Question

I’m quite new to android development and at the moment I’m working with a viewpager, trying to understand how I can handle touch/tap events. I’ve spent all morning searching for answers to this and I can’t seem to find anything that helps me.

Basically I have a viewpager with 5 fragments that all use the same layout. All I want to do is be able to detect when there’s a tap/touch on the stationary view (I don’t want any detection to happen when a view is being dragged).

From what I gather, there seems to be an issue with the ViewPager intercepting all touch events by default. I believe this can be dealt with by using:

myPager.requestDisallowInterceptTouchEvent(true);

At first I dabbled with OnTouchListener and tried to log whether the onTouch method was ever hit – it appeared not. I’ve also seen the GestureDetector class thrown about a lot as a solution to this problem but frankly I feel overwhelmed and I’m not sure which classes/interfaces I should be using here.

All I’d like to do is pick up simple touch/tap events while using a ViewPager.

At the moment I’m using a modified version of the Animation tutorial code from the android developer site. This is what I have in my MainActivity.java file:

package com.example.pbinteractive;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;

public class MainActivity extends FragmentActivity {
    /**
     * The number of pages (wizard steps) to show in this demo.
     */
    private static final int NUM_PAGES = 5;

    /**
     * The pager widget, which handles animation and allows swiping horizontally to access previous
     * and next wizard steps.
     */
    private ViewPager mPager;

    /**
     * The pager adapter, which provides the pages to the view pager widget.
     */
    private PagerAdapter mPagerAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Instantiate a ViewPager and a PagerAdapter.
        mPager = (ViewPager) findViewById(R.id.pager);
        mPagerAdapter = new ScreenSlidePagerAdapter(getSupportFragmentManager());
        mPager.setAdapter(mPagerAdapter);       
    }   

    /**
     * A simple pager adapter that represents 5 {@link ScreenSlidePageFragment} objects, in
     * sequence.
     */
    private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {
        public ScreenSlidePagerAdapter(FragmentManager fm) {
            super(fm);
        }        

        @Override
        public Fragment getItem(int position) {
            return MyPageFragment.create(position);
        }

        @Override
        public int getCount() {
            return NUM_PAGES;
        }
    }   
}

And this is what I have in my MyPageFragment.java file:

package com.example.pbinteractive;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.ViewGroup;

public class MyPageFragment extends Fragment implements OnTouchListener {
    /**
     * The argument key for the page number this fragment represents.
     */
    public static final String ARG_PAGE = "page";

    /**
     * The fragment's page number, which is set to the argument value for {@link #ARG_PAGE}.
     */
    private int mPageNumber;

    /**
     * Factory method for this fragment class. Constructs a new fragment for the given page number.
     */
    public static MyPageFragment create(int pageNumber) {
        MyPageFragment fragment = new MyPageFragment();
        Bundle args = new Bundle();
        args.putInt(ARG_PAGE, pageNumber);
        fragment.setArguments(args);
        return fragment;
    }

    public MyPageFragment() {
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mPageNumber = getArguments().getInt(ARG_PAGE);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // Inflate the layout containing a title and body text.
        ViewGroup rootView = (ViewGroup) inflater
                .inflate(R.layout.fragment_slide, container, false);

        // Set the title view to show the page number.
        //((TextView) rootView.findViewById(android.R.id.text1)).setText(
        //        getString(R.string.title_template_step, mPageNumber + 1));

        return rootView;
    }

    /**
     * Returns the page number represented by this fragment object.
     */
    public int getPageNumber() {
        return mPageNumber;
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        // TODO Auto-generated method stub
        return false;
    }   
}

FYI I’ve checked both of these resources, as they often seem to be cited as the best solution to the problem I’m facing (from what I can gather):

android: ViewPager and HorizontalScrollVIew

Fling gesture detection on grid layout

But I haven’t been able to get much help from them. Like I said I’m quite new to working with android so I’d really like to just get familiar with the basics!

Thanks

EDIT: Just to clarify, I’d like to pick up the touch events within each fragment, since once I get past this hurdle I’d like some fragments to have touch events working while others will just display unresponsive content.

Answer 1

 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
// Inflate the layout containing a title and body text.
ViewGroup rootView = (ViewGroup) inflater
                .inflate(R.layout.fragment_slide, container, false);
LinearLayout layout = (LinearLayout)rootView.findViewById(R.id.layout)// get your root  layout
layout.setOnTouchListener(new OnTouchListener() {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            Log.v(null, "TOUCH EVENT"); // handle your fragment number here
            return false;
        }
    });
      return rootView;
    }