MVP

MVP.kt

MainActivity:

package com.iliyadev.mvp.main

import android.content.Intent
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Button
import com.iliyadev.mvp.R
import com.iliyadev.mvp.login.LoginActivity

class MainActivity : AppCompatActivity(),MainContract.MainView {
    private lateinit var presenter: MainContract.MainPresenter
    private lateinit var btn_login:Button
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        init()
    }
    private fun init(){
        bindViews()
        presenter = MainPresenterImpl(this)
        btn_login.setOnClickListener {
            presenter.handleLoginButton()
        }
    }
    private fun bindViews(){
        btn_login = findViewById(R.id.btn_login)
    }

    override fun showLoginView() {
        startActivity(Intent(this, LoginActivity::class.java))
    }
}

MainContract interface:

package com.iliyadev.mvp.main

interface MainContract {
    interface MainView {
        fun showLoginView()
    }

    interface MainPresenter {
        fun handleLoginButton()
    }
}

MainPresenterImpl:

package com.iliyadev.mvp.main

class MainPresenterImpl(private var view:MainContract.MainView) : MainContract.MainPresenter {

    override fun handleLoginButton() {
        view.showLoginView()
    }
}

LoginPresenterImpl:

package com.iliyadev.mvp.login

import com.iliyadev.mvp.login.data.LoginInteractor
import com.iliyadev.mvp.login.data.UserCrenedtial
import com.iliyadev.mvp.main.MainContract

class LoginPresenterImpl(
    private val view:LoginContract.LoginView,

    ) : LoginContract.LoginPresenter {

    private val interactor = LoginInteractor(this)
    override fun doLogin(userCrenedtial: UserCrenedtial) {
        view.showLoading()
        interactor.login(userCrenedtial)
    }

    override fun onError(message: String) {
        view.hideLoading()
        view.onError(message)
    }

    override fun onSuccess() {
        view.hideLoading()
        view.onSuccess()
    }

}

LoginContract Interface:

package com.iliyadev.mvp.login

import com.iliyadev.mvp.login.data.UserCrenedtial

interface LoginContract {
    interface LoginView {

        fun onError(message: String)

        fun onSuccess()

        fun showLoading()

        fun hideLoading()

    }

    interface LoginPresenter {

        fun doLogin(userCrenedtial: UserCrenedtial)

        fun onError(message: String)

        fun onSuccess()

    }
}

LoginActivity:

package com.iliyadev.mvp.login

import android.app.ProgressDialog
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.widget.Button
import android.widget.EditText
import android.widget.ProgressBar
import android.widget.Toast
import com.google.android.material.button.MaterialButton
import com.iliyadev.mvp.R
import com.iliyadev.mvp.login.data.UserCrenedtial

class LoginActivity : AppCompatActivity(), LoginContract.LoginView {

    private lateinit var txtusername: EditText
    private lateinit var txtpaswword: EditText
    private lateinit var btnSignin: MaterialButton
    private lateinit var progressBar: ProgressBar
    private lateinit var presenter: LoginContract.LoginPresenter

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_login)
        init()
    }

    private fun init() {
        bindView()
        presenter = LoginPresenterImpl(this)

        // Initially hide the ProgressBar
        progressBar.visibility = View.GONE

        btnSignin.setOnClickListener {
            // Show the ProgressBar when the login button is clicked
            showLoading()

            val username = txtusername.text.toString()
            val password = txtpaswword.text.toString()
            val userCredential = UserCrenedtial(username, password)
            presenter.doLogin(userCredential)
        }
    }

    private fun bindView() {
        txtusername = findViewById(R.id.txtUsername)
        txtpaswword = findViewById(R.id.txtPassword)
        btnSignin = findViewById(R.id.logBTN)
        progressBar = findViewById(R.id.progressBar)
    }

    override fun onError(message: String) {
        Toast.makeText(this, message, Toast.LENGTH_LONG).show()
        hideLoading()
    }

    override fun onSuccess() {
        Toast.makeText(this, "Login Successfully!", Toast.LENGTH_LONG).show()
        hideLoading()
    }

    override fun showLoading() {
        progressBar.visibility = View.VISIBLE
        btnSignin.visibility = View.GONE
    }

    override fun hideLoading() {
        progressBar.visibility = View.GONE
        btnSignin.visibility = View.VISIBLE
    }
}

UserCredential:

package com.iliyadev.mvp.login.data

class UserCrenedtial(val username:String,var password:String) {
}

LoginInteractor:

package com.iliyadev.mvp.login.data

import android.os.Handler
import android.os.Looper
import com.iliyadev.mvp.login.LoginContract

class LoginInteractor(private val presenter: LoginContract.LoginPresenter) {

    fun login(userCrenedtial: UserCrenedtial) {
        if (hasError(userCrenedtial)) {
            return
        }

        // Simulate an asynchronous operation (e.g., API call)
        Handler(Looper.getMainLooper()).postDelayed({
            // Check credentials against a server or perform any other operation
            if (userCrenedtial.username == "admin" && userCrenedtial.password == "123") {
                presenter.onSuccess()
            } else {
                presenter.onError("Incorrect username or password")
            }
        }, 2000) // Simulating a delay of 2 seconds, adjust as needed
    }

    private fun hasError(userCrenedtial: UserCrenedtial): Boolean {
        if (userCrenedtial.username.isEmpty() || userCrenedtial.password.isEmpty()) {
            presenter.onError("Please enter a username and password")
            return true
        }

        return false
    }
}