Workaround for bug with RecycleView focus scrolling when navigating with d-pad (http://stackoverflow.com/questions/31596801/recyclerview-focus-scrolling)

GridLayoutManager.java

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.util.AttributeSet;
import android.view.View;

/**
 * {@link GridLayoutManager} extension which introduces workaround for focus finding bug when
 * navigating with dpad.
 *
 * @see <a href="http://stackoverflow.com/questions/31596801/recyclerview-focus-scrolling">http://stackoverflow.com/questions/31596801/recyclerview-focus-scrolling</a>
 */
public class GridLayoutManager extends android.support.v7.widget.GridLayoutManager {

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

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

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

    @Override
    public View onFocusSearchFailed(View focused, int focusDirection,
            RecyclerView.Recycler recycler, RecyclerView.State state) {
        // Need to be called in order to layout new row/column
        View nextFocus = super.onFocusSearchFailed(focused, focusDirection, recycler, state);

        if (nextFocus == null) {
            return null;
        }

        int fromPos = getPosition(focused);
        int nextPos = getNextViewPos(fromPos, focusDirection);

        return findViewByPosition(nextPos);
    }

    /**
     * Manually detect next view to focus.
     *
     * @param fromPos from what position start to seek.
     * @param direction in what direction start to seek. Your regular {@code View.FOCUS_*}.
     * @return adapter position of next view to focus. May be equal to {@code fromPos}.
     */
    protected int getNextViewPos(int fromPos, int direction) {
        int offset = calcOffsetToNextView(direction);

        if (hitBorder(fromPos, offset)) {
            return fromPos;
        }

        return fromPos + offset;
    }

    /**
     * Calculates position offset.
     *
     * @param direction regular {@code View.FOCUS_*}.
     * @return position offset according to {@code direction}.
     */
    protected int calcOffsetToNextView(int direction) {
        int spanCount = getSpanCount();
        int orientation = getOrientation();

        if (orientation == VERTICAL) {
            switch (direction) {
                case View.FOCUS_DOWN:
                    return spanCount;
                case View.FOCUS_UP:
                    return -spanCount;
                case View.FOCUS_RIGHT:
                    return 1;
                case View.FOCUS_LEFT:
                    return -1;
            }
        } else if (orientation == HORIZONTAL) {
            switch (direction) {
                case View.FOCUS_DOWN:
                    return 1;
                case View.FOCUS_UP:
                    return -1;
                case View.FOCUS_RIGHT:
                    return spanCount;
                case View.FOCUS_LEFT:
                    return -spanCount;
            }
        }

        return 0;
    }

    /**
     * Checks if we hit borders.
     *
     * @param from from what position.
     * @param offset offset to new position.
     * @return {@code true} if we hit border.
     */
    private boolean hitBorder(int from, int offset) {
        int spanCount = getSpanCount();

        if (Math.abs(offset) == 1) {
            int spanIndex = from % spanCount;
            int newSpanIndex = spanIndex + offset;
            return newSpanIndex < 0 || newSpanIndex >= spanCount;
        } else {
            int newPos = from + offset;
            return newPos < 0 && newPos >= spanCount;
        }
    }
}

Thank you for sharing this!

Hello, thanks for sharing, i'm trying to implement your workaround, but i can't getting it to work.
The line
"int fromPos = getPosition(focused);"

trows an Exception, saying that can not cast (any layout params here) to recyclerview.layoutparams.

:/ i've tried to use the layout params from the viewitem, but they doesn't have "getViewLayoutPosition()" function :(

what could I do?

hi have a error in Line "int fromPos = getPosition(focused);" , have update form this issue?

hi have a error in Line "int fromPos = getPosition(focused);" , have update form this issue?

use this : getFocusedChild
int fromPos = getPosition(getFocusedChild());

i tried this and t did not work for me. It only shifted it a little by one item.

For AndroidX RecyclerView you can use this code:

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;

import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

public class CustomGridLayoutManager extends GridLayoutManager {

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

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

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

    @Override
    public View onFocusSearchFailed(View focused, int focusDirection,
                                    RecyclerView.Recycler recycler, RecyclerView.State state) {
        // Need to be called in order to layout new row/column
        View nextFocus = super.onFocusSearchFailed(focused, focusDirection, recycler, state);

        if (nextFocus == null) {
            return null;
        }

        int fromPos = getPosition(getFocusedChild());
        int nextPos = getNextViewPos(fromPos, focusDirection);

        return findViewByPosition(nextPos);
    }

    /**
     * Manually detect next view to focus.
     *
     * @param fromPos from what position start to seek.
     * @param direction in what direction start to seek. Your regular {@code View.FOCUS_*}.
     * @return adapter position of next view to focus. May be equal to {@code fromPos}.
     */
    protected int getNextViewPos(int fromPos, int direction) {
        int offset = calcOffsetToNextView(direction);

        if (hitBorder(fromPos, offset)) {
            return fromPos;
        }

        return fromPos + offset;
    }

    /**
     * Calculates position offset.
     *
     * @param direction regular {@code View.FOCUS_*}.
     * @return position offset according to {@code direction}.
     */
    protected int calcOffsetToNextView(int direction) {
        int spanCount = getSpanCount();
        int orientation = getOrientation();

        if (orientation == VERTICAL) {
            switch (direction) {
                case View.FOCUS_DOWN:
                    return spanCount;
                case View.FOCUS_UP:
                    return -spanCount;
                case View.FOCUS_RIGHT:
                    return 1;
                case View.FOCUS_LEFT:
                    return -1;
            }
        } else if (orientation == HORIZONTAL) {
            switch (direction) {
                case View.FOCUS_DOWN:
                    return 1;
                case View.FOCUS_UP:
                    return -1;
                case View.FOCUS_RIGHT:
                    return spanCount;
                case View.FOCUS_LEFT:
                    return -spanCount;
            }
        }

        return 0;
    }

    /**
     * Checks if we hit borders.
     *
     * @param from from what position.
     * @param offset offset to new position.
     * @return {@code true} if we hit border.
     */
    private boolean hitBorder(int from, int offset) {
        int spanCount = getSpanCount();

        if (Math.abs(offset) == 1) {
            int spanIndex = from % spanCount;
            int newSpanIndex = spanIndex + offset;
            return newSpanIndex < 0 || newSpanIndex >= spanCount;
        } else {
            int newPos = from + offset;
            return newPos < 0 && newPos >= spanCount;
        }
    }
}

The issue is still happening when you going down fastly. and also sometime 2 out of 10 it's loosing the focus.

Is there any updated code there?