NewsDetailFragment.java

package com.neosperience.egea;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.view.GestureDetectorCompat;
import android.text.Html;
import android.util.Log;
import android.view.GestureDetector;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.ScrollView;
import android.widget.TextView;

import com.android.volley.toolbox.NetworkImageView;
import com.neosperience.egea.customview.ViewAnimation;
import com.neosperience.egea.utils.concurrency.ObservableRegisterer;
import com.neosperience.egea.utils.concurrency.Observer;
import com.neosperience.egea.utils.volleytoolbox.ImageCacheManager;

public class NewsDetailFragment extends Fragment implements Observer {

    private NetworkImageView news_image;
    private int news_image_height;
    private ScrollView scrollView;

    public NewsDetailFragment() {
        // Empty constructor required for fragment subclasses
    }

    private void checkImageHeight() {
        if (news_image_height == 0)
            news_image_height = news_image.getHeight();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_news_detail, container, false);

        Bundle args = getArguments();
        String title = args.getString("title");
        TextView news_title = (TextView) rootView.findViewById(R.id.news_title);
        news_title.setText(title);

        EgeaApplication.easyTrackerSendScreen(getActivity(), String.format("News Reader Details Screen [%s]", title));

        String description = args.getString("description");
        TextView news_description = (TextView) rootView.findViewById(R.id.news_description);
        if (description != null) {
            news_description.setText(Html.fromHtml(description));
        }

        String imageUrl = args.getString("imageUrl");
        news_image = (NetworkImageView) rootView.findViewById(R.id.news_image);
        if (imageUrl != null) {
            news_image.setImageUrl(imageUrl, ImageCacheManager.getInstance().getImageLoader());
        } else {
            news_image.setVisibility(View.GONE);
        }
        news_image.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                checkImageHeight();
                ViewAnimation.collapse(v);
                // animate(v).setDuration(2000).scaleY(0);
            }
        });

        final GestureDetectorCompat mGestureDetector = new GestureDetectorCompat(getActivity(), new GestureDetector.SimpleOnGestureListener() {
            public int initHeight;
            public int initY;
            @Override
            public boolean onDown(MotionEvent e) {
                checkImageHeight();
                initHeight = news_image.getHeight();
                initY = (int) e.getRawY();
                return false;
            }

            @Override
            public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
                int diffY = (int) (e2.getRawY() - initY);
                int currentHeight = news_image.getHeight();
                boolean canExpand = diffY > 0 && scrollView.getScrollY() == 0 && currentHeight < news_image_height;
                boolean canCollapse = diffY < 0 && currentHeight > 0;

                if (canExpand || canCollapse) { //
                    int calcHeight = initHeight + diffY;
                    if (calcHeight > news_image_height) {
                        calcHeight = news_image_height;
                        initHeight = calcHeight;
                    } else if (calcHeight < 0)  {
                        calcHeight = 0;
                        initHeight = calcHeight;
                    }
                    if (scrollView.getScrollY() != 0) {
                        scrollView.scrollTo(0, 0);
                    }
                    news_image.setLayoutParams(new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, calcHeight));
                    return true;
                } else {
                    initY = (int) e2.getRawY();
                    initHeight = currentHeight;
                }
                return false;
            }

            @Override
            public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
                float diffY = e2.getRawY() - e1.getRawY();
                int currentHeight = news_image.getHeight();
                if (currentHeight > 0 && currentHeight < news_image_height) {
                    if (diffY > 0) {
                        ViewAnimation.expand(news_image, news_image_height);
                    } else {
                        ViewAnimation.collapse(news_image);
                    }
                    return true;
                }
                if (velocityY > 0) {
                    boolean canExpand = velocityY * 0.2 > scrollView.getScrollY();
                    Log.w("", "onFling " + (canExpand ? "[ON] expand" : "[OFF] stay close") + " image - Y: "  +velocityY +" "+  scrollView.getScrollY());
                    if (canExpand) ViewAnimation.expand(news_image, news_image_height);
                }
                return false;
            }
        });

        View.OnTouchListener onTouchView = new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                boolean onTouch = mGestureDetector.onTouchEvent(event);
                if (!onTouch) {
                    if (event.getAction() == MotionEvent.ACTION_UP) {
                        int currentHeight = news_image.getHeight();
                        if (currentHeight > 0 && currentHeight < news_image_height) {
                            if (news_image_height / 2 > currentHeight) {
                                ViewAnimation.collapse(news_image);
                            } else {
                                ViewAnimation.expand(news_image, news_image_height);
                            }
                            onTouch = true;
                        }
                    }
                }
                return onTouch;
            }
        };
        scrollView = (ScrollView) rootView.findViewById(R.id.scrollView);
        scrollView.setOnTouchListener(onTouchView);
        return rootView;
    }

    @Override
    public void onResume() {
        super.onResume();
        news_image.setMaxHeight(getResources().getDisplayMetrics().heightPixels / 5 * 2);
    }
    @Override
    public void update(ObservableRegisterer observable, int code, Bundle args) {
        //TODO complete
    }
}