ChildViewPager.java

package edu.hebtu.movingcampus.view;

import android.content.Context;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

public class ChildViewPager extends ViewPager {
	  /** the last x position */
    private float   lastX;

    /** if the first swipe was from left to right (->), dont listen to swipes from the right */
    private boolean slidingLeft;

    /** if the first swipe was from right to left (<-), dont listen to swipes from the left */
    private boolean slidingRight;

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

    public ChildViewPager(final Context context) {
        super(context);
    }

 
    @Override
    public boolean onTouchEvent(final MotionEvent ev) {
        final int action = ev.getAction();
        switch (action) {
            case MotionEvent.ACTION_DOWN:

                // Disallow parent ViewPager to intercept touch events.
                this.getParent().requestDisallowInterceptTouchEvent(true);

                // save the current x position
                this.lastX = ev.getX();

                break;

            case MotionEvent.ACTION_UP:
                // Allow parent ViewPager to intercept touch events.
                this.getParent().requestDisallowInterceptTouchEvent(false);

                // save the current x position
                this.lastX = ev.getX();

                // reset swipe actions
                this.slidingLeft = false;
                this.slidingRight = false;

                break;

            case MotionEvent.ACTION_MOVE:
                /*
                 * if this is the first item, scrolling from left to
                 * right should navigate in the surrounding ViewPager
                 */
                if (this.getCurrentItem() == 0) {
                    // swiping from left to right (->)?
                    if (this.lastX <= ev.getX() && !this.slidingRight) {
                        // make the parent touch interception active -> parent pager can swipe
                        this.getParent().requestDisallowInterceptTouchEvent(false);
                    } else {
                        /*
                         * if the first swipe was from right to left, dont listen to swipes
                         * from left to right. this fixes glitches where the user first swipes
                         * right, then left and the scrolling state gets reset
                         */
                        this.slidingRight = true;

                        // save the current x position
                        this.lastX = ev.getX();
                        this.getParent().requestDisallowInterceptTouchEvent(true);
                    }
                } else
                /*
                 * if this is the last item, scrolling from right to
                 * left should navigate in the surrounding ViewPager
                 */
                if (this.getCurrentItem() == this.getAdapter().getCount() - 1) {
                    // swiping from right to left (<-)?
                    if (this.lastX >= ev.getX() && !this.slidingLeft) {
                        // make the parent touch interception active -> parent pager can swipe
                        this.getParent().requestDisallowInterceptTouchEvent(false);
                    } else {
                        /*
                         * if the first swipe was from left to right, dont listen to swipes
                         * from right to left. this fixes glitches where the user first swipes
                         * left, then right and the scrolling state gets reset
                         */
                        this.slidingLeft = true;

                        // save the current x position
                        this.lastX = ev.getX();
                        this.getParent().requestDisallowInterceptTouchEvent(true);
                    }
                }

                break;
        }

        super.onTouchEvent(ev);
        return true;
    }
}