Android APIs
Added in API level 1
public interface

TextWatcher

implements NoCopySpan
android.text.TextWatcher
Known Indirect Subclasses

Class Overview

When an object of a type is attached to an Editable, its methods will be called when the text is changed.

Summary

Public Methods
abstract void afterTextChanged(Editable s)
This method is called to notify you that, somewhere within s, the text has been changed.
abstract void beforeTextChanged(CharSequence s, int start, int count, int after)
This method is called to notify you that, within s, the count characters beginning at start are about to be replaced by new text with length after.
abstract void onTextChanged(CharSequence s, int start, int before, int count)
This method is called to notify you that, within s, the count characters beginning at start have just replaced old text that had length before.

Public Methods

public abstract void afterTextChanged (Editable s)

Added in API level 1

This method is called to notify you that, somewhere within s, the text has been changed. It is legitimate to make further changes to s from this callback, but be careful not to get yourself into an infinite loop, because any changes you make will cause this method to be called again recursively. (You are not told where the change took place because other afterTextChanged() methods may already have made other changes and invalidated the offsets. But if you need to know here, you can use setSpan(Object, int, int, int) in onTextChanged(CharSequence, int, int, int) to mark your place and then look up from here where the span ended up.

Parameters
s Editable

public abstract void beforeTextChanged (CharSequence s, int start, int count, int after)

Added in API level 1

This method is called to notify you that, within s, the count characters beginning at start are about to be replaced by new text with length after. It is an error to attempt to make changes to s from this callback.

Parameters
s CharSequence
start int
count int
after int

public abstract void onTextChanged (CharSequence s, int start, int before, int count)

Added in API level 1

This method is called to notify you that, within s, the count characters beginning at start have just replaced old text that had length before. It is an error to attempt to make changes to s from this callback.

Parameters
s CharSequence
start int
before int
count int