Develop Reference

How do I enable the button, when editText.isNotBlank() and checkBox.isChecked?

I have 2 editText fields, a checkbox and a button enabled to false. I need to enable the button when the edittext fields are not empty and the checkbox is checked.
buttonEnter.setOnClickListener {
editTextLogin.addTextChangedListener(object : TextWatcher {
override fun afterTextChanged(s: Editable?) {
editLogin = editTextLogin.text.toString()
buttonEnter.isEnabled = isButtonVisible(editLogin, editPassword, checkBoxAgreement)
}
override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {}
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {}
})
editTextPassword.addTextChangedListener(object : TextWatcher {
override fun afterTextChanged(s: Editable?) {
editPassword = editTextPassword.text.toString()
buttonEnter.isEnabled = isButtonVisible(editLogin, editPassword, checkBoxAgreement)
}
override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {}
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {}
})
checkBoxAgreement.setOnCheckedChangeListener { buttonView, isChecked ->
buttonEnter.isEnabled = isButtonVisible(editLogin, editPassword, checkBoxAgreement)
}
private fun isButtonVisible (a: String, b: String, c: CheckBox): Boolean {
return a.isNotBlank() && b.isNotBlank() && c.isChecked
}
What's wrong here?

Make a function:
private fun updateButtonState() {
buttonEnter.isEnabled = editLogin.isNotBlank() && editPassword.isNotBlank() && checkBoxAgreement.isChecked
}
Call it in the listeners of your text fields and check box:
editTextLogin.addTextChangedListener(object : TextWatcher {
override fun afterTextChanged(s: Editable?) {
editLogin = editTextLogin.text.toString()
updateButtonState()
}
override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {}
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {}
})
editTextPassword.addTextChangedListener(object : TextWatcher {
override fun afterTextChanged(s: Editable?) {
editPassword = editTextPassword.text.toString()
updateButtonState()
}
override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {}
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {}
})
checkBoxAgreement.setOnCheckedChangeListener { buttonView, isChecked ->
updateButtonState()
}

Edit text real data missing when scrolling in a recycler view?

I have a recycler view of edit texts, however when scrolling my data of edit texts sometimes disappear and sometimes repeat itself in other edit texts.
I also use two functions in my adapter to get the values passed for edit texts in my case (product & price) but as I said I don't get the right values so I'm looking for your help guys.
This is my recycler view adapter:
class MyAdapter(var myList: List<ProductModelClass>) : RecyclerView.Adapter<MyAdapter.ViewHolder>() {
inner class ViewHolder(val binding: ItemToAddBinding) : RecyclerView.ViewHolder(binding.root) {}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
val v = ItemToAddBinding.inflate(LayoutInflater.from(parent.context), parent, false)
return ViewHolder(v)
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.binding.etProductName.addTextChangedListener(object : TextWatcher {
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?) {
val text: String = s.toString()
myList[position].product = text
}
})
holder.binding.etPrice.addTextChangedListener(object : TextWatcher {
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?) {
val text: String = s.toString()
myList[position].price = text
}
})
}
override fun getItemCount(): Int {
return myList.size
}
fun getProduct(): ArrayList<String>{
val productList: ArrayList<String> = ArrayList()
for(element in myList) {
productList.add(element.product)
}
return productList
}
fun getPrice(): ArrayList<String>{
val priceList: ArrayList<String> = ArrayList()
for(element in myList) {
priceList.add(element.price)
}
return priceList
}
}

Issue with EditText's On TextChange Listener

In my Recyclerview's Adapter class, I have done something as below:
holder.mEdtDescription.addTextChangedListener(object : TextWatcher {
override fun afterTextChanged(p0: Editable?) {
}
override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
}
override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
listener.onDeleteOrDescribe(position, "" + holder.mEdtDescription.text.toString(), "describe")
}
})
holder.mIvDelete.setOnClickListener {
listener.onDeleteOrDescribe(position, "", "delete")
}
mEdtDescription is EditText.
On deleting some value from the recycler my adapter calls method onDeleteOrDescribe.
Unfortunately, At the same time onTextChanged is also calling.
How can I avoid calling onTextChanged when I am deleting soemthing?
Hope you got the point.
As per the solution, I have tried disabling textWatcher as below :
val textWatcher: TextWatcher = object : TextWatcher {
override fun afterTextChanged(p0: Editable?) {
}
override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
}
override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
ToastUtil.displayShortDurationToast(mContext,"called")
listener.onDeleteOrDescribe(
position,
"" + holder.mEdtDescription.text.toString(),
"describe"
)
}
}
holder.mEdtDescription.addTextChangedListener(textWatcher)
holder.mIvDelete.setOnClickListener {
//listener.onDeleteStep(position)
holder.mEdtDescription.removeTextChangedListener(textWatcher)
listener.onDeleteOrDescribe(position, "", "delete")
holder.mEdtDescription.addTextChangedListener(textWatcher)
}
But, still is calling onTextChange() :(

You could try disabling the TextWatcher temporarily:
val textWatcher : TextWatcher = object : TextWatcher {
override fun afterTextChanged(p0: Editable?) {
}
override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
}
override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
listener.onDeleteOrDescribe(position, holder.mEdtDescription.text.toString(), "describe")
}
}
holder.mEdtDescription.addTextChangedListener(textWatcher)
holder.mIvDelete.setOnClickListener {
holder.mEdtDescription.removeTextChangedListener(textWatcher)
listener.onDeleteOrDescribe(position, "", "delete")
holder.mEdtDescription.addTextChangedListener(textWatcher)
}

TextWatcher Isn't WorkingI'm using Android Studio Kotlin

I don't get any errors when running the code but the addTextChangedListener isn't running when I execute it. I am trying to have the continue button disabled until the user input text. When run, the continue is still enabled. Here is my code
import android.content.Intent
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.text.Editable
import android.text.TextWatcher
import android.widget.Button
import android.widget.EditText
class First_Name_Activity : AppCompatActivity() {
lateinit var editFirstNameText: EditText
lateinit var btnOpenActivity: Button
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_first_name)
editFirstNameText = findViewById(R.id.first_name_edit_text)
btnOpenActivity = findViewById(R.id.first_name_continue_btn)
editFirstNameText.addTextChangedListener(object : TextWatcher {
override fun afterTextChanged(s: Editable?) {
}
override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
}
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
btnOpenActivity.isEnabled=true
}
}
btnOpenActivity.setOnClickListener {
val intent = Intent(this, Last_Name_Activity::class.java)
startActivity(intent)
overridePendingTransition(R.anim.slide_in_right, R.anim.slide_out_left)
}
}
override fun finish() {
super.finish()
overridePendingTransition(R.anim.slide_in_left, R.anim.slide_out_right)
}
}

You mentioned "When run, the continue is still enabled". Have you set the button to be disabled in the XML or through code (in the onCreate method) to be disabled when the app runs? After that, you can do:
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
btnOpenActivity.isEnabled = s?.isNotBlank() == true
}

First check edittext is empty or not then
Write below code inside textwatcher
If(s?.isEmpty()){
btnOpenActivity.isEnabled
}

You can check for empty text in edittext,
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
if (!s.toString().isEmpty()) {
btnOpenActivity.isEnabled=true
} else {
btnOpenActivity.isEnabled=false
}
}
Or
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
if (!editFirstNameText.text.toString().trim().isEmpty()) {
btnOpenActivity.isEnabled=true
} else {
btnOpenActivity.isEnabled=false
}
}

onTextChanged() may be called even when the CharSequence is empty or null. There is a very simple fix to your problem, a null and non-empty check :
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
if(s != null && s.isNotEmpty()){
btnOpenActivity.isEnabled=true
}
}

Edit your code like this
editFirstNameText.addTextChangedListener(object : TextWatcher {
override fun afterTextChanged(s: Editable?) {
}
override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
}
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
//btnOpenActivity.isEnabled==true
//Change this line to line bellow
btnOpenActivity.isEnabled==!s.toString().isEmpty()
}
})//you miss this bracket ')' in your code

Hi this will works for you...
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_sample_text_watcher)
btnOpenActivity.setOnClickListener(View.OnClickListener { })
editFirstNameText.addTextChangedListener(object : TextWatcher {
override fun afterTextChanged(s: Editable?) {
if (s != null) {
btnOpenActivity.isEnabled = s.trim().isNotEmpty()
}
}
override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
}
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
}
})
}
happy_coding :)

How to call function from object?

I can't call function of my class from object inside this class.
How should i do this ?
class LoginActivity: AppCompatActivity(){
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_login)
}
private fun disableLoginButton(){
button_login.isEnabled = false
}
private object textChangeListener: TextWatcher{
override fun afterTextChanged(p0: Editable?) {
}
override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
}
override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
//Here i cannot call function
disableLoginButton() // unresolved reference.
}
}
}
But when i call LoginActivity().disableLoginButton() instead disableLoginButton()it's visible, but fails with
NullPointerException
on login_button

Try this :
class LoginActivity: AppCompatActivity(){
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_login)
editTextSample.addTextChangedListener(object : TextWatcher {
override fun afterTextChanged(s: Editable) {}
override fun beforeTextChanged(s: CharSequence, start: Int,
count: Int, after: Int) {
}
override fun onTextChanged(s: CharSequence, start: Int,
before: Int, count: Int) {
disableLoginButton()
}
})
}
}
private fun disableLoginButton(){
button_login.isEnabled = false
}

EDIT: Doesn't work
From jetbrains team:
In Java and Kotlin, "inner" means "capturing the outer instance", where as "nested" means simply declared inside something else. Java's static classes are only nested, non-static nested classes are inner. In Kotlin you have to explicitly declare something as "inner" (we reversed the Java's convention). So, your object is not inner, btu only nested. And no named object can be inner, in fact: named objects are singletons, so the can not depend on any kind of outer instance.
Try specifying the object as inner:
private inner object textChangeListener: TextWatcher{
override fun afterTextChanged(p0: Editable?) {
}
override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
}
override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int {
//Here i cannot call function
disableLoginButton() // unresolved reference.
}
}
This should allow you to access the outer scope.