TouchImageView is not working for ViewPager

Question

I want to implement pinch zoom effect on an imageView inside a ViewPager. I get the code of how to zoom an image. but when i implement that code inside a ViewPage it didnt work. I have used TouchImageView Class its not working. I have google it for my error,its not satifised me. I couldn't see my image its shows error..

LogCat:

06-06 16:50:44.570: E/AndroidRuntime(30756): FATAL EXCEPTION: main
06-06 16:50:44.570: E/AndroidRuntime(30756): java.lang.NullPointerException
06-06 16:50:44.570: E/AndroidRuntime(30756):  at com.androidbegin.viewpagergridview.ImagePagerAdapter.instantiateItem(ImagePagerAdapter.java:40)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.support.v4.view.ViewPager.addNewItem(ViewPager.java:832)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.support.v4.view.ViewPager.populate(ViewPager.java:982)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.support.v4.view.ViewPager.populate(ViewPager.java:914)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1436)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.View.measure(View.java:15504)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5059)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1396)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.widget.LinearLayout.measureVertical(LinearLayout.java:681)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.widget.LinearLayout.onMeasure(LinearLayout.java:574)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.View.measure(View.java:15504)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5059)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.View.measure(View.java:15504)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5059)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1396)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.widget.LinearLayout.measureVertical(LinearLayout.java:681)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.widget.LinearLayout.onMeasure(LinearLayout.java:574)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.View.measure(View.java:15504)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5059)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2385)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.View.measure(View.java:15504)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1979)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1222)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1395)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1115)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4526)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.Choreographer.doCallbacks(Choreographer.java:555)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.Choreographer.doFrame(Choreographer.java:525)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.os.Handler.handleCallback(Handler.java:615)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.os.Handler.dispatchMessage(Handler.java:92)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.os.Looper.loop(Looper.java:137)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at android.app.ActivityThread.main(ActivityThread.java:4921)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at java.lang.reflect.Method.invokeNative(Native Method)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at java.lang.reflect.Method.invoke(Method.java:511)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1027)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:794)
06-06 16:50:44.570: E/AndroidRuntime(30756):  at dalvik.system.NativeStart.main(Native Method)

ImagePagerAdapater.class

public class ImagePagerAdapter extends PagerAdapter {

        private Activity _activity;
         private LayoutInflater inflater;
    private List<ImageView> images;


    public ImagePagerAdapter(Activity activity,
              List<ImageView> images) {
          this._activity = activity;
          this.images = images;
         }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {

        TouchImageView imgDisplay;
         inflater = (LayoutInflater) _activity
                 .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
         View viewLayout = inflater.inflate(R.layout.view_pager, container,
                 false); //Line number 40

         imgDisplay = (TouchImageView) viewLayout.findViewById(R.id.imgDisplay);

         ((ViewPager) container).addView(viewLayout);

         return viewLayout;
    }



        @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
       // container.removeView(images.get(position));
        ((ViewPager) container).removeView((RelativeLayout) object);
    }

    @Override
    public int getCount() {
        return images.size();
    }

    @Override
    public boolean isViewFromObject(View view, Object o) {
        return view == o;
    }
  }

ImageAdapter.class

public class ImageAdapter extends BaseAdapter {
    private Context mContext;

    public ImageAdapter(Context c) {
        mContext = c;
    }

    public int getCount() {
        return mThumbIds.length;
    }

    public Object getItem(int position) {
        return mThumbIds[position];
    }

    public long getItemId(int position) {
        return 0;
    }

    // Create a new ImageView for each item referenced by the Adapter
    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView imageView;
        if (convertView == null) {  // If it's not recycled, initialize some attributes
            imageView = new ImageView(mContext);
           // imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        } else {
            imageView = (ImageView) convertView;
        }

        imageView.setImageResource(mThumbIds[position]);
        return imageView;
    }

    // References to our images in res > drawable
    public Integer[] mThumbIds = {
            R.drawable.small, R.drawable.small1,
            R.drawable.small2, R.drawable.small3,
            R.drawable.small4, R.drawable.small5,
            R.drawable.small6, R.drawable.small7,
            R.drawable.small8, R.drawable.small9};
}

xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <com.androidbegin.viewpagergridview.TouchImageView
        android:id="@+id/imgDisplay"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:scaleType="fitCenter" />


</RelativeLayout>

Please guide me. What im doing mistake? Thanks a lot in advance..

@SimplePlan What PKG? My package name all correct in that class — Make it Simple, Jun 06 '14 at 11:55
Try changing `View viewLayout = inflater.inflate(R.layout.view_pager, container, false);` to `View viewLayout = inflater.inflate(R.layout.view_pager, null);` — Aniruddha, Jun 06 '14 at 12:07
Check this http://stackoverflow.com/questions/11099897/viewpager-fragmentpageradapter-nullpointer — Aniruddha, Jun 06 '14 at 12:18
@Aniruddha i think need to set image position to display in this `instantiateItem` how to set image position to dispaly — Make it Simple, Jun 06 '14 at 12:19

Kalai.G · Accepted Answer · 2014-06-06T17:13:04.860

1.Why you are getting NullPointerException(NPE)? Inflater is null. Please check the condition

@Override
public Object instantiateItem(ViewGroup container, int position) {

    TouchImageView imgDisplay;
     //Here is the problem i hope
     //  inflater = (LayoutInflater) _activity
     //        .getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
     //try using getContext() instead _activity
       inflater  = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);

     //check whether inflater is null or not
      if(inflater!=null)
          {
             View viewLayout = inflater.inflate(R.layout.view_pager, container,
             false); //Line number 40

             imgDisplay = (TouchImageView) viewLayout.findViewById(R.id.imgDisplay);

            ((ViewPager) container).addView(viewLayout);

          return viewLayout;

           }
         }

2.How to set image position to dispaly? as you discussed in comments. Have a look at here

Pager has some override methods with setOnPageChangeListener. You can get the current position of the image after the page has been scrolled

   mViewPager.setOnPageChangeListener(new SimpleOnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, 
                                   int positionOffsetPixels) {

        }

        @Override
        public void onPageSelected(int position) {

        }

        @Override
        public void onPageScrollStateChanged(int state) {
                     //check for the state
                    if (state == SCROLL_STATE_SETTLING) {

                           // Here code for the image zooming
                         }

        }
    });

Please use debugger and see what these override methods are doing. Then you will be getting some idea on viewpager. Hope this helps for you

TouchImageView is not working for ViewPager

1 Answers1