How to wrap the height of a ViewPager to the height of its current Fragment?

Question

I made a ScrollView containing a ViewPager, but the ViewPager does not grow in height. When the content inside the ViewPager is too big, it get \'pucht\'(?) inside, the tabl

Answer 1

in my case, i created imageslider with viewpager. initial value of child is null also at the end of index, value of child is null. so, i made some upgrades for repitch answer, because it didn't handle (child==null)

ViewPager now looks like:

public class WrapContentViewPager extends ViewPager {

    public WrapContentViewPager(Context context) {
        super(context);
        initPageChangeListener();
    }

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

    private void initPageChangeListener() {
        addOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                requestLayout();
            }
        });
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        View child = getChildAt(getCurrentItem());
        if (child != null) {
            child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
            int h = child.getMeasuredHeight();
            heightMeasureSpec = MeasureSpec.makeMeasureSpec(h, MeasureSpec.EXACTLY);
        } else {for(int i = 0; i < getChildCount(); i++) {
                View child2 = getChildAt(i);
                child2.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
                int h = child2.getMeasuredHeight();
                heightMeasureSpec = MeasureSpec.makeMeasureSpec(h, MeasureSpec.EXACTLY);
        }}
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

}

also, you can add amount of height whatever you want, if the last item of viewpager stick to circlepageindicator, like this : int h = child2.getMeasuredHeight()+50;

Answer 2

You can customize the ViewPager to resize the ViewPager to it's current page size on page swipe.

You can use the below code.

public class WrapContentViewPager extends ViewPager {

    private int mCurrentPagePosition = 0;

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

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

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        try {
            boolean wrapHeight = MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST;
            if (wrapHeight) {
                View child = getChildAt(mCurrentPagePosition);
                if (child != null) {
                child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
                int h = child.getMeasuredHeight();

                heightMeasureSpec = MeasureSpec.makeMeasureSpec(h, MeasureSpec.EXACTLY);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    public void reMeasureCurrentPage(int position) {
        mCurrentPagePosition = position;
        requestLayout();
    }
}

Declare it in xml:

    <your.package.name.WrapContentViewPager
            android:id="@+id/view_pager"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">
    </your.package.name.WrapContentViewPager>

After that call reMeasureCurrentpage function on page swipe.

final WrapContentViewPager wrapContentViewPager = (WrapContentViewPager) findViewById(R.id.view_pager);

wrapContentViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

    }

    @Override
    public void onPageSelected(int position) {
        wrapContentViewPager.reMeasureCurrentPage(wrapContentViewPager.getCurrentItem());
    }

    @Override
    public void onPageScrollStateChanged(int state) {

    }
});

Answer 3

I really liked @abhishek-v answer, but made some upgrades:

• addPageChangeListener(...) called inside our ViewPager (don't need to call reMeasureCurrentPage(...) manually outside on page swipe)
• don't need to store mCurrentPagePosition, because we can use getCurrentItem()
• removed waste try/catch block

ViewPager now looks like:

public class WrapContentViewPager extends ViewPager {

    public WrapContentViewPager(Context context) {
        super(context);
        initPageChangeListener();
    }

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

    private void initPageChangeListener() {
        addOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                requestLayout();
            }
        });
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        View child = getChildAt(getCurrentItem());
        if (child != null) {
            child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
            int h = child.getMeasuredHeight();
            heightMeasureSpec = MeasureSpec.makeMeasureSpec(h, MeasureSpec.EXACTLY);
        }
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

}

Answer 4

If these answer still can't fix the problem, I can provide another choice. At the PagerAdapter java file, you can measure the page height manually and set the container's LayoutParams.height in instantiateItem method. Like this:

@Override
public Object instantiateItem(@NonNull ViewGroup container, int position) {
    View view = generateView(mContext, position);
    view.measure(View.MeasureSpec.makeMeasureSpec(DensityUtil.getScreenWidth(mContext), View.MeasureSpec.EXACTLY), View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
    container.getLayoutParams().height = view.getMeasuredHeight();
    container.addView(view);
    return view;
}

Answer 5

Finally found a better solution for WrapContentViewPager!

The other solution contain some bug that hard to be solved, but I think this solution can be simply applied in our code

I found it on this site https://github.com/akhahaha/burn-android/blob/master/app/src/main/java/com/ucla/burn/android/WrapContentViewPager.java

Here is the code

public class WrapContentViewPager extends ViewPager {
        public WrapContentViewPager(Context context) {
            super(context);
        }

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

        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

            int height = 0;
            for (int i = 0; i < getChildCount(); i++) {
                View child = getChildAt(i);
                child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
                int h = child.getMeasuredHeight();
                if (h > height) height = h;
            }

            heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);

            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }
    }

Answer 6

On Android 8.0, you have to invoke another requestLayout to make it work:

....@Abhishek's answer

sharePager.post(new Runnable() {
            @Override
            public void run() {
                sharePager.requestLayout();
            }
        });