fragmentdnd

Library for Android that makes drag and drop between fragments possible.

Getting started

In your build.gradle:

 dependencies {
    compile 'com.gvoltr.fragmentdnd:fragment-dnd:1.0'
 }

In your activity_layout add DragLayer as last view :

<!-- All other views-->
...
<com.gvoltr.fragmentdnd.DragLayer
        android:id="@+id/drag_layer"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

Now you need to create custom View that implements DropTarget interface, for example:

public class DroppableRelativeLayout extends RelativeLayout implements DropTarget {

    private OnDropListener dropListener;

    @Override
    public void setOnDropListener(OnDropListener listener) {
        dropListener = listener;
    }

    @Override
    public void onDrop(View v, String tag, String placeTag, Object dragInfo) {
        dropListener.onDrop(this, v, tag, placeTag, dragInfo);
    }

    @Override
    public void onDragEnter(View v, String tag, String placeTag, Object dragInfo) {

    }

    @Override
    public void onDragOver(View v, String tag, String placeTag, Object dragInfo) {

    }

    @Override
    public void onDragExit(View v, String tag, String placeTag, Object dragInfo) {

    }

    @Override
    public boolean acceptDrop(View v, int x, int y, String tag, String placeTag, Object dragInfo) {
        return getVisibility() == View.VISIBLE;
    }

Add this view to any Fragment, set OnDropListener and add it to DragLayer:

    dragLayer.addDropTarget(dropTarget, placeTag);

Add any View from Fragment as draggable View to DragLayer:

    dragLayer.addDraggableView(v, tag, placeTag, data);

Thats all, from now you can drag views added as draggable to any drop target.

To avoid memory leaks you need to remove all views from Fragment in onDestroy():

    dragLayer.removeAllItemsForTag(placeTag);

You can change data object for View at any time:

    dragLayer.changeDataForDraggableView(v, data);

Enable RecyclerView

Dragging elements from RecyclerView is possible, all you need is to add/remove OnItemTouchListener provided by DragLayer depends on lifecycle events:

  @Override
    public void onStart() {
        super.onStart();
        if (dragActivity != null) {
            recyclerView.addOnItemTouchListener(dragActivity.getViewTouchListenerForRecyclerView());
        }
    }

    @Override
    public void onStop() {
        super.onStop();
        if (dragActivity != null) {
            recyclerView.removeOnItemTouchListener(dragActivity.getViewTouchListenerForRecyclerView());
        }
    }

License

Copyright 2016 Stanislav Havrosh

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.