Touch Support

Eli Hart edited this page Aug 15, 2017 · 12 revisions

(Since 2.3.0)

Epoxy helps you easily integrate RecyclerView's ItemTouchHelper with your Epoxy controllers and models. There is support for both dragging and swiping views.

The sample app demonstrates a bit of what is possible:

Sample touch support gif

Check out the code of the sample app for implementation details.

Basic Usage

The easiest way to set up touch support is through the EpoxyTouchHelper class.

Dragging

You can easily enable long press to drag and rearrange views like this:

EpoxyTouchHelper.initDragging(epoxyController) // an EpoxyController must be used
        .withRecyclerView(recyclerView) // The recyclerview the controller is used with
        .forVerticalList() // Specify the directions that you want to drag in
        .withTarget(MyModel.class) // Specify the type of model or models that should be draggable
        .andCallbacks(new DragCallbacks<MyModel>() {

          @Override
          public void onModelMoved(int fromPosition, int toPosition,
              MyModel modelBeingMoved, View itemView) {
              // Called when a view has been dragged to a new position.
              // Epoxy will automatically update the models in the controller and notify
              // the RecyclerView of the move

              // You MUST use this callback to update your data to reflect the move
          }
        
        // You may optionally implement the below methods as hooks into the drag lifecycle.
        // This allows you to style or animate the view as it is dragged.
    
        @Override
        public void onDragStarted(MyModel model, View itemView, int adapterPosition) {
    
        }
    
        @Override
        public void onDragReleased(MyModel model, View itemView) {
    
        }
    
        @Override
        public void clearView(MyModel model, View itemView) {
    
        }

       @Override
       public boolean isDragEnabledForModel(MyModel model) {
          // Override this to toggle disabling dragging for a model
          return true;
       }
});

Swiping

Initialize swiping like this:

EpoxyTouchHelper.initSwiping(recyclerView)
        .leftAndRight() // Which directions to allow
        .withTarget(MyModel.class) // Specify the type of model or models that should be swipable
        .andCallbacks(new SwipeCallbacks<MyModel>() {

          @Override
          public void onSwipeCompleted(MyModel model, View itemView, int position,
              int direction) {
            // Use must use this callback to update data to remove the item at the given position
            // You must also request a model build on the EpoxyController once the data is updated
          }
        });

        // You may optionally implement the below methods as hooks into the swipe lifecycle.
        // This allows you to style or animate the view as it is swiped.

        @Override
        public void onSwipeStarted(MyModel model, View itemView, int adapterPosition) {
    
        }
    
        @Override
        public void onSwipeProgressChanged(MyModel model, View itemView, float swipeProgress) {
    
        }
    
        @Override
        public void onSwipeReleased(MyModel model, View itemView) {
    
        }
    
        @Override
        public void clearView(MyModel model, View itemView) {
    
        }

       @Override
       public boolean isSwipeEnabledForModel(MyModel model) {
          // Override this to toggle disabling swipe for a model
          return true;
       }

Further Configuration

EpoxyTouchHelper makes it very simple to set up dragging and swiping, and also provides a fair amount of flexibility in configuring them. However, if you want more control over the configuration you may implement EpoxyModelTouchCallback directly and create your own ItemTouchHelper instance.

The EpoxyModelTouchCallback provides a number of wrapper methods to make working with Epoxy models simpler, while still providing direct access to the underlying RecyclerView touch callbacks.

If you want even more control, you could implement EpoxyTouchHelperCallback, which is just a small wrapper over ItemTouchHelper.Callback to convert all viewholder parameters to Epoxy view holders.

You can’t perform that action at this time.
You signed in with another tab or window. Reload to refresh your session. You signed out in another tab or window. Reload to refresh your session.
Press h to open a hovercard with more details.