Problem: I've been trying unsuccessfully to append a file extension which follows the cursor in real-time as a user types.
What I've tried: I've been trying to use the .addTextChangedListener() which I think is correct, but having an issue trying to make the idea happen. Debugging shows is continually looping and so it gives the appearance of freezing. I looked at a couple post here on the forum but the ones suggested when I entered this post title dealt with prefixes and not suffixes.
EditText field with highlighted area representing text to follow right of cursor:
One of my poor attempts to make it work:
private void setupAddDBEditText(){
mDBToAdd.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
#Override
public void afterTextChanged(Editable s) {
if(s.toString().contains(".db"))
mDBToAdd.setText(s.toString().substring(0,s.toString().length()-3));
mDBToAdd.setText(s + ".db");
}
}
You will need to remove the listener when you change the text (that's why you are getting an infinite loop).
You can make a custom TextWatcher to handle this sort of thing (below) that removes itself as a watcher, changes the text and puts the cursor in the right place, then adds itself back.
public class FileExtensionTextWatcher implements TextWatcher {
private final String extension;
private final EditText text;
FileExtensionTextWatcher(EditText t, String ext) {
extension = ext;
text = t;
}
// you may want to change around the logic in here to allow for
// odd entries or other changes - but the overall approach should
// be similar
private String removeAutoExtension(String s) {
String ext = "." + extension;
if( s.contains(ext) ) {
int ei = s.lastIndexOf(ext);
if( ei == 0 ) return "";
String trailingChar = "";
if( ei < s.length() - ext.length() ) {
trailingChar = s.substring(ei+ext.length());
}
return s.substring(0,ei) + trailingChar;
}
else {
return s;
}
}
#Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) { }
#Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) { }
#Override
public void afterTextChanged(Editable txt) {
if( txt == null ) return;
String currentText = txt.toString();
String filename = removeAutoExtension(currentText);
int initCursor = filename.length();
String displayedText;
if( filename.isEmpty() ) {
displayedText = filename;
}
else {
displayedText = filename + "." + extension;
}
text.removeTextChangedListener(this);
txt.clear();
txt.insert(0, displayedText);
text.setSelection(initCursor);
text.addTextChangedListener(this);
}
}
You would then use it like this
EditText e = findViewById(R.id.edit_text);
e.addTextChangedListener(new FileExtensionTextWatcher(e, "db"));
Here is a demo GIF of how it looks.
There are some changes you may want to make to handle things like whether the user is allowed to enter their own extension (this form does not allow it - but you could change that with some extra logic in the custom watcher).
I have an EditText field with a Customer Text Watcher on it. In a piece of code I need to change the value in the EditText which I do using .setText("whatever").
The problem is as soon as I make that change the afterTextChanged method gets called which created an infinite loop. How can I change the text without it triggering afterTextChanged?
I need the text in the afterTextChanged method so don't suggest removing the TextWatcher.
Short answer
You can check which View currently has the focus to distinguish between user and program triggered events.
EditText myEditText = (EditText) findViewById(R.id.myEditText);
myEditText.addTextChangedListener(new TextWatcher() {
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
if (myEditText.hasFocus()) {
// is only executed if the EditText was directly changed by the user
}
}
//...
});
Long answer
As an addition to the short answer:
In case myEditText already has the focus when you programmatically change the text you should call clearFocus(), then you call setText(...) and after you you re-request the focus. It would be a good idea to put that in a utility function:
void updateText(EditText editText, String text) {
boolean focussed = editText.hasFocus();
if (focussed) {
editText.clearFocus();
}
editText.setText(text);
if (focussed) {
editText.requestFocus();
}
}
For Kotlin:
Since Kotlin supports extension functions your utility function could look like this:
fun EditText.updateText(text: String) {
val focussed = hasFocus()
if (focussed) {
clearFocus()
}
setText(text)
if (focussed) {
requestFocus()
}
}
You could unregister the watcher, and then re-register it.
Alternatively, you could set a flag so that your watcher knows when you have just changed the text yourself (and therefore should ignore it).
Java:
public class MyTextWatcher implements TextWatcher {
private EditText editText;
// Pass the EditText instance to TextWatcher by constructor
public MyTextWatcher(EditText editText) {
this.editText = editText;
}
#Override
public void afterTextChanged(Editable e) {
// Unregister self before update
editText.removeTextChangedListener(this);
// The trick to update text smoothly.
e.replace(0, e.length(), e.toString());
// Re-register self after update
editText.addTextChangedListener(this);
}
...
}
Kotlin:
class MyTextWatcher(private val editText: EditText) : TextWatcher {
override fun afterTextChanged(e: Editable) {
editText.removeTextChangedListener(this)
e.replace(0, e.length, e.toString())
editText.addTextChangedListener(this)
}
...
}
Usage:
et_text.addTextChangedListener(new MyTextWatcher(et_text));
You may feel a little bit lag when entering text rapidly if you are using editText.setText() instead of editable.replace().
Easy trick to fix ... as long a your logic to derive the new edit text value is idempotent (which it probably would be, but just saying). In your listener method, only modify the edit text if the current value is different than the last time you modified the value.
e.g.,
TextWatcher tw = new TextWatcher() {
private String lastValue = "";
#Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
#Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
#Override
public void afterTextChanged(Editable editable) {
// Return value of getNewValue() must only depend
// on the input and not previous state
String newValue = getNewValue(editText.getText().toString());
if (!newValue.equals(lastValue)) {
lastValue = newValue;
editText.setText(newValue);
}
}
};
You can use Kotlin DSL syntax to have the generic solution for this:
fun TextView.applyWithDisabledTextWatcher(textWatcher: TextWatcher, codeBlock: TextView.() -> Unit) {
this.removeTextChangedListener(textWatcher)
codeBlock()
this.addTextChangedListener(textWatcher)
}
And inside your TextWatcher, you can use it as:
editText.applyWithDisabledTextWatcher(this) {
text = formField.name
}
I use that way:
mEditText.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {}
#Override
public void afterTextChanged(Editable s) {
if (mEditText.isFocused()) { //<-- check if is focused
mEditText.setTag(true);
}
}
});
And every time you need to change text programatically, first clear the focus
mEditText.clearFocus();
mEditText.setText(lastAddress.complement);
The problem can be easily solved using tag filed and you don't even have to deal with editText's focus.
Setting the text and the tag programmatically
editText.tag = "dummyTag"
editText.setText("whatever")
editText.tag = null
Checking for the tag in onTextChanged
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
if (editText.tag == null) {
// your code
}
}
This works good for me
EditText inputFileName; // = (EditText)findViewbyId(R.id...)
inputFileName.addTextChangedListener(new TextWatcher() {
public void afterTextChanged(Editable s) {
//unregistering for event in order to prevent infinity loop
inputFileName.removeTextChangedListener(this);
//changing input's text
String regex = "[^a-z0-9A-Z\\s_\\-]";
String fileName = s.toString();
fileName = fileName.replaceAll(regex, "");
s.replace(0, s.length(), fileName); //here is setting new text
Log.d("tag", "----> FINAL FILE NAME: " + fileName);
//registering back for text changes
inputFileName.addTextChangedListener(this);
}
public void beforeTextChanged(CharSequence s, int start, int count, int after) { }
public void onTextChanged(CharSequence s, int start, int before, int count) { }
});
If you need to stay focused on EditText change text you could request focus:
if (getCurrentFocus() == editText) {
editText.clearFocus();
editText.setText("...");
editText.requestFocus();
}
It's easy just do it like this
editText.addTextChangedListener(object : TextWatcher {
private var isEditing = false
override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
}
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
}
override fun afterTextChanged(s: Editable?) {
if(!isEditing){
isEditing = true
editText.setText("Hello World!")
isEditing = false
}
}
})
in this way it don't stock in infinite loop
try this logic:
I wanted to setText("") without going to infinite loop and this code works for me. I hope you can modify this to fit your requirement
final EditText text= (EditText)findViewById(R.id.text);
text.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
#Override
public void afterTextChanged(Editable s) {
if(s.toString().isEmpty())return;
text.setText("");
//your code
}
});
Here's a handy class that provides a simpler interface than TextWatcher for the normal case of wanting to see changes as they occur. It also allows for ignoring the next change as the OP requested.
public class EditTexts {
public final static class EditTextChangeListener implements TextWatcher {
private final Consumer<String> onEditTextChanged;
private boolean ignoreNextChange = false;
public EditTextChangeListener(Consumer<String> onEditTextChanged){
this.onEditTextChanged = onEditTextChanged;
}
public void ignoreNextChange(){
ignoreNextChange = true;
}
#Override public void beforeTextChanged(CharSequence __, int ___, int ____, int _____) { }
#Override public void onTextChanged(CharSequence __, int ___, int ____, int _____) { }
#Override public void afterTextChanged(Editable s) {
if (ignoreNextChange){
ignoreNextChange = false;
} else {
onEditTextChanged.accept(s.toString());
}
}
}
}
Use it like this:
EditTexts.EditTextChangeListener listener = new EditTexts.EditTextChangeListener(s -> doSomethingWithString(s));
editText.addTextChangedListener(listener);
Whenever you want to modify the contents of editText without causing a cascade of recursive edits, do this:
listener.ignoreNextChange();
editText.setText("whatever"); // this won't trigger the listener
My variant:
public class CustomEditText extends AppCompatEditText{
TextWatcher l;
public CustomEditText(Context context, AttributeSet attrs) {
super(context, attrs);
}
public void setOnTextChangeListener(TextWatcher l) {
try {
removeTextChangedListener(this.l);
} catch (Throwable e) {}
addTextChangedListener(l);
this.l = l;
}
public void setNewText(CharSequence s) {
final TextWatcher l = this.l;
setOnTextChangeListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
#Override
public void afterTextChanged(Editable s) {
}
});
setText(s);
post(new Runnable() {
#Override
public void run() {
setOnTextChangeListener(l);
}
});
}
}
Set listeners only using setOnTextChangeListener() and set text only using setNewText (I wanted to override setText(), but it is final)
I've created an abstract class which mitigates the cyclic issue of when a modification to the EditText is made via a TextWatcher.
/**
* An extension of TextWatcher which stops further callbacks being called as a result of a change
* happening within the callbacks themselves.
*/
public abstract class EditableTextWatcher implements TextWatcher {
private boolean editing;
#Override
public final void beforeTextChanged(CharSequence s, int start, int count, int after) {
if (editing)
return;
editing = true;
try {
beforeTextChange(s, start, count, after);
} finally {
editing = false;
}
}
abstract void beforeTextChange(CharSequence s, int start, int count, int after);
#Override
public final void onTextChanged(CharSequence s, int start, int before, int count) {
if (editing)
return;
editing = true;
try {
onTextChange(s, start, before, count);
} finally {
editing = false;
}
}
abstract void onTextChange(CharSequence s, int start, int before, int count);
#Override
public final void afterTextChanged(Editable s) {
if (editing)
return;
editing = true;
try {
afterTextChange(s);
} finally {
editing = false;
}
}
public boolean isEditing() {
return editing;
}
abstract void afterTextChange(Editable s);
}
Very simple, set text with this method
void updateText(EditText et, String text) {
if (!et.getText().toString().equals(text))
et.setText(text);
}
My solution for this is a lot like the others only it's my custom spin on it using viewbindings
I created the following TextWatcher
class ControlledTextWatcher(
private val parent: TextView,
private val onChange: ((text: CharSequence?, start: Int, before: Int, count: Int) -> Unit)?,
private val beforeChange: ((text: CharSequence?, start: Int, count: Int, after: Int) -> Unit)? = null,
private val afterChange: ((editable: Editable?) -> Unit)? = null
) : TextWatcher {
init {
parent.addTextChangedListener(this)
}
private var enabled = true
var text: String?
get() = parent.value
set(value) {
this.enabled = false
parent.text = value
this.enabled = true
}
var res: Int
get() = throw RuntimeException("String resource cannot be retrieved after being set")
set(value) {
parent.text = parent.context.getString(value)
}
override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
if (enabled)
beforeChange?.invoke(s, start, count, after)
}
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
if (enabled)
onChange?.invoke(s, start, before, count)
}
override fun afterTextChanged(s: Editable?) {
if (enabled)
afterChange?.invoke(s)
}
fun detach() {
parent.removeTextChangedListener(this)
}
}
and I use it mainly with view bindings like so
class TestActivity : AppCompatActivity() {
class TestActivity : AppCompatActivity() {
private lateinit var binding: ActivityTestBinding
private val edit by lazy { ControlledTextWatcher(binding.text, this::textChanged }
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityTestBinding.inflate(layoutInflater)
setContentView(binding.root)
}
so when I wish to make changes to the actual EditText I use the text or res attribute of the ControlledTextWatcher like so:
edit.text = "hello world" //this does not trigger the text watcher
but when the user alters the EditText it will trigger
unfortunatelly with this solution if you want to alter other parameters of the EditText, you either have to get the original EditText through bindings or copy those functions to the ControlledTextWatcher
also you have to be careful when making changes in afterChange because the change is posted to the TextView so you may end up with an endless loop
You should ensure your implementation of text changes is stable and does not change the text if no change is needed. Normally that would be any content that's already been through the watcher once.
The most common mistake is to set a new text in the associated EditText or the Editable even though the text was not actually changes.
On top of that, if you make your changes to the Editable instead of some specific View, you can easily resuse your watcher, and also you can test it in isolation with some unit tests to ensure it has the outcome you want.
Since Editable is an interface you could even use a dummy implementation of it that throws a RuntimeException if any of its methods are called that try to change its contents, when testing content that should be stable.
My way to do the thing:
In the write segment
EditText e_q;
e_q = (EditText) parentView.findViewWithTag("Bla" + i);
int id=e_q.getId();
e_q.setId(-1);
e_q.setText("abcd...");
e_q.setId(id);
The listener
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
int id = view.getId();
if(id==-1)return;
....
Works anyway.
I've implemented the MultiAutoCompleteTextView and everything is working fine but now I want to suggestions at any point the user press the first character of the suggested words. Basically the suggestions appears at the start of the text and when the last character in the text is ","
So, this is my words list:
{"/Bag","/Carton","/Kg","/20cm"}
And I want suggestions to appear if the user press something like: 567/
I've tried overriding the enoughFilter() in my custom class like this:
public static Tokenizer mTokenizer = new MultiAutoCompleteTextView.CommaTokenizer();
#Override
public boolean enoughToFilter() {
Editable text = getText();
int end = getSelectionEnd();
if (end < 0 || mTokenizer == null) {
return false;
}
int start = mTokenizer.findTokenStart(text, end);
if (end - start >= getThreshold() || text.charAt(text.length()-1) == '/') {
return true;
} else {
return false;
}
}
But this doesn't work at all and it crashes my code. Anyone with the idea?
And finally I was able to achieve this by overriding enoughFilter(), performFiltering() and replaceText() in my custom class.
So, for anyone who wants to implement something similar, check my code below:
public class MyAutoCompleteEdittext extends MultiAutoCompleteTextView
{
public static Tokenizer mTokenizer = new MultiAutoCompleteTextView.CommaTokenizer();
public MyAutoCompleteEdittext(Context context){
super(context);
}
public MyAutoCompleteEdittext(Context context, AttributeSet attrs){
super(context,attrs);
}
public MyAutoCompleteEdittext(Context context, AttributeSet attrs,int defStyle ){
super(context,attrs,defStyle);
}
#Override
public boolean enoughToFilter() {
String subText = getText().toString().substring(0,getSelectionEnd());
if(subText.contains("/"))
return true;
return false;
}
#Override
protected void performFiltering(CharSequence text, int start, int end, int keyCode)
{
super.performFiltering(text,findTokenStart(text.toString(),end),end,0);
}
#Override
protected void replaceText(CharSequence text) {
clearComposingText();
Editable editable = getText();
int end = getSelectionEnd();
int start = findTokenStart(editable.toString(),end);
String original = TextUtils.substring(editable, start, end);
QwertyKeyListener.markAsReplaced(editable, start, end, original);
editable.replace(start, end, mTokenizer.terminateToken(text));
}
private int findTokenStart(String allText, int end){
return allText.substring(0,end).lastIndexOf("/");
}
}
If you want more customization, check the source code HERE. That helps me a lot.
I have multiple EditTexts and I want to change the input of all of them at the same time, as I modify only one.(all of them take decimal numbers as input)
I stored the EditTexts in an array named 'editTexts'.
Here's what I tried
//Set the listener for each element
for (int i=0; i<editTexts.length; i++) {
final int finalI = i;
editTexts[i].addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
//if the editText which is currently edited is empty, set the input for all the rest to be '0.0'
if (editTexts[finalI].getText().toString().trim().length() == 0) {
for(EditText e : editTexts) {
if (e == editTexts[finalI])
continue;
e.setText("0.0");
}
} else {
float no = Float.parseFloat(s.toString() + "");
//Set the input of all the other editTexts to be the decimal number entered, multiplied by 2
for(EditText e : editTexts){
if(e == editTexts[finalI])
continue;
e.setText(no*2+"");
}
}
}
#Override
public void afterTextChanged(Editable s) {
}
})
}
In this case the multiplication coefficient is just an example, it's not always gonna be 2. I used it just to test it out.
For some reason, when I change the input value, the app freezes.
Any help? Thanks!
Use LiveData to store your user input values.
Once it's value changes you can set value to each EditText. I think it is an easy way to implement.
Try it like this:
// et_x1, et_x2 and et_x3 are ids of EditTexts
//set inputType for all EditTexts as numberDecimal
EditText editText1 = findViewById(R.id.et_x1);
final EditText editText2 = findViewById(R.id.et_x2);
final EditText editText3 = findViewById(R.id.et_x3);
editText1.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
String value = s.toString();
double x;
if (!value.equals("")) {
x = Double.parseDouble(value);
} else {
x = 0.0;
}
editText2.setText(Editable.Factory.getInstance().newEditable((String.valueOf(Math.pow(x, 2)))));
editText3.setText(
Editable.Factory.getInstance().newEditable((String.valueOf(Math.pow(x, 3)))));
}
#Override
public void afterTextChanged(Editable s) {
}
});
Hope it helps you!
The code below produce an stackoverflow error. The idea is to format the amount when or after user type an amount.
500 -> 500.00
1000 -> 1 000.00
29999.55-> 29 999.55
..
..
..
edit_amount.addTextChangedListener(new TextWatcher() {
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
#Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// TODO Auto-generated method stub
}
#Override
public void afterTextChanged(Editable s) {
if (edit_amount.getText().toString().length()>0){
edit_amount.setText(
currencyFormat(edit_amount.getText().toString()));
}else {}
}
});
public String currencyFormat(String number){
String credits="";
try {
//en, us
if (TextUtils.isEmpty(MyApplication.pref.GetPreferences("AppCurrency"))){
credits = NumberFormat.getCurrencyInstance(new Locale("fr", "FR")).format(Double.valueOf(number));
}else {
if (MyApplication.pref.GetPreferences("AppCurrency").equals("Euro")) {
credits = NumberFormat.getCurrencyInstance(new Locale("fr", "FR")).format(Double.valueOf(number));
} else {
credits = NumberFormat.getCurrencyInstance(new Locale("en", "US")).format(Double.valueOf(number));
}
}
}catch(Exception ex){
credits = "mCredits";
}
return credits;
}
Your code doesn't work because when you call edit_amount.setText(...) then the afterTextChanged(Editable s) is triggered and then edit_amount.setText(...) is triggered and so on. You need to change your logic to do what you want and avoid stack overflow.
For example you could unregister TextWatcher, setText and then register it again.
Alternatively, you can set a flag so that your TextWatcher knows when you change the text yourself and then instruct TextWatcher to ignore it.
To avoid recursive invocation of afterTextChanged callback you can set up additional chek. Smth like this
#Override
public void afterTextChanged(Editable s) {
if (et.getText().toString().length() > 0) {
String src = et.getText().toString();
String origin = currencyFormat(src);
if(!src.equals(origin)) {
et.setText(currencyFormat(et.getText().toString()));
}
}
}
Try below code :
private String current = "";
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
if(!s.toString().equals(current)){
[your_edittext].removeTextChangedListener(this);
String cleanString = s.toString().replaceAll("[$,.]", "");
double parsed = Double.parseDouble(cleanString);
String formatted = NumberFormat.getCurrencyInstance().format((parsed/100));
current = formatted;
[your_edittext].setText(formatted);
[your_edittext].setSelection(formatted.length());
[your_edittext].addTextChangedListener(this);
}
}