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 have a RecyclerView with an EditText in each row. Each EditText has a TextWatcher attached to it and an object in an array to store information about the row and the value of the EditText.
The problem I'm facing is that when the row goes offscreen, it gets recycled, but in that process, onTextChanged is called with an empty string, meaning an empty string is being saved to the row's information object. When that row is loaded again, it just loads a blank value, effectively deleting whatever content was in the EditText before. This seems like very useless functionality, because (as far as I can tell) there's no way to differentiate between a recycle clear and the user actually clearing the value in the EditText, making EditTexts in a RecyclerView completely useless.
my onBindViewHolder method is this:
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
int value = indicators.get(position).getValue();
System.out.println("VALUE: " + indicator.getValue());
if (value == -1) {
viewHolder.inputBox.setText("");
} else {
viewHolder.inputBox.setText(Integer.toString(value));
}
viewHolder.editListener.updatePosition(position);
}
My TextWatcher is this:
private class EditBoxListener implements TextWatcher {
private int position;
private CharSequence sequence;
private boolean initialCall = true;
public void updatePosition(int _position) {
position = _position;
}
#Override
public void beforeTextChanged(CharSequence charSequence, int start, int count, int after) {}
#Override
public void onTextChanged(CharSequence charSequence, int start, int before, int count) {
System.out.println("TEXT CHANGED TO: " + charSequence.toString());
if (!initialCall) {
int value = -1;
try {
value = Integer.parseInt(charSequence.toString());
} catch (Exception e) {}
if (indicators.size() > 0) {
indicators.get(position).setValue(value);
}
} else {
initialCall = false;
}
}
#Override
public void afterTextChanged(Editable editable) {}
}
Well one way to combat this would be to simply check if the text is blank or not before doing anything with it, perhaps something like this (forgive my poor formatting):
#Override
public void onTextChanged(CharSequence charSequence, int start, int before, int count) {
if (!charSequence.equals("")) {
System.out.println("TEXT CHANGED TO: " + charSequence.toString());
if (!initialCall) {
int value = -1;
try {
value = Integer.parseInt(charSequence.toString());
} catch (Exception e) {}
if (indicators.size() > 0) {
indicators.get(position).setValue(value);
}
} else {
initialCall = false;
}
}
}
I want to make a search from an ArrayList of custom objects and from those objects populate a ListView but I really don't know where to start....
Here's what I've got.
I get the search from a EditText and in an EditorActionListener I know when to start looking:
edittext.setOnEditorActionListener(new OnEditorActionListener() {
#Override
public boolean onEditorAction(TextView arg0, int arg1, KeyEvent arg2) {
//I got this from this site, another question
int searchListLength = medicos.size();
for (int i = 0; i < searchListLength; i++) {
if (medicos.get(i).getNombre().contains(edittext.getText().toString()))) {
//This is where Im suposed to do something but I dont know what to use to fill the ListView
}
}
return false;
}
});
Following is the structure of the custom object:
public class Medico implements Serializable{
private static final long serialVersionUID = 1L;
String nombre, especialidad1,especialidad2,especialidad3,celular,mail,telefono1,telefono2,ext,hospital,direccion;
double latitud,longitud;
public Medico(){}
public Medico(String nombre, String esp1,String esp2, String esp3, String cel,String mail,String tel1,String tel2, String ext,String hospital, String direccion, double lat, double lon){
this.nombre=nombre; //and so on.....
}
public void setNombre(String s){
this.nombre=s;
}
public void setEspecialidad1(String s){
this.especialidad1=s;
}
public String getNombre(){
return this.nombre;
}
public String getEspecialidad1(){
return this.especialidad1;
}
}
and so on.....
Thanks!
UPDATE (Code to update Adapter):
public void updatedData(ArrayList<Medico> itemsArrayList) {
myAdapter.clear();
if (itemsArrayList != null){
for (Medico object : itemsArrayList) {
//myAdapter.insert((Medico) object, myAdapter.getCount());
myAdapter.addAll(object);
//myAdapter.addAll(itemsArrayList);
}
}
myAdapter.notifyDataSetChanged();
}
You need to update the Adapter that you are using to to populate the ListView.
edittext.setOnEditorActionListener(new OnEditorActionListener() {
#Override
public boolean onEditorAction(TextView arg0, int arg1, KeyEvent arg2) {
//I will store the matches on this list.
List<Medico> resultado = new ArrayList<Medico>();
int searchListLength = medicos.size();
for (int i = 0; i < searchListLength; i++) {
if (medicos.get(i).getNombre().contains(searchsds)) {
// I found a match, I will add it to results
resultado.add(medicos.get(i));
}
}
//At the end, update the Adapter. I will assume that you have something like this.
myAdapter.setValues(resultado);
//You must write the code to set the values on your adapter. If you could post the way you are populating the list view I could help you out with more information.
return false;
}
});
i use a TextWatcher to change pressed key value. my goal is that replace some characters while typing. for example when i type keys, if reached "S" character, replaces it with "a" character. my question is: should i do it in beforeTextChanged?? how? can anyone give me an example?
I know that this post is a couple of years old, but both versions did not work for me and have build a hybrid between the two answers.
#Override
public void afterTextChanged(Editable editable) {
if (editable.toString().contains(",")) {
Editable ab = new SpannableStringBuilder(editable.toString().replace(",", ""));
editable.replace(0, editable.length(), ab);
}
}
Using beforeTextChanged won't be useful because it won't interrupt the actual printing of the key to the EditText. I would use something similar to:
public void afterTextChanged(Editable s) {
if(s.length() > 0 && s.toString().charAt(s.length()-1) == 'S')
{
final String newText = s.toString().substring(0, s.length()-1) + "a";
editText.setText(newText);
}
}
I added some toString()'s, not 100% sure how Editable works but I think that should cover it.
You have to do it in the afterTextChanged, but don't forget to detach
and reattach the TextChangedListener to prevent an endless loop.A simple example is shown below :
public void afterTextChanged(Editable s) {
editText.removeTextChangedListener(this);
//.. do changes here ..//
editText.setText(newText);
editText.addTextChangedListener(this);
}
But there is another problem when you call setText, it causes the cursor to move to the end of the text inside the textView. So you have to calculate the new position for the curser yourself, remember user may enter the multiple characters at once by pasting or delete a selected part of the text.Here is a more complete example. This watcher class removes all nonnumeric characters of the text.
public class NumWatcher implements TextWatcher {
private EditText editText;
private int selPos;
private String oldString, newString;
public NumWatcher(EditText editText) {
this.editText = editText;
}
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
selPos = editText.getSelectionStart();
oldString = myFilter(s.toString());
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
#Override
public void afterTextChanged(Editable s) {
editText.removeTextChangedListener(this);
newString = myFilter(s.toString());
editText.setText(newString);
int newPos = selPos + (newString.length() - oldString.length());
if (newPos < 0) newPos = 0;
editText.setSelection(newPos);
editText.addTextChangedListener(this);
}
public String myFilter(String s) {
String digits;
digits = s.replaceAll("[^0-9]", "");
if (s.equals("")) return "";
return digits;
}
}
#Override
public void afterTextChanged(Editable arg0) {
Editable ab = new SpannableStringBuilder(arg0.toString().replace("S", "a"));
arg0 = ab ;
}