Calendar and PagerAdapter - Unlimited Views

Question

In my activity, I\'m using ViewPager to swipe left/right and show month view accordingly. I\'m passing the month and year values from onCreate to the PagerAdapter:<

Answer 1

I have achieve to implement this but not perfectly by using each page as 3 fragments. When User swift right or left, It will set back to middle and update new data source for each fragment.

In Main

MonthViewContentFragment[] fragList = new MonthViewContentFragment[3];
fragList[0] = MonthViewContentFragment.newInstance(prevMonth);
fragList[1] = MonthViewContentFragment.newInstance(currentMonth);
fragList[2] = MonthViewContentFragment.newInstance(nextMonth);

ViewPager monthPage = (ViewPager) v.findViewById(R.id.monthview_content);
MonthPageAdapter monthPageAdapter = new MonthPageAdapter(getFragmentManager(), fragList);
monthPage.setAdapter(monthPageAdapter);
monthPage.setOnPageChangeListener(this);
monthPage.setCurrentItem(1, false);

in onPageScrollStateChanged

if (state == ViewPager.SCROLL_STATE_IDLE) {

    if (focusPage < PAGE_CENTER) {
        currentMonth.add(Calendar.MONTH, -1);
    } else if (focusPage > PAGE_CENTER) {
        currentMonth.add(Calendar.MONTH, 1);    
    }
    monthPageAdapter.setCalendar(currentMonth);
    monthPage.setCurrentItem(1, false);
    updateTitle();
}

in onPageSelected

public void onPageSelected(int position) {
        // TODO Auto-generated method stub
        focusPage = position;
}

In MonthPageAdapter

    MonthViewContentFragment[] fragList;    
    MonthViewContentFragment temp; 
    int fragNumber = 3;

    public MonthPageAdapter(FragmentManager fm, MonthViewContentFragment[] fragList) {
        super(fm);
        this.fragList = fragList;
    }

    @Override
    public int getItemPosition(Object object) {
        // TODO Auto-generated method stub
        return POSITION_NONE;
    }
    @Override
    public Fragment getItem(int position) {
        return fragList[position];      
    }

    @Override
    public int getCount() {
        return 3;
    }
    public void setCalendar(Calendar currentMonth) {

        Calendar prevMonth = Calendar.getInstance();
        prevMonth.setTime(currentMonth.getTime());
        prevMonth.add(Calendar.MONTH, -1);

        Calendar nextMonth = Calendar.getInstance();
        nextMonth.setTime(currentMonth.getTime());
        nextMonth.add(Calendar.MONTH, 1);
            //update all 3 fragments
        fragList[0].updateUI(prevMonth);
        fragList[1].updateUI(currentMonth);
        fragList[2].updateUI(nextMonth);
    }

In MonthViewContentFragment

    @Override
    public void updateUI(Calendar monthYear) {

        View v = getView();
        if (v == null)
            return;
        //setNewDataSource calcurate new List<String> date
        calendarViewAdapter.setNewDataSource(monthYear);
        calendarViewAdapter.notifyDataSetChanged();
    }

This is not perfect because when user swift too fast. The scroll is not change to idle yet then ViewPager reach its end.

Answer 2

I'm not sure i understand this (never used this viewPager, have always used another HorizontalViewSlider instead), but for your onPageScrollStateChanged() why do you have a special case for focusedPage==0 and focusedPage==2 ?

if nothing is special about Jan and March, maybe remove everything inside onPageScrollStateChanged() ?

my guess is that the flickering is from when you call setGridCellAdapter() because that will refresh the page from calling notifyDataSetChanged.