1 files changed, 132 insertions, 0 deletions
diff --git a/src/com/android/documentsui/StubSelectionTracker.java b/src/com/android/documentsui/StubSelectionTracker.java
new file mode 100644
index 000000000..1a392144f
--- /dev/null
+++ b/src/com/android/documentsui/StubSelectionTracker.java
@@ -0,0 +1,132 @@
+/*
+ * Copyright 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.documentsui;
+
+import android.os.Bundle;
+
+import androidx.recyclerview.selection.MutableSelection;
+import androidx.recyclerview.selection.Selection;
+import androidx.recyclerview.selection.SelectionTracker;
+import androidx.recyclerview.widget.RecyclerView.AdapterDataObserver;
+
+import java.util.Set;
+
+/**
+ * A stub SelectionTracker used by DocsSelectionHelper before a real SelectionTracker has been
+ * initialized by DirectoryFragment.
+ * @param <K> Selection key type which extends {@link SelectionTracker}.
+ */
+public class StubSelectionTracker<K> extends SelectionTracker<K> {
+
+    @Override
+    public void addObserver(SelectionObserver observer) {
+    }
+
+    @Override
+    public boolean hasSelection() {
+        return false;
+    }
+
+    @Override
+    public Selection<K> getSelection() {
+        return new MutableSelection<K>();
+    }
+
+    @Override
+    public void copySelection(MutableSelection<K> dest) {
+    }
+
+    @Override
+    public boolean isSelected(K key) {
+        return false;
+    }
+
+    @Override
+    public void restoreSelection(Selection<K> selection) {
+    }
+
+    @Override
+    public boolean clearSelection() {
+        return false;
+    }
+
+    @Override
+    public boolean setItemsSelected(Iterable<K> keys, boolean selected) {
+        return false;
+    }
+
+    @Override
+    public boolean select(K key) {
+        return false;
+    }
+
+    @Override
+    public boolean deselect(K key) {
+        return false;
+    }
+
+    @Override
+    protected AdapterDataObserver getAdapterDataObserver() {
+        return null;
+    }
+
+    @Override
+    public void startRange(int position) {
+    }
+
+    @Override
+    public void extendRange(int position) {
+    }
+
+    @Override
+    public void endRange() {
+    }
+
+    @Override
+    public boolean isRangeActive() {
+        return false;
+    }
+
+    @Override
+    public void anchorRange(int position) {
+    }
+
+    @Override
+    public void extendProvisionalRange(int position) {
+    }
+
+    @Override
+    public void setProvisionalSelection(Set<K> newSelection) {
+    }
+
+    @Override
+    public void clearProvisionalSelection() {
+    }
+
+    @Override
+    public void mergeProvisionalSelection() {
+    }
+
+    @Override
+    public void onSaveInstanceState(Bundle state) {
+    }
+
+    @Override
+    public void onRestoreInstanceState(Bundle state) {
+    }
+
+}