Bottomsheetdialogfragment + viewpager + fragment + recyclerview sliding problem

Recently, a pop-up window needs several Tab Switch , Every Tab Is a list that can slide up and down , Based on this design , It's easy to think of using BottomSheetDialogFragment + ViewPager+Fragment+RecyclerView, The old driver came up to do , It is found that after writing, only the first page list can slide, and other pages cannot slide ,what? What happened? , First eliminate the problem of your own code , Take questions and go Google, The main reason is because BottomSheetBehavior Of findScrollingChild The method has nothing to do with ViewPager Update to find child elements view Things that are , So it can only get one page to slide , Then we need to be right BottomSheetBehavior Make changes , In this case, you need to define yourself BottomSheetDialog：

Method 1：

private View findScrollingChild(View view) {
    if (view instanceof NestedScrollingChild) {
        return view;
    }
    if (view instanceof ViewGroup) {
        ViewGroup group = (ViewGroup) view;
        for (int i = 0, count = group.getChildCount(); i < count; i++) {
            View scrollingChild = findScrollingChild(group.getChildAt(i));
            if (scrollingChild != null) {
                return scrollingChild;
            }
        }
    }
    return null;
}

After modification ：

@VisibleForTesting
    View findScrollingChild(View view) {
        if (ViewCompat.isNestedScrollingEnabled(view)) {
            return view;
        }
        if (view instanceof ViewPager) {
            ViewPager viewPager = (ViewPager) view;
            View currentViewPagerChild = viewPager.getChildAt(viewPager.getCurrentItem());
//            View currentViewPagerChild = ViewPagerUtils.getCurrentView(viewPager);
            if (currentViewPagerChild == null) {
                return null;
            }
 
            View scrollingChild = findScrollingChild(currentViewPagerChild);
            if (scrollingChild != null) {
                return scrollingChild;
            }
        } else if (view instanceof ViewGroup) {
            ViewGroup group = (ViewGroup) view;
            for (int i = 0, count = group.getChildCount(); i < count; i++) {
                View scrollingChild = findScrollingChild(group.getChildAt(i));
                if (scrollingChild != null) {
                    return scrollingChild;
                }
            }
        }
        return null;
    }

Method 2. Be careful ： This method is troublesome , Change your mind , Now that it's located to be ViewPager Sliding problem , Now? Google Not having ViewPager2 Yes , and ViewPager2 The bottom layer is made of RecycleView Realization , It should be able to solve this problem , It is as expected ,ViewPager2 It has indeed solved this problem Code sharing ：

xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/rl_root_view"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:fillViewport="true">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="372dp"
        android:background="@drawable/shape_gift_bg"
        android:clickable="true"
        android:orientation="vertical">

        <View
            android:layout_width="30dp"
            android:layout_height="4dp"
            android:layout_gravity="center_horizontal"
            android:layout_marginVertical="10dp"
            android:background="@drawable/shape_gray_525367_2dp" />

        <com.google.android.material.tabs.TabLayout
            android:id="@+id/tb_layout"
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:layout_marginTop="8dp"
            android:background="@color/transparent"
            app:tabIndicatorColor="@android:color/transparent"
            app:tabIndicatorHeight="0dp"
            app:tabMode="fixed"
            app:tabRippleColor="@android:color/transparent" />

        <androidx.viewpager2.widget.ViewPager2
            android:id="@+id/vp_select_seat"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_marginTop="10dp" />

    </LinearLayout>

</RelativeLayout>

Dialog Java Code ：

public class RowWheatDialog extends BottomSheetDialogFragment {

    private final static FunbitLog logger = new FunbitLog(RowWheatDialog.class.getSimpleName());

    private RelativeLayout mRootView;
    private TabLayout mTitleTabLayout;
    private ViewPager2 mViewPager;
    private OnClickedListener mListener;
    private List<Fragment> mFragmentList = new ArrayList<>();

    private List<VoiceRoomInfo> mBossSeatList = new ArrayList<>();
    private List<VoiceRoomInfo> mRegularSeatList = new ArrayList<>();

    private BossSeatFragment mBossSeatFragment;

    private RegularSeatFragment mRegularSeatFragment;
    private FragmentAdapter mFragmentAdapter;
    private TabLayoutMediator mTabLayoutMediator;

    private boolean isPPNeedPick = false;

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setStyle(BottomSheetDialogFragment.STYLE_NORMAL, R.style.CustomBottomSheetDialogTheme);
    }

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.dialog_row_wheat, container, false);
        return view;
    }

    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        logger.d("onViewCreated()");
        mRootView = view.findViewById(R.id.rl_root_view);
        mTitleTabLayout = view.findViewById(R.id.tb_layout);
        mViewPager = view.findViewById(R.id.vp_select_seat);
        initTab();
        mRootView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                dismiss();
            }
        });
    }

    public void setOnClickedListener(OnClickedListener listener) {
        this.mListener = listener;
    }

    public void setIsPPNeedPick(boolean ppNeedPick) {
        this.isPPNeedPick = ppNeedPick;
    }

    public void setData(List<VoiceRoomInfo> bossSeatList, List<VoiceRoomInfo> regularSeatList) {
        logger.d("setData  bossSeatList : " + bossSeatList + "  regularSeatList : " + regularSeatList);
        this.mBossSeatList = bossSeatList;
        this.mRegularSeatList = regularSeatList;

        if (mBossSeatFragment != null) {
            mBossSeatFragment.setData(bossSeatList);
        }

        if (mRegularSeatFragment != null) {
            mRegularSeatFragment.setData(regularSeatList);
        }
        updateTitleTabLayoutTitle();
    }

    public void updateTitleTabLayoutTitle() {
        if (mTitleTabLayout == null) {
            return;
        }

        int tabCount = mTitleTabLayout.getTabCount();
        for (int i = 0; i < tabCount; i++) {
            TabLayout.Tab tab = mTitleTabLayout.getTabAt(i);
            if (tab == null) {
                continue;
            }
            if (tab.getPosition() == 0) {
                View view01 = tab.getCustomView();
                if (view01 != null) {
                    TextView textView01 = view01.findViewById(R.id.subtab_tv);
                    if (textView01 != null) {
                        textView01.setText(ResourceUtil.getString(R.string.boss_seat_label_count, (mBossSeatList == null ? 0 : mBossSeatList.size())));
                    }
                }
            } else {
                View view02 = tab.getCustomView();
                if (view02 != null) {
                    TextView textView02 = view02.findViewById(R.id.subtab_tv);
                    if (textView02 != null) {
                        textView02.setText(ResourceUtil.getString(R.string.regular_seat_label_count, (mRegularSeatList == null ? 0 : mRegularSeatList.size())));
                    }
                }
            }
        }
    }

    public interface OnClickedListener {

        void onPickClicked(VoiceRoomInfo voiceRoomInfo, boolean isPP, int position);

    }

    @Override
    public void onResume() {
        super.onResume();
        logger.d("onResume() mBossSeatList " + mBossSeatList);
        if (mBossSeatFragment != null) {
            mBossSeatFragment.setData(mBossSeatList);
        }

        if (mRegularSeatFragment != null) {
            mRegularSeatFragment.setData(mRegularSeatList);
        }
        updateTitleTabLayoutTitle();
    }


    public void initTab() {
        logger.d("initTab()");
        mBossSeatFragment = new BossSeatFragment();
        mBossSeatFragment.setData(mBossSeatList);
        mFragmentList.add(mBossSeatFragment);
        if (isPPNeedPick) {
            mRegularSeatFragment = new RegularSeatFragment();
            mRegularSeatFragment.setData(mRegularSeatList);
            mFragmentList.add(mRegularSeatFragment);
            mTitleTabLayout.setVisibility(View.VISIBLE);
            mRegularSeatFragment.setOnClickedListener(new RegularSeatFragment.OnClickedListener() {
                @Override
                public void onPickClicked(VoiceRoomInfo voiceRoomInfo, boolean isPP, int position) {
                    if (mListener != null) {
                        mListener.onPickClicked(voiceRoomInfo, true, position);
                    }
                }
            });
        } else {
            mTitleTabLayout.setVisibility(View.GONE);
        }

        mFragmentAdapter = new FragmentAdapter(getActivity());
        mViewPager.setAdapter(mFragmentAdapter);

        mTabLayoutMediator = new TabLayoutMediator(mTitleTabLayout, mViewPager, new TabLayoutMediator.TabConfigurationStrategy() {
            @Override
            public void onConfigureTab(@NonNull TabLayout.Tab tab, int position) {
                logger.d("TabLayoutMediator  onConfigureTab () " + tab + " position : " + position);
                switch (position) {
                    case 0:
                        tab.setCustomView(R.layout.item_seat_subtab);
                        TextView textView0 = tab.getCustomView().findViewById(R.id.subtab_tv);
                        textView0.setText(ResourceUtil.getString(R.string.boss_seat_label_count, (mBossSeatList == null ? 0 : mBossSeatList.size())));
                        break;
                    case 1:
                        if (isPPNeedPick) {
                            tab.setCustomView(R.layout.item_seat_subtab);
                            TextView textView1 = tab.getCustomView().findViewById(R.id.subtab_tv);
                            textView1.setText(ResourceUtil.getString(R.string.regular_seat_label_count, (mRegularSeatList == null ? 0 : mRegularSeatList.size())));
                        }
                        break;
                    default:
                        break;
                }
            }
        });
        mTabLayoutMediator.attach();

        mViewPager.registerOnPageChangeCallback(changeCallback);

        mBossSeatFragment.setOnClickedListener(new BossSeatFragment.OnClickedListener() {
            @Override
            public void onPickClicked(VoiceRoomInfo voiceRoomInfo, boolean isPP, int position) {
                if (mListener != null) {
                    mListener.onPickClicked(voiceRoomInfo, false, position);
                }
            }
        });
    }

    private ViewPager2.OnPageChangeCallback changeCallback = new ViewPager2.OnPageChangeCallback() {
        @Override
        public void onPageSelected(int position) {
            int tabCount = mTitleTabLayout.getTabCount();
            for (int i = 0; i < tabCount; i++) {
                TabLayout.Tab tab = mTitleTabLayout.getTabAt(i);
                if (tab.getPosition() == position) {
                    updateTab(tab, true);
                } else {
                    updateTab(tab, false);
                }
            }
        }
    };

    private void updateTab(TabLayout.Tab tab, boolean isSelected) {
        if (tab == null || tab.getCustomView() == null) {
            return;
        }
        TextView textView = tab.getCustomView().findViewById(R.id.subtab_tv);
        TextView textViewLine = tab.getCustomView().findViewById(R.id.subtab_line_view);
        if (isSelected) {
            textView.setTextColor(ResourceUtil.getColor(R.color.white));
            textViewLine.setVisibility(View.VISIBLE);
            textView.setTextAppearance(getContext(), R.style.TextStyleRobotoBold);
        } else {
            textView.setTextColor(ResourceUtil.getColor(R.color.AmongCancelColor));
            textView.setTextAppearance(getContext(), R.style.TextStyleRobotoMedium);
            textViewLine.setVisibility(View.GONE);
        }
    }


    public class FragmentAdapter extends FragmentStateAdapter {

        public FragmentAdapter(@NonNull FragmentActivity fragmentActivity) {
            super(fragmentActivity);
        }

        @NonNull
        @Override
        public Fragment createFragment(int position) {
            return mFragmentList.get(position);
        }

        @Override
        public int getItemCount() {
            return mFragmentList.size();
        }
    }

    @Override
    public void onDestroyView() {

        logger.d("onDestroyView()");
        if (mTabLayoutMediator != null) {
            mTabLayoutMediator.detach();
        }
        if (mViewPager != null) {
            mViewPager.unregisterOnPageChangeCallback(changeCallback);
        }
        super.onDestroyView();

    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        logger.d("onDestroy()");
    }
}