Question

I’m using WebView in ViewPager to display images from internet. WebView is used because of it’s built in zoom controls. I want to enable my users to zoom images in pager, but when they swipe to the next image, to restore original zoom on previous image.
I tried few things, from which only one gives me the funcionality I desire, but it is not a good enough solution, because there is a blinking when swipeing through pages.

mPager.setOnPageChangeListener(new OnPageChangeListener(
            ) {

        @Override
        public void onPageSelected(int arg0) {
            currImg = arg0;
            //System.out.println("On page selected");
        }

        @Override
        public void onPageScrolled(int arg0, float arg1, int arg2) {
            // TODO Auto-generated method stub
            //System.out.println("On page scrolled");

        }

        @Override
        public void onPageScrollStateChanged(int arg0) {
            // TODO Auto-generated method stub
            if(arg0 == 2) {
                //mPager.getAdapter().
                mPager.getAdapter().notifyDataSetChanged();
                System.out.println("Notifying Data Set Changed " + mPager.getCurrentItem());
            }

        }
    });

In ViewPager adapter I have overrided getItemPosition so it would return POSITON_NONE.
This is not a good solution because pages are refreshed on every swipe and there is no smooth transition between pages. Any suggestions are welcome.

Answer 1

This has shown to be a best way to revert the page to initial zoom state:

    pager.setOnPageChangeListener(new OnPageChangeListener() {
        public void onPageScrollStateChanged(int arg0) {}
        public void onPageScrolled(int arg0, float arg1, int arg2) {}
        public void onPageSelected(int arg0) {
            System.out.println("onPageSelected -> arg0 = " + arg0);

            if (currPage != arg0) {
                mAdapter.notifyDataSetChanged();
                currPage = arg0;
            }
        }
    });

Than, in your adapter class you override getItemPosition method like this:

@Override
public int getItemPosition(Object object) {
    if (((ExtendedWebView) object).getScale() != webScale) {
        return POSITION_NONE;
    }
    return POSITION_UNCHANGED;
}