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

		pageHeight = getMeasuredHeight();

		final int count = getChildCount();
		for (int i = 0; i < count; i++) {
			// getChildAt(i).measure(MeasureSpec.makeMeasureSpec(getMeasuredWidth(),
			// MeasureSpec.EXACTLY),
			// MeasureSpec.makeMeasureSpec(pageHeight,
			// MeasureSpec.UNSPECIFIED));
			getChildAt(i).measure(
					MeasureSpec.makeMeasureSpec(getMeasuredWidth(),
							MeasureSpec.EXACTLY),
					MeasureSpec
							.makeMeasureSpec(pageHeight, MeasureSpec.EXACTLY));
		}

		if (mFirstLayout) {
			scrollTo(getScrollYForPage(mCurrentPage), 0);
			mFirstLayout = false;
		}
	}
Gets the value that getScrollX() should return if the specified page is
the current page (and no other scrolling is occurring). Use this to pass
a value to scrollTo(), for example.

@param whichPage
@return
app/src/main/java/pro/alexzaitsev/freepager/library/view/core/VerticalPager.java