1 files changed, 83 insertions, 0 deletions
diff --git a/java/com/android/dialer/speeddial/draghelper/SpeedDialItemTouchHelperCallback.java b/java/com/android/dialer/speeddial/draghelper/SpeedDialItemTouchHelperCallback.java
new file mode 100644
index 000000000..d1d9f478b
--- /dev/null
+++ b/java/com/android/dialer/speeddial/draghelper/SpeedDialItemTouchHelperCallback.java
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 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.dialer.speeddial.draghelper;
+
+import android.support.annotation.NonNull;
+import android.support.v7.widget.RecyclerView;
+import android.support.v7.widget.RecyclerView.ViewHolder;
+import android.support.v7.widget.helper.ItemTouchHelper;
+
+/** {@link ItemTouchHelper} for Speed Dial favorite contacts. */
+public class SpeedDialItemTouchHelperCallback extends ItemTouchHelper.Callback {
+
+  private final ItemTouchHelperAdapter adapter;
+
+  public SpeedDialItemTouchHelperCallback(ItemTouchHelperAdapter adapter) {
+    this.adapter = adapter;
+  }
+
+  @Override
+  public boolean isLongPressDragEnabled() {
+    // We'll manually call ItemTouchHelper#startDrag
+    return false;
+  }
+
+  @Override
+  public boolean isItemViewSwipeEnabled() {
+    // We don't want to enable swiping
+    return false;
+  }
+
+  @Override
+  public boolean canDropOver(
+      @NonNull RecyclerView recyclerView, @NonNull ViewHolder current, @NonNull ViewHolder target) {
+    return adapter.canDropOver(target);
+  }
+
+  @Override
+  public int getMovementFlags(@NonNull RecyclerView recyclerView, @NonNull ViewHolder viewHolder) {
+    if (!adapter.canDropOver(viewHolder)) {
+      return makeMovementFlags(0, 0);
+    }
+
+    int dragFlags =
+        ItemTouchHelper.UP | ItemTouchHelper.DOWN | ItemTouchHelper.START | ItemTouchHelper.END;
+    return makeMovementFlags(dragFlags, /* swipeFlags */ 0);
+  }
+
+  @Override
+  public boolean onMove(
+      @NonNull RecyclerView recyclerView,
+      @NonNull ViewHolder viewHolder,
+      @NonNull ViewHolder target) {
+    adapter.onItemMove(viewHolder.getAdapterPosition(), target.getAdapterPosition());
+    return true;
+  }
+
+  @Override
+  public void onSwiped(@NonNull ViewHolder viewHolder, int direction) {
+    // No-op since we don't support swiping
+  }
+
+  /** RecyclerView adapters interested in drag and drop should implement this interface. */
+  public interface ItemTouchHelperAdapter {
+
+    void onItemMove(int fromPosition, int toPosition);
+
+    boolean canDropOver(ViewHolder target);
+  }
+}