main_activity.kt

package com.arcane.coldstorage

import android.graphics.Bitmap
import android.os.Bundle
import android.view.Menu
import android.view.MenuItem
import android.widget.Button
import android.widget.ImageView
import androidx.appcompat.app.AppCompatActivity
import com.arcane.coldstorage.cache.ImageCache
import com.arcane.coldstoragecache.callback.OnValueFetchedCallback
import com.arcane.coldstoragecache.converter.impl.StringToBitmapConverter

class MainActivity : AppCompatActivity(), OnValueFetchedCallback<Any?> {

    companion object {
        val URLS = arrayListOf(
            "https://images.unsplash.com/photo-1452857297128-d9c29adba80b?ixlib=rb-1.2.1&w=1000&q=80",
            "https://i.ytimg.com/vi/Pc20_oJQusc/maxresdefault.jpg",
            "https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcS1HHodR1IgMESyE95LqwLRTRFnfCpmKKw5RQHqnP_kWV9ugKaiIQ&s"
        )
    }

    /**
     * An instance of image cache.
     */
    private val imageCache: ImageCache = ImageCache()

    /**
     * The image view where the images will be displayed.
     */
    private lateinit var imageView: ImageView

    /**
     * The button used to change the image.
     */
    private lateinit var changeButton: Button

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        imageView = findViewById(R.id.image_view)
        changeButton = findViewById(R.id.change)
        checkImageCaching()
        changeButton.setOnClickListener {
            checkImageCaching()
        }
    }

    /**
     * Method to test image caching.
     */
    private fun checkImageCaching() {
        val converter = StringToBitmapConverter()
        imageCache.get(
            URLS.shuffled().take(1)[0],
            this,
            converter
        )

    }

    /**
     * When the image is downloaded , adding the image to
     * the image view.
     */
    override fun valueFetched(output: Any?) {
        imageCache.commitToSharedPref(applicationContext)
        runOnUiThread {
            val outputAsBitmap = output as Bitmap
            imageView.setImageBitmap(outputAsBitmap)
        }
    }