HorizontalScrollView滚到当前tab,并且居中显示

1、CustomSlidingTabLayout

public class CustomSlidingTabLayout extends HorizontalScrollView implements ViewPager.OnPageChangeListener {}
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HorizontalScrollView滚到当前tab,并且居中显示

    /**
     * HorizontalScrollView滚到当前tab,并且居中显示
     */
    private void scrollToCurrentTab() {
        if (mAdapter.getTabItemCount() <= 0) {
            return;
        }

        int tabItemPosition = mAdapter.getTabItemPositionByPagePosition(mCurrentPage);
        int offset = (int) (mCurrentPositionOffset * mTabsContainer.getChildAt(tabItemPosition).getWidth());
        /**当前Tab的left+当前Tab的Width乘以positionOffset*/
        int newScrollX = mTabsContainer.getChildAt(tabItemPosition).getLeft() + offset;
        if (mCurrentPage > 0 || offset > 0) {
            /**HorizontalScrollView移动到当前tab,并居中*/
            newScrollX -= getWidth() / 2 - getPaddingLeft();
            calcIndicatorRect();
            newScrollX += ((mTabRect.right - mTabRect.left) / 2);
        }

        if (newScrollX != mLastScrollX) {
            mLastScrollX = newScrollX;
            /** scrollTo（int x,int y）:x,y代表的不是坐标点,而是偏移量
             *  x:表示离起始位置的x水平方向的偏移量
             *  y:表示离起始位置的y垂直方向的偏移量
             */
            scrollTo(newScrollX, 0);
        }
    }

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2、SlidingTabLayout

public class SlidingTabLayout extends HorizontalScrollView implements ViewPager.OnPageChangeListener {}
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HorizontalScrollView滚到当前tab,并且居中显示：

 /**
     * HorizontalScrollView滚到当前tab,并且居中显示
     */
    private void scrollToCurrentTab() {
        if (mTabCount <= 0) {
            return;
        }

        int offset = (int) (mCurrentPositionOffset * mTabsContainer.getChildAt(mCurrentTab).getWidth());
        /**当前Tab的left+当前Tab的Width乘以positionOffset*/
        int newScrollX = mTabsContainer.getChildAt(mCurrentTab).getLeft() + offset;

        if (mCurrentTab > 0 || offset > 0) {
            /**HorizontalScrollView移动到当前tab,并居中*/
            newScrollX -= getWidth() / 2 - getPaddingLeft();
            calcIndicatorRect();
            newScrollX += ((mTabRect.right - mTabRect.left) / 2);
        }

        if (newScrollX != mLastScrollX) {
            mLastScrollX = newScrollX;
            /** scrollTo（int x,int y）:x,y代表的不是坐标点,而是偏移量
             *  x:表示离起始位置的x水平方向的偏移量
             *  y:表示离起始位置的y垂直方向的偏移量
             */
            scrollTo(newScrollX, 0);
        }
    }
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