Changing text in Android on text change causes overflow error
I want to create an application that can transform text the user enters in an EditText
widget in real time, and I've added a TextWatcher
to allow me to do stuff on text change, but it's causing an overflow error because I'm basically creating an endless loop (onTextChange -> code to change text -> onTextChange -> etc...
).
Anyone got an idea on how to get around this issue?
Here's an example
private boolean isEditable = true;
private EditText text;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
text = (EditText) findViewById(R.id.editText1);
text.addTextChangedListener(new TextWatcher() {
@Override
public void afterTextChanged(Editable s) {
}
@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 (isEditable) {
isEditable = false;
styleText(s.toString());
} else {
isEditable = true;
}
}
});
}
private void styleText(String completeText) {
text.setText(completeText + " test");
}
And while the above actually seems to be working, I cannot get it to work with Html.fromHtml();
, which is what I intend to use.
EDITED AGAIN
public class Main extends Activity implements TextWatcher {
private EditText text;
/** Called when the activity is firs开发者_如何学Ct created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
text = (EditText) findViewById(R.id.editText1);
text.addTextChangedListener(this);
}
@Override
public void afterTextChanged(Editable s) {
text.removeTextChangedListener(this);
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
text.addTextChangedListener(this);
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
text.removeTextChangedListener(this);
text.setText("Test!");
}
}
It's throwing a StackOverflowException
on line 37, which is "text.setText("Test!");
"
EDIT: And works, no exception is thrown:
txtwt = new TextWatcher(){
@Override
public void afterTextChanged(Editable s) {
Log.i("REACHES AFTER", "YES");
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
Log.i("REACHES BEFORE", "YES");
}
@Override
public void onTextChanged(CharSequence s, int start, int before,
int count) {
text.removeTextChangedListener(txtwt);//after this line you do the editing code
text.setText("TEST");
Log.i("REACHES ON", "YES");
text.addTextChangedListener(txtwt); // you register again for listener callbacks
}};
text = (EditText) findViewById(R.id.editText1);
text.addTextChangedListener(txtwt);
This is the Logcat proof, when I dramatically pushed keys :
08-28 19:53:21.265: INFO/REACHES BEFORE(492): YES
08-28 19:53:21.276: INFO/REACHES ON(492): YES
08-28 19:53:21.276: INFO/REACHES AFTER(492): YES
08-28 19:53:21.296: INFO/REACHES BEFORE(492): YES
08-28 19:53:21.305: INFO/REACHES ON(492): YES
08-28 19:53:21.305: INFO/REACHES AFTER(492): YES
08-28 19:53:21.745: INFO/REACHES BEFORE(492): YES
08-28 19:53:21.755: INFO/REACHES ON(492): YES
08-28 19:53:21.755: INFO/REACHES AFTER(492): YES
08-28 19:53:21.775: INFO/REACHES BEFORE(492): YES
08-28 19:53:21.785: INFO/REACHES ON(492): YES
08-28 19:53:21.785: INFO/REACHES AFTER(492): YES
08-28 19:53:22.698: INFO/REACHES BEFORE(492): YES
08-28 19:53:22.705: INFO/REACHES ON(492): YES
08-28 19:53:22.705: INFO/REACHES AFTER(492): YES
08-28 19:53:23.855: INFO/REACHES BEFORE(492): YES
08-28 19:53:23.865: INFO/REACHES ON(492): YES
08-28 19:53:23.865: INFO/REACHES AFTER(492): YES
08-28 19:53:24.385: INFO/REACHES BEFORE(492): YES
08-28 19:53:24.395: INFO/REACHES ON(492): YES
08-28 19:53:24.395: INFO/REACHES AFTER(492): YES
08-28 19:53:24.485: INFO/REACHES BEFORE(492): YES
08-28 19:53:24.485: INFO/REACHES ON(492): YES
08-28 19:53:24.485: INFO/REACHES AFTER(492): YES
08-28 19:53:24.515: INFO/REACHES BEFORE(492): YES
08-28 19:53:24.525: INFO/REACHES ON(492): YES
08-28 19:53:24.525: INFO/REACHES AFTER(492): YES
08-28 19:53:24.625: INFO/REACHES BEFORE(492): YES
08-28 19:53:24.635: INFO/REACHES ON(492): YES
08-28 19:53:24.635: INFO/REACHES AFTER(492): YES
08-28 19:53:24.654: INFO/REACHES BEFORE(492): YES
08-28 19:53:24.665: INFO/REACHES ON(492): YES
08-28 19:53:24.665: INFO/REACHES AFTER(492): YES
private String originalValue;
void onTextChanged(CharSequence text, int start, int before, int after) {
if (text.toString().equals(originalValue)) {
// do nothing
} else {
//change your text
originalValue = text.toString();
}
}
Edited:
public void onTextChanged(CharSequence s, int start, int before, int count) {
String currentText = s.toString();
if (currentText.equals(originalValue)) { //the originalValue must be defined outside of the Watcher
originalValue = styleText(currentText);
// text.setText(originalValue); //if styleText doesn't do this
} else {
return;
}
}
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