnMapChangedCallback(callback); + } + } + + private static class OnMapChangedCallback + extends ObservableMap.OnMapChangedCallback, K, V> { + + private final WeakReference> weakAdapter; + + private OnMapChangedCallback(ObservableArrayMapAdapter adapter) { + weakAdapter = new WeakReference<>(adapter); + } + + @Override + public void onMapChanged(ObservableMap sender, K key) { + final ObservableArrayMapAdapter adapter = weakAdapter.get(); + if (adapter != null) + adapter.notifyDataSetChanged(); + else + sender.removeOnMapChangedCallback(this); + } + } +}