Develop Reference

Associate EditText with a TextView for labeling purposes

Hi I am learning Android programming and have run into an issue that I couldn't get a clear answer to through researching.
I have a TextView which serves as a label for my EditText. I have a method which checks if the EditText is an empty String. If the string is empty I want to be able to get a reference to the TextView that corresponds to that EditText in order to make a toast saying something like "please enter a value for ".
I've looked into getLabelFor/setLabelFor but is there a way to do this in the layout XML?
What is best practice for this type of functionality.

You're describing a functionally that is build in to EditText. There is a special field you can define in xml called hint, which is the recommended way to label an EditText rather than a nearby TextView. Additionally, EditText has a method called setError() (link). If the user attempts to hit a submit button, for example, you can check to see if the EditText is empty and if so, call setError().

I wonder if the following is the thing that you need
TextWatcher inputTextWatcher = new TextWatcher() {
public void beforeTextChanged(CharSequence s, int start, int count, int after){
}
public void onTextChanged(CharSequence s, int start, int before, int count) {
if (s.toString().equals("")) {
textView.setText("please enter a value for ..");
} else {
textView.setText("<the textedit is not empty>");
}
}
public void afterTextChanged(Editable s) {
}
};
editText.addTextChangedListener(inputTextWatcher);

How to catch key pressed with the virtual keyboard and disable it for EditText in Android?

I need to control pressed buttons, before they goes to my EditText widget. It's should work like filter.
For example: I need that user could fill EditText only with digits 1,2,3,4,5 other symbols must be ignored. So the part of buttons on virtual keyboard should be disabled or I need to catch last pressed symbol, analyze it and disable for EditText.
Who knows the way how to solve this problem?
Thanks..

statusEdt.addTextChangedListener(new TextWatcher(){
public void afterTextChanged(Editable s) {}
public void beforeTextChanged(CharSequence s, int start, int count, int after) {}
public void onTextChanged(CharSequence s, int start, int before, int count) {
//do stuff
charTxt.setText(statusEdt.getText().length() + "/140");
}
});
I used this TextChangedListener(TextWatcher) to keep a count of how many characters had been typed into an EditText for a Twitter client I made. You could probably use a listener like this. You'll want to override beforeTextChanged or onTextChanged. These methods will pass you whatever CharSequence has been typed. You can check what was typed in and if it is not valid input you can remove it by calling setText() and passing in whatever has been typed so far minus the invalid characters.

What you probably need is an InputFilter.
For example to allow only digits, sign and decimal point:
editText.setFilters(DigistKeyListener.getInstance(true, true));

How to change focus from one editbox to another in android

I have three editboxes which has retrict to enter only one numeric digit on each box.when i enter the value of first box the focus should be moved from 1st box to 2nd.After entering value to 2nd box.,its focus should automatically moved to 2nd to 3rd like that i need to do.Could anybody help me regarding this?

You can use requestFocus() API to shift the focus from the code,
Keep listening for the text, using textWatcher, once specified limit is reached, call EditTextreference.requestFocus() to shift the focus.

This code moves focus from one EditText to another when EditText length greater than 1.
EditText et1,et2;
et1 = (EditText)findViewById(R.id.id1);
et2 = (EditText)findViewById(R.id.id2);
et1.addTextChangedListener(new TextWatcher()
{
public void afterTextChanged(Editable s)
{
// Abstract Method of TextWatcher Interface.
}
public void beforeTextChanged(CharSequence s,
int start, int count, int after)
{
// Abstract Method of TextWatcher Interface.
}
public void onTextChanged(CharSequence s,
int start, int before, int count)
{
Integer textlength = et1.getText().length();
if(textlength>=1){ //If text length greater than 1 move to next EditText
et2.requestFocus();
}
}
});

Android - How can I trigger a validation for an edittext field

I need to implement an edittext field that just allows user input from 20 to 60. If user input a number that is out of range, a dialog will display and force user to input again.
So the text watcher is not useful because it cannot prevent user input a number that lower than 20.
The onFocusChangedListener is neither, if user clicks on 'done' button, the edittext doesn't lost focus, so the trigger doesn't fire as well.
Besides, the edittext is inside a tab view, so when user clicks on another tab, the trigger fires but user cannot input value for that edittext any more.

Alvin is right ... this is my code to do something with text once entered, but could have as easily been a validation sequence:
smsMsgBody_editText.addTextChangedListener(new TextWatcher() {
public void onTextChanged(CharSequence s, int start, int before, int count) {
// Do something fancy
public void beforeTextChanged(CharSequence s, int start, int count, int after) { }
public void afterTextChanged(Editable s) { }
});

How about keeping track of the EditText field with onTextChanged?

use these
android:maxLength="2" android:numeric="integer"
then when you get the number like: number.gettext() you make validations like if number>60 and lower then 20 you can do number.setHint("number no valid");

Android EditText boxes

I want to cause the focus of one edit text box to move to another on editting (meaning you can only type on letter before it automatically moves on to the next edit text).
It's the "on edit" that I can't get my head around. Can anyone help me out with a simple example? Theres a lot I need to implement it into, so just a basic understanding should set the ball rolling ^_^

I do not really recommend this. With soft keyboards and multiple languages, what exactly is "one letter"? After all, a soft keyboard might enter in an entire word, like it or not.

CommonsWare makes an excellent point: you can't prevent the user from adding more characters to the EditText box, however you can listen to what's changed and act on that. Here's how to:
EditText editbox = (EditText) findViewById(R.id.MyEditBoxName);
editbox.addTextChangedListener(new TextWatcher()
{
public void beforeTextChanged(CharSequence s, int start, int count, int after)
{
}
public void onTextChanged(CharSequence s, int start, int before, int count)
{
}
public void afterTextChanged(Editable s)
{
// Test s for length, request focus for the next edit.
// editbox2.requestFocus();
}
});
Be careful not to get yourself into an infinite loop changing the editbox, any changes you make will cause these methods to be called again recursively.