I have used Custom ViewPager which extends Viewpager . I have used gesture detector to do the scroll event.
here is my code,
public class VerticalViewPager extends ViewPager {
private GestureDetector gestureDetector;
public boolean isScrollEvent;
public VerticalViewPager(Context context) {
super(context);
init();
}
public VerticalViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init() {
gestureDetector=new GestureDetector(getContext(),new GestureListener());
setPageTransformer(true, new VerticalPageTransformer());
setOverScrollMode(OVER_SCROLL_NEVER);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
boolean res=gestureDetector.onTouchEvent((ev));
Log.d("event", "interceotontouch " + res);
return res;
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
boolean res= gestureDetector.onTouchEvent((ev));
if((ev.getAction() == MotionEvent.ACTION_CANCEL ||ev.getAction()==MotionEvent.ACTION_UP)) {
if(isScrollEvent) {
try {
endFakeDrag();
} catch (Exception e) {}
}
return true;
}
Log.d("event", "ontouch "+res);
return res;
}
public void setScrollDuration(int duration) {
mScroller.setScrollDuration(duration);
}
private final class GestureListener extends GestureDetector.SimpleOnGestureListener {
@Override
public boolean onSingleTapUp(MotionEvent e) {
isScrollEvent=false;
Log.d("touch","singletap");
return false;
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
Log.d("touch","fling");
isScrollEvent=false;
try {
float diffY = e2.getY() - e1.getY();
if (diffY > 20) {
onSwipeDown();
return false;
} else if(diffY<-20){
onSwipeUp();
return false;
}
else
{
endFakeDrag();
int id = getCurrentItem();
setCurrentItem(id, true);
}
} catch (Exception exception) {
exception.printStackTrace();
}
return false;
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
Log.d("touch", "scroll" + " " + distanceX);
beginFakeDrag();
fakeDragBy(-distanceY);
isScrollEvent=true;
return true;
}
}
public void onSwipeUp() {
setCurrentItem(getCurrentItem() + 1);
}
public void onSwipeDown() {
setCurrentItem(getCurrentItem() - 1);
}
}
And this is my PageTranformer,
public class VerticalPageTransformer implements android.support.v4.view.ViewPager.PageTransformer {
@Override
public void transformPage(View view, float position) {
final float MIN_SCALE = 0.85f;
final float MIN_ALPHA = 0.5f;
if (position < -1) {
view.setAlpha(0);
} else if (position <= 0) { // [-1,0]
view.setAlpha(1);
view.setTranslationX(-1 * view.getWidth() * position);
float yPosition = position * view.getHeight();
view.setTranslationY(yPosition);
view.setScaleX(1);
view.setScaleY(1);
} else if (position <= 1) { // (0,1]
view.setAlpha(1 - position);
view.setTranslationX(-1 * view.getWidth() * position);
float scaleFactor = MIN_SCALE + (1 - MIN_SCALE) * (1 - Math.abs(position));
view.setScaleX(scaleFactor);
view.setScaleY(scaleFactor);
} else {
view.setAlpha(0);
}
}
}
Everything works fine. But the problem is , When I click something in the current page, onClick() event invoked. But it doesn't update the view. The view gets updated after changing the page.
This is my adapter,
public class MainViewPagerAdapter extends PagerAdapter {
private Context context;
private List<NHBean> newslist = new ArrayList<>();
ImageLoader imageLoader;
List<String> list = new ArrayList<String>();
SharedPreferences preferences;
SimpleDateFormat dateTimeFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
SimpleDateFormat displayFormat = new SimpleDateFormat("MMM dd, hh:mm a");
public MainViewPagerAdapter(Context context) {
this.context = context;
preferences = context.getSharedPreferences("NewsUpdatePref", Context.MODE_PRIVATE);
imageLoader = new ImageLoader(context);
String serialized = preferences.getString("BOOKMARKS", null);
if (serialized != null)
list.addAll(Arrays.asList(TextUtils.split(serialized, ",")));
}
public void addItems(List<NHBean> newslist) {
this.newslist.clear();
this.newslist.addAll(newslist);
notifyDataSetChanged();
}
@Override
public Object instantiateItem(final ViewGroup collection, int position) {
LayoutInflater inflater = LayoutInflater.from(context);
final NHBean nhBean = newslist.get(position);
Log.d("ImageURL"+position,nhBean.getImageUrl());
ViewGroup layout;
layout= (ViewGroup) inflater.inflate(R.layout.page, collection, false);
TextView text = (TextView) layout.findViewById(R.id.text);
TextView timeText = (TextView) layout.findViewById(R.id.time_text);
TextView textHead = (TextView) layout.findViewById(R.id.text_head);
ImageView shareNews = layout. findViewById(R.id.share_news);
ImageView firstPage = layout. findViewById(R.id.first_page);
final ImageView bookmark=layout.findViewById(R.id.bookmark);
firstPage.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
((MainActivity)context).moveToFirstPage();
}
});
shareNews.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//code for share
}
}
});
bookmark.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.d("clicked","yes");
if (list.contains(nhBean.getDate())) {
list.remove(nhBean.getDate());
bookmark.setImageResource(R.drawable.bookmark_not_added);
} else {
bookmark.setImageResource(R.drawable.bookmark_added);
list.add(nhBean.getDate());
}
preferences.edit().putString("BOOKMARKS", TextUtils.join(",", list)).apply();
}
});
try {
timeText.setText(displayFormat.format(dateTimeFormat.parse(nhBean.getDate())));
} catch (Exception e) {
}
text.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
((MainActivity) context).setToolBarVisibility();
}
});
if (list.contains(nhBean.getDate())) {
bookmark.setImageResource(R.drawable.bookmark_added);
} else {
bookmark.setImageResource(R.drawable.bookmark_not_added);
}
textHead.setText(nhBean.getHeadline());
text.setText(nhBean.getContent() + "\n");
textHead.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(context, WebViewActivity.class);
intent.putExtra("text_head", nhBean.getHeadline());
intent.putExtra("news_url", nhBean.getNewsUrl());
context.startActivity(intent);
}
});
collection.addView(layout);
return layout;
}
@Override
public void destroyItem(ViewGroup collection, int position, Object view) {
collection.removeView((View)view);
}
@Override
public int getCount() {
return newslist.size();
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
@Override
public CharSequence getPageTitle(int position) {
return null;
}
public NHBean getItem(int position) {
return newslist.get(position);
}
}
When I click these buttons, the onClick() is invoked. Look at bookmark button onclick, setImageResource() is not done. But surprisingly when I scroll, the button image is changed.
Edit:
My MainActivity code,
mainViewPager = findViewById(R.id.flip_view);
mainViewPagerAdapter = new MainViewPagerAdapter(this);
mainViewPager.setAdapter(mainViewPagerAdapter);
mainViewPager.setScrollDuration(300);
mainViewPager.addOnPageChangeListener(new VerticalViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {}
@Override
public void onPageSelected(int position) {
if (position != 0 || !toolbar.getTitle().toString().equals(getString(R.string.allnews))) {
swipeRefreshLayout.setEnabled(false);
} else
swipeRefreshLayout.setEnabled(true);
}
@Override
public void onPageScrollStateChanged(int state) {
}
});
updateNews();
And the method code,
public void updateNews() {
try {
final ArrayList<NHBean> headlines_1 = DBHelper.getInstance(this).getHeadlines();
mainViewPagerAdapter.addItems(headlines_1);
swipeRefreshLayout.setRefreshing(false);
} catch (Throwable e) {
e.printStackTrace();
}
}
And also the start animation for each page gets stuck when the page is selected.
Help me !!! Thanks in advance
The problem is not with the code,
I have used android:hardwareAccelerated="false" in Manifest. After lots of research, I found this.
I just changed,
android:hardwareAccelerated="true"
which solved my problem.