Wifi 源码学习之wifi列表

wifi系列博客地址：

Wifi源码学习（Android5.1）之wifi开关
Wifi源码学习（Android5.1）之wifi optionItem
Wifi源码学习（Android5.1）之wifi列表

Wifi 列表：

Settings\src\com\android\settings\wifi\WifiSettings.java

首先看一下这个类。

public class WifiSettings extends RestrictedSettingsFragment
        implements DialogInterface.OnClickListener, Indexable  {

继承了 Fragment，那就按照 Fragment 的生命周期思想来学习就好了。

@Override
public void onResume() {
    final Activity activity = getActivity();
    super.onResume();
    if (mWifiEnabler != null) {
        mWifiEnabler.resume(activity);
    }
    // 注册 广播接受者，接收什么广播呢？看下边
    activity.registerReceiver(mReceiver, mFilter);
    //更新界面
    updateAccessPoints();
}

// 注册的广播，源码中根据这些广播，来动态的修改界面中的显示

mFilter.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION);
mFilter.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);
mFilter.addAction(WifiManager.NETWORK_IDS_CHANGED_ACTION);
mFilter.addAction(WifiManager.SUPPLICANT_STATE_CHANGED_ACTION);
mFilter.addAction(WifiManager.CONFIGURED_NETWORKS_CHANGED_ACTION);
mFilter.addAction(WifiManager.LINK_CONFIGURATION_CHANGED_ACTION);
mFilter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);
mFilter.addAction(WifiManager.RSSI_CHANGED_ACTION);

根据当前 wifi 的状态来更新界面
// 单独抽离出来写成一个单纯根据 wifi 状态来更新界面的方法，便于复用。

/**
 * Shows the latest access points available with supplemental information like
 * the strength of network and the security for it.
 */
private void updateAccessPoints() {
    // Safeguard from some delayed event handling
    if (getActivity() == null) return;
    if (isUiRestricted()) {
        addMessagePreference(R.string.wifi_empty_list_user_restricted);
        return;
    }
    // 获取wifi状态
    final int wifiState = mWifiManager.getWifiState();
    //when we update the screen, check if verbose logging has been turned on or off
    mVerboseLogging = mWifiManager.getVerboseLoggingLevel();
    switch (wifiState) {
        // wifi 为可用状态
        case WifiManager.WIFI_STATE_ENABLED:
            // AccessPoints are automatically sorted with TreeSet.
            // 获取数据
            final Collection accessPoints =
                    constructAccessPoints(getActivity(), mWifiManager, mLastInfo,
                            mLastNetworkInfo);
            // 清空历史
            getPreferenceScreen().removeAll();
            if (accessPoints.size() == 0) {
                // 没有数据就显示无可用 WiFi 界面
                addMessagePreference(R.string.wifi_empty_list_wifi_on);
            }
            // 有数据就显示
            for (AccessPoint accessPoint : accessPoints) {
                // Ignore access points that are out of range.
                if (accessPoint.getLevel() != -1) {
                    getPreferenceScreen().addPreference(accessPoint);
                }
            }
            break;
        // wifi 正在打开...
        case WifiManager.WIFI_STATE_ENABLING:
            getPreferenceScreen().removeAll();
            break;
        // wifi 正在关闭...
        case WifiManager.WIFI_STATE_DISABLING:
            addMessagePreference(R.string.wifi_stopping);
            break;
        // wifi 不可用状态
        case WifiManager.WIFI_STATE_DISABLED:
            setOffMessage();
            break;
    }
}

// 获取wifi信息的方法

/** Returns sorted list of access points */
private static List constructAccessPoints(Context context,
        WifiManager wifiManager, WifiInfo lastInfo, NetworkInfo lastNetworkInfo) {
    ArrayList accessPoints = new ArrayList();
    /** Lookup table to more quickly update AccessPoints by only considering objects with the
     * correct SSID.  Maps SSID -> List of AccessPoints with the given SSID.  */
    Multimap apMap = new Multimap();
      // 获取已经 配置过的 wifi
    final List configs = wifiManager.getConfiguredNetworks();
    if (configs != null) {
        // Update "Saved Networks" menu option.
        if (savedNetworksExist != (configs.size() > 0)) {
            savedNetworksExist = !savedNetworksExist;
            if (context instanceof Activity) {
                ((Activity) context).invalidateOptionsMenu();
            }
        }
        for (WifiConfiguration config : configs) {
            if (config.selfAdded && config.numAssociation == 0) {
                continue;
            }
            AccessPoint accessPoint = new AccessPoint(context, config);
            if (lastInfo != null && lastNetworkInfo != null) {
                accessPoint.update(lastInfo, lastNetworkInfo);
            }
            accessPoints.add(accessPoint);
            apMap.put(accessPoint.ssid, accessPoint);
        }
    }
    // 获取搜索到的 wifi 信息
    final List results = wifiManager.getScanResults();
    if (results != null) {
        for (ScanResult result : results) {
            // Ignore hidden and ad-hoc networks.
            if (result.SSID == null || result.SSID.length() == 0 ||
                    result.capabilities.contains("[IBSS]")) {
                continue;
            }
            boolean found = false;
            // 如果已经存在，则进行更新，为了快速更新界面，看上边 apMap 的英文注释
            for (AccessPoint accessPoint : apMap.getAll(result.SSID)) {
                if (accessPoint.update(result))
                    found = true;
            }
            if (!found) {
                // 如果没有，则重新创建新对象，进行添加
                AccessPoint accessPoint = new AccessPoint(context, result);
                if (lastInfo != null && lastNetworkInfo != null) {
                    accessPoint.update(lastInfo, lastNetworkInfo);
                }
                accessPoints.add(accessPoint);
                // 添加到 apMap 中
                apMap.put(accessPoint.ssid, accessPoint);
            }
        }
    }
    // Pre-sort accessPoints to speed preference insertion
    // 将wifi进行排序（按照是否已经连接，信号量等）
    Collections.sort(accessPoints);
    return accessPoints;
}

wifi 列表的生成源码分析暂时就到这儿了。