最近看了一下美团的开源的移动端页面模块化的开发框架Shield分析一下实现原理
git地址源码demo的下载
首先分析一下Demo中的DividerFragment,generaterDefaultConfigAgentList,在父类AgentManagerFragment中会被调用，主要的作用是new组件的配置信息类，加入到list中返回，下边看一下DividerAgentConfig这个组件的配置类
public class DividerFragment extends AbsExampleFragment {
RecyclerView mRecyclerView;
@RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN)
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
mRecyclerView = new RecyclerView(getContext());
return mRecyclerView;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setAgentContainerView(mRecyclerView);
}
@Override
protected ArrayList<AgentListConfig> generaterDefaultConfigAgentList() {
ArrayList<AgentListConfig> configs = new ArrayList<>();
configs.add(new DividerAgentConfig());
return configs;
}
@Override
public String functionName() {
return "Divider";
}
} 实现了AgentListConfig接口，
getAgentInfoList()方法在后边的分析中会调用，现在看一下方法的实现，首先建立了一个三维数组，然后调用AgentInfohelper.getAgents()把三维数组转成Map<String,AgentInfo>返回。
public class DividerAgentConfig implements AgentListConfig {
private static final String AGENT_PKG_NAME = "com.example.shield.divider.agent.";
@Override
public boolean shouldShow() {
return true;
}
@Override
public Map<String, AgentInfo> getAgentInfoList() {
String[][][] agentArray = {
{
{"default_divider", AGENT_PKG_NAME + "TestDividerAgent"},
}
};
return AgentInfoHelper.getAgents(agentArray);
}
@Override
public Map<String, Class<? extends AgentInterface>> getAgentList() {
return null;
}
} 看一下DividerFragment的父类AgentManagerFragment,实现了AgentCellBridgeInterface,DriverInterface,ShieldConainer
Interface,在onActivityCreated中通过getAgentManager获取CommonAgentManager（继承了LightAgentManager）对象，
j接下来调用CommonAgentManager的setupAgent,看一下setupAgent的参数，genneraterDefaultConfigList()就是上边DividerFragment实现的，在CommonAgentManager没有对setupAgent进行实现，我们看一下他的父类LightAgentManager的实现的方法
AgentManagerFragment:
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
cellManager = getCellManager();
if (cellManager instanceof SectionRecyclerCellManager) {
((SectionRecyclerCellManager) cellManager).setWhiteBoard(whiteBoard);
}
agentManager = getAgentManager();
agentManager.setupAgents(savedInstanceState, generaterDefaultConfigAgentList());
if (pageContainer != null) {
pageContainer.onActivityCreated(savedInstanceState);
setAgentContainerView(pageContainer.getAgentContainerView());
}
}
setupAgents调用了重载方法，最后调用setDefaulAgent，在第一行中调用getDefaultAgentList（调用DividerAgentConfig的getAgentInfoList,在前面已经分析）获取Map对象,然后进行对Map遍历，调用constructAgents反射构造组件对象，然后拼接index，key设置成组件的属性，复合组件递归调用setupAgent进行初始化，组件的key保存在agentlist，组件保存在agents这个Map对象，到这里，根据组件的配置的信息，对组件的初始完成
组件是如何进行渲染的呢，然后继续分析setupAgents，遍历agentList,获取组件对象，调用组件的onCreate声明周期，然后继续调用agentCellBridgeInterface的updateCells对象，传入刚刚初始化的组件list，agentCellBridgeInterface是LightAgentmanager在构造函数传入的对象，所以回到AgentManagerFragment，的updateCell
LightAgentManager：@Override
public void setupAgents(Bundle savedInstanceState, ArrayList<AgentListConfig> defaultConfig) { //第二个参数是组件的信息
setupAgents(defaultConfig);
ArrayList<AgentInterface> addList = new ArrayList<AgentInterface>();
for (String name : agentList) {
AgentInterface agent = agents.get(name); //根据key获取组件
if (agent != null) {
Bundle b = savedInstanceState == null ? null : savedInstanceState.getBundle("agent/"
+ name);
agent.onCreate(b); //回调组件的onCreate
addList.add(agent);
}
}
agentCellBridgeInterface.updateCells(addList, null, null);
dispatchCellChanged(fragment.getActivity(), null, null);
}protected void setDefaultAgent(ArrayList<AgentListConfig> defaultConfig, String keyPath, String index) {
Map<String, AgentInfo> defaultAgent = getDefaultAgentList(defaultConfig); //对组件进行初始化
if (defaultAgent == null) {
// throw new RuntimeException("generaterDefaultAgent() can not return null");
Log.e("Shield", "generaterDefaultAgent() can not return null");
return;
}
try {
for (Map.Entry<String, AgentInfo> entry : defaultAgent.entrySet()) { //遍历组件info的map
String key;
if (!"".equals(keyPath)) {
key = keyPath + AGENT_SEPARATE + entry.getKey();
} else {
key = entry.getKey();
}
if (!agents.containsKey(key)) {
agentList.add(key);
AgentInterface cellAgent = constructAgents(entry.getValue().agentClass); //反射构造类的实例
if (cellAgent != null) {
String childIndex;
if (!"".equals(keyPath)) {
childIndex = index + "." + entry.getValue().index;
} else {
childIndex = entry.getValue().index;
}
cellAgent.setIndex(childIndex);
cellAgent.setHostName(key);
agents.put(key, cellAgent);
if (cellAgent instanceof ShieldContainerInterface) {
setDefaultAgent(((ShieldContainerInterface) cellAgent).generaterConfigs(), key, childIndex);
}
}
}
}
} catch (Exception e) {
// Log.e(TAG, e.toString());
}
}protected Map<String, AgentInfo> getDefaultAgentList(ArrayList<AgentListConfig> defaultConfig) {
if (defaultConfig == null) {
Log.e("Shield", "generaterDefaultConfigAgentList return null");
// throw new RuntimeException("generaterDefaultConfigAgentList return null");
return null;
}
for (AgentListConfig agentListConfig : defaultConfig) { //遍历配置的组件信息
try {
if (agentListConfig.shouldShow()) {
Map<String, AgentInfo> result = agentListConfig.getAgentInfoList(); //获取封装好的组件的key AgentInfo
if (result == null) {
result = new LinkedHashMap<String, AgentInfo>();
Map<String, Class<? extends AgentInterface>> tmp = agentListConfig.getAgentList(); //null
for (Map.Entry<String, Class<? extends AgentInterface>> entry : tmp.entrySet()) {
result.put(entry.getKey(), new AgentInfo(entry.getValue(), ""));
}
}
return result;
}
} catch (Exception e) {
// if (Environment.isDebug()) {
// throw new RuntimeException("there has a exception " + e);
// }
e.printStackTrace();
return null;
}
}
// throw new RuntimeException("getDefaultAgentList() agentListConfig no one should be shown?");
Log.e("Shield", "getDefaultAgentList() agentListConfig no one should be shown?");
return null;
}
updateCell，调用了cellManagerde updateCells,cellManager是SectionRecyclerCellManager对象
@Override
public void updateCells(ArrayList<AgentInterface> addList, ArrayList<AgentInterface> updateList, ArrayList<AgentInterface> deleteList) {
cellManager.updateCells(addList, updateList, deleteList);
} 看一下SectionRecyclerCellManager的updateCells,首先遍历模块组件的对象，然后根据组件对象的信息，创建SectionPieceAdapter(继承RecyclerView.Adapter),把模块组件，模块组件信息，刚刚创建的适配器封装成Cell,加入hashMap对象cells，然后遍历需要更新删除的组件集合，对cells进行更改，最后一行比较是重点
@Override
public void updateCells(ArrayList<AgentInterface> addList, ArrayList<AgentInterface> updateList, ArrayList<AgentInterface> deleteList) {
//添加新的
if (addList != null && !addList.isEmpty()) {
for (AgentInterface addAgent : addList) {
if (addAgent.getSectionCellInterface() != null) {
RecyclerView.Adapter adapter = createRecyclerViewAdapter(addAgent); //创建RecyclerView的适配器
Cell c = new Cell(); //封装成Cell
c.owner = addAgent;
c.name = addAgent.getAgentCellName();
c.recyclerViewAdapter = adapter;
cells.put(getCellName(addAgent), c); //cell放在集合cells中
}
}
}
//更新原来有的位置
//只更新之前存在的Agent的Cell的index
//因为是viewgroup会有多个cell,需要把agent对应的多个cell的index都更新,之后统一notify
if (updateList != null && !updateList.isEmpty()) { //需要更新的cell
HashMap<String, Cell> copyOfCells = (HashMap<String, Cell>) cells.clone();
for (AgentInterface updateCell : updateList) {
if (updateCell.getSectionCellInterface() != null) {
for (Map.Entry<String, Cell> entry : copyOfCells.entrySet()) {
//判断owner属于该agent,并且之前的name是和目前cellNam+内部顺序一致(找到对应的Cell)
if (entry.getValue().owner == updateCell) {
//替换cell的index
Cell temp = entry.getValue();
cells.remove(entry.getKey());
cells.put(getCellName(updateCell), temp);
}
}
}
}
}
//删除需要删除的
if (deleteList != null && !deleteList.isEmpty()) { //需要删除的cell
for (AgentInterface deleteCell : deleteList) {
Iterator<Map.Entry<String, Cell>> itr = cells.entrySet().iterator();
while (itr.hasNext()) {
Cell c = itr.next().getValue();
if (c.owner == deleteCell) {
itr.remove();
}
}
}
}
notifyCellChanged(); //更新cell
}
最后调用updateAgentContainer,对cell进行分组，保存在二维结构cellGroup，重新排列index，继续遍历cell集合，cell模块组件保存的适配器封装成FinalPieceAdapter（类似于代理模式，通过FinalPieceAdapter调用SectionPieceAdapter）,调用addCellToContainerView()方法，把cell模块组件的适配器封装到MergeSectionDividerAdapter内（把适配器进行整合具体代码后边进行分析），最后更新适配器
public void updateAgentContainer() {
sort = new ArrayList<Cell>(cells.values()); //获取cells的value
Collections.sort(sort, cellComparator); //对sort进行排序
resetAgentContainerView(); //重新设置
//根据多维index（xx.xx.xx.xx）还原实际的二维结构分组。
cellGroup = new ArrayList<>();
ArrayList<Cell> cellArrayList = new ArrayList<>();
CellGroupIndex currentCellGroup = null;
for (Cell cell : sort) { //对sort进行遍历 进行分组
String indexStr = cell.owner.getIndex(); //获取index
CellGroupIndex cellGroupIndex = createCellGroup(indexStr); //创建cellGroup
if (currentCellGroup == null) {
cellArrayList = new ArrayList<>();
cellArrayList.add(cell);
} else {
boolean isSameGroup = isSameGroup(currentCellGroup, cellGroupIndex);
if (isSameGroup) {
cellArrayList.add(cell);
} else {
cellGroup.add(cellArrayList);
cellArrayList = new ArrayList<>();
cellArrayList.add(cell);
}
}
currentCellGroup = cellGroupIndex;
}
if (cellArrayList != null && (!cellArrayList.isEmpty())) {
cellGroup.add(cellArrayList);
}
//根据实际的二维结构数组重排index
if (cellGroup != null) {
for (int i = 0; i < cellGroup.size(); i++) {
if (cellGroup.get(i) == null) continue;
for (int j = 0; j < cellGroup.get(i).size(); j++) {
if (cellGroup.get(i).get(j) == null) continue;
try {
Cell cell = cellGroup.get(i).get(j); //遍历获取cell
cell.groupIndex = AgentInfoHelper.addZeroPrefix(i, AgentInfoHelper.getIntStrLength(cellGroup.size()));
cell.innerIndex = AgentInfoHelper.addZeroPrefix(j, AgentInfoHelper.getIntStrLength(cellGroup.get(i).size()));
} catch (Exception e) {
e.printStackTrace();
continue;
}
}
}
}
if (!sort.isEmpty()) {
for (int i = 0; i < sort.size(); i++) {
Cell c = sort.get(i);
if (c.recyclerViewAdapter == null)
continue;
FinalPieceAdapter finalPieceAdapter;
if (c.recyclerViewAdapter instanceof FinalPieceAdapter) {
finalPieceAdapter = (FinalPieceAdapter) c.recyclerViewAdapter;
} else {
finalPieceAdapter = new FinalPieceAdapter(mContext, (PieceAdapter) c.recyclerViewAdapter, groupManager); //cell的adapter封装一下
}
groupManager.addAdapter(finalPieceAdapter, i, c.groupIndex); //封装adapter
c.recyclerViewAdapter = finalPieceAdapter; //封装好的adapter赋值给cell
if (whiteBoard != null) {
if (finalPieceAdapter.getTotalItemCount() > 0) {
whiteBoard.putBoolean(ShieldConst.AGENT_VISIBILITY_KEY + c.owner.getHostName(), true);
} else {
whiteBoard.putBoolean(ShieldConst.AGENT_VISIBILITY_KEY + c.owner.getHostName(), false);
}
}
addCellToContainerView(c);
}
}
mergeRecyclerAdapter.notifyDataSetChanged();
} 到这里，我们完成了组件模块的初始化，根据组件模块创建适配器，适配器的整合（后边进行具体分析）那么适配器是如何关联到recyclerView上的呢，我们看一下DividerFragment,onActivityFragment,调用setAgentContainerView,最后调用SectionRecyclerCellManager的setAgentContainerView
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setAgentContainerView(mRecyclerView);
}@Override
public void setAgentContainerView(RecyclerView containerView) { //给recyclerView设置adapter
if (containerView == null) {
return;
}
this.recyclerView = containerView;
if (recyclerView.getLayoutManager() == null) {
layoutManager = new LinearLayoutManagerWithSmoothOffset(mContext);
layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
recyclerView.setLayoutManager(layoutManager);
} else if (recyclerView.getLayoutManager() instanceof LinearLayoutManager) {
layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
}
recyclerView.setAdapter(mergeRecyclerAdapter);
if (mCanExposeScreen) {
recyclerView.removeOnScrollListener(mOnScrollListener);
recyclerView.addOnScrollListener(mOnScrollListener);
}
}现在关于组建的渲染工作完成
对于多个组建的适配器如何整合继续分析
SectionRecyclerManager的addCellToContainerView调用了MergeSectionDividerAdapter的addAdapter,把Cell的适配器添加到MergeSectionDividerAdapter pieces集合，getItemViewType的参数分别代表了第几个section，section的第几行，根据参数查找对应的SectionPosition的信息，从pieces中回去adapter，返回type类型，在onCreateViewHolder，根据viewType获取对应的adapter，然后调用adapter的onCreateViewHolder，到这里基本的逻辑分析完了，只是个人的见解，希望有更好的分析，我可以参考学习
public void addAdapter(PieceAdapter adapter) {
adapter.registerAdapterDataObserver(mObserver);
pieces.add(adapter);
updateInfo();
notifyDataSetChanged();
}@Override
public int getItemViewType(int sectionIndex, int position) { //根据传递过来的sectionIndex，position获取type
DetailSectionPositionInfo info = getDetailSectionPositionInfo(sectionIndex, position); //获取section的position
if (info != null) {
PieceAdapter adapter =
pieces.get(info.adapterIndex); //获取adapter的信息
if (adapter != null) {
int type = adapter.getItemViewType(info.adapterSectionIndex, info.adapterSectionPosition); //获取type
Pair<String, Integer> pair = new Pair<>(adapter.getMappingKey(), type);
if (typeMap.containsKey(pair)) {
return typeMap.get(pair);
}
}
}
return 0;
}@Override
public BasicHolder onCreateViewHolder(ViewGroup parent, int viewType) {
Pair<String, Integer> pair = getAdapterType(viewType);
if (pair != null && !TextUtils.isEmpty(pair.first)) {
PieceAdapter adapter = getAdapterByMappingKey(pair.first);
if (adapter != null) {
if (performanceManager != null) {
Date start = new Date();
BasicHolder holder = adapter.onCreateViewHolder(parent, pair.second);
Date end = new Date();
performanceManager.insertRecord(pageName, adapter, "onCreateView", start.getTime(), end.getTime());
return holder;
} else {
return adapter.onCreateViewHolder(parent, pair.second);
}
}
}
return null;
}
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