Android ViewPager Prev/Next Button

Question

Okay, so I\'m developing an Android app that utilises a ViewPager to display pages.

Within each page, I have a set of buttons to use for navigating between pages (in

Answer 1

A failproof upgrade to sweggersen's and Alex Orlov's answer,

// For scrolling to next item
nextPageButton.setOnClickListener(new OnClickListener() {

    @Override
    public void onClick(View view) {
        viewPager.setCurrentItem(getNextPossibleItemIndex(1), true);
    }
});

// For scrolling to previous item
previousPageButton.setOnClickListener(new OnClickListener() {

    @Override
    public void onClick(View view) {
        viewPager.setCurrentItem(getNextPossibleItemIndex(-1), true);
    }
});

Add getNextPossibleItemIndex() method in your Activity/Fragment,

private int getNextPossibleItemIndex (int change) {

    int currentIndex = viewPager.getCurrentItem();
    int total = viewPager.getAdapter().getCount();

    if (currIndex + change < 0) {
        return 0;
    }

    return Math.abs((currentIndex + change) % total) ;
}

This way, you will be able to change currentItem without worrying about IndexOutOfBoundsException as suggested by Heinrich's comment. Note that using this method, items will be displayed like a circular list.

1 -> 2 -> 3 -> 1 -> 2 -> 3 -> 1

But going back, it will stop at first item

1 <- 1 <- 2 <- 3