Add simple caching when downloading image

apng_library/src/main/java/oupson/apng/ApngAnimator.kt

@@ -1,5 +1,6 @@
 package oupson.apng
 
+import android.content.Context
 import android.graphics.*
 import android.graphics.drawable.AnimationDrawable
 import android.os.Environment
@@ -13,7 +14,7 @@ import java.io.IOException
 import java.net.URL
 
 
-class ApngAnimator {
+class ApngAnimator(val context: Context) {
     var isPlaying = true
         private set(value) {field = value}
 
@@ -32,13 +33,11 @@ class ApngAnimator {
 
     var background : Bitmap? = null
 
-    val imageView : ImageView?
+    var imageView : ImageView? = null
 
-    constructor() {
-        imageView = null
-    }
-    constructor(imageView : ImageView) {
+    fun loadInto(imageView: ImageView) : ApngAnimator {
         this.imageView = imageView
+        return this
     }
 
     /**
@@ -102,7 +101,7 @@ class ApngAnimator {
     private fun loadUrl(url : URL) {
         doAsync(exceptionHandler = {e -> throw e}) {
             // Download PNG
-            val extractedFrame = APNGDisassembler(Loader().load(url)).pngList
+            val extractedFrame = APNGDisassembler(Loader().load(context!!, url)).pngList
             // Set last frame
             lastFrame = extractedFrame[0]
 
@@ -221,7 +220,7 @@ class ApngAnimator {
                 counter = 0
             }
             val delay = Frames[counter].delay
-            imageView.setImageBitmap(generatedFrame[counter])
+            imageView?.setImageBitmap(generatedFrame[counter])
             counter++
             myHandler.postDelayed({
                 ifmustPlay()

apng_library/src/main/java/oupson/apng/Loader.kt

@@ -1,28 +1,40 @@
 package oupson.apng
 
+import android.content.Context
+import android.util.Log
 import java.io.BufferedInputStream
 import java.io.ByteArrayOutputStream
+import java.io.File
 import java.io.IOException
 import java.net.URL
 
 class Loader {
-    fun load(url : URL) : ByteArray {
-        try {
-            val connection = url.openConnection()
-            connection.connect()
-            val input = BufferedInputStream(connection.getInputStream())
-            val output = ByteArrayOutputStream()
-            val data = ByteArray(1024)
-            var count = 0
-            while ({count = input.read(data); count}() != -1) {
-                output.write(data, 0, count)
+    fun load( context: Context, url : URL) : ByteArray {
+        val currenDir = context.filesDir
+        val fileTXT = File(currenDir, "apngLoader.txt")
+        var filePNG = File(currenDir, "apngLoader.png")
+        if (fileTXT.exists() && url.toString() == fileTXT.readText()) {
+            return filePNG.readBytes()
+        } else {
+            try {
+                val connection = url.openConnection()
+                connection.connect()
+                val input = BufferedInputStream(connection.getInputStream())
+                val output = ByteArrayOutputStream()
+                val data = ByteArray(1024)
+                var count = 0
+                while ({ count = input.read(data); count }() != -1) {
+                    output.write(data, 0, count)
+                }
+                output.flush()
+                output.close()
+                input.close()
+                fileTXT.writeText(url.toString())
+                filePNG.writeBytes(output.toByteArray())
+                return output.toByteArray()
+            } catch (e: IOException) {
+                throw e
             }
-            output.flush()
-            output.close()
-            input.close()
-            return output.toByteArray()
-        } catch (e: IOException) {
-            throw e
         }
     }
 }

app-test/src/main/java/oupson/apngcreator/Main2Activity.kt

@@ -6,6 +6,7 @@ import android.os.Bundle
 import android.provider.MediaStore
 import android.support.v7.app.AppCompatActivity
 import android.util.Log
+import kotlinx.android.synthetic.main.activity_main.*
 import kotlinx.android.synthetic.main.activity_main2.*
 import org.jetbrains.anko.sdk27.coroutines.onClick
 import oupson.apng.ApngAnimator
@@ -20,7 +21,7 @@ class Main2Activity : AppCompatActivity() {
 
     override fun onResume() {
         super.onResume()
-        val animator = ApngAnimator(imageView3)
+        val animator = ApngAnimator(this).loadInto(imageView2)
         val uri = intent.data
         if (uri.toString().contains("file:///")) {
             animator.load(uri.path)

app-test/src/main/java/oupson/apngcreator/MainActivity.kt

@@ -37,10 +37,10 @@ class MainActivity : AppCompatActivity() {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
 
-        animator = ApngAnimator(imageView)
+        animator = ApngAnimator(this).loadInto(imageView)
         animator.load(imageUrl)
 
-        Picasso.get().load(imageUrl).into(imageView2);
+        Picasso.get().load(imageUrl).into(imageView2)
 
         play.setOnClickListener {
             animator.play()