MainActivity.kt

package com.asissuthar.validation

import android.os.Bundle
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.lifecycle.lifecycleScope
import com.asissuthar.validation.databinding.ActivityMainBinding
import com.asissuthar.validation.formfields.FormFieldText
import kotlinx.coroutines.flow.launchIn
import kotlinx.coroutines.flow.onEach
import kotlinx.coroutines.launch
import reactivecircus.flowbinding.android.view.clicks

class MainActivity : AppCompatActivity() {
    private val binding by lazy { ActivityMainBinding.inflate(layoutInflater) }

    private val fieldUsername by lazy {
        FormFieldText(
            scope = lifecycleScope,
            textInputLayout = binding.tilUsername,
            textInputEditText = binding.etUsername,
            validation = { value ->
                when {
                    value.isNullOrBlank() -> "Username is required."
                    else -> null
                }
            }
        )
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(binding.root)

        binding.btnSubmit.clicks().onEach {
            submit()
        }.launchIn(lifecycleScope)
    }


    private fun submit() = lifecycleScope.launch {
        binding.btnSubmit.isEnabled = false

        fieldUsername.disable()
        if (fieldUsername.validate()) {

            // use field data here
            fieldUsername.value

            showToast("Submit successful!")
        }
        fieldUsername.enable()

        binding.btnSubmit.isEnabled = true
    }

    private fun showToast(message: String) {
        Toast.makeText(this, message, Toast.LENGTH_LONG).show()
    }
}