accessibility service is not started

I want to log all toasts events in android ics (4.0.3), but I was unable to log any system event. Service is just not started!

According to this question: onAccessibilityEvent(AccessibilityEvent event) not intercepting notification

MyAccessibilityService.java

package com.test.toasts2;

import android.accessibilityservice.AccessibilityService;
import android.accessibilityservice.AccessibilityServiceInfo;
import android.app.Notification;
import android.os.Parcelable;
import android.util.Log;
import android.view.accessibility.AccessibilityEvent;
import android.widget.Toast;

public class MyAccessibilityService extends AccessibilityService {


    public static final String TAG = "volumeMaster";

    @Override
    public void onAccessibilityEvent(AccessibilityEvent event)
    {
        Log.v(TAG, "***** onAccessibilityEvent");
        Toast.makeText(getApplicationContext(), "Got event from: " + event.getPackageName(), Toast.LENGTH_LONG).show();
    }

    @Override
    public void onInterrupt()
    {
        Log.v(TAG, "***** onInterrupt");
    }

    @Override
    public void onServiceConnected()
    {
        Log.v(TAG, "***** onServiceConnected");       


        AccessibilityServiceInfo info = new AccessibilityServiceInfo();
        info.eventTypes = AccessibilityEvent.TYPE_NOTIFICATION_STATE_CHANGED;
        info.notificationTimeout = 100;
        info.feedbackType = AccessibilityEvent.TYPES_ALL_MASK;
        setServiceInfo(info);

    }
}

Toast2Activity.java

package com.test.toasts2;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.Toast;

public class Toast2Activity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Intent i = new Intent(this, MyAccessibilityService.class);
        startService(i);
    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.test.toasts2"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="15" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
<service android:name=".MyAccessibilityService" android:label="@string/app_name" android:enabled="true" android:exported="false">
        <intent-filter>
            <action android:name="android.accessibilityservice.AccessibilityService" />
        </intent-filter>

</service>

        <activity
            android:name=".Toast2Activity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

I included activity tag in manifest (to start service on app start), and also tried to remove. Nothing changed. Service is just not started. I don't get notification in log cat (Log.v in onServiceConected).

I am compiling this as normal app (not system app), android 4.0.3. Am I doing something wrong?

Attached project (may be mistake is somewhere else, or maybe I am compiling it wrong): https://dl.dropbox.com/u/1928109/toast2.zip

回答1:

You need to enable the accessibility service from the system settings menu:

Install your app on the testing device.
With the app installed on the device, change the following setting on the device:

Home Screen > System Settings > Accessibility > Accessibility Services > Toast2 > Change from Off to On,

where Toast2 is your app name.
Then run your app.

AFAIK there is no method to set accessibility programmatically to On mode from within your app. As a workaround you can prompt the user to change the setting and if they agree by clicking a button, launch the accessibility system settings like so:

Intent intent = new Intent(android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS);
startActivityForResult(intent, 0);

回答2:

As a complementary answer to the comments, one more thing worth noting is that you have to declare permission - android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE" in your service, or else there will be no switch in setting->accessibility.