How can I fill RecyclerView with GridLayoutManager from right to left

Question

I'm trying to fill some data into a RecyclerView with GridLayoutManager:

GridLayoutManager layoutManager = new GridLayoutManager(this, 3, GridLayoutManager.VERTICAL, false);

This will fill the data into the grid from left to right. The first item will be put into top-left place, etc.

But the app I'm developing is designed for an RTL language, so I need to make it fill from right to left.

I tried to change the last argument to true. But it just scrolled the RecyclerView all the way down.

Also setting layoutDirection attribute for RecyclerView doesn't work (without considering that my min API is 16 and this attribute is added for API17+):

<android.support.v7.widget.RecyclerView
        android:id="@+id/grid"
        android:layoutDirection="rtl"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

How can I create a right to left filled grid using RecyclerView?

Answer 1

Create a class that extends GridLayoutMAnager ,and override the isLayoutRTL() method like this:

public class RtlGridLayoutManager extends GridLayoutManager {

    public RtlGridLayoutManager(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
    }

    public RtlGridLayoutManager(Context context, int spanCount) {
        super(context, spanCount);
    }

    public RtlGridLayoutManager(Context context, int spanCount, int orientation, boolean reverseLayout) {
        super(context, spanCount, orientation, reverseLayout);
    }

    @Override
    protected boolean isLayoutRTL(){
        return true;
    }
}

Answer 2

The answer by Mohammad is true but you do not need to create a new class. you can simply override isLayoutRTL method.

GridLayoutManager lm = new GridLayoutManager(this, 2) {
    @Override
    protected boolean isLayoutRTL() {
        return true;
    }
};

Answer 3

There is a better way to do it

You can programmatically change the layout direction of the RecycleView

workHourRecycler = view.findViewById(R.id.market_hours_recycler);
workHourRecycler.setLayoutManager(new GridLayoutManager(getContext(),4));

//Programtically set the direction
workHourRecycler.setLayoutDirection(View.LAYOUT_DIRECTION_RTL);

Answer 4

On the face of it, GridLayouManager should fill rows from right when getLayoutDirection() gives ViewCompat.LAYOUT_DIRECTION_RTL. Normally, this direction will be inherited from the RecyclerView's container.

But if this does not work as expected, or you need to push it down to API 16, or you some device with bad implementation of RTL support, you can simply pull the GridLayoutManager from github, and use a custom manager that you tune to your liking.

It may be enough to extend the stock GridLayoutManager and override layoutChunk().

Answer 5

Its very simple, just call method setReverseLayout as,

GridLayoutManager layoutManager = new GridLayoutManager(this, 3, GridLayoutManager.VERTICAL, false);
layoutManager.setReverseLayout(true);