Android自定义控件之RecyclerView打造万能ViewPager TabLayout(仿今日头条Tab滑动、Tab多布局、indicator蠕动、自定义indicator、文字颜色渐变、自定义Fragment)

allprojects {
		repositories {
			        maven { url 'https://www.jitpack.io' }
		}
	}

dependencies {
api 'com.github.AnJiaoDe:TabLayoutNiubility:V1.2.8'
}

api 'androidx.viewpager2:viewpager2:1.0.0'//版本必须>=1.0.0

    ViewPager2 viewPager2 = findViewById(R.id.view_pager);
        TabLayoutNoScroll tabLayoutLine = findViewById(R.id.tablayout);
//        tabLayoutLine.setSpace_horizontal(0).setSpace_vertical(0);
        FragPageAdapterVp2NoScroll<String> fragmentPageAdapter = new FragPageAdapterVp2NoScroll<String>(this) {
            @Override
            public Fragment createFragment(String bean, int position) {
                return FragmentTab2.newInstance(FragmentTab2.TAB_NAME2, getList_bean().get(position));
            }

            @Override
            public void bindDataToTab(TabNoScrollViewHolder holder, int position, String bean, boolean isSelected) {
                TextView textView = holder.getView(R.id.tv);
                if (isSelected) {
                    textView.setTextColor(0xffe45540);
                    textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD));
                } else {
                    textView.setTextColor(0xff444444);
                    textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL));
                }
                textView.setText(bean);
            }

            @Override
            public int getTabLayoutID(int position, String bean) {
                return R.layout.item_tab_center;
            }
        };

        TabAdapterNoScroll<String> tabAdapter = new TabMediatorVp2NoScroll<String>(tabLayoutLine, viewPager2).setAdapter(fragmentPageAdapter);

        List<String> list = new ArrayList<>();
        list.add("关注");
        list.add("推荐");
        list.add("上课");
        list.add("抗疫");
        fragmentPageAdapter.add(list);
        tabAdapter.add(list);

            @Override
            public int getTabLayoutID(int position, String bean) {
                if (position == 0) {
                    return R.layout.item_tab_msg;
                }
                return R.layout.item_tab;
            }

   ViewPager2 viewPager2 = findViewById(R.id.view_pager);
        TabLayoutScroll tabLayoutLine = findViewById(R.id.tablayout);
//        tabLayoutLine.setSpace_horizontal(dpAdapt(20)).setSpace_vertical(dpAdapt(8));
        FragPageAdapterVp2<String> fragmentPageAdapter = new FragPageAdapterVp2<String>(this) {

            @Override
            public Fragment createFragment(String bean, int position) {
                return FragmentTab2.newInstance(FragmentTab2.TAB_NAME2, getList_bean().get(position));
            }

            @Override
            public void bindDataToTab(TabViewHolder holder, int position, String bean, boolean isSelected) {
                TextView textView = holder.getView(R.id.tv);
                if (isSelected) {
                    textView.setTextColor(0xffe45540);
                    textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD));
                } else {
                    textView.setTextColor(0xff444444);
                    textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL));
                }
                textView.setText(bean);
            }

            @Override
            public int getTabLayoutID(int position, String bean) {
                if (position == 0) {
                    return R.layout.item_tab_msg;
                }
                return R.layout.item_tab;
            }
        };
        TabAdapter<String> tabAdapter = new TabMediatorVp2<String>(tabLayoutLine, viewPager2).setAdapter(fragmentPageAdapter);

        List<String> list = new ArrayList<>();
        list.add("关注");
        list.add("推荐");
        list.add("视频");
        list.add("抗疫");
        list.add("酷玩");
        list.add("彩票");
        list.add("漫画");
        fragmentPageAdapter.add(list);
        tabAdapter.add(list);

   ViewPager2 viewPager2= findViewById(R.id.view_pager);
        TabLayoutScroll tabLayoutNiubility= findViewById(R.id.tablayout);

//        tabLayoutTriangle.setSpace_horizontal(dpAdapt(20)).setSpace_vertical(dpAdapt(8));
        FragPageAdapterVp2<String> fragmentPageAdapter = new FragPageAdapterVp2<String>(this) {

            @Override
            public Fragment createFragment(String bean, int position) {
                return FragmentTab2.newInstance(FragmentTab2.TAB_NAME2, getList_bean().get(position));
            }

            @Override
            public void bindDataToTab(TabViewHolder holder, int position, String bean, boolean isSelected) {
                TextView textView = holder.getView(R.id.tv);
                if (isSelected) {
                    textView.setTextColor(0xffe45540);
                    textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD));
                } else {
                    textView.setTextColor(0xff444444);
                    textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL));
                }
                textView.setText(bean);
            }

            @Override
            public int getTabLayoutID(int position, String bean) {
                return R.layout.item_tab;
            }
        };

        TabAdapter<String> tabAdapter = new TabMediatorVp2<String>(tabLayoutNiubility, viewPager2).setAdapter(fragmentPageAdapter);

        List<String> list = new ArrayList<>();
        list.add("关注");
        list.add("推荐");
        list.add("彩票");
        list.add("漫画");
        fragmentPageAdapter.add(list);
        tabAdapter.add(list);

  ViewPager viewPager= findViewById(R.id.view_pager);
        TabLayoutScroll tabLayoutLine= findViewById(R.id.tablayout);

//        tabLayoutLine.setSpace_horizontal(dpAdapt(20)).setSpace_vertical(dpAdapt(8));
        FragPageAdapterVp<String> fragmentPageAdapter = new FragPageAdapterVp<String>(getSupportFragmentManager(),
                FragmentStatePagerAdapter.BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT) {
            @Override
            public Fragment createFragment(String bean, int position) {
                return FragmentTab1.newInstance(FragmentTab1.TAB_NAME1, getList_bean().get(position));
            }

            @Override
            public void bindDataToTab(TabViewHolder holder, int position, String bean, boolean isSelected) {
                TextView textView = holder.getView(R.id.tv);
                if (isSelected) {
                    textView.setTextColor(0xffe45540);
                    textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD));
                } else {
                    textView.setTextColor(0xff444444);
                    textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL));
                }
                textView.setText(bean);
            }

            @Override
            public int getTabLayoutID(int position, String bean) {
                if (position == 0) {
                    return R.layout.item_tab_msg;
                }
                return R.layout.item_tab;
            }
        };

        TabAdapter<String> tabAdapter = new TabMediatorVp<String>(tabLayoutLine, viewPager).setAdapter(fragmentPageAdapter);

        List<String> list = new ArrayList<>();
        list.add("关注");
        list.add("推荐");
        list.add("酷玩");
        list.add("彩票");
        list.add("漫画");
        fragmentPageAdapter.add(list);
        tabAdapter.add(list);

 ViewPager2 viewPager2= findViewById(R.id.view_pager);
        TabLayoutNoScroll tabLayoutNoScroll= findViewById(R.id.tablayout);
        FragPageAdapterVp2NoScroll<TabBean> fragmentPageAdapter = new FragPageAdapterVp2NoScroll<TabBean>(this) {

            @Override
            public Fragment createFragment(TabBean bean, int position) {
                return FragmentTab2.newInstance(FragmentTab2.TAB_NAME2, getList_bean().get(position).getText());
            }

            @Override
            public void bindDataToTab(TabNoScrollViewHolder holder, int position, TabBean bean, boolean isSelected) {
                TextView textView = holder.getView(R.id.tv);
                if (isSelected) {
                    textView.setTextColor(0xff00ff00);
                    holder.setImageResource(R.id.iv,bean.getResID_selected());
                } else {
                    textView.setTextColor(0xff444444);
                    holder.setImageResource(R.id.iv,bean.getResID_normal());
                }
                textView.setText(bean.getText());
            }

            @Override
            public int getTabLayoutID(int position, TabBean bean) {
                if (position == 2) {
                    return R.layout.item_tab_main_circle;
                }
                return R.layout.item_tab_main;
            }
        };

        TabAdapterNoScroll<TabBean> tabAdapter = new TabMediatorVp2NoScroll<TabBean>(tabLayoutNoScroll, viewPager2).setAdapter(fragmentPageAdapter);

        List<TabBean> list = new ArrayList<>();
        list.add(new TabBean("消息",R.drawable.msg,R.drawable.msg_selected));
        list.add(new TabBean("通讯录",R.drawable.friends,R.drawable.friends_selected));
        list.add(new TabBean("朋友圈",R.drawable.circle,R.drawable.circle_selected));
        list.add(new TabBean("我",R.drawable.my,R.drawable.my_selected));
        fragmentPageAdapter.add(list);
        tabAdapter.add(list);

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

  @Override
    public Object instantiateItem(@NonNull ViewGroup container, int position) {
        // If we already have this item instantiated, there is nothing
        // to do.  This can happen when we are restoring the entire pager
        // from its saved state, where the fragment manager has already
        // taken care of restoring the fragments we previously had instantiated.
        if (mFragments.size() > position) {
            Fragment f = mFragments.get(position);
            if (f != null) {
                return f;
            }
        }

        if (mCurTransaction == null) {
            mCurTransaction = mFragmentManager.beginTransaction();
        }

        Fragment fragment = getItem(position);
        if (DEBUG) Log.v(TAG, "Adding item #" + position + ": f=" + fragment);
        if (mSavedState.size() > position) {
            Fragment.SavedState fss = mSavedState.get(position);
            if (fss != null) {
                fragment.setInitialSavedState(fss);
            }
        }
        while (mFragments.size() <= position) {
            mFragments.add(null);
        }
        fragment.setMenuVisibility(false);
        if (mBehavior == BEHAVIOR_SET_USER_VISIBLE_HINT) {
            fragment.setUserVisibleHint(false);
        }

        mFragments.set(position, fragment);
        mCurTransaction.add(container.getId(), fragment);

        if (mBehavior == BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT) {
            mCurTransaction.setMaxLifecycle(fragment, Lifecycle.State.STARTED);
        }

        return fragment;
    }

 if (mFragments.size() > position) {
            Fragment f = mFragments.get(position);
            if (f != null) {
                return f;
            }
        }

private void ensureFragment(int position) {
        long itemId = getItemId(position);
//        if (!mFragments.containsKey(itemId)) {
            // TODO(133419201): check if a Fragment provided here is a new Fragment
            Fragment newFragment = createFragment(position);
            newFragment.setInitialSavedState(mSavedStates.get(itemId));
            mFragments.put(itemId, newFragment);
//        }
    }

public abstract class PageContainer {
    protected View view;
    protected Context context;
    private PageContainerChildManager pageContainerChildManager=new PageContainerChildManager();
    private PageContainer pageContainerParent;

    public PageContainer(PageContainer pageContainerParent) {
        this.pageContainerParent = pageContainerParent;
    }

    public Context getContext() {
        return context;
    }

    public View getView() {
        return view;
    }

    public abstract View onCreateView(LayoutInflater layoutInflater, ViewGroup container);

    public  void onResume(boolean isFirstResume){}

    public  void onStop(){}

    public  void onDestroyView(){}

    public final PageContainerChildManager getPageContainerChildManager() {
        return pageContainerChildManager;
    }

    public final PageContainer getPageContainerParent() {
        return pageContainerParent;
    }
}

public class PageContainerTab2 extends PageContainer {
    private View view;
    private String bean;

    public PageContainerTab2(PageContainer pageContainerParent,String bean) {
        super(pageContainerParent);
        this.bean = bean;
    }

    @Override
    public View onCreateView(LayoutInflater layoutInflater, ViewGroup container) {
        view=layoutInflater.inflate(R.layout.fragment_tab2, container, false);
        LogUtils.log("onCreateView",bean);
        TextView textView = view.findViewById(R.id.tv);
        textView.setText(bean);
        return view;
    }

    @Override
    public void onResume(boolean isFirstResume) {
        super.onResume(isFirstResume);
        LogUtils.log("onResumetab2",bean+isFirstResume);
    }

    @Override
    public void onStop() {
        super.onStop();
        LogUtils.log("onStop",bean);

    }

    @Override
    public void onDestroyView() {
        super.onDestroyView();
        LogUtils.log("onDestroyViewPageContainerTab2",bean);

    }
}

tabLayoutScroll.getIndicatorView().getIndicator().setColor_indicator();

/**
     * 设置indicator进度
     * @param progress
     * @return
     */
    public Indicator setProgress(int progress) {
        this.progress = progress;
        viewIndicator.invalidate();
        return  this;
    }

    public int getProgress() {
        return progress;
    }

    public int getWidth_indicator_max() {
        return width_indicator_max;
    }

    /**
     * 设置indicator最大长度
     * @param width_indicator_max
     * @return
     */
    public Indicator setWidth_indicator_max(int width_indicator_max) {
        this.width_indicator_max = width_indicator_max;
        return  this;
    }

    /**
     * 设置indicator颜色
     * @param color_indicator
     * @return
     */
    public Indicator setColor_indicator(int color_indicator) {
        paint_indicator.setColor(color_indicator);
        return  this;
    }

    /**
     * 设置indicator高度
     * @param height_indicator
     * @return
     */
    public Indicator setHeight_indicator(int height_indicator) {
        this.height_indicator = height_indicator;
        return  this;
    }

    public int getHeight_indicator() {
        return height_indicator;
    }

    public Paint getPaint_indicator() {
        return paint_indicator;
    }

    /**
     * 设置indicator选中时的长度
     * @param width_indicator_selected
     * @return
     */
    public Indicator setWidth_indicator_selected(int width_indicator_selected) {
        this.width_indicator_selected = width_indicator_selected;
        return  this;
    }

    public int getWidth_indicator_selected() {
        return width_indicator_selected;
    }

    public int getWidth_indicator() {
        return width_indicator;
    }

    /**
     * 设置indicator当前长度
     * @param width_indicator
     * @return
     */
    public Indicator setWidth_indicator(int width_indicator) {
        this.width_indicator = Math.min(width_indicator_max, width_indicator);
        return  this;
    }

public class IndicatorTriangleView extends View implements IIndicatorView {
    private Path path;
    private Indicator indicator;
    private int height;
    public IndicatorTriangleView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        indicator=new Indicator(this);
        //实例化路径
        path = new Path();

        indicator=new Indicator(this);

        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.IndicatorTriangleView);

        indicator.setWidth_indicator_selected(typedArray.getDimensionPixelSize(R.styleable.IndicatorTriangleView_width_indicator_selected, ScreenUtils.dpAdapt(context,12)));
        indicator.setWidth_indicator_max(typedArray.getDimensionPixelSize(R.styleable.IndicatorTriangleView_width_indicator_max, ScreenUtils.dpAdapt(context,48)));
        indicator.setHeight_indicator(typedArray.getDimensionPixelSize(R.styleable.IndicatorTriangleView_height_indicator, ScreenUtils.dpAdapt(context,6)));
        indicator.setColor_indicator(typedArray.getColor(R.styleable.IndicatorTriangleView_color_indicator, 0xffe45540));

        indicator.setWidth_indicator(ScreenUtils.dpAdapt(context,30));
        typedArray.recycle();

    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
        height=getHeight();
    }

    @Override
    public <T extends View> T getView() {
        return (T) this;
    }

    @Override
    public Indicator getIndicator() {
        return indicator;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        path.reset();
        path.moveTo(indicator.getProgress(), height);// 此点为多边形的起点
        path.lineTo(indicator.getProgress() + indicator.getWidth_indicator() * 1f / 2, height - indicator.getHeight_indicator());
        path.lineTo(indicator.getProgress() + indicator.getWidth_indicator(), height);
        path.close(); // 使这些点构成封闭的多边形
        indicator.getPaint_indicator().setStyle(Paint.Style.FILL);
        canvas.drawPath(path, indicator.getPaint_indicator());
    }
}

   /**
         * This method will be invoked when the current page is scrolled, either as part
         * of a programmatically initiated smooth scroll or a user initiated touch scroll.
         *
         * @param position Position index of the first page currently being displayed.
         *                 Page position+1 will be visible if positionOffset is nonzero.
         * @param positionOffset Value from [0, 1) indicating the offset from the page at position.
         * @param positionOffsetPixels Value in pixels indicating the offset from position.
         */
        public void onPageScrolled(int position, float positionOffset,
                @Px int positionOffsetPixels) {
        }

        /**
         * This method will be invoked when a new page becomes selected. Animation is not
         * necessarily complete.
         *
         * @param position Position index of the new selected page.
         */
        public void onPageSelected(int position) {
        }

        /**
         * Called when the scroll state changes. Useful for discovering when the user begins
         * dragging, when a fake drag is started, when the pager is automatically settling to the
         * current page, or when it is fully stopped/idle. {@code state} can be one of {@link
         * #SCROLL_STATE_IDLE}, {@link #SCROLL_STATE_DRAGGING} or {@link #SCROLL_STATE_SETTLING}.
         */
        public void onPageScrollStateChanged(@ScrollState int state) {
        }

public class HorizontalRecyclerView extends RecyclerView {
    private LinearItemDecoration linearItemDecoration;
    //永远<=0
    private int offsetX = 0;
    public HorizontalRecyclerView(Context context) {
        this(context, null);
    }

    public HorizontalRecyclerView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        addOnScrollListener(new OnScrollListener() {
            @Override
            public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);
                offsetX -= dx;
            }

        });
        SimpleItemAnimator simpleItemAnimator = (SimpleItemAnimator) getItemAnimator();
        if (simpleItemAnimator != null) simpleItemAnimator.setSupportsChangeAnimations(false);

    }

    /**
     * x为正，表示手指往左滑,x为负，表示手指往右滑
     *
     * @param x
     * @param y
     */
    @Override
    public void scrollBy(int x, int y) {
        super.scrollBy(x, y);
    }

    /**
     * x<=0
     * 比如 x=0,表示滑动到RecyclerView最左边，完全显示第一个item,
     * 比如 x=-100,表示RecyclerView左边100像素的界面被隐藏
     *
     * @param x
     * @param y
     */
    @Override
    public void scrollTo(int x, int y) {
        scrollBy(offsetX - x, y);
    }

    public int getOffsetX() {
        return offsetX;
    }


    @Override
    public void setAdapter(Adapter adapter) {
        setLayoutManager(new LinearLayoutManager(getContext(), LinearLayoutManager.HORIZONTAL, false));
        super.setAdapter(adapter);
    }
}

package com.cy.tablayoutniubility;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import androidx.viewpager2.widget.ViewPager2;

import static androidx.viewpager2.widget.ViewPager2.SCROLL_STATE_IDLE;

/**
 * @Description:
 * @Author: cy
 * @CreateDate: 2020/7/29 18:42
 * @UpdateUser:
 * @UpdateDate: 2020/7/29 18:42
 * @UpdateRemark:
 * @Version:
 */
public class TabLayoutMediatorVp2
    {
    
   private 
   TabLayoutNiubility tabLayout;
    
   private 
   ViewPager2 viewPager2;
    
   private 
   TabAdapter<T> tabAdapter;
    
   private 
   int position_scroll_last 
   = 
   0;
    
   private 
   int diff 
   = 
   0;
    
   private 
   int diff_click 
   = 
   0;
    
   private 
   int toScroll 
   = 
   0;
    
   private 
   int offsetX_last 
   = 
   0;
    
   private 
   int offsetX_last_click 
   = 
   0;
    
   private 
   int offsetX_touch 
   = 
   0;
    
   private 
   boolean rvScrolledByVp 
   = 
   false;
    
   private 
   boolean rvScrolledByTouch 
   = 
   false;
    
   private 
   boolean scrolledByClick 
   = 
   false;
    
   private 
   int position_selected_last 
   = 
   0;
    
   private 
   boolean op_click_last 
   = 
   false;
    
   private 
   int click_position_last 
   = 
   -
   1;

    
   public 
   TabLayoutMediatorVp2(
   TabLayoutNiubility 
   tabLayout, 
   final 
   ViewPager2 
   viewPager2) {
        
   this
   .tabLayout 
   = tabLayout;
        
   this
   .viewPager2 
   = viewPager2;
    }

    
   public 
   TabAdapter<T> 
   setAdapter(
   final 
   FragmentPageAdapterVp2<T> 
   fragmentPageAdapter) {
        tabAdapter 
   = 
   new 
   TabAdapter<T>() {
            
   @Override
            
   public 
   void 
   bindDataToView(
   TabViewHolder 
   holder, 
   int 
   position, 
   T 
   bean, 
   boolean 
   isSelected) {
                fragmentPageAdapter
   .bindDataToTab( holder, position, bean, isSelected);
            }

            
   @Override
            
   public 
   int 
   getItemLayoutID(
   int 
   position, 
   T 
   bean) {
                
   return fragmentPageAdapter
   .getTabLayoutID(position, bean);
            }

            
   @Override
            
   public 
   void 
   onItemClick(
   TabViewHolder 
   holder, 
   int 
   position, 
   T 
   bean) {
                
   //点击tabLayout的item,会先回调onPageSelected,然后回调onPageScrolled
                
   //标志复位
                rvScrolledByTouch 
   = 
   false;
                offsetX_touch 
   = 
   0;
                
   //标志：tablayout的滑动是由点击item触发的
                scrolledByClick 
   = 
   true;
                position_selected_last 
   = viewPager2
   .getCurrentItem();
                viewPager2
   .setCurrentItem(position);
                
   //让indicator立马指向currentItem
                
   RecyclerView
   .
   ViewHolder viewHolder 
   = tabLayout
   .getHorizontalRecyclerView()
   .findViewHolderForAdapterPosition(viewPager2
   .getCurrentItem());
                
   if (viewHolder 
   != 
   null) {

                    tabLayout
   .getIndicatorView()
   .getIndicator()
   .setWidth_indicator(tabLayout
   .getIndicatorView()
   .getIndicator()
   .getWidth_indicator_selected())
                            .setProgress((
   int) (viewHolder
   .itemView
   .getLeft()
                                    
   + viewHolder
   .itemView
   .getWidth() 
   * 
   1f 
   / 
   2
                                    
   - tabLayout
   .getIndicatorView()
   .getIndicator()
   .getWidth_indicator() 
   / 
   2));

                } 
   else {
                    
   //不可见，width_indicator为0
                    tabLayout
   .getIndicatorView()
   .getIndicator()
   .setWidth_indicator(
   0)
   .invalidate();
                }
                fragmentPageAdapter
   .onTabClick( holder, position, bean);
            }
        };


        tabLayout
   .getHorizontalRecyclerView()
   .addOnScrollListener(
   new 
   RecyclerView.
   OnScrollListener() {
            
   @Override
            
   public 
   void 
   onScrolled(
   @NonNull 
   RecyclerView 
   recyclerView, 
   int 
   dx, 
   int 
   dy) {
                
   super
   .onScrolled(recyclerView, dx, dy);
                
   //如果是手指滑动tabLayout，需要记录滑动的距离
                
   if (
   !rvScrolledByVp) {
                    rvScrolledByTouch 
   = 
   true;
                    offsetX_touch 
   -= dx;
                }
                
   //indicator需要跟着滑动
                
   RecyclerView
   .
   ViewHolder viewHolder 
   = tabLayout
   .getHorizontalRecyclerView()
   .findViewHolderForAdapterPosition(viewPager2
   .getCurrentItem());
                
   if (viewHolder 
   != 
   null) {
                    tabLayout
   .getIndicatorView()
   .getIndicator()
   .setWidth_indicator(tabLayout
   .getIndicatorView()
   .getIndicator()
   .getWidth_indicator_selected())
                            .setProgress((
   int) (viewHolder
   .itemView
   .getLeft()
                                    
   + viewHolder
   .itemView
   .getWidth() 
   * 
   1f 
   / 
   2
                                    
   - tabLayout
   .getIndicatorView()
   .getIndicator()
   .getWidth_indicator() 
   / 
   2));
                } 
   else {
                    
   //不可见，width_indicator为0
                    tabLayout
   .getIndicatorView()
   .getIndicator()
   .setWidth_indicator(
   0)
   .invalidate();
                }

            }
        });

        viewPager2
   .registerOnPageChangeCallback(
   new 
   ViewPager2.
   OnPageChangeCallback() {
            
   @Override
            
   public 
   void 
   onPageSelected(
   int 
   position) {
                
   super
   .onPageSelected(position);
                
   //通知tabAdapter更新选中项
                tabAdapter
   .setPositionSelected(viewPager2
   .getCurrentItem());
            }

            
   /**注意：滑动很快的时候，即使到了另外的page,positionOffsetPixels不一定会出现0

                * @param position

                * @param positionOffset

                * @param positionOffsetPixels

                */
            
   @Override
            
   public 
   void 
   onPageScrolled(
   int 
   position, 
   float 
   positionOffset, 
   int 
   positionOffsetPixels) {
                
   super
   .onPageScrolled(position,positionOffset,positionOffsetPixels);
                
   int centerX 
   = (
   int) (tabLayout
   .getWidth() 
   * 
   1f 
   / 
   2);
                
   //说明上次手指滑动了tabLayout，现在手指滑动viewpager,需要将tablayout复位
                
   if (rvScrolledByTouch 
   && offsetX_touch 
   != 
   0) {
                    tabLayout
   .getHorizontalRecyclerView()
   .stopScroll();
                    
   //标志不是由手指滑动tablayout
                    rvScrolledByVp 
   = 
   true;
                    tabLayout
   .getHorizontalRecyclerView()
   .scrollBy(offsetX_touch, 
   0);
                    rvScrolledByVp 
   = 
   false;
                    
   //立刻复位
                    rvScrolledByTouch 
   = 
   false;
                    offsetX_touch 
   = 
   0;
                    
   //这里不能修改position_scroll_last，因为只要上次手指滑动了tablayout,然后手指滑动viewapger，onPageScrolled会被回调多次
                    
   //在后面去修改position_scroll_last即可

   //                    position_scroll_last = position;
                    
   return;
                }
                
   //点击item后，onPageSelected先回调，然后还会继续回调onPageScrolled，直到onPageScrolled=position_selected，从page index 滑动到 page index+1，
                
   //position == viewPager2.getCurrentItem() - 1说明点击的item在当前position之后
                
   //position == viewPager2.getCurrentItem()说明点击的item在当前position之前
                
   //viewpager滑动中，才处理，
                
   if (scrolledByClick) {
                    
   if ((position 
   == viewPager2
   .getCurrentItem() 
   - 
   1 
   || position 
   == viewPager2
   .getCurrentItem())) {
                        
   RecyclerView
   .
   ViewHolder viewHolder 
   = tabLayout
   .getHorizontalRecyclerView()
   .findViewHolderForAdapterPosition(viewPager2
   .getCurrentItem());
                        
   if (viewHolder 
   != 
   null) {
                            
   //indicator想要指向正中间，计算TabLayout需要滑动的距离
                            
   if (diff_click 
   == 
   0)
                                diff_click 
   = (
   int) (viewHolder
   .itemView
   .getLeft() 
   + viewHolder
   .itemView
   .getWidth() 
   * 
   1f 
   / 
   2 
   - centerX);
                            
   //获取tablayout的偏移量，永远<=0
                            
   if (offsetX_last_click 
   == 
   0)
                                offsetX_last_click 
   = tabLayout
   .getHorizontalRecyclerView()
   .getOffsetX();
                            
   if (positionOffset 
   != 
   0) {
                                
   //scrollBy调用一次，onScrolled回调一次
                                
   //标志不是由手指滑动tablayout
                                rvScrolledByVp 
   = 
   true;
                                
   //往右滑
                                
   if (position_selected_last 
   < viewPager2
   .getCurrentItem()) {
                                    tabLayout
   .getHorizontalRecyclerView()
   .scrollTo((
   int) (offsetX_last_click 
   - (diff_click 
   * positionOffset)), 
   0);
                                } 
   else {
                                    
   //往左滑
                                    tabLayout
   .getHorizontalRecyclerView()
   .scrollTo((
   int) (offsetX_last_click 
   - (diff_click 
   * (
   1 
   - positionOffset))), 
   0);
                                }
                                rvScrolledByVp 
   = 
   false;
                            }

                        } 
   else {
                            
   //不可见，width_indicator为0
                            tabLayout
   .getIndicatorView()
   .getIndicator()
   .setWidth_indicator(
   0)
   .invalidate();
                        }

                    }
                    position_scroll_last 
   = position;
                    
   return;
                }
                
   /**

                    * 手指左右滑动Viewpager，触发下面所有代码

                    */
                
   TabViewHolder viewHolder 
   = (
   TabViewHolder) tabLayout
   .getHorizontalRecyclerView()
   .findViewHolderForAdapterPosition(position);
                
   if (viewHolder 
   != 
   null) {
                    
   int width_half 
   = (
   int) (viewHolder
   .itemView
   .getWidth() 
   * 
   1f 
   / 
   2);
                    
   int left 
   = viewHolder
   .itemView
   .getLeft();
                    
   int space 
   = tabLayout
   .getHorizontalRecyclerView()
   .getItemDecoration()
   .getSpace_horizontal();
                    
   TabViewHolder viewHolder_behind 
   = (
   TabViewHolder) tabLayout
   .getHorizontalRecyclerView()
   .findViewHolderForAdapterPosition(position 
   + 
   1);
                    
   if (position 
   == 
   0) {
                        
   //TabLayout刚显示，indicator会指向第0个item
                        diff 
   = 
   0;
                        offsetX_last 
   = 
   0;
                        
   if (viewHolder_behind 
   != 
   null)
                            
   //计算indicator指向下一个item需要滑动的距离
                            toScroll 
   = (
   int) (width_half
                                    
   + tabLayout
   .getHorizontalRecyclerView()
   .getItemDecoration()
   .getSpace_horizontal()
                                    
   + viewHolder_behind
   .itemView
   .getWidth() 
   * 
   1f 
   / 
   2);
                    } 
   else 
   if (position_scroll_last 
   < position) {
                        
   //说明从page index 滑动到了page index+1,
                        
   if (viewHolder_behind 
   != 
   null) {
                            
   //indicator想要指向正中间，计算TabLayout需要滑动的距离
                            diff 
   = (
   int) (viewHolder_behind
   .itemView
   .getLeft() 
   + viewHolder_behind
   .itemView
   .getWidth() 
   * 
   1f 
   / 
   2 
   - centerX);
                            
   //下一个item都在正中间的前面，无需滑动，而且可以避免出现负数导致recyclerView抖动
                            
   if (diff 
   < 
   0) diff 
   = 
   0;
                            
   //获取上次tablayout的偏移量，永远<=0
                            offsetX_last 
   = tabLayout
   .getHorizontalRecyclerView()
   .getOffsetX();
                            
   //计算indicator指向下一个item需要滑动的距离
                            toScroll 
   = (
   int) (width_half
                                    
   + tabLayout
   .getHorizontalRecyclerView()
   .getItemDecoration()
   .getSpace_horizontal()
                                    
   + viewHolder_behind
   .itemView
   .getWidth() 
   * 
   1f 
   / 
   2);
                        }

                    } 
   else 
   if (position_scroll_last 
   > position) {
                        
   //说明从page index 滑动到了page index-1
                        
   //indicator想要指向正中间，计算TabLayout需要滑动的距离
                        diff 
   = (
   int) (left 
   + width_half 
   - centerX);
                        
   //position的item在正中间的后面，无需滑动，而且可以避免出现正数导致recyclerView抖动
                        
   if (diff 
   > 
   0) diff 
   = 
   0;
                        
   //获取上次tablayout的偏移量，永远<=0
                        offsetX_last 
   = tabLayout
   .getHorizontalRecyclerView()
   .getOffsetX();
                        
   if (viewHolder_behind 
   != 
   null)
                            
   //计算indicator指向position的item需要滑动的距离
                            toScroll 
   = (
   int) (width_half
                                    
   + tabLayout
   .getHorizontalRecyclerView()
   .getItemDecoration()
   .getSpace_horizontal()
                                    
   + viewHolder_behind
   .itemView
   .getWidth() 
   * 
   1f 
   / 
   2);
                    } 
   else 
   if (op_click_last) {
                        
   //如果position_scroll_last==position,并且上次操作是点击item,
                        
   if (position 
   == click_position_last) {
                            
   //说明现在是正要从page index 滑动到page index+1
                            
   if (viewHolder_behind 
   != 
   null) {
                                
   //indicator想要指向正中间，计算TabLayout需要滑动的距离
                                diff 
   = (
   int) (viewHolder_behind
   .itemView
   .getLeft() 
   + viewHolder_behind
   .itemView
   .getWidth() 
   * 
   1f 
   / 
   2 
   - centerX);
                                
   //获取上次tablayout的偏移量，永远<=0
                                offsetX_last 
   = tabLayout
   .getHorizontalRecyclerView()
   .getOffsetX();
                                
   //计算indicator指向position的item需要滑动的距离
                                toScroll 
   = (
   int) (width_half
                                        
   + tabLayout
   .getHorizontalRecyclerView()
   .getItemDecoration()
   .getSpace_horizontal()
                                        
   + viewHolder_behind
   .itemView
   .getWidth() 
   * 
   1f 
   / 
   2);
                            }
                        }
                        op_click_last 
   = 
   false;
                    }
                    
   //diff==0,无需滑动，positionOffset==0,无需滑动，当前position和上次滑动的position相等，才执行滑动操作
                    
   if (diff 
   != 
   0 
   && positionOffset 
   != 
   0 
   && position_scroll_last 
   == position) {
                        
   //标志，tabLayout滑动，不是因为手指滑动tablayout导致的
                        rvScrolledByVp 
   = 
   true;
                        
   if (diff 
   > 
   0) {
                            
   //scrollBy调用一次，onScrolled回调一次
                            
   //手指往左滑动，positionOffset由小变大
                            tabLayout
   .getHorizontalRecyclerView()
   .scrollTo((
   int) (offsetX_last 
   - (diff 
   * positionOffset)), 
   0);
                        } 
   else {
                            
   //手指往右滑动，positionOffset由大变小
                            tabLayout
   .getHorizontalRecyclerView()
   .scrollTo((
   int) (offsetX_last 
   - (diff 
   * (
   1 
   - positionOffset))), 
   0);
                        }
                        
   //标志复位
                        rvScrolledByVp 
   = 
   false;
                    }
                    
   //计算Width_indicator,Width_indicator由小变大再变小，2个item中间时最大
                    tabLayout
   .getIndicatorView()
   .getIndicator()
   .setWidth_indicator(
   Math
   .max(tabLayout
   .getIndicatorView()
   .getIndicator()
   .getWidth_indicator_selected(),
                            (
   int) (tabLayout
   .getIndicatorView()
   .getIndicator()
   .getWidth_indicator_selected() 
   +
                                    (positionOffset 
   == 
   0 
   ? 
   0 
   : tabLayout
   .getIndicatorView()
   .getIndicator()
   .getWidth_indicator_max() 
   * (
   0.5 
   - 
   Math
   .abs(
   0.5 
   - positionOffset))))))
                            .setProgress((
   int) (left
                                    
   + width_half
                                    
   - tabLayout
   .getIndicatorView()
   .getIndicator()
   .getWidth_indicator() 
   / 
   2
                                    
   + (toScroll 
   * positionOffset)));

                    
   if (toScroll 
   != 
   0)
                        
   //手指往左滑动，positionOffset由小变大
                        
   //手指往右滑动，positionOffset由大变小
                        
   if (viewHolder_behind 
   != 
   null)
                            fragmentPageAdapter
   .onTabScrolled(viewHolder, position, 
   false, 
   1 
   - positionOffset,
                                    viewHolder_behind, position 
   + 
   1, 
   true, positionOffset);

                } 
   else {
                    
   //viewpager嵌套viewpager的时候，内层viewpager向右滑动了以后又向左滑动，会导致tablayout
                    
   //position对应的item不可见，所以要滑动到对应的position
                    tabLayout
   .getHorizontalRecyclerView()
   .scrollToPosition(position);
                    viewHolder 
   = (
   TabViewHolder) tabLayout
   .getHorizontalRecyclerView()
   .findViewHolderForAdapterPosition(position);
                    
   //scrollToPosition一调用，不会立马滑动完毕，所以还会有存在null的时候，
                    
   if(viewHolder
   !=
   null){
                        
   int width_half 
   = (
   int) (viewHolder
   .itemView
   .getWidth() 
   * 
   1f 
   / 
   2);
                        
   int left 
   = viewHolder
   .itemView
   .getLeft();
                        tabLayout
   .getIndicatorView()
   .getIndicator()
   .setWidth_indicator(tabLayout
   .getIndicatorView()
   .getIndicator()
   .getWidth_indicator_selected())
                                .setProgress((
   int) (left
                                        
   + width_half
                                        
   - tabLayout
   .getIndicatorView()
   .getIndicator()
   .getWidth_indicator() 
   / 
   2));
                    }
   else {
                        tabLayout
   .getIndicatorView()
   .getIndicator()
   .setWidth_indicator(
   0)
   .invalidate();
                    }

                }

                position_scroll_last 
   = position;
            }

            
   @Override
            
   public 
   void 
   onPageScrollStateChanged(
   int 
   state) {
                
   switch (state) {
                    
   case 
   SCROLL_STATE_IDLE
   :
                        
   //记录上次操作的是点击item
                        
   if (scrolledByClick) {
                            click_position_last 
   = viewPager2
   .getCurrentItem();
                            op_click_last 
   = 
   true;
                        }
                        
   //标志复位
                        scrolledByClick 
   = 
   false;
                        diff_click 
   = 
   0;
                        offsetX_last_click 
   = 
   0;
                        
   break;
                }
            }
        });

        tabLayout
   .setAdapter(tabAdapter);

        viewPager2
   .setAdapter(fragmentPageAdapter);

        
   return tabAdapter;
    }

}

  

        removeAllViews();
        for (int i = 0; i < tabNoScrollAdapter.getItemCount(); i++) {
            TabNoScrollViewHolder tabNoScrollViewHolder = tabNoScrollAdapter.onCreateViewHolder(i, tabNoScrollAdapter.getList_bean().get(i), this);
            tabNoScrollViewHolder.setPositionAdapter(i);
            sparseArrayViewHolder.put(i, tabNoScrollViewHolder);
            addView(tabNoScrollViewHolder.itemView, new LinearLayout.LayoutParams(0, ViewGroup.LayoutParams.MATCH_PARENT, 1));
            ItemChanged(i);
        }

 SimpleItemAnimator simpleItemAnimator = (SimpleItemAnimator) getItemAnimator();
 if (simpleItemAnimator != null) simpleItemAnimator.setSupportsChangeAnimations(false);