gridTest.java

private void checkPostsDisplayOnGridView(List<Post> postsToCheck, int position) {
    int columnCount = 5;
    int size = postsToCheck.size() + position;
    int pos = 0;
  
    for (int i = position; i < size; i++) {
        // The first item starts as selected, clicking on this would open the Playback Activity
        checkItemAtPosition(i, postsToCheck.get(pos));
  
        // If we get to the end of the current row then we need to go down to the next one
        if (((i + 1) % columnCount) == 0) {
            int nextRowStart = i + columnCount;
            int nextRowEnd = nextRowStart - columnCount + 1;
            for (int n = nextRowStart; n >= nextRowEnd; n--) {
                checkItemAtPosition(n, postsToCheck.get(n - position));
            }
            // Set i to the start of the row beneath the one we've just checked
            i = i + columnCount;
        }
        pos++;
    }
}