A MultiImageLoader for loading multiple images using Volley on Android. Implementation of MultiNetworkImageView included.

MultiImageLoader.java

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

import android.widget.ImageView;

import com.android.volley.VolleyError;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.ImageLoader.ImageContainer;
import com.android.volley.toolbox.ImageLoader.ImageListener;

public class MultiImageLoader {

    private final ImageLoader mImageLoader;

    public static MultiImageLoader wrap(ImageLoader imageLoader) {
        return new MultiImageLoader(imageLoader);
    }

    private MultiImageLoader(ImageLoader imageLoader) {
        mImageLoader = imageLoader;
    }

    public MultiImageContainer get(List<String> requestUrls, final ImageListener listener) {
        return get(requestUrls, listener, 0, 0);
    }

    public MultiImageContainer get(List<String> requestUrls, ImageListener imageListener, int maxWidth, int maxHeight) {
        return get(requestUrls, imageListener, maxWidth, maxHeight, ImageView.ScaleType.CENTER_INSIDE);
    }

    public MultiImageContainer get(final List<String> requestUrls, ImageListener imageListener, int maxWidth,
            int maxHeight, ImageView.ScaleType scaleType) {
        MultiImageContainer multiImageContainer = new MultiImageContainer(requestUrls);
        loadNext(multiImageContainer, new ArrayList<>(requestUrls), imageListener, maxWidth, maxHeight, scaleType, true);
        return multiImageContainer;
    }

    private void loadNext(final MultiImageContainer multiImageContainer, final List<String> requestUrls,
            final ImageListener imageListener, final int maxWidth, final int maxHeight,
            final ImageView.ScaleType scaleType, final boolean firstLoad) {
        if (multiImageContainer.isCancelled || requestUrls.isEmpty()) {
            return;
        }

        ImageContainer imageContainer = mImageLoader.get(requestUrls.remove(0), new ImageListener() {
            @Override
            public void onResponse(ImageContainer response, boolean isImmediate) {
                if (response.getBitmap() != null || firstLoad) {
                    imageListener.onResponse(response, isImmediate);
                }

                if (response.getBitmap() != null) {
                    // Current loading complete. Lets load the next one.
                    loadNext(multiImageContainer, requestUrls, imageListener, maxWidth, maxHeight, scaleType, false);
                }
            }

            @Override
            public void onErrorResponse(VolleyError error) {
                if (firstLoad) {
                    imageListener.onErrorResponse(error);
                }
            }
        }, maxWidth, maxHeight, scaleType);
        multiImageContainer.add(imageContainer);
    }

    public class MultiImageContainer {

        private final List<String>         mUrls;

        private final List<ImageContainer> mImageContainers;

        private boolean                    isCancelled;

        public MultiImageContainer(List<String> urls) {
            mUrls = urls;
            mImageContainers = new ArrayList<>();
        }

        public List<String> getRequestUrls() {
            return mUrls;
        }

        private boolean add(ImageContainer imageContainer) {
            return mImageContainers.add(imageContainer);
        }

        public void cancelRequests() {
            isCancelled = true;

            for (ImageContainer imageContainer : mImageContainers) {
                imageContainer.cancelRequest();
            }
        }
    }
}

MultiNetworkImageView.java

import java.util.List;

import android.content.Context;
import android.util.AttributeSet;
import android.view.ViewGroup;
import android.widget.ImageView;

import com.android.volley.VolleyError;
import com.android.volley.toolbox.ImageLoader;

public class MultiNetworkImageView extends ImageView {

    /** The URLs of the network image to load */
    private List<String>                         mUrls;

    /**
     * Resource ID of the image to be used as a placeholder until the network
     * image is loaded.
     */
    private int                                  mDefaultImageId;

    /**
     * Resource ID of the image to be used if the network response fails.
     */
    private int                                  mErrorImageId;

    /** Local copy of the MultiImageLoader. */
    private MultiImageLoader                     mMultiImageLoader;

    /** Current ImageContainer. (either in-flight or finished) */
    private MultiImageLoader.MultiImageContainer mMultiImageContainer;

    private ImageLoader.ImageListener            mImageListener;

    public MultiNetworkImageView(Context context) {
        this(context, null);
    }

    public MultiNetworkImageView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public MultiNetworkImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    public void setImageUrls(List<String> urls, MultiImageLoader MultiImageLoader) {
        mUrls = urls;
        mMultiImageLoader = MultiImageLoader;
        loadImageIfNecessary(false);
    }

    public void setListener(ImageLoader.ImageListener imageListener) {
        mImageListener = imageListener;
    }

    public void setDefaultImageResId(int defaultImage) {
        mDefaultImageId = defaultImage;
    }

    public void setErrorImageResId(int errorImage) {
        mErrorImageId = errorImage;
    }

    void loadImageIfNecessary(final boolean isInLayoutPass) {
        int width = getWidth();
        int height = getHeight();
        ScaleType scaleType = getScaleType();

        boolean wrapWidth = false, wrapHeight = false;
        if (getLayoutParams() != null) {
            wrapWidth = getLayoutParams().width == ViewGroup.LayoutParams.WRAP_CONTENT;
            wrapHeight = getLayoutParams().height == ViewGroup.LayoutParams.WRAP_CONTENT;
        }

        // if the view's bounds aren't known yet, and this is not a
        // wrap-content/wrap-content view, hold off on loading the image.
        boolean isFullyWrapContent = wrapWidth && wrapHeight;
        if (width == 0 && height == 0 && !isFullyWrapContent) {
            return;
        }

        // if the URL to be loaded in this view is empty, cancel any old
        // requests and clear the currently loaded image.
        if (mUrls == null || mUrls.isEmpty()) {
            if (mMultiImageContainer != null) {
                mMultiImageContainer.cancelRequests();
                mMultiImageContainer = null;
            }
            setDefaultImageOrNull();
            return;
        }

        // if there was an old request in this view, check if it needs to be
        // canceled.
        if (mMultiImageContainer != null && mMultiImageContainer.getRequestUrls() != null) {
            if (mMultiImageContainer.getRequestUrls().equals(mUrls)) {
                // if the request is from the same URL, return.
                return;
            } else {
                // if there is a pre-existing request, cancel it if it's
                // fetching a different URL.
                mMultiImageContainer.cancelRequests();
                setDefaultImageOrNull();
            }
        }

        // Calculate the max image width / height to use while ignoring
        // WRAP_CONTENT dimens.
        int maxWidth = wrapWidth ? 0 : width;
        int maxHeight = wrapHeight ? 0 : height;

        // The pre-existing content of this view didn't match the current URL.
        // Load the new image from the network.
        MultiImageLoader.MultiImageContainer newContainer = mMultiImageLoader.get(mUrls,
                new ImageLoader.ImageListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        if (mErrorImageId != 0) {
                            setImageResource(mErrorImageId);
                        }

                        onErrorResponseReceived(error);
                    }

                    @Override
                    public void onResponse(final ImageLoader.ImageContainer response, boolean isImmediate) {
                        /*
                         * If this was an immediate response that was delivered
                         * inside of a layout pass do not set the image
                         * immediately as it will trigger a requestLayout inside
                         * of a layout. Instead, defer setting the image by
                         * posting back to the main thread.
                         */
                        if (isImmediate && isInLayoutPass) {
                            post(new Runnable() {
                                @Override
                                public void run() {
                                    onResponse(response, false);
                                }
                            });
                            return;
                        }

                        if (response.getBitmap() != null) {
                            setImageBitmap(response.getBitmap());
                        } else if (mDefaultImageId != 0) {
                            setImageResource(mDefaultImageId);
                        }

                        onResponseReceived(response, isImmediate);
                    }
                }, maxWidth, maxHeight, scaleType);

        // update the ImageContainer to be the new bitmap container.
        mMultiImageContainer = newContainer;
    }

    private void onErrorResponseReceived(VolleyError error) {
        if (mImageListener != null) {
            mImageListener.onErrorResponse(error);
        }
    }

    private void onResponseReceived(ImageLoader.ImageContainer response, boolean isImmediate) {
        if (mImageListener != null) {
            mImageListener.onResponse(response, isImmediate);
        }
    }

    private void setDefaultImageOrNull() {
        if (mDefaultImageId != 0) {
            setImageResource(mDefaultImageId);
        } else {
            setImageBitmap(null);
        }
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
        loadImageIfNecessary(true);
    }

    @Override
    protected void onDetachedFromWindow() {
        if (mMultiImageContainer != null) {
            // If the view was bound to an image request, cancel it and clear
            // out the image from the view.
            mMultiImageContainer.cancelRequests();
            setImageBitmap(null);
            // also clear out the container so we can reload the image if
            // necessary.
            mMultiImageContainer = null;
        }
        setListener(null);
        super.onDetachedFromWindow();
    }

    @Override
    protected void drawableStateChanged() {
        super.drawableStateChanged();
        invalidate();
    }
}