公共適配器的設(shè)計(jì)

背景：

電商類的應(yīng)用可能會(huì)有千變?nèi)f幻的業(yè)務(wù)需求。舉個(gè)例子首頁(yè)是整個(gè)應(yīng)用的重要入口，所以這個(gè)頁(yè)面產(chǎn)品對(duì)于業(yè)務(wù)區(qū)塊的設(shè)計(jì)是多種多樣的，現(xiàn)在已經(jīng)差不多有將近20多種的樣式view組成后面有可能會(huì)繼續(xù)增加，而現(xiàn)在很多view的代碼實(shí)現(xiàn)是在Adapter實(shí)現(xiàn)的，造成的后果是Adapter的類相當(dāng)?shù)挠纺[，而且判斷分支多，增加一個(gè)類型對(duì)于原有的類就要進(jìn)行修改，不符合設(shè)計(jì)的開閉原則，而且view的復(fù)用性相對(duì)較差。在此背景下重新設(shè)計(jì)一個(gè)通用的適配。

需求和目標(biāo)：

1.全站統(tǒng)一使用一個(gè)Adapter。

2.view和數(shù)據(jù)model構(gòu)建一個(gè)Holder單一的對(duì)象用于復(fù)用，脫離和Adapter的綁定

核心類設(shè)計(jì)：

1.MultiTypeFactory是一個(gè)holde創(chuàng)建的工廠類，主要的功能是根據(jù)Modle類型的管理和holder類型管理，然后根據(jù)adapter傳回的Modle類型進(jìn)行已經(jīng)注冊(cè)的Holder的進(jìn)行生產(chǎn)不同類型的holder創(chuàng)建。通過

public class MultiTypeFactory implements TypeFactory {
    private List<Class<Type>> mTypes = new ArrayList<>();
    private List<Class<BaseViewHolder>> mHolders = new ArrayList<>();
    private List<Integer> mLayoutReses = new ArrayList<>();
    private Map<Integer, Class<View>> mViewMap = new HashMap<>();

    @Override
    public BaseViewHolder createViewHolder(Context context, int type) {

        try {
            View view;
            Class h = mHolders.get(type);
            Class c = mViewMap.get(mLayoutReses.get(type));
            if (c != null && !c.equals(NullView.class)) {
                Constructor constructor = c.getConstructor(Context.class);
                view = (View) constructor.newInstance(context);
            } else {
                view = View.inflate(context, mLayoutReses.get(type), null);
            }
            Constructor constructor = h.getConstructor(View.class);
            return (BaseViewHolder) constructor.newInstance(view);
        } catch ( NoSuchMethodException e ) {
            e.printStackTrace();
        } catch ( InstantiationException e ) {
            e.printStackTrace();
        } catch ( IllegalAccessException e ) {
            e.printStackTrace();
        } catch ( InvocationTargetException e ) {
            e.printStackTrace();
        }

        return null;
    }

    @Override
    public int indexOfType(Class c) {
        return mTypes.indexOf(c);
    }

    private TypeFactory regist(Class c, Class h, int layoutRes) {
        mTypes.add(c);
        mHolders.add(h);
        mLayoutReses.add(layoutRes);
        return this;
    }

    private TypeFactory regist(Class c, Class h, Class v, int layoutRes) {
        regist(c, h, layoutRes);
        mViewMap.put(layoutRes, v);
        return this;
    }

    @Override
    public TypeFactory regist(Class<? extends BaseViewHolder> h) {
        if (h == null) {
            throw new NullPointerException("holder should not be null");
        }
        if (mHolders.contains(h)) {
            throw new IllegalStateException("this holder has been Registed");
        }
        ModelView mv = h.getAnnotation(ModelView.class);
        Class c = mv.model();
        Class v = mv.view();
        int l = mv.resId();
        regist(c, h, v, l);
        return this;
    }

    @Override
    public int typeSize() {
        return mTypes.size();
    }


}

2.LvMultiTypeAdapter listview的公共適配器設(shè)計(jì)，可全站工程使用不用再費(fèi)勁的創(chuàng)建一個(gè)個(gè)adapter了

public class LvMultiTypeAdapter extends BaseAdapter implements Adapter {
    private TypeFactory typeFactory;
    private List<Type> models=new ArrayList<>();
    private DotContext mDotContext = null;
    private Handler mExternalSafeHandler;
    private Handler mInsideSafeHandler;
    private LoadMoreModel mMoreModel = new LoadMoreModel();

    public LvMultiTypeAdapter(List<Type> models, TypeFactory typeFactoryt) {
        this.models = models;
        this.typeFactory = typeFactoryt;
    }
    public LvMultiTypeAdapter(TypeFactory typeFactory) {
        this.typeFactory = typeFactory;
        typeFactory.regist(LoadMoreHolder.class);
    }

    public void addData(List<Type> types) {
        if (ObjectUtils.isObjectNotNull(models)) {
            models.addAll(types);
            notifyDataSetChanged();
        }
    }

    @Override
    public int getCount() {
        return isModelsNotNull() ? models.size() : 0;
    }

    @Override
    public Type getItem(int position) {
        return isModelsNotNull() ? models.get(position) : null;
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public int getItemViewType(int position) {
        return isModelsNotNull() ? gainViewType(position) : -1;
    }

    private int gainViewType(int position) {
        return typeFactory.indexOfType(models.get(position).getClass());
    }

    @Override
    public int getViewTypeCount() {
        return typeFactory.typeSize();
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        BaseViewHolder baseViewHolder = typeFactory.createViewHolder(parent.getContext(), gainViewType(position));
        baseViewHolder.bindVM(models.get(position), position, this);
        return baseViewHolder.itemView;
    }

    ....

    @Override
    public void notifyDataSetChanged() {
        super.notifyDataSetChanged();
    }


}

3.MultiTypeAdapter當(dāng)然也少不了recycleview的實(shí)現(xiàn)，強(qiáng)烈建議全站使用recycleview去實(shí)現(xiàn)

public class MultiTypeAdapter extends RecyclerView.Adapter<BaseViewHolder> implements Adapter {
    private TypeFactory typeFactory;

    public List<Type> getModels() {
        return models;
    }

    public void setModels(List<Type> models) {
        this.models = models;
    }

    private List<Type> models = new ArrayList<>();
    private DotContext mDotContext = null;
    private Handler mExternalSafeHandler;
    private Handler mInsideSafeHandler;
    private LoadMoreModel mMoreModel = new LoadMoreModel();

    public MultiTypeAdapter(List<Type> models, TypeFactory typeFactory) {
        this.models = models;
        this.typeFactory = typeFactory;
        typeFactory.regist(LoadMoreHolder.class);
    }

    public MultiTypeAdapter(TypeFactory typeFactory) {
        this.typeFactory = typeFactory;
        typeFactory.regist(LoadMoreHolder.class);
    }

    @Override
    public BaseViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        return typeFactory.createViewHolder(parent.getContext(), viewType);
    }

    @Override
    public void onBindViewHolder(BaseViewHolder holder, int position) {
        holder.bindVM(models.get(position), position, this);
    }

    ....

    public void clear() {
        if (ObjectUtils.isObjectNotNull(models)) {
            models.clear();

        }
        notifyDataSetChanged();
    }
}

4.BaseViewHolder全局基礎(chǔ)holder，調(diào)用者只需關(guān)心數(shù)據(jù)模型和視圖的綁定添加了 model數(shù)據(jù)和view的注解實(shí)現(xiàn)，可以讓工廠累獲取通過反射拿到不同類型holder的實(shí)例

public abstract class BaseViewHolder<T extends Type> extends RecyclerView.ViewHolder {
    private SparseArray<View> views;
    public View mItemView;
    protected BaseDotBuilder dotBuilder;
    protected DotContext doter;

    public <E extends View> E getView(int resID) {
        E view = (E) views.get(resID);
        if (view == null) {
            view = (E) mItemView.findViewById(resID);
            views.put(resID, view);
        }
        return view;
    }

    public abstract void bindVM(T model, int position, Adapter adapter);

    public void bindHolder(T model, int position, Adapter adapter) {
        bindAction(adapter, position);
        bindVM(model, position, adapter);
    }

    public BaseViewHolder(View itemView) {
        super(itemView);
        views = new SparseArray<>();
        this.mItemView = itemView;
    }

    ...

    protected ExposureTrack bindExposureTrack(T t, ExposureTrack e) {
        return null;
    }


}

5.Adapter 為了BaseViewHolde適配listview 和 recycleView創(chuàng)建適配器接口

public interface Adapter {
    int getItemSize();

    int getType(int position);

    DotContext getDoter();

    void setDoter(DotContext dotContext);

    int getItemCounts();


    Handler getExternalHandler();

    HolderAction getHolderCallBack();

    void registInsideHandler(Handler safeHandler);

    Handler getInsideHandler();

    void notifyDataChanged();

}

6. HolderAction事件回調(diào)接口給外部調(diào)用，暴露holde給調(diào)用者，可以在數(shù)據(jù)綁定的時(shí)候提供給修改功能增加擴(kuò)展性

public interface HolderAction {

    void onBindAction(BaseViewHolder holder, int pos);

    void onAfterAction(BaseViewHolder holder, int pos, int actionType);

}

7. Type 所有Holder對(duì)應(yīng)的數(shù)據(jù)模型都實(shí)現(xiàn)這個(gè)類型接口

/**
 * 適配器item基礎(chǔ)類型
 * Created by hzzhudiqing on 2017/2/23.
 */

public interface Type {

}

8. DataType<T> 數(shù)據(jù)模型的包裝類用于父子級(jí)數(shù)據(jù)關(guān)聯(lián)，方便 type模型數(shù)據(jù)的構(gòu)造

/**
 * Created by hzzhudiqing on 2017/3/3.
 */

public class DataType<T> implements Type {
    T t;


    public T getT() {
        return t;
    }

    public DataType<T> setT(T t) {
        this.t = t;
        return this;
    }

}

使用方式

模型數(shù)據(jù)的創(chuàng)建

public class DeliveryGood extends DataType<Delivery> implements Type, Serializable {

    .....   
}

業(yè)務(wù)相關(guān)holder創(chuàng)建

@ModelView(model = DeliveryGood.class, resId = R.layout.pay_delivery_good)
public class DeliveryGoodHolder extends BaseViewHolder<DeliveryGood> {

    public static final int PRE_SALE = 1;
    private TextView mPayDeliveryGoodName;
    private KaolaImageView mPayDeliveryGoodSaleReturnIcon;
    private TextView mPayDeliveryGoodSaleReturnDesc;
    private TextView mPayDeliveryGoodPriceTv;
    private TextView mPayDeliveryGoodNumTv;
    private TextView mPaySkutv;

    public DeliveryGoodHolder(View itemView) {
        super(itemView);
    }

    @Override
    public void bindVM(DeliveryGood model, int position, Adapter adapter) {

        ...
    }

    ...
}

Adapter的注冊(cè)調(diào)用

 List<Type> types = DeliverProcesser.bulidDeliveryTypes(deliveries);
            final TypeFactory factory = new MultiTypeFactory()
                    .regist(DeliveryGoodHolder.class)
                    .regist(DeliveryWarehouseHolder.class)
                    .regist(RemarkHolder.class);
            final MultiTypeAdapter multiTypeAdapter = new MultiTypeAdapter(types, factory);
            GridLayoutManager layoutManager = new GridLayoutManager(getContext(), 1);

            mDeliveryRv.setLayoutManager(layoutManager);

            mDeliveryRv.setAdapter(multiTypeAdapter);

效果圖：