Question

I use android.support.v4.app.FragmentActivity for create a app with multi fragment/panels that can be access by drag/swipe between different part of the app.
In one of my fragment I has a zoomable view and my problem is in case I is on the zoomable view I will prevent the use for drag/swipe to a other fragment.

I has try to hack into android.support.v4.view.ViewPager for get the action from on Touch event but not work.

I has try all of this case but not work:
(All code is a a part of subclass to android.support.v4.view.ViewPager)

Case 1:

// Not working
@Override
protected void onPageScrolled(int position, float offset, int offsetPixels) {
    if (isPreventDrag()) {
        super.onPageScrolled(position, 1, 0);
    } else {
        super.onPageScrolled(position, offset, offsetPixels);
    }
}

Case 2:

// Work but stop all event include the event to the target image view.
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    switch (ev.getAction()) {
        case MotionEvent.ACTION_DOWN:
            lastX = ev.getX(); // float 
            lockScroll = false;
            return super.onInterceptTouchEvent(ev);
        case MotionEvent.ACTION_MOVE:
            this.lockScroll = this.isPreventDrag();
            break;
    }
    if (lockScroll) {
        ev.setLocation(lastX, ev.getY());
        return super.onInterceptTouchEvent(ev);
    } else {
        return super.onInterceptTouchEvent(ev);
    }
}

Case 3:

// Work good, but by some unknown error I can drag the screen
// some pixels before this stop the event.
@Override
public boolean onTouchEvent(MotionEvent ev) {

    if (this.isPreventDrag()) {
        return true;
    } else {
        return super.onTouchEvent(ev);
    }
}

I want a easy way to deactivate stop or deactivate if the use is allow to switch to a other Fragment.

Here is a working code for me, I don’t know what error I do before.

// This work for me,
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    if (this.isPreventDrag()) {
        return false;
    } else {
        return super.onInterceptTouchEvent(ev);
    }
}

Answer 1

I use this ViewPager class to control ‘swipeability’ of viewpager:

public class MyViewPager extends ViewPager {

    public MyViewPager(Context context) {
        super(context);
    }

    public MyViewPager(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    private boolean blockSwipe = false;
    public void setBlockSwipe(boolean blockSwipe) {
        this.blockSwipe = blockSwipe;
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent arg0) {
        if (blockSwipe)
            return false;
        else 
            return super.onInterceptTouchEvent(arg0);
    }

}