LetsPlayActivity

package com.surelabsid.pengenalanhuruf

import android.media.MediaPlayer
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.provider.MediaStore
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.RelativeLayout
import androidx.viewpager.widget.PagerAdapter
import androidx.viewpager.widget.ViewPager
import com.bumptech.glide.Glide
import com.surelabsid.pengenalanhuruf.databinding.ActivityLetsPlayBinding
import com.surelabsid.pengenalanhuruf.databinding.ItemGambarAdapterBinding

class LetsPlayActivity : AppCompatActivity() {
    //deklarasi view binding
    private lateinit var binding: ActivityLetsPlayBinding

    //dekrasikan resource yang akan kita pakai
    private val huruf = arrayListOf("A", "B", "C", "D", "E", "F")

    //deklarasikan gambar huruf
    private val gambarHuruf = arrayListOf(
        R.drawable.a,
        R.drawable.b,
        R.drawable.c,
        R.drawable.d,
        R.drawable.e,
        R.drawable.f
    )

    //deklrasi suara hurufnya
    private val suaraHuruf = arrayListOf(
        R.raw.a,
        R.raw.b,
        R.raw.c,
        R.raw.d,
        R.raw.e,
        R.raw.f,
    )

    //private pageAdapter
    private lateinit var  adapter: PagerAdapter
    //dekrasi media player
    private var mMediaPlayer: MediaPlayer? = null

    //deklarasi variable untuk event ketika halaman di swipe kiri/kanan
    private val onPageListener = object: ViewPager.OnPageChangeListener{
        override fun onPageScrolled(
            position: Int,
            positionOffset: Float,
            positionOffsetPixels: Int
        ) {

        }

        //ini dipanggil ketika halaman di munculkan/sedang aktif
        override fun onPageSelected(position: Int) {
            startAudio(position)
        }

        override fun onPageScrollStateChanged(state: Int) {

        }

    }
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        binding = ActivityLetsPlayBinding.inflate(layoutInflater)
        setContentView(binding.root)

        adapter = AdapterGambar()
        binding.viewPager.adapter = adapter
        binding.viewPager.addOnPageChangeListener(onPageListener)

        //pemutaran suara pertama kali
        binding.viewPager.currentItem = 0

        //function untuk memutar suara berdasarkan index array suara huruf
        startAudio(0)
    }

    private fun destroyMediaPlayer(){
        if(mMediaPlayer != null){
            mMediaPlayer?.reset()
            mMediaPlayer?.release()
        }

        mMediaPlayer = null
    }

    override fun onStop() {
        super.onStop()
        destroyMediaPlayer()
    }

    private fun startAudio(position: Int) {
        if(mMediaPlayer != null){
            mMediaPlayer?.reset()
            mMediaPlayer?.release()
        }

        // prepare suara huruf sesuai dengan posisi halaman yang sedang aktif sekarang
        mMediaPlayer = MediaPlayer.create(this@LetsPlayActivity, suaraHuruf[position])
        mMediaPlayer?.start()
    }

    private inner class AdapterGambar: PagerAdapter(){

        override fun getCount(): Int {
            return gambarHuruf.size
        }

        override fun isViewFromObject(view: View, `object`: Any): Boolean {
            return view === `object` as RelativeLayout
        }

        override fun destroyItem(container: ViewGroup, position: Int, `object`: Any) {
            container.removeView(`object` as RelativeLayout)
        }

        override fun instantiateItem(container: ViewGroup, position: Int): Any {
            //deklrasi layout untuk masing-masing halaman
            val binding = ItemGambarAdapterBinding.inflate(
                LayoutInflater.from(container.context), container, false
            )

            //load gambar hurufnya pake glide
            Glide.with(this@LetsPlayActivity)
                .load(gambarHuruf[position])
                .into(binding.gambarHuruf)

            //jangan lupa set hurufnya sesuai dengan page yang aktif sekarang
            binding.huruf.text = huruf[position]

            //load gambar untuk imageview say it
            Glide.with(this@LetsPlayActivity)
                .load(R.drawable.audio)
                .into(binding.sayIt)

            //kasih klik untuk ikon/imageview say it. Buat puter ulang suaranya
            binding.sayIt.setOnClickListener {
                this@LetsPlayActivity.startAudio(position)
            }

            //tambahin element ke view pager
            (container as ViewPager).addView(binding.root)

            return binding.root
        }

    }

}