Android Gallery scroll is slow while using DiscLru Cache and Volley

Question

I have implemented Gallery view with Google I\O Volley Volley, Volley presentation and succeed to download images and doing cache.

First, when I was using LruCache for caching, It was very good and Gallery scrolling is nice. But LruCache is not maintaining 16MB of memory but caching only 4MB. I want do cache upto 16MB.

So I shifted to use DiscLruCache in place of LruCache. It doing cache as i want (16MB). But problem is Gallery view scrolling is very slow and it is not smooth while downloading and after doing all cache (16MB).

here is my code.

    package com.technotalkative.volleyimageloading;

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

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

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.Display;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.view.ViewGroup.MarginLayoutParams;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.TextView;

import com.android.volley.toolbox.NetworkImageView;

public class SimpleViewFrag extends Fragment {

    public static final String TAG = SimpleViewFrag.class.getSimpleName();
    private Gallery mGallery;
    private List<MyCataLogData> simpleViewList = new ArrayList<MyCataLogData>();
    MainActivity mainActivity;
    private LayoutInflater inflater;
    private int height;
    private int width;
    private int mItemWidth;
    private int mItemHeight;
    private SimpleViewAdapter mAdapter;

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

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Display display = getActivity().getWindowManager().getDefaultDisplay();
        height = display.getHeight();
        width = display.getWidth();

        mItemWidth = (int) (width / 1.7f);
        mItemHeight = (int) (height / 3f);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        this.inflater = inflater;
        View v = null;
        v = inflater.inflate(R.layout.simple_view, container, false);


//      String s = getArguments().getString(UCConstants.CATALOG_CONTENT_KEY);
        mGallery = (Gallery) v.findViewById(R.id.simpleViewGalleruy);

        mAdapter = new SimpleViewAdapter();
        mGallery.setAdapter(mAdapter);

//      mGallery.setSelection(1);

        DisplayMetrics metrics = new DisplayMetrics();
        getActivity().getWindowManager().getDefaultDisplay().getMetrics(metrics);

        // set gallery to left side
        MarginLayoutParams mlp = (MarginLayoutParams) mGallery.getLayoutParams();
        mlp.setMargins(-((int) (metrics.widthPixels / 3.8f)), mlp.topMargin,
                    mlp.rightMargin, mlp.bottomMargin);

        parseJsonForCataLog();


        mGallery.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> arg0, View arg1, int position,
                    long arg3) {
                Log.e(TAG, "position: ====="+position);

            }
        });

        return v;
    }

    public class SimpleViewAdapter extends BaseAdapter {

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

        @Override
        public Object getItem(int position) {
            return simpleViewList.get(position);
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            NetworkImageView networkImageView = null;
            TextView tvTitle = null;
            TextView tvText = null;
            View childView = null;


            if (convertView == null) {
                childView = inflater.inflate(R.layout.simple_view_content_item, null);
            } else {
                childView = convertView;
            }

            if (childView != null) {

                networkImageView = (NetworkImageView) childView
                        .findViewById(R.id.networkImageView);

                networkImageView.getLayoutParams().width = mItemWidth;
                networkImageView.getLayoutParams().height = LayoutParams.MATCH_PARENT;

                //getting an object for gallery item
                MyCataLogData cld = simpleViewList.get(position);
                if (networkImageView != null) {
                         networkImageView
                            .setImageUrl(cld.getSimpleImageUrl(), ImageCacheManager.getInstance().getImageLoader());
                }
                tvTitle = (TextView) childView.findViewById(R.id.title);
                if (tvTitle != null) {
                    tvTitle.setText(cld.getSimpleTitle());
                }

                tvText = (TextView) childView.findViewById(R.id.text);
                if (tvText != null) {
                    tvText.setText(cld.getSimpleText());
                }

            }
            return childView;
        }
    }

    protected void parseJsonForCataLog() {
        try {

            String jsonObjectString = getArguments().getString("JSONObject");

            JSONObject rootResponce = new JSONObject(jsonObjectString);

            Log.e(TAG, "rootResponce: " + rootResponce);
            JSONArray simpleArray = rootResponce.optJSONArray("SIMPLE");

            if(simpleArray == null)
                return;

            for (int i = 0; i < simpleArray.length(); i++) {
                JSONObject childMenuObject = simpleArray.getJSONObject(i);

                String textSimple = childMenuObject.optString("text");
                String titleSimple = childMenuObject.optString("title");
                String imageUrlSimple = childMenuObject.optString("imageUrl");

                MyCataLogData mcld = new MyCataLogData(null ,textSimple, titleSimple, imageUrlSimple);
                simpleViewList.add(mcld);
//              Log.e(TAG, "" + childMenuObject);
            }

            mAdapter.notifyDataSetChanged();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Answer 1

I had the same problem for a ListView but I found a solution in googles iosched application. You can try to apply the following but Gallery being deprecated I suggest using a horizontal list view like TwoWayView by Lucas Rocha. This solution can be applied to it, just implement TwoWayView.OnScrollListener instead

add the AbsListView onscroll listener methods and stop volley while scrolling fast/flinging

public class SimpleViewFrag extends Fragment implements AbsListView.OnScrollListener {

    ListView mListView;
    mListView.setOnScrollListener(this);

@Override
public void onScrollStateChanged( AbsListView view, int scrollState ) {
    // Pause disk cache access to ensure smoother scrolling
    if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_FLING) {
        VolleyHelper.getImageLoader().getRequestQueue().stop();
    } else {
        VolleyHelper.getImageLoader().getRequestQueue().start();
    }
}

@Override
public void onScroll( AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount ) {

}

Answer 2

If I understood you correctly (cant' find the ImageLoader initialization in your sample), it seems you are providing a disk cache to the Volley ImageLoader constructor, when you should be providing a memory cache.

If your memory cache is too limited in size you should either edit the code to make it bigger, or find / create a new implementation of the ImageCache interface that works the way you want it.

Whatever you choose - do not use a disk cache where a memory cache is expected.