1 files changed, 92 insertions, 0 deletions
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/util/recyclerview/ItemTouchHelperDragCallback.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/util/recyclerview/ItemTouchHelperDragCallback.java
new file mode 100644
index 000000000..0fd24581d
--- /dev/null
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/util/recyclerview/ItemTouchHelperDragCallback.java
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2015 Paul Burke
+ *
+ * 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 org.sufficientlysecure.keychain.ui.util.recyclerview;
+
+import android.support.v7.widget.RecyclerView;
+import android.support.v7.widget.helper.ItemTouchHelper;
+
+/**
+ * An implementation of {@link ItemTouchHelper.Callback} that enables basic drag & drop and
+ * swipe-to-dismiss. Drag events are automatically started by an item long-press.<br/>
+ * </br/>
+ * Expects the <code>RecyclerView.Adapter</code> to listen for {@link
+ * ItemTouchHelperAdapter} callbacks and the <code>RecyclerView.ViewHolder</code> to implement
+ * {@link ItemTouchHelperViewHolder}.
+ */
+public class ItemTouchHelperDragCallback extends ItemTouchHelper.Callback {
+
+    private final ItemTouchHelperAdapter mAdapter;
+
+    public ItemTouchHelperDragCallback(ItemTouchHelperAdapter adapter) {
+        mAdapter = adapter;
+    }
+
+    @Override
+    public boolean isLongPressDragEnabled() {
+        return false;
+    }
+
+    @Override
+    public boolean isItemViewSwipeEnabled() {
+        return false;
+    }
+
+    @Override
+    public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
+        // Enable drag and swipe in both directions
+        final int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN;
+        final int swipeFlags = 0;
+        return makeMovementFlags(dragFlags, swipeFlags);
+    }
+
+    @Override
+    public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder source,
+                          RecyclerView.ViewHolder target) {
+        if (source.getItemViewType() != target.getItemViewType()) {
+            return false;
+        }
+
+        // Notify the adapter of the move
+        mAdapter.onItemMove(source, target, source.getAdapterPosition(), target.getAdapterPosition());
+        return true;
+    }
+
+    @Override
+    public void onSwiped(RecyclerView.ViewHolder viewHolder, int i) {
+        // we don't support swipe
+    }
+
+    @Override
+    public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {
+        if (actionState != ItemTouchHelper.ACTION_STATE_IDLE) {
+            // Let the view holder know that this item is being moved or dragged
+            ItemTouchHelperViewHolder itemViewHolder = (ItemTouchHelperViewHolder) viewHolder;
+            itemViewHolder.onItemSelected();
+        }
+
+        super.onSelectedChanged(viewHolder, actionState);
+    }
+
+    @Override
+    public void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
+        super.clearView(recyclerView, viewHolder);
+
+        // Tell the view holder it's time to restore the idle state
+        ItemTouchHelperViewHolder itemViewHolder = (ItemTouchHelperViewHolder) viewHolder;
+        itemViewHolder.onItemClear();
+    }
+}