Android集成GoogleCast异常问题解析

Android集成Google Cast异常 Android 集成异常 2023-02-10 12:02:11 210人浏览安东尼

摘要

目录GoogleCast 异常问题需求Fragment/Activity 启动时查询Available Cast DevicesFragment/Activity 处于前台时，动态获

GoogleCast 异常问题

项目中集成 Google Cast 功能时，部分机型遇到一些问题

需求

项目中Cast需求有点特别，默认Cast Button处于不可见状态。 APP进入前台时，查询周围是否有可用Cast设备，有才显示Cast Button, 否则隐藏

根据流程，我们有两种情况需要处理

Fragment/Activity 启动时查询Available Cast Devices

暂命名方法1

代码实现如下： Fragment -> onResume(), checkCastDevices:

    public static boolean checkCastDevice(Context activity) {
        MediaRouter mediaRouter = MediaRouter.getInstance(activity);
        List<mediarouter.routeinfo> routes = mediaRouter.getRoutes();
        if (routes != null &amp;&amp; routes.size() != 0) {
            for (MediaRouter.RouteInfo info : routes) {
                if (info.getDeviceType() != MediaRouter.RouteInfo.CONNECTioN_STATE_DISCONNECTED
                        && !info.isDefault() && !info.isBluetooth() && !info.isDeviceSpeaker()) {
                    return true;
                }
            }
        }
        return false;
    }

Fragment/Activity 处于前台时，动态获取Availabe Cast Devices

暂命名方法2

监听了addCastStateListener CastContext.addCastStateListener(this)


    @Override
    public void onCastStateChanged(int i) {
        stateListenerListTemp.clear();
        stateListenerListTemp.addAll(stateListenerList);
        switch (i) {
            case CastState.CONNECTED:
                for (CastStateListener listener : stateListenerListTemp) {
                    listener.connected();
                }
                break;
            case CastState.CONNECTING:
                for (CastStateListener listener : stateListenerListTemp) {
                    listener.connecting();
                }
                break;
            case CastState.NO_DEVICES_AVAILABLE:  //has not available devices
                for (CastStateListener listener : stateListenerListTemp) {
                    listener.nodevicesAvailable();  // hide cast button
                }
                break;
            case CastState.NOT_CONNECTED:  //has available devices, but not connect
                for (CastStateListener listener : stateListenerListTemp) {
                    listener.notConnected();  // show cast button
                }
                break;
        }
        stateListenerListTemp.clear();
    }

依据上述实现，可以即时监听Cast Devices的变化，动态更新Cast Button的可见性

问题

新增了一个有个需求， Toolbar上新增了一个视图，需要根据Cast Button的可见性来设置视图可见性，即二者可见性互斥，但在测试中发现一些问题。

部分设备上，例如Remi Note 4，上述两个方法都无效

问题1，方法1 只有在进程销毁后第一次启动可以获取周围Available Cast Devices，之后关闭APP重启一直返回false
问题2，方法2 APP处于前台时，断开WIFI时，Cast Button消失，重新连接WIFI，Cast Button可见，但代码中并没有收到Cast Devices 状态更新的回调，设置Cast Button Visibility的代码并未执行，这就出现一种情况：虽然Cast Button不可见，但是新增的视图却并未显示。

分析

问题1

当App进程销毁后重新启动，可以成功获取Cast Devices，说明初始化CastContext时，主动扫描了周边Routes, 而App关闭后重新打开，部分设备未主动扫描，所以获取状态失败。

问题2

当Cast Button可见时，断开WIFI连接，因为没有收到onCastStateChanged的回调，CastButton.SetVisibility(View.GONE)并未执行, 但是Cast Button 却不可见了，打开Developers options--Show layouts bounds开关，发现Cast Button 在布局中存在，但是图标却不可见，那么有两种可能： - Cast Button的Drawable 被移除了 - Cast Button被设为View.INVISIBLE

但是onCastStateChanged的回调并未执行，但是Cast Button 状态却有变化，那只能说明Cast Button内部监听了连接状态的变化，并内部处理了展示状态。

项目中Cast Button是一个MediaRouteButton，查询源码

public class MediaRouteButton extends View {
    private static final String TAG = "MediaRouteButton";
    private static ConnectivityReceiver sConnectivityReceiver;
    private int mVisibility = VISIBLE;
    private boolean mAlwaysVisible;
    public MediaRouteButton(Context context) {
        this(context, null);
    }
    public MediaRouteButton(Context context, AttributeSet attrs) {
        this(context, attrs, R.attr.mediaRouteButtonStyle);
    }
    public MediaRouteButton(Context context, AttributeSet attrs, int defStyleAttr) {
        super(MediaRouterThemeHelper.createThemedButtonContext(context), attrs, defStyleAttr);
        if (sConnectivityReceiver == null) {
            sConnectivityReceiver = new ConnectivityReceiver(context.getApplicationContext());
        }
    }
    @Override
    public void onAttachedToWindow() {
        super.onAttachedToWindow();
        sConnectivityReceiver.reGISterReceiver(this);
    }
    @Override
    public void onDetachedFromWindow() {
        if (!isInEditMode()) {
            sConnectivityReceiver.unregisterReceiver(this);
        }
        super.onDetachedFromWindow();
    }
    void refreshVisibility() {
        //set VISIBLE or INVISIBLE
        super.setVisibility(mVisibility == VISIBLE
                && !(mAlwaysVisible || sConnectivityReceiver.isConnected())
                ? INVISIBLE : mVisibility);
    }
    
    private static final class ConnectivityReceiver extends BroadcastReceiver {
        private final Context mContext;
        // If we have no infORMation, assume that the device is connected
        private boolean mIsConnected = true;
        private List<MediaRouteButton> mButtons;
        ConnectivityReceiver(Context context) {
            mContext = context;
            mButtons = new ArrayList<MediaRouteButton>();
        }
        public void registerReceiver(MediaRouteButton button) {
            if (mButtons.size() == 0) {
                IntentFilter intentFilter = new IntentFilter();
                intentFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
                mContext.registerReceiver(this, intentFilter);
            }
            mButtons.add(button);
        }
        public void unregisterReceiver(MediaRouteButton button) {
            mButtons.remove(button);
            if (mButtons.size() == 0) {
                mContext.unregisterReceiver(this);
            }
        }
        public boolean isConnected() {
            return mIsConnected;
        }
        @Override
        public void onReceive(Context context, Intent intent) {
            final String action = intent.getAction();
            if (ConnectivityManager.CONNECTIVITY_ACTION.equals(action)) {
                boolean isConnected = !intent.getBooleanExtra(
                        ConnectivityManager.EXTRA_NO_CONNECTIVITY, false);
                if (mIsConnected != isConnected) {
                    mIsConnected = isConnected;
                    for (MediaRouteButton button: mButtons) {
                        button.refreshVisibility();
                    }
                }
            }
        }
    }
}

源码中可见，内部定义了ConnectivityReceiver来监听连接状态的变化，从而内部控制MediaRouteButton的显示。

解决

问题1

App启动时，虽然主动扫描周边Routes，来更新可以Cast Devices状态

    //Init Cast
    public static void initCast(Context context) {
        if (context == null)
            return;
        if (initialized) {
            CastContextManager.getInstance().addRouter(context);
            return;
        }
        initialized = true;
        //初始化CastContextManager
        ....
    }
    public void addRouter(Context context) {
        if(castContext !=null){
            MediaRouter mediaRouter = MediaRouter.getInstance(context);
            mediaRouter.removeCallback(callback);
            mediaRouter.addCallback(MediaRouteSelector.EMPTY, callback, MediaRouter.CALLBACK_FLAG_PERFORM_ACTIVE_SCAN);
        }
    }
    private final MediaRouter.Callback callback = new MediaRouter.Callback() {
        @Override
        public void onProviderAdded(MediaRouter router, MediaRouter.ProviderInfo provider) {
            super.onProviderAdded(router, provider);
            ZenLogger.dd("MXMediaRouter", () -> "onProviderAdded  " + provider.getRoutes());
        }
        @Override
        public void onProviderRemoved(MediaRouter router, MediaRouter.ProviderInfo provider) {
            super.onProviderRemoved(router, provider);
            ZenLogger.dd("MXMediaRouter", () -> "onProviderRemoved  " + provider.getRoutes());
        }
        @Override
        public void onProviderChanged(MediaRouter router, MediaRouter.ProviderInfo provider) {
            super.onProviderChanged(router, provider);
            ZenLogger.dd("MXMediaRouter", () -> "onProviderChanged  " + provider.getRoutes());
        }
    };

问题2

因为无法收到onCastStateChanged的回调，而且MediaRouteButton内部监听了连接状态的变化来更新显示，那么我们也效仿相同的实现，通过监听当前连接状态，结合MediaRouteButton的可见性，来判断Available Cast Devices

当前连接断开，直接隐藏MediaRouteButton
当前连接恢复，查询是否有Available Cast Devices，来设置MediaRouteButton可见
再判断MediaRouteButton是否可见，来设置新视图的可见性

    public static boolean checkCastDevice(Context activity) {
        //如果当前无连接， 说明unavailable Cast devices
        if (!NetworkMonitor.isConnected(App.applicationContext())) return false;
        MediaRouter mediaRouter = MediaRouter.getInstance(activity);
        List<MediaRouter.RouteInfo> routes = mediaRouter.getRoutes();
        if (routes != null && routes.size() != 0) {
            for (MediaRouter.RouteInfo info : routes) {
                if (info.getDeviceType() != MediaRouter.RouteInfo.CONNECTION_STATE_DISCONNECTED
                        && !info.isDefault() && !info.isBluetooth() && !info.isDeviceSpeaker()) {
                    return true;
                }
            }
        }
        return false;
    }
    private NetworkMonitor.OnNetworkListener onNetWorkListener = (last, current) -> {
        showMediaRouteButton(CastHelper.checkCastDevice(getActivity()));
        //check MediaRouteButton isVisible
        ...
    };