diff --git a/.idea/caches/build_file_checksums.ser b/.idea/caches/build_file_checksums.ser
index 31c05ff..9c70bde 100644
Binary files a/.idea/caches/build_file_checksums.ser and b/.idea/caches/build_file_checksums.ser differ
diff --git a/apng_library/build.gradle b/apng_library/build.gradle
index f8bfbf2..0ef1836 100644
--- a/apng_library/build.gradle
+++ b/apng_library/build.gradle
@@ -10,7 +10,7 @@ android {
         versionCode 1
         versionName "1.0.9"
 
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
 
     }
     buildTypes {
@@ -26,11 +26,11 @@ android {
 }
 
 dependencies {
-    implementation 'com.android.support:appcompat-v7:28.0.0'
+    implementation 'androidx.appcompat:appcompat:1.0.0'
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
     testImplementation 'junit:junit:4.12'
-    androidTestImplementation 'com.android.support.test:runner:1.0.2'
-    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
+    androidTestImplementation 'androidx.test:runner:1.1.0'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0'
 
     implementation "org.jetbrains.anko:anko:$anko_version"
 
diff --git a/apng_library/src/androidTest/java/oupson/apng/ExampleInstrumentedTest.java b/apng_library/src/androidTest/java/oupson/apng/ExampleInstrumentedTest.java
index b223968..bf654ea 100644
--- a/apng_library/src/androidTest/java/oupson/apng/ExampleInstrumentedTest.java
+++ b/apng_library/src/androidTest/java/oupson/apng/ExampleInstrumentedTest.java
@@ -1,9 +1,8 @@
 package oupson.apng;
 
 import android.content.Context;
-import android.support.test.InstrumentationRegistry;
-import android.support.test.runner.AndroidJUnit4;
-
+import androidx.test.InstrumentationRegistry;
+import androidx.test.runner.AndroidJUnit4;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
diff --git a/apng_library/src/main/java/oupson/apng/APNGDisassembler.kt b/apng_library/src/main/java/oupson/apng/APNGDisassembler.kt
index 35f70ecf..c2b482c 100644
--- a/apng_library/src/main/java/oupson/apng/APNGDisassembler.kt
+++ b/apng_library/src/main/java/oupson/apng/APNGDisassembler.kt
@@ -25,8 +25,8 @@ class APNGDisassembler {
         private var tnrs: ByteArray? = null
         private var maxWidth = 0
         private var maxHeight = 0
-        private var blend_op: Utils.Companion.blend_op = Utils.Companion.blend_op.APNG_BLEND_OP_SOURCE
-        private var dispose_op: Utils.Companion.dispose_op = Utils.Companion.dispose_op.APNG_DISPOSE_OP_NONE
+        private var blendOp: Utils.Companion.BlendOp = Utils.Companion.BlendOp.APNG_BLEND_OP_SOURCE
+        private var disposeOp: Utils.Companion.DisposeOp = Utils.Companion.DisposeOp.APNG_DISPOSE_OP_NONE
         private var ihdr = IHDR()
 
         var apng: Apng = Apng()
@@ -98,17 +98,17 @@ class APNGDisassembler {
                             val fcTL = fcTL()
                             fcTL.parse(byteArray)
                             delay = fcTL.delay
-                            yOffset = fcTL.y_offset
-                            xOffset = fcTL.x_offset
-                            blend_op = fcTL.blend_op
-                            dispose_op = fcTL.dispose_op
+                            yOffset = fcTL.yOffset
+                            xOffset = fcTL.xOffset
+                            blendOp = fcTL.blendOp
+                            disposeOp = fcTL.disposeOp
                             val width = fcTL.pngWidth
                             val height = fcTL.pngHeight
 
                             if (xOffset + width > maxWidth) {
-                                throw BadApng("`y_offset` + `height` must be <= `IHDR` height")
+                                throw BadApng("`yOffset` + `height` must be <= `IHDR` height")
                             } else if (yOffset + height > maxHeight) {
-                                throw BadApng("`y_offset` + `height` must be <= `IHDR` height")
+                                throw BadApng("`yOffset` + `height` must be <= `IHDR` height")
                             }
 
                             png?.addAll(pngSignature.toList())
@@ -129,15 +129,15 @@ class APNGDisassembler {
                             crC32.update(iend, 0, iend.size)
                             png!!.addAll(iend.toList())
                             png!!.addAll(to4Bytes(crC32.value.toInt()).toList())
-                            apng.frames.add(Frame(png!!.toByteArray(), delay, xOffset, yOffset, maxWidth, maxHeight, blend_op, dispose_op))
+                            apng.frames.add(Frame(png!!.toByteArray(), delay, xOffset, yOffset, maxWidth, maxHeight, blendOp, disposeOp))
                             png = ArrayList()
                             val fcTL = fcTL()
                             fcTL.parse(byteArray)
                             delay = fcTL.delay
-                            yOffset = fcTL.y_offset
-                            xOffset = fcTL.x_offset
-                            blend_op = fcTL.blend_op
-                            dispose_op = fcTL.dispose_op
+                            yOffset = fcTL.yOffset
+                            xOffset = fcTL.xOffset
+                            blendOp = fcTL.blendOp
+                            disposeOp = fcTL.disposeOp
                             val width = fcTL.pngWidth
                             val height = fcTL.pngHeight
                             png!!.addAll(pngSignature.toList())
@@ -159,7 +159,7 @@ class APNGDisassembler {
                         crC32.update(iend, 0, iend.size)
                         png!!.addAll(iend.toList())
                         png!!.addAll(to4Bytes(crC32.value.toInt()).toList())
-                        apng.frames.add(Frame(png!!.toByteArray(), delay, xOffset, yOffset, maxWidth, maxHeight, blend_op, dispose_op))
+                        apng.frames.add(Frame(png!!.toByteArray(), delay, xOffset, yOffset, maxWidth, maxHeight, blendOp, disposeOp))
                     }
                     Utils.IDAT -> {
                         if (png == null) {
diff --git a/apng_library/src/main/java/oupson/apng/Apng.kt b/apng_library/src/main/java/oupson/apng/Apng.kt
index a5b61cb..d6df1d9 100644
--- a/apng_library/src/main/java/oupson/apng/Apng.kt
+++ b/apng_library/src/main/java/oupson/apng/Apng.kt
@@ -3,14 +3,14 @@ package oupson.apng
 import android.graphics.Bitmap
 import android.graphics.BitmapFactory
 import android.os.Environment
-import oupson.apng.ImageUtils.BitmapDiffCalculator
-import oupson.apng.ImageUtils.PngEncoder
-import oupson.apng.ImageUtils.PnnQuantizer
 import oupson.apng.chunks.IDAT
 import oupson.apng.exceptions.NoFrameException
+import oupson.apng.imageUtils.BitmapDiffCalculator
+import oupson.apng.imageUtils.PngEncoder
+import oupson.apng.imageUtils.PnnQuantizer
 import oupson.apng.utils.Utils
-import oupson.apng.utils.Utils.Companion.getBlend_op
-import oupson.apng.utils.Utils.Companion.getDispose_op
+import oupson.apng.utils.Utils.Companion.getBlendOp
+import oupson.apng.utils.Utils.Companion.getDisposeOp
 import oupson.apng.utils.Utils.Companion.pngSignature
 import oupson.apng.utils.Utils.Companion.to2Bytes
 import oupson.apng.utils.Utils.Companion.to4Bytes
@@ -21,7 +21,9 @@ import java.util.zip.CRC32
  * Create an APNG file
  */
 class Apng {
+    @Suppress("MemberVisibilityCanBePrivate")
     var maxWidth : Int? = null
+    @Suppress("MemberVisibilityCanBePrivate")
     var maxHeight : Int? = null
 
     /**
@@ -34,99 +36,29 @@ class Apng {
     var frames : ArrayList<Frame> = ArrayList()
 
     // region addFrames
-
     /**
      * Add a frame to the APNG
-     * @param bitmap The bitamp to add
-     */
-    fun addFrames(bitmap: Bitmap) {
-        frames.add(Frame(PngEncoder.encode(bitmap, true)))
-    }
-
-    /**
-     * Add a frame to the APNG
-     * @param bitmap The bitamp to add
-     * @param delay Delay of the frame
-     */
-    fun addFrames(bitmap: Bitmap, delay : Float) {
-        frames.add(Frame(PngEncoder.encode(bitmap, true), delay))
-    }
-
-    /**
-     * Add a frame to the APNG
-     * @param bitmap The bitamp to add
-     * @param delay Delay of the frame
-     * @param dispose_op `dispose_op` specifies how the output buffer should be changed at the end of the delay (before rendering the next frame).
-     * @param blend_op `blend_op` specifies whether the frame is to be alpha blended into the current output buffer content, or whether it should completely replace its region in the output buffer.
-     */
-    fun addFrames(bitmap: Bitmap, delay: Float, dispose_op: Utils.Companion.dispose_op, blend_op: Utils.Companion.blend_op) {
-        frames.add(Frame(PngEncoder.encode(bitmap, true), delay, blend_op, dispose_op))
-    }
-
-    /**
-     * Add a frame to the APNG
-     * @param bitmap The bitamp to add
+     * @param bitmap The bitmap to add
      * @param delay Delay of the frame
      * @param xOffset The X offset where the frame should be rendered
      * @param yOffset The Y offset where the frame should be rendered
-     * @param dispose_op `dispose_op` specifies how the output buffer should be changed at the end of the delay (before rendering the next frame).
-     * @param blend_op `blend_op` specifies whether the frame is to be alpha blended into the current output buffer content, or whether it should completely replace its region in the output buffer.
+     * @param disposeOp `DisposeOp` specifies how the output buffer should be changed at the end of the delay (before rendering the next frame).
+     * @param blendOp `BlendOp` specifies whether the frame is to be alpha blended into the current output buffer content, or whether it should completely replace its region in the output buffer.
      */
-    fun addFrames(bitmap: Bitmap, delay: Float, xOffset : Int, yOffset : Int, dispose_op: Utils.Companion.dispose_op, blend_op: Utils.Companion.blend_op) {
-        frames.add(Frame(PngEncoder.encode(bitmap, true), delay, xOffset, yOffset, blend_op, dispose_op))
+
+    fun addFrames(bitmap : Bitmap, index : Int? = null, delay : Float = 1000f, xOffset : Int = 0, yOffset : Int = 0, disposeOp: Utils.Companion.DisposeOp = Utils.Companion.DisposeOp.APNG_DISPOSE_OP_NONE, blendOp: Utils.Companion.BlendOp = Utils.Companion.BlendOp.APNG_BLEND_OP_SOURCE) {
+        if (index == null)
+            frames.add(Frame(PngEncoder.encode(bitmap, true), delay, xOffset, yOffset, blendOp, disposeOp))
+        else
+            frames.add(index, Frame(PngEncoder.encode(bitmap, true), delay, xOffset, yOffset, blendOp, disposeOp))
     }
 
-    /**
-     * Add a frame to the APNG
-     * @param index Index where we add the frame
-     * @param bitmap The bitamp to add
-     */
-    fun addFrames(index : Int, bitmap: Bitmap) {
-        frames.add(index, Frame(PngEncoder.encode(bitmap, true)))
-    }
-
-    /**
-     * Add a frame to the APNG
-     * @param index Index where we add the frame
-     * @param bitmap The bitamp to add
-     * @param delay Delay of the frame
-     */
-    fun addFrames(index : Int, bitmap: Bitmap, delay : Float) {
-        frames.add(index, Frame(PngEncoder.encode(bitmap, true), delay))
-    }
-
-    /**
-     * Add a frame to the APNG
-     * @param index Index where we add the frame
-     * @param bitmap The bitamp to add
-     * @param delay Delay of the frame
-     * @param dispose_op `dispose_op` specifies how the output buffer should be changed at the end of the delay (before rendering the next frame).
-     * @param blend_op `blend_op` specifies whether the frame is to be alpha blended into the current output buffer content, or whether it should completely replace its region in the output buffer.
-     */
-    fun addFrames(index: Int, bitmap: Bitmap, delay: Float, dispose_op: Utils.Companion.dispose_op, blend_op: Utils.Companion.blend_op) {
-        frames.add(index, Frame(PngEncoder.encode(bitmap, true), delay, blend_op, dispose_op))
-    }
-
-    /**
-     * Add a frame to the APNG
-     * @param index Index where we add the frame
-     * @param bitmap The bitamp to add
-     * @param delay Delay of the frame
-     * @param xOffset The X offset where the frame should be rendered
-     * @param yOffset The Y offset where the frame should be rendered
-     * @param dispose_op `dispose_op` specifies how the output buffer should be changed at the end of the delay (before rendering the next frame).
-     * @param blend_op `blend_op` specifies whether the frame is to be alpha blended into the current output buffer content, or whether it should completely replace its region in the output buffer.
-     */
-    fun addFrames(index: Int, bitmap: Bitmap, delay: Float, xOffset : Int, yOffset : Int, dispose_op: Utils.Companion.dispose_op, blend_op: Utils.Companion.blend_op) {
-        frames.add(index, Frame(PngEncoder.encode(bitmap, true), delay, xOffset, yOffset, blend_op, dispose_op))
-    }
-
-    fun addFrames(frame : Frame) {
-        frames.add(frame)
-    }
-
-    fun addFrames(index: Int,frame : Frame) {
-        frames.add(index, frame)
+    @Suppress("unused")
+    fun addFrames(frame : Frame, index: Int? = null) {
+        if (index == null)
+            frames.add(frame)
+        else
+            frames.add(index, frame)
     }
     //endregion
 
@@ -139,7 +71,6 @@ class Apng {
         val res = ArrayList<Byte>()
         // Add PNG signature
         res.addAll(pngSignature.toList())
-
         // Add Image Header
         res.addAll(generateIhdr().toList())
 
@@ -178,9 +109,9 @@ class Apng {
             fcTL.addAll(to2Bytes(frames[0].delay.toInt()).toList())
             fcTL.addAll(to2Bytes(1000).toList())
 
-            // Add dispose_op and blend_op
-            fcTL.add(getDispose_op(frames[0].dispose_op).toByte())
-            fcTL.add(getBlend_op(frames[0].blend_op).toByte())
+            // Add DisposeOp and BlendOp
+            fcTL.add(getDisposeOp(frames[0].disposeOp).toByte())
+            fcTL.add(getBlendOp(frames[0].blendOp).toByte())
 
             // Create CRC
             val crc = CRC32()
@@ -247,9 +178,9 @@ class Apng {
             fcTL.addAll(to2Bytes(frames[0].delay.toInt()).toList())
             fcTL.addAll(to2Bytes(1000).toList())
 
-            // Add dispose_op and blend_op
-            fcTL.add(getDispose_op(frames[0].dispose_op).toByte())
-            fcTL.add(getBlend_op(frames[0].blend_op).toByte())
+            // Add DisposeOp and BlendOp
+            fcTL.add(getDisposeOp(frames[0].disposeOp).toByte())
+            fcTL.add(getBlendOp(frames[0].blendOp).toByte())
 
             // Generate CRC
             val crc = CRC32()
@@ -302,8 +233,8 @@ class Apng {
             fcTL.addAll(to2Bytes(frames[i].delay.toInt()).toList())
             fcTL.addAll(to2Bytes(1000).toList())
 
-            fcTL.add(getDispose_op(frames[i].dispose_op).toByte())
-            fcTL.add(getBlend_op(frames[i].blend_op).toByte())
+            fcTL.add(getDisposeOp(frames[i].disposeOp).toByte())
+            fcTL.add(getBlendOp(frames[i].blendOp).toByte())
 
             val crc = CRC32()
             crc.update(fcTL.toByteArray(), 0, fcTL.size)
@@ -359,6 +290,7 @@ class Apng {
      * @param maxHeight Max height of the APNG
      * @return An image cover
      */
+    @Suppress("MemberVisibilityCanBePrivate")
     fun generateCover(bitmap: Bitmap, maxWidth : Int, maxHeight : Int) : Bitmap {
         return Bitmap.createScaledBitmap(bitmap, maxWidth, maxHeight, false)
     }
@@ -371,7 +303,7 @@ class Apng {
         val ihdr = ArrayList<Byte>()
 
         // We need a body var to know body length and generate crc
-        val ihdr_body = ArrayList<Byte>()
+        val ihdrBody = ArrayList<Byte>()
 
         // Get max height and max width of all the frames
         maxHeight = frames.sortedByDescending { it.height }[0].height
@@ -384,20 +316,20 @@ class Apng {
         // Add chunk body length
         ihdr.addAll(to4Bytes(frames[0].ihdr.body.size).toList())
         // Add IHDR
-        ihdr_body.addAll(byteArrayOf(0x49.toByte(), 0x48.toByte(), 0x44.toByte(), 0x52.toByte()).toList())
+        ihdrBody.addAll(byteArrayOf(0x49.toByte(), 0x48.toByte(), 0x44.toByte(), 0x52.toByte()).toList())
 
         // Add the max width and height
-        ihdr_body.addAll(to4Bytes(maxWidth!!).toList())
-        ihdr_body.addAll(to4Bytes(maxHeight!!).toList())
+        ihdrBody.addAll(to4Bytes(maxWidth!!).toList())
+        ihdrBody.addAll(to4Bytes(maxHeight!!).toList())
 
         // Add complicated stuff like depth color ...
         // If you want correct png you need same parameters. Good solution is to create new png.
-        ihdr_body.addAll(frames[0].ihdr.body.copyOfRange(8, 13).toList())
+        ihdrBody.addAll(frames[0].ihdr.body.copyOfRange(8, 13).toList())
 
         // Generate CRC
         val crC32 = CRC32()
-        crC32.update(ihdr_body.toByteArray(), 0, ihdr_body.size)
-        ihdr.addAll(ihdr_body)
+        crC32.update(ihdrBody.toByteArray(), 0, ihdrBody.size)
+        ihdr.addAll(ihdrBody)
         ihdr.addAll(to4Bytes(crC32.value.toInt()).toList())
         return ihdr.toByteArray()
     }
@@ -437,12 +369,13 @@ class Apng {
      * @param keepCover Keep the cover
      * @param sizePercent Reduce image width/height by percents.
      */
-    fun reduceSize( maxColor : Int, keepCover : Boolean? = null, sizePercent : Int? = null) {
+    @Suppress("unused")
+    fun reduceSize(maxColor : Int, keepCover : Boolean? = null, sizePercent : Int? = null) {
         val apng = Apng()
         if (keepCover != false) {
             if (cover != null) {
                 if (sizePercent != null) {
-                    cover = Bitmap.createScaledBitmap(cover, (cover!!.width.toFloat() * sizePercent.toFloat() / 100f).toInt(), (cover!!.height.toFloat() * sizePercent.toFloat() / 100f).toInt(), false)
+                    cover = Bitmap.createScaledBitmap(cover!!, (cover!!.width.toFloat() * sizePercent.toFloat() / 100f).toInt(), (cover!!.height.toFloat() * sizePercent.toFloat() / 100f).toInt(), false)
                     val pnn = PnnQuantizer(cover)
                     cover = pnn.convert(maxColor, false)
                 }
@@ -458,9 +391,9 @@ class Apng {
             val pnn = PnnQuantizer(btm)
             val btmOptimised = pnn.convert(maxColor, false)
             if (sizePercent != null) {
-                apng.addFrames(btmOptimised, it.delay, (it.x_offsets.toFloat() * sizePercent.toFloat() / 100f).toInt(), (it.y_offsets.toFloat() * sizePercent.toFloat() / 100f).toInt(), it.dispose_op, it.blend_op)
+                apng.addFrames(btmOptimised, 0, it.delay, (it.x_offsets.toFloat() * sizePercent.toFloat() / 100f).toInt(), (it.y_offsets.toFloat() * sizePercent.toFloat() / 100f).toInt(), it.disposeOp, it.blendOp)
             } else {
-                apng.addFrames(btmOptimised, it.delay, it.x_offsets, it.y_offsets, it.dispose_op, it.blend_op)
+                apng.addFrames(btmOptimised, 0, it.delay, it.x_offsets, it.y_offsets, it.disposeOp, it.blendOp)
             }
         }
         frames = apng.frames
@@ -481,7 +414,7 @@ class Apng {
             frames[i].byteArray = PngEncoder.encode(diffCalculator.res, true)
             frames[i].x_offsets = diffCalculator.xOffset
             frames[i].y_offsets = diffCalculator.yOffset
-            frames[i].blend_op = Utils.Companion.blend_op.APNG_BLEND_OP_OVER
+            frames[i].blendOp = Utils.Companion.BlendOp.APNG_BLEND_OP_OVER
         }
     }
 }
\ No newline at end of file
diff --git a/apng_library/src/main/java/oupson/apng/ApngAnimator.kt b/apng_library/src/main/java/oupson/apng/ApngAnimator.kt
index 23770a6..26b5a84 100644
--- a/apng_library/src/main/java/oupson/apng/ApngAnimator.kt
+++ b/apng_library/src/main/java/oupson/apng/ApngAnimator.kt
@@ -39,10 +39,12 @@ class ApngAnimator(private val context: Context?) {
     var anim: CustomAnimationDrawable? = null
     private var activeAnimation: CustomAnimationDrawable? = null
     private var doOnLoaded : (ApngAnimator) -> Unit = {}
+    @Suppress("PrivatePropertyName")
     @SuppressWarnings("WeakerAccess")
     private var AnimationLoopListener : () -> Unit = {}
     private var duration : ArrayList<Float>? = null
     private var scaleType : ImageView.ScaleType? = null
+    @Suppress("MemberVisibilityCanBePrivate")
     var isApng = false
     @SuppressWarnings("WeakerAccess")
     var loadNotApng = true
@@ -56,6 +58,7 @@ class ApngAnimator(private val context: Context?) {
     /**
      * Specify if the library could load non apng file
      */
+    @Suppress("unused")
     @SuppressWarnings("WeakerAccess")
     fun loadNotApng(boolean: Boolean) {
         val editor = sharedPreferences?.edit()
@@ -78,6 +81,7 @@ class ApngAnimator(private val context: Context?) {
      * @param speed The speed
      * @throws NotApngException
      */
+    @Suppress("unused")
     @SuppressWarnings("WeakerAccess")
     fun load(file: File, speed: Float? = null, apngAnimatorOptions: ApngAnimatorOptions? = null) : ApngAnimator {
         doAsync {
@@ -230,12 +234,13 @@ class ApngAnimator(private val context: Context?) {
             } else if (File(string).exists()) {
                 var pathToLoad = if (string.startsWith("content://")) string else "file://$string"
                 pathToLoad = pathToLoad.replace("%", "%25").replace("#", "%23")
-                val bytes = context!!.contentResolver.openInputStream(Uri.parse(pathToLoad)).readBytes()
+                val bytes = context?.contentResolver?.openInputStream(Uri.parse(pathToLoad))?.readBytes()
+                bytes ?: throw Exception("File are empty")
                 if (isApng(bytes)) {
                     load(bytes, speed, apngAnimatorOptions)
                 } else {
                     if (loadNotApng) {
-                        context.runOnUiThread {
+                        context?.runOnUiThread {
                             imageView?.setImageBitmap(BitmapFactory.decodeByteArray(bytes, 0, bytes.size))
                         }
                     } else {
@@ -284,25 +289,25 @@ class ApngAnimator(private val context: Context?) {
             // Write buffer to canvas
             canvas.drawBitmap(bitmapBuffer, 0f, 0f, null)
             // Clear current frame rect
-            // If `blend_op` is APNG_BLEND_OP_SOURCE all color components of the frame, including alpha, overwrite the current contents of the frame's output buffer region.
-            if (it.blend_op == Utils.Companion.blend_op.APNG_BLEND_OP_SOURCE) {
-                canvas.drawRect(it.x_offsets!!.toFloat(), it.y_offsets!!.toFloat(), it.x_offsets!! + current.width.toFloat(), it.y_offsets!! + current.height.toFloat(), { val paint = Paint(); paint.xfermode = PorterDuffXfermode(PorterDuff.Mode.CLEAR); paint }())
+            // If `BlendOp` is APNG_BLEND_OP_SOURCE all color components of the frame, including alpha, overwrite the current contents of the frame's output buffer region.
+            if (it.blendOp == Utils.Companion.BlendOp.APNG_BLEND_OP_SOURCE) {
+                canvas.drawRect(it.x_offsets.toFloat(), it.y_offsets.toFloat(), it.x_offsets + current.width.toFloat(), it.y_offsets + current.height.toFloat(), { val paint = Paint(); paint.xfermode = PorterDuffXfermode(PorterDuff.Mode.CLEAR); paint }())
             }
             // Draw the bitmap
-            canvas.drawBitmap(current, it.x_offsets!!.toFloat(), it.y_offsets!!.toFloat(), null)
+            canvas.drawBitmap(current, it.x_offsets.toFloat(), it.y_offsets.toFloat(), null)
             generatedFrame.add(btm)
             // Don't add current frame to bitmap buffer
             when {
-                extractedFrame[i].dispose_op == Utils.Companion.dispose_op.APNG_DISPOSE_OP_PREVIOUS -> {
+                extractedFrame[i].disposeOp == Utils.Companion.DisposeOp.APNG_DISPOSE_OP_PREVIOUS -> {
                     //Do nothings
                 }
                 // Add current frame to bitmap buffer
                 // APNG_DISPOSE_OP_BACKGROUND: the frame's region of the output buffer is to be cleared to fully transparent black before rendering the next frame.
-                it.dispose_op == Utils.Companion.dispose_op.APNG_DISPOSE_OP_BACKGROUND -> {
+                it.disposeOp == Utils.Companion.DisposeOp.APNG_DISPOSE_OP_BACKGROUND -> {
                     val res = Bitmap.createBitmap(extractedFrame[0].maxWidth!!, extractedFrame[0].maxHeight!!, Bitmap.Config.ARGB_8888)
                     val can = Canvas(res)
                     can.drawBitmap(btm, 0f, 0f, null)
-                    can.drawRect(it.x_offsets!!.toFloat(), it.y_offsets!!.toFloat(), it.x_offsets!! + it.width.toFloat(), it.y_offsets!! + it.height.toFloat(), { val paint = Paint(); paint.xfermode = PorterDuffXfermode(PorterDuff.Mode.CLEAR); paint }())
+                    can.drawRect(it.x_offsets.toFloat(), it.y_offsets.toFloat(), it.x_offsets + it.width.toFloat(), it.y_offsets + it.height.toFloat(), { val paint = Paint(); paint.xfermode = PorterDuffXfermode(PorterDuff.Mode.CLEAR); paint }())
                     bitmapBuffer = res
                 }
                 else -> bitmapBuffer = btm
diff --git a/apng_library/src/main/java/oupson/apng/Frame.kt b/apng_library/src/main/java/oupson/apng/Frame.kt
index 84c1e66..c893121 100644
--- a/apng_library/src/main/java/oupson/apng/Frame.kt
+++ b/apng_library/src/main/java/oupson/apng/Frame.kt
@@ -37,8 +37,8 @@ class Frame {
     var maxWidth : Int? = null
     var maxHeight : Int? = null
 
-    var blend_op: Utils.Companion.blend_op
-    var dispose_op : Utils.Companion.dispose_op
+    var blendOp: Utils.Companion.BlendOp
+    var disposeOp : Utils.Companion.DisposeOp
 
     constructor(byteArray: ByteArray) {
         if (isPng(byteArray)) {
@@ -46,8 +46,8 @@ class Frame {
             Log.e("tag", byteArray.size.toString())
             // Get width and height for image
             delay = 1000f
-            blend_op = Utils.Companion.blend_op.APNG_BLEND_OP_SOURCE
-            dispose_op = Utils.Companion.dispose_op.APNG_DISPOSE_OP_NONE
+            blendOp = Utils.Companion.BlendOp.APNG_BLEND_OP_SOURCE
+            disposeOp = Utils.Companion.DisposeOp.APNG_DISPOSE_OP_NONE
             var cursor = 8
             while (cursor < byteArray.size) {
                 val chunk = byteArray.copyOfRange(cursor, cursor + Utils.parseLength(byteArray.copyOfRange(cursor, cursor + 4)) + 12)
@@ -70,14 +70,14 @@ class Frame {
             }
 
             this.delay = delay
-            blend_op = Utils.Companion.blend_op.APNG_BLEND_OP_SOURCE
-            dispose_op = Utils.Companion.dispose_op.APNG_DISPOSE_OP_NONE
+            blendOp = Utils.Companion.BlendOp.APNG_BLEND_OP_SOURCE
+            disposeOp = Utils.Companion.DisposeOp.APNG_DISPOSE_OP_NONE
         } else {
             throw NotPngException()
         }
     }
 
-    constructor(byteArray: ByteArray, delay : Float, blend_op: Utils.Companion.blend_op, dispose_op: Utils.Companion.dispose_op) {
+    constructor(byteArray: ByteArray, delay : Float, blendOp: Utils.Companion.BlendOp, disposeOp: Utils.Companion.DisposeOp) {
         if (isPng(byteArray)) {
             this.byteArray = byteArray
             // Get width and height for image
@@ -93,14 +93,14 @@ class Frame {
 
             this.maxWidth = -1
             this.maxHeight = -1
-            this.blend_op = blend_op
-            this.dispose_op = dispose_op
+            this.blendOp = blendOp
+            this.disposeOp = disposeOp
         } else {
             throw NotPngException()
         }
     }
 
-    constructor(byteArray: ByteArray, delay : Float, xOffsets : Int, yOffsets : Int, blend_op: Utils.Companion.blend_op, dispose_op: Utils.Companion.dispose_op) {
+    constructor(byteArray: ByteArray, delay : Float, xOffsets : Int, yOffsets : Int, blendOp: Utils.Companion.BlendOp, disposeOp: Utils.Companion.DisposeOp) {
         if (isPng(byteArray)) {
             this.byteArray = byteArray
             // Get width and height for image
@@ -118,14 +118,14 @@ class Frame {
 
             this.maxWidth = -1
             this.maxHeight = -1
-            this.blend_op = blend_op
-            this.dispose_op = dispose_op
+            this.blendOp = blendOp
+            this.disposeOp = disposeOp
         } else {
             throw NotPngException()
         }
     }
 
-    constructor(byteArray: ByteArray, delay : Float, xOffsets : Int, yOffsets : Int, maxWidth : Int, maxHeight : Int, blend_op: Utils.Companion.blend_op, dispose_op: Utils.Companion.dispose_op) {
+    constructor(byteArray: ByteArray, delay : Float, xOffsets : Int, yOffsets : Int, maxWidth : Int, maxHeight : Int, blendOp: Utils.Companion.BlendOp, disposeOp: Utils.Companion.DisposeOp) {
         if (isPng(byteArray)) {
             this.byteArray = byteArray
             // Get width and height for image
@@ -143,8 +143,8 @@ class Frame {
 
             this.maxWidth = maxWidth
             this.maxHeight = maxHeight
-            this.blend_op = blend_op
-            this.dispose_op = dispose_op
+            this.blendOp = blendOp
+            this.disposeOp = disposeOp
         } else {
             throw NotPngException()
         }
diff --git a/apng_library/src/main/java/oupson/apng/chunks/IDAT.kt b/apng_library/src/main/java/oupson/apng/chunks/IDAT.kt
index 8b33bec..cfd6cf7 100644
--- a/apng_library/src/main/java/oupson/apng/chunks/IDAT.kt
+++ b/apng_library/src/main/java/oupson/apng/chunks/IDAT.kt
@@ -3,6 +3,7 @@ package oupson.apng.chunks
 import oupson.apng.utils.Utils.Companion.parseLength
 
 class IDAT : Chunk {
+    @Suppress("PropertyName")
     var IDATBody: ArrayList<ByteArray> = ArrayList()
     override var body = byteArrayOf()
 
diff --git a/apng_library/src/main/java/oupson/apng/chunks/fcTL.kt b/apng_library/src/main/java/oupson/apng/chunks/fcTL.kt
index ed68156..db1962b 100644
--- a/apng_library/src/main/java/oupson/apng/chunks/fcTL.kt
+++ b/apng_library/src/main/java/oupson/apng/chunks/fcTL.kt
@@ -1,10 +1,11 @@
 package oupson.apng.chunks
 
 import oupson.apng.utils.Utils
-import oupson.apng.utils.Utils.Companion.getBlend_op
-import oupson.apng.utils.Utils.Companion.getDispose_op
+import oupson.apng.utils.Utils.Companion.getBlendOp
+import oupson.apng.utils.Utils.Companion.getDisposeOp
 import oupson.apng.utils.Utils.Companion.parseLength
 
+@Suppress("ClassName")
 class fcTL : Chunk {
     override var body : ByteArray = byteArrayOf()
 
@@ -16,11 +17,11 @@ class fcTL : Chunk {
     var delay : Float = -1f
 
     // x and y offsets
-    var x_offset : Int = 0
-    var y_offset : Int = 0
+    var xOffset : Int = 0
+    var yOffset : Int = 0
 
-    var blend_op : Utils.Companion.blend_op = Utils.Companion.blend_op.APNG_BLEND_OP_SOURCE
-    var dispose_op : Utils.Companion.dispose_op = Utils.Companion.dispose_op.APNG_DISPOSE_OP_NONE
+    var blendOp : Utils.Companion.BlendOp = Utils.Companion.BlendOp.APNG_BLEND_OP_SOURCE
+    var disposeOp : Utils.Companion.DisposeOp = Utils.Companion.DisposeOp.APNG_DISPOSE_OP_NONE
 
     override fun parse(byteArray: ByteArray) {
         val i = 4
@@ -37,21 +38,21 @@ class fcTL : Chunk {
                  * If the the value of the numerator is 0 the decoder should render the next frame as quickly as possible, though viewers may impose a reasonable lower bound.
                  */
             // Get delay numerator
-            val delay_num = parseLength(byteArray.copyOfRange(i + 24, i + 26)).toFloat()
+            val delayNum = parseLength(byteArray.copyOfRange(i + 24, i + 26)).toFloat()
             // Get delay denominator
-            var delay_den = parseLength(byteArray.copyOfRange(i + 26, i + 28)).toFloat()
+            var delayDen = parseLength(byteArray.copyOfRange(i + 26, i + 28)).toFloat()
 
             // If the denominator is 0, it is to be treated as if it were 100 (that is, `delay_num` then specifies 1/100ths of a second).
-            if (delay_den == 0f) {
-                delay_den = 100f
+            if (delayDen == 0f) {
+                delayDen = 100f
             }
-            delay = (delay_num / delay_den * 1000)
+            delay = (delayNum / delayDen * 1000)
             // Get x and y offsets
-            x_offset = parseLength(byteArray.copyOfRange(i + 16, i + 20))
-            y_offset = parseLength(byteArray.copyOfRange(i + 20, i + 24))
+            xOffset = parseLength(byteArray.copyOfRange(i + 16, i + 20))
+            yOffset = parseLength(byteArray.copyOfRange(i + 20, i + 24))
             body = byteArray.copyOfRange(i + 4, i + bodySize + 4)
-            blend_op = getBlend_op(String.format("%02x", byteArray[33]).toLong(16).toInt())
-            dispose_op = getDispose_op(String.format("%02x", byteArray[32]).toLong(16).toInt())
+            blendOp = getBlendOp(String.format("%02x", byteArray[33]).toLong(16).toInt())
+            disposeOp = getDisposeOp(String.format("%02x", byteArray[32]).toLong(16).toInt())
         }
     }
 }
\ No newline at end of file
diff --git a/apng_library/src/main/java/oupson/apng/ImageUtils/BitmapDiffCalculator.kt b/apng_library/src/main/java/oupson/apng/imageUtils/BitmapDiffCalculator.kt
similarity index 96%
rename from apng_library/src/main/java/oupson/apng/ImageUtils/BitmapDiffCalculator.kt
rename to apng_library/src/main/java/oupson/apng/imageUtils/BitmapDiffCalculator.kt
index ed98464..850e21a 100644
--- a/apng_library/src/main/java/oupson/apng/ImageUtils/BitmapDiffCalculator.kt
+++ b/apng_library/src/main/java/oupson/apng/imageUtils/BitmapDiffCalculator.kt
@@ -1,10 +1,10 @@
-package oupson.apng.ImageUtils
+package oupson.apng.imageUtils
 
 import android.graphics.Bitmap
 import android.graphics.Canvas
 import android.graphics.Color
 import android.graphics.Paint
-import android.support.annotation.ColorInt
+import androidx.annotation.ColorInt
 import oupson.apng.utils.Utils
 import java.util.*
 
@@ -12,7 +12,7 @@ class BitmapDiffCalculator(firstBitmap: Bitmap, secondBitmap : Bitmap) {
     val res : Bitmap
     var xOffset : Int = 0
     var yOffset : Int = 0
-    var blend_op = Utils.Companion.blend_op.APNG_BLEND_OP_OVER
+    var blendOp = Utils.Companion.BlendOp.APNG_BLEND_OP_OVER
     init {
         val difBitmap = Bitmap.createBitmap(firstBitmap.width, firstBitmap.height, Bitmap.Config.ARGB_8888)
         val difCanvas = Canvas(difBitmap)
diff --git a/apng_library/src/main/java/oupson/apng/ImageUtils/PngEncoder.kt b/apng_library/src/main/java/oupson/apng/imageUtils/PngEncoder.kt
similarity index 99%
rename from apng_library/src/main/java/oupson/apng/ImageUtils/PngEncoder.kt
rename to apng_library/src/main/java/oupson/apng/imageUtils/PngEncoder.kt
index b3526c6..aaa75d1 100644
--- a/apng_library/src/main/java/oupson/apng/ImageUtils/PngEncoder.kt
+++ b/apng_library/src/main/java/oupson/apng/imageUtils/PngEncoder.kt
@@ -1,4 +1,4 @@
-package oupson.apng.ImageUtils
+package oupson.apng.imageUtils
 
 import android.graphics.Bitmap
 import java.io.ByteArrayOutputStream
@@ -182,6 +182,7 @@ class PngEncoder {
          * @param offset The starting point to write to.
          * @return The next place to be written to in the pngBytes array.
          */
+        @Suppress("unused")
         private fun writeInt2(n: Int, offset: Int): Int {
             val temp = byteArrayOf((n shr 8 and 0xff).toByte(), (n and 0xff).toByte())
             return writeBytes(temp, offset)
diff --git a/apng_library/src/main/java/oupson/apng/ImageUtils/PnnQuantizer.java b/apng_library/src/main/java/oupson/apng/imageUtils/PnnQuantizer.java
similarity index 99%
rename from apng_library/src/main/java/oupson/apng/ImageUtils/PnnQuantizer.java
rename to apng_library/src/main/java/oupson/apng/imageUtils/PnnQuantizer.java
index 56fcd47..17888f6 100644
--- a/apng_library/src/main/java/oupson/apng/ImageUtils/PnnQuantizer.java
+++ b/apng_library/src/main/java/oupson/apng/imageUtils/PnnQuantizer.java
@@ -1,4 +1,4 @@
-package oupson.apng.ImageUtils;
+package oupson.apng.imageUtils;
 
 /* Fast pairwise nearest neighbor based algorithm for multilevel thresholding
 Copyright (C) 2004-2016 Mark Tyler and Dmitry Groshev
diff --git a/apng_library/src/main/java/oupson/apng/utils/Utils.kt b/apng_library/src/main/java/oupson/apng/utils/Utils.kt
index ab62432..01d046d 100644
--- a/apng_library/src/main/java/oupson/apng/utils/Utils.kt
+++ b/apng_library/src/main/java/oupson/apng/utils/Utils.kt
@@ -19,7 +19,7 @@ class Utils {
             if (!isPng(byteArray)) return false
             try {
                 val acTL = byteArrayOf(0x61, 0x63, 0x54, 0x4c)
-                val IDAT = byteArrayOf(0x49, 0x44, 0x41, 0x54)
+                @Suppress("LocalVariableName") val IDAT = byteArrayOf(0x49, 0x44, 0x41, 0x54)
                 for (i in 0 until byteArray.size) {
                     val it = byteArray.copyOfRange(i, i + 4)
                     // if byteArray contain acTL
@@ -40,66 +40,66 @@ class Utils {
          */
         val pngSignature: ByteArray = byteArrayOf(0x89.toByte(), 0x50.toByte(), 0x4E.toByte(), 0x47.toByte(), 0x0D.toByte(), 0x0A.toByte(), 0x1A.toByte(), 0x0A.toByte())
 
-        enum class dispose_op {
+        enum class DisposeOp {
             APNG_DISPOSE_OP_NONE,
             APNG_DISPOSE_OP_BACKGROUND,
             APNG_DISPOSE_OP_PREVIOUS
         }
 
         /**
-         * Get the int equivalent to the dispose_op
-         * @param dispose_op The dispose_op
-         * @return An int equivalent to the dispose_op
+         * Get the int equivalent to the DisposeOp
+         * @param disposeOp The DisposeOp
+         * @return An int equivalent to the DisposeOp
          */
-        fun getDispose_op(dispose_op: dispose_op) : Int {
-            return when(dispose_op) {
-                Companion.dispose_op.APNG_DISPOSE_OP_NONE -> 0
-                Companion.dispose_op.APNG_DISPOSE_OP_BACKGROUND -> 1
-                Companion.dispose_op.APNG_DISPOSE_OP_PREVIOUS -> 2
+        fun getDisposeOp(disposeOp: DisposeOp) : Int {
+            return when(disposeOp) {
+                Companion.DisposeOp.APNG_DISPOSE_OP_NONE -> 0
+                Companion.DisposeOp.APNG_DISPOSE_OP_BACKGROUND -> 1
+                Companion.DisposeOp.APNG_DISPOSE_OP_PREVIOUS -> 2
             }
         }
 
         /**
-         * Get the dispose_op enum equivalent to the int
-         * @param int Int of the dispose_op
-         * @return A dispose_op
+         * Get the DisposeOp enum equivalent to the int
+         * @param int Int of the DisposeOp
+         * @return A DisposeOp
          */
-        fun getDispose_op(int: Int) : dispose_op {
+        fun getDisposeOp(int: Int) : DisposeOp {
             return when(int) {
-                0 -> dispose_op.APNG_DISPOSE_OP_NONE
-                1 -> dispose_op.APNG_DISPOSE_OP_BACKGROUND
-                2 -> dispose_op.APNG_DISPOSE_OP_PREVIOUS
-                else -> dispose_op.APNG_DISPOSE_OP_NONE
+                0 -> DisposeOp.APNG_DISPOSE_OP_NONE
+                1 -> DisposeOp.APNG_DISPOSE_OP_BACKGROUND
+                2 -> DisposeOp.APNG_DISPOSE_OP_PREVIOUS
+                else -> DisposeOp.APNG_DISPOSE_OP_NONE
             }
         }
 
-        enum class blend_op() {
+        enum class BlendOp {
             APNG_BLEND_OP_SOURCE,
             APNG_BLEND_OP_OVER
         }
 
         /**
-         * Get the int equivalent to the blend_op
-         * @param blend_op The blend_op
-         * @return An int equivalent to the blend_op
+         * Get the int equivalent to the BlendOp
+         * @param blendOp The BlendOp
+         * @return An int equivalent to the BlendOp
          */
-        fun getBlend_op(blend_op: blend_op) : Int {
-            return when(blend_op) {
-                Companion.blend_op.APNG_BLEND_OP_SOURCE -> 0
-                Companion.blend_op.APNG_BLEND_OP_OVER -> 1
+        fun getBlendOp(blendOp: BlendOp) : Int {
+            return when(blendOp) {
+                Companion.BlendOp.APNG_BLEND_OP_SOURCE -> 0
+                Companion.BlendOp.APNG_BLEND_OP_OVER -> 1
             }
         }
 
         /**
-         * Get the blend_op enum equivalent to the int
-         * @param int Int of the blend_op
-         * @return A blend_op
+         * Get the BlendOp enum equivalent to the int
+         * @param int Int of the BlendOp
+         * @return A BlendOp
          */
-        fun getBlend_op(int : Int) : blend_op {
+        fun getBlendOp(int : Int) : BlendOp {
             return when(int) {
-                0 -> blend_op.APNG_BLEND_OP_SOURCE
-                1 -> blend_op.APNG_BLEND_OP_OVER
-                else -> blend_op.APNG_BLEND_OP_SOURCE
+                0 -> BlendOp.APNG_BLEND_OP_SOURCE
+                1 -> BlendOp.APNG_BLEND_OP_OVER
+                else -> BlendOp.APNG_BLEND_OP_SOURCE
             }
         }
 
@@ -137,12 +137,12 @@ class Utils {
             return lengthString.toLong(16).toInt()
         }
 
-        val fcTL = Arrays.toString(byteArrayOf(0x66, 0x63, 0x54, 0x4c))
-        val IEND = Arrays.toString(byteArrayOf(0x49, 0x45, 0x4e, 0x44))
-        val IDAT = Arrays.toString(byteArrayOf(0x49, 0x44, 0x41, 0x54))
-        val fdAT = Arrays.toString(byteArrayOf(0x66, 0x64, 0x41, 0x54))
-        val plte = Arrays.toString(byteArrayOf(0x50, 0x4c, 0x54, 0x45))
-        val tnrs = Arrays.toString(byteArrayOf(0x74, 0x52, 0x4e, 0x53))
-        val IHDR = Arrays.toString(byteArrayOf(0x49, 0x48, 0x44, 0x52))
+        val fcTL : String = Arrays.toString(byteArrayOf(0x66, 0x63, 0x54, 0x4c))
+        val IEND : String = Arrays.toString(byteArrayOf(0x49, 0x45, 0x4e, 0x44))
+        val IDAT : String = Arrays.toString(byteArrayOf(0x49, 0x44, 0x41, 0x54))
+        val fdAT : String = Arrays.toString(byteArrayOf(0x66, 0x64, 0x41, 0x54))
+        val plte : String = Arrays.toString(byteArrayOf(0x50, 0x4c, 0x54, 0x45))
+        val tnrs : String = Arrays.toString(byteArrayOf(0x74, 0x52, 0x4e, 0x53))
+        val IHDR : String = Arrays.toString(byteArrayOf(0x49, 0x48, 0x44, 0x52))
     }
 }
\ No newline at end of file
diff --git a/app-test/build.gradle b/app-test/build.gradle
index c51d110..1784ea4 100644
--- a/app-test/build.gradle
+++ b/app-test/build.gradle
@@ -12,7 +12,7 @@ android {
         targetSdkVersion 28
         versionCode 1
         versionName "1.0"
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
     // Configure only for each module that uses Java 8
     // language features (either in its source code or
@@ -35,17 +35,17 @@ dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
 
     //noinspection GradleCompatible
-    implementation 'com.android.support:appcompat-v7:27.1.1'
-    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
+    implementation 'androidx.appcompat:appcompat:1.0.2'
+    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
     testImplementation 'junit:junit:4.12'
-    androidTestImplementation 'com.android.support.test:runner:1.0.2'
-    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
+    androidTestImplementation 'androidx.test:runner:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
     implementation "org.jetbrains.anko:anko:$anko_version"
     implementation 'com.squareup.picasso:picasso:2.71828'
     implementation project(":apng_library")
     // implementation fileTree(include: ['*.aar'], dir: 'libs')
     //implementation 'com.github.oupson:Kapng-Android:1.0.0'
-    implementation 'com.android.support:design:27.1.1' // where X.X.X version
+    implementation 'com.google.android.material:material:1.0.0' // where X.X.X version
     implementation "org.jetbrains.anko:anko-appcompat-v7:$anko_version"
     implementation "org.jetbrains.anko:anko-design:$anko_version"
     implementation "org.jetbrains.anko:anko-constraint-layout:$anko_version"
diff --git a/app-test/src/androidTest/java/oupson/apngcreator/ExampleInstrumentedTest.kt b/app-test/src/androidTest/java/oupson/apngcreator/ExampleInstrumentedTest.kt
index 2d70ec6..ae350dd 100644
--- a/app-test/src/androidTest/java/oupson/apngcreator/ExampleInstrumentedTest.kt
+++ b/app-test/src/androidTest/java/oupson/apngcreator/ExampleInstrumentedTest.kt
@@ -1,7 +1,7 @@
 package oupson.apngcreator
 
-import android.support.test.InstrumentationRegistry
-import android.support.test.runner.AndroidJUnit4
+import androidx.test.InstrumentationRegistry
+import androidx.test.runner.AndroidJUnit4
 import org.junit.Assert.assertEquals
 import org.junit.Test
 import org.junit.runner.RunWith
diff --git a/app-test/src/main/java/oupson/apngcreator/CreatorActivity.kt b/app-test/src/main/java/oupson/apngcreator/CreatorActivity.kt
index 73c441c..37e840a 100644
--- a/app-test/src/main/java/oupson/apngcreator/CreatorActivity.kt
+++ b/app-test/src/main/java/oupson/apngcreator/CreatorActivity.kt
@@ -8,11 +8,11 @@ import android.graphics.BitmapFactory
 import android.graphics.Color
 import android.os.Bundle
 import android.os.Environment
-import android.support.design.widget.FloatingActionButton
-import android.support.v7.app.AppCompatActivity
 import android.text.Html
 import android.view.View
 import android.widget.ListView
+import androidx.appcompat.app.AppCompatActivity
+import com.google.android.material.floatingactionbutton.FloatingActionButton
 import org.jetbrains.anko.*
 import org.jetbrains.anko.design.appBarLayout
 import org.jetbrains.anko.design.floatingActionButton
diff --git a/app-test/src/main/java/oupson/apngcreator/Main2Activity.kt b/app-test/src/main/java/oupson/apngcreator/Main2Activity.kt
index a00d3c8..513db95 100644
--- a/app-test/src/main/java/oupson/apngcreator/Main2Activity.kt
+++ b/app-test/src/main/java/oupson/apngcreator/Main2Activity.kt
@@ -4,11 +4,11 @@ import android.Manifest
 import android.content.pm.PackageManager
 import android.graphics.Color
 import android.os.Bundle
-import android.support.v4.app.ActivityCompat
-import android.support.v4.content.ContextCompat
-import android.support.v7.app.AppCompatActivity
 import android.view.View
 import android.widget.ImageView
+import androidx.appcompat.app.AppCompatActivity
+import androidx.core.app.ActivityCompat
+import androidx.core.content.ContextCompat
 import org.jetbrains.anko.backgroundColor
 import org.jetbrains.anko.imageView
 import org.jetbrains.anko.matchParent
diff --git a/app-test/src/main/java/oupson/apngcreator/MainActivity.kt b/app-test/src/main/java/oupson/apngcreator/MainActivity.kt
index 3806231..08e978a 100644
--- a/app-test/src/main/java/oupson/apngcreator/MainActivity.kt
+++ b/app-test/src/main/java/oupson/apngcreator/MainActivity.kt
@@ -3,12 +3,12 @@ package oupson.apngcreator
 import android.graphics.Color
 import android.graphics.drawable.GradientDrawable
 import android.os.Bundle
-import android.support.constraint.ConstraintLayout
-import android.support.v7.app.AppCompatActivity
 import android.text.Html
 import android.util.Log
 import android.view.View
 import android.widget.Toolbar
+import androidx.appcompat.app.AppCompatActivity
+import androidx.constraintlayout.widget.ConstraintLayout
 import com.squareup.picasso.Picasso
 import org.jetbrains.anko.*
 import org.jetbrains.anko.constraint.layout.ConstraintSetBuilder
diff --git a/gradle.properties b/gradle.properties
index b2b3bb2..16508a5 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -6,6 +6,8 @@
 # http://www.gradle.org/docs/current/userguide/build_environment.html
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
+android.enableJetifier=true
+android.useAndroidX=true
 org.gradle.jvmargs=-Xmx1536m
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. More details, visit