如何检查 JellyBean 中的 Talkback 是否处于活动状态

Question

This question 询问如何知道 Android Talkback 是否处于活动状态；直到果冻豆为止。从 Android 4.1 开始，这些步骤不再起作用，因为提到的光标是空的。

话虽如此，我想问的是是否有办法在 Jelly Bean 中进行相同的检查。

编辑 我试图搜索 TalkBack 代码并找到它here。 为了检查 TalkBack 是否处于活动状态，我使用以下代码：

Intent screenReaderIntent = new Intent("android.accessibilityservice.AccessibilityService");
screenReaderIntent.addCategory("android.accessibilityservice.category.FEEDBACK_SPOKEN");
List<ResolveInfo> screenReaders = getPackageManager().queryIntentServices(screenReaderIntent, 0);
Cursor cursor = null;
ContentResolver cr = getContentResolver();
for (ResolveInfo screenReader : screenReaders) {
    cursor = cr.query(Uri.parse("content://" + screenReader.serviceInfo.packageName
            + ".providers.StatusProvider"), null, null, null, null);
    //here, cursor is not null, but calling cursor.moveToFirst() returns false, which means the cursor is empty
}

话虽如此，如果光标为空，我们如何知道 TalkBack 是否正在运行？

编辑 2 根据@JoxTraex 的建议，我现在发送一个广播来查询是否启用了 TalkBack：

Intent i = new Intent();
i.setAction("com.google.android.marvin.talkback.ACTION_QUERY_TALKBACK_ENABLED_COMMAND");
sendBroadcast(i);

现在我应该如何接收响应？

我尝试将以下内容添加到清单中，但我的接收器没有收到任何响应：

<receiver android:name="my.package.MyBroadcastReceiver"
android:permission="com.google.android.marvin.talkback.PERMISSION_SEND_INTENT_BROADCAST_COMMANDS_TO_TALKBACK">
<intent-filter>
    <action android:name="com.google.android.marvin.talkback.ACTION_QUERY_TALKBACK_ENABLED_COMMAND" />
</intent-filter>

Answer 1

使用AccessibilityManager 可以更轻松地实现这一点。

AccessibilityManager am = (AccessibilityManager) getSystemService(ACCESSIBILITY_SERVICE);
boolean isAccessibilityEnabled = am.isEnabled();
boolean isExploreByTouchEnabled = am.isTouchExplorationEnabled();

Answer 2

您可以检查已启用的语音无障碍服务器

fun Context.isScreenReaderEnabled(): Boolean {
    val accessibilityManager = getSystemService(Context.ACCESSIBILITY_SERVICE) as AccessibilityManager

    if (!accessibilityManager.isEnabled)
        return false

    val serviceInfoList = accessibilityManager.getEnabledAccessibilityServiceList(AccessibilityServiceInfo.FEEDBACK_SPOKEN)

    if (serviceInfoList.isNullOrEmpty())
        return false

    return true
}

Answer 3

在查看 TalkBackService.java 时，我发现了这些代码段。这些细分应该提供一些关于如何查询状态的见解。

代码

/**
     * {@link Intent} broadcast action for querying the state of TalkBack. </p>
     * Note: Sending intent broadcast commands to TalkBack must be performed
     * through {@link Context#sendBroadcast(Intent, String)}
     */
    @Deprecated
    // TODO(caseyburkhardt): Remove when we decide to no longer support intent broadcasts for
    // querying the current state of TalkBack.
    public static final String ACTION_QUERY_TALKBACK_ENABLED_COMMAND = "com.google.android.marvin.talkback.ACTION_QUERY_TALKBACK_ENABLED_COMMAND";

    /**
     * Result that TalkBack is enabled.
     *
     * @see #ACTION_QUERY_TALKBACK_ENABLED_COMMAND
     */
    public static final int RESULT_TALKBACK_ENABLED = 0x00000001;

    /**
     * Result that TalkBack is disabled.
     *
     * @see #ACTION_QUERY_TALKBACK_ENABLED_COMMAND
     */
    public static final int RESULT_TALKBACK_DISABLED = 0x00000002;

    /**
     * Permission to send {@link Intent} broadcast commands to TalkBack.
     */
    public static final String PERMISSION_SEND_INTENT_BROADCAST_COMMANDS_TO_TALKBACK = "com.google.android.marvin.talkback.PERMISSION_SEND_INTENT_BROADCAST_COMMANDS_TO_TALKBACK";

    /**
     * Tag for logging.
     */
    private static final String LOG_TAG = "TalkBackService";

public static final String ACTION_QUERY_TALKBACK_ENABLED_COMMAND = "com.google.android.marvin.talkback.ACTION_QUERY_TALKBACK_ENABLED_COMMAND";
..

            } else if (ACTION_QUERY_TALKBACK_ENABLED_COMMAND.equals(intentAction)) {
            // TODO(caseyburkhardt): Remove this block when we decide to no
            // longer support
            // intent broadcasts for determining the state of TalkBack in
            // favor of the content
            // provider method.
            if (sInfrastructureInitialized) {
                setResultCode(RESULT_TALKBACK_ENABLED);
            } else {
                setResultCode(RESULT_TALKBACK_DISABLED);
            }
        }
            ...
    }

说明

您必须使用以下操作向 TalkBackService 发送 Intent 广播：

public static final String ACTION_QUERY_TALKBACK_ENABLED_COMMAND = "com.google.android.marvin.talkback.ACTION_QUERY_TALKBACK_ENABLED_COMMAND";

然后检查 Extras 的内容并进行相应的处理。

还确保您拥有正确的权限：

public static final String PERMISSION_SEND_INTENT_BROADCAST_COMMANDS_TO_TALKBACK = "com.google.android.marvin.talkback.PERMISSION_SEND_INTENT_BROADCAST_COMMANDS_TO_TALKBACK";

Answer 4

我不确定这是实现建议的最佳方式，但我设法通过使用以下代码完成了这项工作：

Intent screenReaderIntent = new Intent("android.accessibilityservice.AccessibilityService");
screenReaderIntent.addCategory("android.accessibilityservice.category.FEEDBACK_SPOKEN");
List<ResolveInfo> screenReaders = getPackageManager().queryIntentServices(screenReaderIntent, 0);
Cursor cursor = null;
int status = 0;
ContentResolver cr = getContentResolver();

List<String> runningServices = new ArrayList<String>();
ActivityManager manager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
    runningServices.add(service.service.getPackageName());
}

for (ResolveInfo screenReader : screenReaders) {
    cursor = cr.query(Uri.parse("content://" + screenReader.serviceInfo.packageName
            + ".providers.StatusProvider"), null, null, null, null);

    if (cursor != null && cursor.moveToFirst()) { //this part works for Android <4.1
        status = cursor.getInt(0);
        cursor.close();
        if (status == 1) {
            //screen reader active!
        } else {
            //screen reader inactive
        }
    } else {  //this part works for Android 4.1+
        if (runningServices.contains(screenReader.serviceInfo.packageName)) {
            //screen reader active!
        } else {
            //screen reader inactive
        }
    }
}

这可能不是最好的方法，但它是我能想到的唯一一种适用于 Jelly Bean 和以前的 Android 版本的方法