The document discusses accessibility services in Android, which allow automation of tasks and accessing blocked actions/information. It covers configuring an accessibility service class and manifest, available events, flags, and actions. It provides examples of retrieving UI elements, checking for specific text, and drawing overlays. Accessibility services can enable new features but require careful handling due to instability, difficult access, and potential permission loss.

1. Acessibilidade
O novo modo Deus no android

2. Gustavo Monteiro
Android Developer
Florianópolis - SC
/Pteroto
gustavosmonteiro@outlook.com
@pteroto

3. Quando utilizar a acessibilidade?
Automação de tarefas
Acesso a ações bloqueadas por meio de código
Acesso a informações bloqueadas
Sua imaginação é o limite!

4. Configuração básica
Classe do serviço de acessibilidade
Definição no AndroidManifest
Definindo parâmetros no xml de configuração

5. public class AccessibilityServiceExample extends AccessibilityService {
@Override
public void onAccessibilityEvent(AccessibilityEvent accessibilityEvent) {
}
@Override
public void onInterrupt() {
}
}
Classe Básica

6. <service
android:name=".AccessibilityServiceStudyControl"
android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE"
android:label="@string/accessibility_service_label">
<intent-filter>
<action android:name="android.accessibilityservice.AccessibilityService" />
</intent-filter>
<meta-data
android:name="android.accessibilityservice"
android:resource="@xml/accessibility_service_config" />
</service>
AndroidManifest

7. <accessibility-service
xmlns:android="http://schemas.android.com/apk/res/android"
android:accessibilityFlags="flagDefault"
android:canRetrieveWindowContent="true"
android:accessibilityEventTypes="typeAllMask"
android:accessibilityFeedbackType="feedbackAllMask"
android:notificationTimeout="100"
android:description="@string/accessibility_service_description"
android:packageNames="com.android.chrome"/>
Xml de configuração

8. EventTypes
Click
Window Content Changed
Text Changed
Scrolled
Window State Changed

9. Flags
Include Not Important Views
Report View Ids

10. FeedbackTypes
Haptic
Visual
Generic

11. Perform Actions
GLOBAL_ACTION_HOME
GLOBAL_ACTION_BACK
GLOBAL_ACTION_NOTIFICATIONS
ACTION_CLICK
ACTION_COPY
ACTION_PASTE

12. Objetos essenciais da
API de acessibilidade
AccessibilityNodeInfo
AccessibilityEvent

13. Na prática

14. @Override
protected void onServiceConnected() {
super.onServiceConnected();
performGlobalAction(GLOBAL_ACTION_BACK);
}

15. @Override
public void onAccessibilityEvent(AccessibilityEvent event) {
if (!AccessibilityServiceManager.getInstance().getServiceStatus())
return;
AccessibilityNodeInfo source = event.getSource();
if (source != null) {
AccessibilityNodeInfo root = findRoot(source);
if (root != null) {
AccessibilityNodeInfoCompat rootCompat =
new AccessibilityNodeInfoCompat(root);
...
}
}
}

16. private AccessibilityNodeInfo findRoot(AccessibilityNodeInfo node) {
try {
AccessibilityNodeInfo parent = node.getParent();
if (parent == null) {
return node;
} else {
return findRoot(parent);
}
} catch (Exception e) {
return null;
}
}

17. private final static String URL_BAR_ID = "com.android.chrome:id/url_bar";
private final static String URL_TWITCHTV = "twitch.tv";
...
List<AccessibilityNodeInfoCompat> urlBarList =
rootCompat.findAccessibilityNodeInfosByViewId(URL_BAR_ID);
if (urlBarList.size() > 0) {
String url = urlBarList.get(0).getText().toString();
if (url.contains(URL_TWITCHTV)) {
performGlobalAction(GLOBAL_ACTION_HOME);
}
}

18. performGlobalAction(GLOBAL_ACTION_BACK);
onServiceConnected()

19. if
(!AccessibilityServiceManager.getInstance()
.getServiceStatus())
return;

20. if (url.contains(URL_TWITCHTV)) {
performGlobalAction(GLOBAL_ACTION_HOME);

22. Exemplo 2
List<AccessibilityNodeInfoCompat> textViews =
rootCompat.findAccessibilityNodeInfosByText("doge");
for (AccessibilityNodeInfoCompat node : textViews) {
drawingDoge(node);
}

23. ...
Rect rc = new Rect();
node.getBoundsInScreen(rc);
...
...
ViewGroup viewGroup = (ViewGroup) LayoutInflater.from(this).
inflate(R.layout.doge_layout, null);
...
layoutParams.x = rc.right + dogeOffsetX;
layoutParams.y = rc.centerY() + dogeOffsetY;
windowManager.addView(viewGroup, layoutParams);

24. ...
dogeContainer.layoutParams.x = rc.right + dogeOffsetX;
dogeContainer.layoutParams.y = rc.centerY() + dogeOffsetY;
windowManager.updateViewLayout(dogeContainer.viewGroup,
dogeContainer.layoutParams);
...

26. Cuidados
Instabilidade
Difícil Acesso
Perda da Permissão
!

27. Dicas
Singleton
Service Bind
SharedPreference
Banco de dados

29. Referências
https://developer.android.com/guide/topics/ui/accessibility/index.html
https://developer.android.com/reference/android/view/accessibility/AccessibilityEvent.html
https://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html
https://developer.android.com/reference/android/view/accessibility/AccessibilityNodeInfo.html

30. Obrigado!
slides.com/gustavomonteiro/acessibilidade-palestra
github.com/Pteroto/androiddevconf_example1
github.com/Pteroto/androiddevconf_example2