ConfigListFragment: Implement config selection and removal

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

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

@@ -1,21 +1,31 @@
 package com.wireguard.android;
 
+import android.content.res.Resources;
+import android.databinding.ObservableArrayMap;
 import android.os.Bundle;
 import android.util.Log;
+import android.view.ActionMode;
 import android.view.LayoutInflater;
+import android.view.Menu;
+import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.AbsListView;
 import android.widget.AdapterView;
 import android.widget.ListView;
 
 import com.wireguard.android.databinding.ConfigListFragmentBinding;
 import com.wireguard.config.Config;
 
+import java.util.LinkedList;
+import java.util.List;
+
 /**
  * Fragment containing the list of known WireGuard configurations.
  */
 
 public class ConfigListFragment extends BaseConfigFragment {
+    private ListView listView;
 
     @Override
     public View onCreateView(final LayoutInflater inflater, final ViewGroup parent,
@@ -23,7 +33,9 @@ public class ConfigListFragment extends BaseConfigFragment {
         final ConfigListFragmentBinding binding =
                 ConfigListFragmentBinding.inflate(inflater, parent, false);
         binding.setConfigs(VpnService.getInstance().getConfigs());
-        final ListView listView = binding.getRoot().findViewById(R.id.config_list);
+        final View root = binding.getRoot();
+        listView = root.findViewById(R.id.config_list);
+        listView.setMultiChoiceModeListener(new ConfigListModeListener());
         listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
             @Override
             public void onItemClick(final AdapterView<?> parent, final View view,
@@ -36,18 +48,15 @@ public class ConfigListFragment extends BaseConfigFragment {
             @Override
             public boolean onItemLongClick(final AdapterView<?> parent, final View view,
                                            final int position, final long id) {
-                final Config config = (Config) parent.getItemAtPosition(position);
-                final VpnService service = VpnService.getInstance();
-                if (config == null || service == null)
-                    return false;
-                if (config.isEnabled())
-                    service.disable(config.getName());
-                else
-                    service.enable(config.getName());
+                setConfigChecked(null);
+                listView.setChoiceMode(AbsListView.CHOICE_MODE_MULTIPLE_MODAL);
+                listView.setItemChecked(position, true);
                 return true;
             }
         });
-        return binding.getRoot();
+        binding.executePendingBindings();
+        setConfigChecked(getCurrentConfig());
+        return root;
     }
 
     @Override
@@ -57,5 +66,83 @@ public class ConfigListFragment extends BaseConfigFragment {
         final BaseConfigActivity activity = ((BaseConfigActivity) getActivity());
         if (activity != null && activity.getCurrentConfig() != config)
             activity.setCurrentConfig(config);
+        if (listView != null)
+            setConfigChecked(config);
+    }
+
+    @Override
+    public void onDestroyView() {
+        super.onDestroyView();
+        listView = null;
+    }
+
+    private void setConfigChecked(final Config config) {
+        if (config != null) {
+            final int position = VpnService.getInstance().getConfigs().indexOfKey(config.getName());
+            if (position >= 0)
+                listView.setItemChecked(position, true);
+        } else {
+            final int position = listView.getCheckedItemPosition();
+            if (position >= 0)
+                listView.setItemChecked(position, false);
+        }
+    }
+
+    private class ConfigListModeListener implements AbsListView.MultiChoiceModeListener {
+        private final List<Config> configsToRemove = new LinkedList<>();
+
+        @Override
+        public boolean onActionItemClicked(final ActionMode mode, final MenuItem item) {
+            switch (item.getItemId()) {
+                case R.id.menu_action_delete:
+                    // Ensure an unmanaged config is never the current config.
+                    if (configsToRemove.contains(getCurrentConfig()))
+                        setCurrentConfig(null);
+                    for (final Config config : configsToRemove)
+                        VpnService.getInstance().remove(config.getName());
+                    configsToRemove.clear();
+                    mode.finish();
+                    return true;
+                default:
+                    return false;
+            }
+        }
+
+        @Override
+        public void onItemCheckedStateChanged(final ActionMode mode, final int position,
+                                              final long id, final boolean checked) {
+            if (checked)
+                configsToRemove.add((Config) listView.getItemAtPosition(position));
+            else
+                configsToRemove.remove(listView.getItemAtPosition(position));
+            final int count = configsToRemove.size();
+            final Resources resources = listView.getContext().getResources();
+            mode.setTitle(resources.getQuantityString(R.plurals.list_delete_title, count, count));
+        }
+
+        @Override
+        public boolean onCreateActionMode(final ActionMode mode, final Menu menu) {
+            mode.getMenuInflater().inflate(R.menu.config_list_delete, menu);
+            return true;
+        }
+
+        @Override
+        public void onDestroyActionMode(final ActionMode mode) {
+            configsToRemove.clear();
+            listView.post(new Runnable() {
+                @Override
+                public void run() {
+                    listView.setChoiceMode(AbsListView.CHOICE_MODE_SINGLE);
+                    // Restore the previous selection (before entering the action mode).
+                    setConfigChecked(getCurrentConfig());
+                }
+            });
+        }
+
+        @Override
+        public boolean onPrepareActionMode(final ActionMode mode, final Menu menu) {
+            configsToRemove.clear();
+            return false;
+        }
     }
 }