onMeasure

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

        mRulerView.measure(widthMeasureSpec, heightMeasureSpec);
        mNowView.measure(widthMeasureSpec, heightMeasureSpec);

        final int width = mRulerView.getMeasuredWidth();
        final int height = mRulerView.getMeasuredHeight();

        for (int i = 0; i < getChildCount(); i++) {
            View child = getChildAt(i);
            if (child instanceof ScheduleItemView) {
                child.measure(widthMeasureSpec, heightMeasureSpec);
            }
        }

        setMeasuredDimension(resolveSize(width, widthMeasureSpec),
                resolveSize(height, heightMeasureSpec));
    }