How to remove spacing between rows in RecyclerView using GridLayoutManager

Question

I am trying to have a full screen grid with a RecyclerView with a GridLayoutManager but for some reason a horizontal space is added between the rows and at the top and bottom of my RecyclerView. I can't get rid of it. I searched for solutions and tried an ItemDecorator by setting the dimensions to 0 explicitly but that didn't work. Nothing else worked.

The image.

The code for my ItemDecorator is pretty standard, included.

private class RecyclerViewItemDecorator extends RecyclerView.ItemDecoration {
    private int spaceInPixels;

    public RecyclerViewItemDecorator(int spaceInPixels) {
        this.spaceInPixels = spaceInPixels;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view,
                               RecyclerView parent, RecyclerView.State state) {
        outRect.left = spaceInPixels;
        outRect.right = spaceInPixels;
        outRect.bottom = spaceInPixels;
        if (parent.getChildLayoutPosition(view) == 0) {
            outRect.top = spaceInPixels;
        } else {
            outRect.top = 0;
        }
    }
}

These are the layout files I use.

/layout/activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.korah.moviesapp.MainActivity">

    <fragment
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/main_fragment"
        android:name="com.example.korah.moviesapp.MainActivityFragment"
        tools:layout="@layout/activity_main_fragment"
        >
    </fragment>

</RelativeLayout>

/layout/activity_main_fragment.xml

<?xml version="1.0" encoding="utf-8"?>

<android.support.v7.widget.RecyclerView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/movies_recycler"
    xmlns:android="http://schemas.android.com/apk/res/android">    
    </android.support.v7.widget.RecyclerView>

/layout/activity_movies_grid.xml

<?xml version="1.0" encoding="utf-8"?>

<ImageView
    android:id="@+id/imageView"
    android:src="@drawable/interst"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    xmlns:android="http://schemas.android.com/apk/res/android" />

Answer 1

Should be because of the scaling of Image rather than anything else. So try setting scaleType of ImageView as fitXY.

<ImageView
    android:id="@+id/imageView"
    android:src="@drawable/interst"
    android:layout_width="wrap_content"
    android:scaleType="fitXY"
    android:layout_height="wrap_content"
    xmlns:android="http://schemas.android.com/apk/res/android" />