Vertical Scroll is returning null

[tagrudev]

I am trying to implement the library but I got my head stuck on this issue can you please point me out what I am doing wrong ?

That's the debug info

03-07 11:29:00.979    1755-1755/com.project.app E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.project.app, PID: 1755
    java.lang.NullPointerException
            at com.comcast.freeflow.core.FreeFlowContainer.getViewChanges(FreeFlowContainer.java:615)
            at com.comcast.freeflow.core.FreeFlowContainer.moveViewport(FreeFlowContainer.java:1064)
            at com.comcast.freeflow.core.FreeFlowContainer.moveViewportBy(FreeFlowContainer.java:1004)
            at com.comcast.freeflow.core.FreeFlowContainer.onTouchEvent(FreeFlowContainer.java:848)
            at android.view.View.dispatchTouchEvent(View.java:7706)
            at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2210)
            at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1945)
            at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
            at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
            at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
            at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
            at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
            at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
            at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
            at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
            at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
            at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
            at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
            at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
            at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2068)
            at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1515)
            at android.app.Activity.dispatchTouchEvent(Activity.java:2458)
            at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2016)
            at android.view.View.dispatchPointerEvent(View.java:7886)
            at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:3954)
            at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:3833)
            at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3399)
            at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3449)
            at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3418)
            at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3525)
            at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3426)
            at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:3582)
            at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3399)
            at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3449)
            at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3418)
            at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3426)
            at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3399)
            at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:5602)
            at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:5582)
            at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:5553)
            at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:5682)
            at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:185)
            at android.view.InputEventReceiver.nativeConsumeBatchedInputEvents(Native Method)
            at android.view.InputEventReceiver.consumeBatchedInputEvents(InputEventReceiver.java:176)
            at android.view.ViewRootImpl.doConsumeBatchedInput(ViewRootImpl.java:5655)
            at android.view.ViewRootImpl$ConsumeBatchedInputRunnable.run(ViewRootImpl.java:5701)
            at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
            at android.view.Choreographer.doCallbacks(Choreographer.java:574)
            at android.view.Choreographer.doFrame(Choreographer.java:542)
            at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
            at android.os.Handler.handleCallback(Handler.java:733)
            at android.os.Handler.dispat

Here is my Fragment

package com.project.app.fragments;

import android.app.Activity;
import android.content.Context;
import android.graphics.Point;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.Display;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;

import com.comcast.freeflow.core.AbsLayoutContainer;
import com.comcast.freeflow.core.FreeFlowContainer;
import com.comcast.freeflow.core.FreeFlowItem;
import com.comcast.freeflow.core.Section;
import com.comcast.freeflow.core.SectionedAdapter;
import com.comcast.freeflow.layouts.FreeFlowLayout;
import com.comcast.freeflow.layouts.VGridLayout;
import com.comcast.freeflow.layouts.VLayout;
import com.koushikdutta.urlimageviewhelper.UrlImageViewHelper;
import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.JsonHttpResponseHandler;
import com.loopj.android.http.RequestParams;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.List;

import de.keyboardsurfer.android.widget.crouton.Configuration;
import de.keyboardsurfer.android.widget.crouton.Crouton;
import de.keyboardsurfer.android.widget.crouton.Style;
import com.project.app.R;
import com.project.app.models.Event;
import com.project.app.models.Photo;
import com.project.app.models.User;
import com.project.app.models.Venue;
import com.project.app.ui.ArtbookLayout;
import com.project.app.utils.Fields;

public class VenueGalleryFragment extends Fragment {
    Activity venueActivity;
    FreeFlowContainer ffContainer;
    ArtbookLayout custom;
    FreeFlowLayout[] layouts;
    VenuePhotosListAdapter adapter;
    Venue venue;
    AsyncHttpClient client;
    RequestParams photosParams;
    User currentUser;
    List<Photo> photos = new ArrayList<Photo>();

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_venue_gallery, container, false);
        venue = (Venue) venueActivity.getIntent().getExtras().getSerializable("venue");

        ffContainer = (FreeFlowContainer) rootView.findViewById(R.id.ffcGallery);
        Display display = venueActivity.getWindowManager().getDefaultDisplay();
        Point size = new Point();
        display.getSize(size);

        custom = new ArtbookLayout();
        layouts = new FreeFlowLayout[]{custom};

        // Get the images
        client = new AsyncHttpClient();
        client.setTimeout(Fields.DEFAULT_TIMEOUT);
        currentUser = User.currentUser();
        photosParams = new RequestParams();

        adapter = new VenuePhotosListAdapter(venueActivity);
        ffContainer.setLayout(layouts[0]);
        ffContainer.setAdapter(adapter);

        client.get(Fields.GRAPH_VENUES_URL + "/" + venue.venueId + "/photos", photosParams, new JsonHttpResponseHandler() {
            @Override
            public void onSuccess(int statusCode, JSONObject response) {
                venueActivity.setProgressBarIndeterminateVisibility(Boolean.FALSE);
                try {
                    JSONArray photosArray = response.getJSONArray("photos");
                    for (int i = 0; i < photosArray.length(); i++) {
                        JSONObject photo = photosArray.getJSONObject(i);
                        photos.add(Photo.fromJson(photo));
                    }

                } catch (JSONException e) {
                    e.printStackTrace();
                }
                adapter.update(photos);
                ffContainer.dataInvalidated();
                ffContainer.setOnItemClickListener(new AbsLayoutContainer.OnItemClickListener() {
                    @Override
                    public void onItemClick(AbsLayoutContainer parent, FreeFlowItem proxy) {

                    }
                });

                ffContainer.addScrollListener( new FreeFlowContainer.OnScrollListener() {

                    @Override
                    public void onScroll(FreeFlowContainer container) {
                    }
                });
            }
        });

        return rootView;
    }

    protected class VenuePhotosListAdapter implements SectionedAdapter {

        private Context context;
        private Section section;

        public VenuePhotosListAdapter(Context context) {
            this.context = context;
            section = new Section();
            section.setSectionTitle("Pics");
        }

        public void update(List<Photo> photos){

            for(Photo o : photos){
                section.getData().add(o);
            }
        }
        @Override
        public long getItemId(int section, int position) {
            return section * 1000 + position;
        }

        @Override
        public View getItemView(int sectionIndex, int position, View convertView, ViewGroup parent) {
            if (convertView == null) {
                convertView = LayoutInflater.from(context).inflate(R.layout.list_item_pic_view, parent, false);
            }
            ImageView img = (ImageView) convertView.findViewById(R.id.pic);
            Photo p = (Photo) (section.getData().get(position));
            UrlImageViewHelper.setUrlDrawable(img, p.imageUrl, getResources().getDrawable(R.drawable.logo));
            return convertView;
        }

        @Override
        public View getHeaderViewForSection(int section, View convertView,
                                            ViewGroup parent) {
            return null;
        }

        @Override
        public int getNumberOfSections() {
            if(section.getData().size() == 0) return 0;
            return 1;
        }

        @Override
        public Section getSection(int index) {
            return section;
        }

        @Override
        public Class[] getViewTypes() {
            return new Class[] { LinearLayout.class };
        }

        @Override
        public Class getViewType(FreeFlowItem proxy) {
            return LinearLayout.class;
        }

        @Override
        public boolean shouldDisplaySectionHeaders() {
            return false;
        }

    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        venueActivity = activity;
    }

}

[tagrudev]

This seems to happen even when I am trying to switch from one layout to another hmm any ideas ?

[arpit]

I'll need some more info here, like the layouts etc. Please upload a compiling android project with this bug and I can take a look.