Develop Reference

Android AccessibilityService performAction() method not working

I am developing an accessibility service for Android. The service calls an app, and that app has a RecyclerView. Then I want to click on an element of the RecyclerView with performAction(AccessibilityNodeInfo.ACTION_CLICK) but it is not working. I know there are a few similar questions but none of them works for me. Also I checked the official documentation for the class of the performAction method https://developer.android.com/reference/android/view/accessibility/AccessibilityNodeInfo
This is my code:
#Override
public void onAccessibilityEvent(Accessibility event){
AccessibilityNodeInfo source = event.getSource();
if(source != null){
List<AccessibilityNodeInfo> list = source.findAccessibilityNOdeInfosByText("mystring");
list.get(0).performAction(AccessibilityNodeInfo.ACTION_CLICK);
}
}
This is my configuration xml file:
<accessibility-srvice xmlns...
android:accessibilityFeedbackType = "feedbackGeneric"
android:AccessibilityFlags = "flagDefault"
android:canPerformGestures = "true"
android:canRetrieveWIndowCOntent = "true"
I think I misunderstood something, but i don't know what can be. Any help is appreciated.

The simple answer is that while finding the node by text is fine, that particular node was not the node with the desired onClick event. The solution is to call
list.get(0).getParent().performAction(AccessibilityNodeInfo.ACTION_CLICK)
The clarifying discussion is below
I think .performAction(AccessibilityNodeInfo.ACTION_CLICK) is right, but there might be some other concerns. Sorry for posting as an answer but a comment is too small.
Are you sure the onAccessibilityEvent is being called? I don't think that is the right event, but I can't be sure. Maybe put a log in there to ensure it's calling the event when you expect it to be called.
Also, looking at the source might restrict your search, maybe instead of event.getSource() try using rootInActiveWindow (I use Kotlin so it might have a method, see https://developer.android.com/reference/android/accessibilityservice/AccessibilityService#getRootInActiveWindow(int))
EDIT: 28 March 2022
I have run this code on my own accessibility service and it does click the button. But it's very prone to overflow.
var ranOnce = false // prevent overflow
override fun onAccessibilityEvent(event: AccessibilityEvent?) {
if (event == null) return
if (event.eventType == TYPE_WINDOW_STATE_CHANGED) return
if (event.source != null && !ranOnce) {
val nodeList = rootInActiveWindow.findAccessibilityNodeInfosByText("Menu")
//event.source.findAccessibilityNodeInfosByText("Menu") // <-- always nothing in list
Log.d("onAccessibilityEvent", "List of nodes: $nodeList")
if (nodeList.size > 0) {
android.util.Log.d("onAccessibilityEvent", "Node info: ${nodeList[0]}")
ranOnce = true
nodeList[0].performAction(AccessibilityNodeInfo.ACTION_CLICK) //<-- caused an infinite loop!
} else {
Log.d("onAccessibilityEvent", "No nodes found")
}
} else {
Log.d("onAccessibilityEvent", "event.source is null!")
}
}

Android Studio - Condition is always true?

This would be the first time I post a question since I couldn't find the answer to this. Something really weird is happening with my if/else statements. My code was working perfectly for the past week, but recently it kept on telling me that a statement is always true?
My code is the following:
int checking = 1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (checking != 1) {
speaker.setChecked(true);
} else if (checking == 1) {
speaker.setChecked(false);
}
}
This says checking == 1 is always true which makes sense, but if I switch it around to:
if (checking == 1) {
speaker.setChecked(true);
} else if (checking != 1) {
speaker.setChecked(false);
}
This says that checking != 1 is always true as well. Can someone help?

It's just a logic of editor. In first if statement, you check checking == 1 and the second if statement, you negative the statement. The editor will understand the second if statement alway true
I think you should replace else if to else. Sorry my bad English.

The reason why you are seeing this warning is:
You have set int checking = 1 and you are either checking:
if (checking != 1) which is always true
Or checking == 1 which is also always true
Due to this other else if condition will not be executed at all.
The warning will be only removed if you try to change value of checking either at runtime or using some conditions at compile time.
If your intention is just to set the speaker.setChecked() you can do following:
speaker.setChecked(checking == 1)
Note: This will not remove the warning

Try this
int checking = 1;
boolean isChecked = false;
isChecked = ((checking == 1) ? true : false)
speaker.setChecked(isChecked)

Android executing both IF and ELSE statement together

I am working with FireBase Notifications and I can send a notification which will send the user to the webview page I input on the console.
The problem is that when it matches the IF statement is fires the else statement too, what could be the cause of this?
if(getIntent().getExtras()!=null) {
for (String key : getIntent().getExtras().keySet()) {
if (key.equals("url")){
mwebView.loadUrl("http://example.com/" + getIntent().getExtras().getString(key));
}else {
mwebView.loadUrl("http://example.com");
}
}
}
Because it executes both at the same time the app crashes.
Also when I load the app the usual way it matches the with:
if(getIntent().getExtras()!=null)
and then loads the else statement. Shouldnt getExtras be null?
When I first install a new instance of the app it uses the following statement:
if(getIntent().getExtras()==null) {
if (haveNetworkConnection()) {
mwebView.loadUrl("http://example.com");
} else {
mwebView.loadUrl("file:///android_asset/myerrorpage.html");
}
}
Update:
As I cannot find out why this it happening I am trying another approach, How would I get the variable outside of the loop to use like the following:
if(getIntent().getExtras()!=null) {
for (String key : getIntent().getExtras().keySet()) {
String valuex = getIntent().getExtras().getString(key);
}
}
if (haveNetworkConnection()) {
mwebView.loadUrl("http://example.com/" + valuex);
} else {
mwebView.loadUrl("file:///android_asset/myerrorpage.html");
}

If and Else can not both be executed in one go.
You should check your other code and ensure, that this code section is not executed twice for some reason (once with TRUE and once with FALSE).

Standalone return expression explanation

I was online looking at some android coding examples and i came across a method that had a return expression by itself,and i was wondering if someone could explain what that means.
Here is the code sample:
if(tempText.getText().length() ==0){
Toast.makeText(this, "Please enter a valid number", Toast.LENGTH_LONG).show();
return;
}

This is the If condition which checks for the length of the text which is "0" or not. If its "0" then it will show the Toast message and will return from or exit from the if loop an no further execution will processed.

using if condition you are checking for the length of text, if it is 0 then you are showing Toast
Using a return Keyword within a class, with a method
A method returning nothing
public void Void_Method()
{
<statements>
return;
}
A method returning a String
public String String_Method()
{
String s = "its Ridiculous to do such kind of work, people here are just aim less";
return s;
}
A method returning an Int value
public int Int_Method()
{
int i = 5;
return(i);
}
I hope this will help you understand the use of return keyword, and as name suggest - The return keyword is always used with a method only to specify that the method is going to return something.

Android Null Checker

I have a program that relates to a database. I start out my program by inserting a row using the following command.
long id = db.insertMajor(null, null, null, null);
it works perfect. I than alter the information but lets ignore that since for the time being I commented out all those lines. Now I want to check and see if it is null which is should be. If it is not null than I would like to check a checkbox. if it is null than I want to leave the box unchecked. So far I have this line to test.
String change = db.getMajorTitle(value).getString(1);
if (change.equals(null)) {
filled = false;
}
the filled boolean will check the box or not. If the database field is filled or not I always get a checkmark. Whats wrong?
UPDATE:
Since no one has figure it out I will post most of my code to try and help figure it out. I have also reset my emulator to ensure there is not problems with corrupted data.
chk1.setChecked(checker(1));
chk2.setChecked(checker(2));
chk3.setChecked(checker(3));
chk4.setChecked(checker(4));
}
boolean checker(int value){
DBAdapter db = new DBAdapter(this);
boolean filled = false;
db.open();
for (int i = 1; i <= 4; i++) {
String change = db.getMajorTitle(value).getString(1);
if (change == null) {
filled = false;
}else{
filled = true;
}
}
db.close();
return filled;
}
If someone copies this and it works can you please tell me what might be wrong with my emulator or eclipse or whatever. Thanks everyone for there input.
FINISHED:
I noticed that at another part in my program I changed null to "". I would like to thank everyone for being right and showing me different ways to code it.

You really don't need if statements for this.
filled = (change != null);

if (change.equals(null)) {
If change instance is not null, the above condition always returns false. Read Object equality constraints for more info.
If you want to check against null use
if( change == null) {
// change is null, update filled field
} else {
// change is not null, update filled field
}
If the database field is filled or not
I always get a checkmark. Whats wrong?
I guess that you would have initialized the filled field as true and never set it as false since your if condition always returns false or throws NullPointerException.

User ExceptionHandling mechanism. then you will succeed. Like
try {
if(change!=null)
{
//do ur work,if not null
}
else
{
// do some thing
}
}catch(NullPointerException e)
{
//do ur work,if null.
}