Choice Mode in a RecyclerView?

Question

I'm trying to figure out how to achieve the same effect of

mListView.setChoiceMode(ListView.CHOICE_MODE_SINGLE);

in a RecyclerView implementation. Please help.

Solution 1

There is no built-in support for a "choice mode" structure with RecyclerView. Your options are to either roll it yourself or use a third-party library that offers it. The DynamicRecyclerView library offers choice modes, but I have not tried it.

This sample app demonstrates implementing it yourself, in this case using the activated state to indicate which is the current choice. The overall pattern is:

• Have your RecyclerView.ViewHolder detect a UI operation that indicates a choice (click on a row? click on a RadioButton in the row? etc.).

• Keep track of the selection at the level of your RecyclerView.Adapter. In my case, a ChoiceCapableAdapter handles that, in conjunction with a SingleChoiceMode class that implements a ChoiceMode strategy.

• When a choice is made, update the newly-chosen row to reflect the choice and update the previously-chosen row to reflect that it is no longer chosen. findViewHolderForPosition() on RecyclerView can help here -- if you track the position of the last choice, findViewHolderForPosition() can give you the ViewHolder for that choice, so you can "un-choose" it.

• Keep track of the choice across configuration changes, by putting it in the saved instance state of the activity or fragment that is managing the RecyclerView.

Solution 2

I've created a library for this kind of choice mode applied to the RecyclerView, maybe it can help:

Description

This library has been created to help the integration of a multi-choice selection to the RecyclerView

Implementation

The integration with Gradle is very easy, you just need the jcenter repository and the library:

repositories {
    jcenter()
}
...

dependencies {
    compile 'com.davidecirillo.multichoicerecyclerview:multichoicerecyclerview:1.0.1'
}

Main steps for usage

Add the MultiChoiceRecyclerView to your xml file

<com.davidecirillo.multichoicesample.MultiChoiceRecyclerView
    android:id="@+id/multiChoiceRecyclerView"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

Instanciate you object and connect the view

MultiChoiceRecyclerView mMultiChoiceRecyclerView = (MultiChoiceRecyclerView) findViewById(R.id.multiChoiceRecyclerView);

Extend you adapter to the MultiChoiceAdapter and add it to the RecyclerView as per normal usage

public class MyAdapter extends MultiChoiceAdapter<MyViewHolder> {

    public MyAdapter(ArrayList<String> stringList, Context context) {
        this.mList = stringList;
        this.mContext = context;
    }

    ...
} 

MyAdapter myAdapter = new MyAdapter(mList, getApplicationContext());
mMultiChoiceRecyclerView.setAdapter(myAdapter);

For more information and customisations: https://github.com/dvdciri/MultiChoiceRecyclerView