How to access viewpager from a view from the pageradapter?

Question

I have a ViewPager and a custom PagerAdapter.
In the pager adapter there is a view that onClick I would like to move to the next page.
I implemented the following:

@Override  
public Object instantiateItem(final ViewGroup container, int position) {     
  view.setOnClickListener(
     (view) -> {  
        int current = ((ViewPager)container).getCurrentItem(); 
        ((ViewPager) container).setCurrentItem(current + 1, true);  
    }   
  );    
}    

This works but I am not sure I should be accessing the view pager from inside the adapter like that.
What is the standard way to do this?

Answer 1

Your method is ok. If you want cleaner arcitecture you should pass ViewPager as an interface to your adapter. And your code will be like this:

public interface Pager {
    /**
    * Super method where you do 
    * int current = ((ViewPager)container).getCurrentItem(); 
    * ((ViewPager) container).setCurrentItem(current + 1, true);  
    * but in ViewPager. So you don't need to cast it any more.
    */
    void goToNextItem();
}

private Pager pager;

@Override  
public Object instantiateItem(final ViewGroup container, int position) {     
  view.setOnClickListener(
     (view) -> {  
        pager.goToNextItem();
    }   
  );    
}

Answer 2

@Anton Potapov 的方法效果很好，但更简单的方法是将您的 viewpager 设为公开并使用其父级访问它，如下所示：

((ParentActivity)context).viewPager.setCurrentItem(position++);