From 8c46295631863dfb727fbf7f78316cf9635c69f4 Mon Sep 17 00:00:00 2001
From: tateisu <tateisu@gmail.com>
Date: Thu, 1 Feb 2018 18:30:46 +0900
Subject: [PATCH] =?UTF-8?q?=E3=83=AA=E3=83=95=E3=82=A1=E3=82=AF=E3=82=BF?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 apng/src/main/java/jp/juggler/apng/Apng.kt    |  10 +-
 .../jp/juggler/apng/ApngAnimationControl.kt   |  49 +++---
 .../java/jp/juggler/apng/ApngBackground.kt    |  62 ++++----
 .../main/java/jp/juggler/apng/ApngBitmap.kt   |  16 +-
 .../main/java/jp/juggler/apng/ApngChunk.kt    |  62 ++++----
 .../main/java/jp/juggler/apng/ApngDecoder.kt  |  26 ++--
 .../jp/juggler/apng/ApngDecoderCallback.kt    |   2 +-
 .../main/java/jp/juggler/apng/ApngEnums.kt    |  52 +++----
 .../java/jp/juggler/apng/ApngFrameControl.kt  |  72 ++++-----
 .../java/jp/juggler/apng/ApngImageHeader.kt   |  68 ++++----
 .../main/java/jp/juggler/apng/ApngPalette.kt  |   9 +-
 .../java/jp/juggler/apng/ApngParseError.kt    |   3 +
 .../jp/juggler/apng/ApngTransparentColor.kt   |  39 ++---
 .../main/java/jp/juggler/apng/IdatDecoder.kt  | 146 +++++++++---------
 .../main/java/jp/juggler/apng/ParseError.kt   |   3 -
 .../java/jp/juggler/apng/util/BufferPool.kt   |  16 +-
 .../java/jp/juggler/apng/util/ByteSequence.kt |   5 +-
 .../jp/juggler/apng/util/ByteSequenceQueue.kt |  67 ++++----
 .../jp/juggler/apng/util/StreamTokenizer.kt   | 120 +++++++-------
 .../main/java/jp/juggler/apng/ApngFrames.kt   |  22 +--
 20 files changed, 414 insertions(+), 435 deletions(-)
 create mode 100644 apng/src/main/java/jp/juggler/apng/ApngParseError.kt
 delete mode 100644 apng/src/main/java/jp/juggler/apng/ParseError.kt

diff --git a/apng/src/main/java/jp/juggler/apng/Apng.kt b/apng/src/main/java/jp/juggler/apng/Apng.kt
index c65c3b24..2b00fd92 100644
--- a/apng/src/main/java/jp/juggler/apng/Apng.kt
+++ b/apng/src/main/java/jp/juggler/apng/Apng.kt
@@ -1,9 +1,9 @@
 package jp.juggler.apng
 
 class Apng {
-    var header: ApngImageHeader? = null
-    var background: ApngBackground? = null
-    var animationControl: ApngAnimationControl? = null
-    internal var palette: ApngPalette? = null
-    internal var transparentColor: ApngTransparentColor? = null
+	var header : ApngImageHeader? = null
+	var background : ApngBackground? = null
+	var animationControl : ApngAnimationControl? = null
+	internal var palette : ApngPalette? = null
+	internal var transparentColor : ApngTransparentColor? = null
 }
diff --git a/apng/src/main/java/jp/juggler/apng/ApngAnimationControl.kt b/apng/src/main/java/jp/juggler/apng/ApngAnimationControl.kt
index 0e70d049..f5f24fbb 100644
--- a/apng/src/main/java/jp/juggler/apng/ApngAnimationControl.kt
+++ b/apng/src/main/java/jp/juggler/apng/ApngAnimationControl.kt
@@ -4,29 +4,28 @@ package jp.juggler.apng
 
 import jp.juggler.apng.util.ByteSequence
 
-
-class ApngAnimationControl internal constructor(src: ByteSequence) {
-
-    companion object {
-        const val PLAY_INDEFINITELY =0
-    }
-
-    // This must equal the number of `fcTL` chunks.
-    // 0 is not a valid value.
-    // 1 is a valid value for a single-frame APNG.
-    val numFrames: Int
-
-    //  if it is 0, the animation should play indefinitely.
-    // If nonzero, the animation should come to rest on the final frame at the end of the last play.
-    val numPlays: Int
-
-    init {
-        numFrames = src.readInt32()
-        numPlays = src.readInt32()
-    }
-
-    override fun toString() ="ApngAnimationControl(numFrames=$numFrames,numPlays=$numPlays)"
-    
-    val isFinite :Boolean
-        get() = numPlays > PLAY_INDEFINITELY
+class ApngAnimationControl internal constructor(src : ByteSequence) {
+	
+	companion object {
+		const val PLAY_INDEFINITELY = 0
+	}
+	
+	// This must equal the number of `fcTL` chunks.
+	// 0 is not a valid value.
+	// 1 is a valid value for a single-frame APNG.
+	val numFrames : Int
+	
+	//  if it is 0, the animation should play indefinitely.
+	// If nonzero, the animation should come to rest on the final frame at the end of the last play.
+	val numPlays : Int
+	
+	init {
+		numFrames = src.readInt32()
+		numPlays = src.readInt32()
+	}
+	
+	override fun toString() = "ApngAnimationControl(numFrames=$numFrames,numPlays=$numPlays)"
+	
+	val isFinite : Boolean
+		get() = numPlays > PLAY_INDEFINITELY
 }
diff --git a/apng/src/main/java/jp/juggler/apng/ApngBackground.kt b/apng/src/main/java/jp/juggler/apng/ApngBackground.kt
index 05db9d34..96185fd6 100644
--- a/apng/src/main/java/jp/juggler/apng/ApngBackground.kt
+++ b/apng/src/main/java/jp/juggler/apng/ApngBackground.kt
@@ -4,34 +4,36 @@ package jp.juggler.apng
 
 import jp.juggler.apng.util.ByteSequence
 
-class ApngBackground internal constructor(colorType: ColorType, src: ByteSequence) {
-
-    val red: Int
-    val green: Int
-    val blue: Int
-    val index: Int
-
-    init {
-        when (colorType) {
-            ColorType.GREY, ColorType.GREY_ALPHA -> {
-                val v = src.readUInt16()
-                red = v
-                green = v
-                blue = v
-                index = -1
-            }
-            ColorType.RGB, ColorType.RGBA -> {
-                red = src.readUInt16()
-                green = src.readUInt16()
-                blue = src.readUInt16()
-                index = -1
-            }
-            ColorType.INDEX -> {
-                red = -1
-                green = -1
-                blue = -1
-                index = src.readUInt8()
-            }
-        }
-    }
+class ApngBackground internal constructor(colorType : ColorType, src : ByteSequence) {
+	
+	val red : Int
+	val green : Int
+	val blue : Int
+	val index : Int
+	
+	init {
+		when(colorType) {
+			ColorType.GREY, ColorType.GREY_ALPHA -> {
+				val v = src.readUInt16()
+				red = v
+				green = v
+				blue = v
+				index = - 1
+			}
+			
+			ColorType.RGB, ColorType.RGBA -> {
+				red = src.readUInt16()
+				green = src.readUInt16()
+				blue = src.readUInt16()
+				index = - 1
+			}
+			
+			ColorType.INDEX -> {
+				red = - 1
+				green = - 1
+				blue = - 1
+				index = src.readUInt8()
+			}
+		}
+	}
 }
\ No newline at end of file
diff --git a/apng/src/main/java/jp/juggler/apng/ApngBitmap.kt b/apng/src/main/java/jp/juggler/apng/ApngBitmap.kt
index 9f1b435d..f6479701 100644
--- a/apng/src/main/java/jp/juggler/apng/ApngBitmap.kt
+++ b/apng/src/main/java/jp/juggler/apng/ApngBitmap.kt
@@ -11,7 +11,7 @@ class ApngBitmap(var width : Int, var height : Int) {
 	fun reset(width : Int, height : Int) {
 		val newSize = width * height
 		if(newSize > colors.size)
-			throw ParseError("can't resize to $width x $height , it's greater than initial size")
+			throw ApngParseError("can't resize to $width x $height , it's greater than initial size")
 		this.width = width
 		this.height = height
 		// 透明な黒で初期化する
@@ -24,11 +24,7 @@ class ApngBitmap(var width : Int, var height : Int) {
 		private var pos : Int = 0
 		var step : Int = 1
 		
-		fun setPixel(argb : Int) : Pointer {
-			//	if( pos == width) println("setPixel 0x%x".format(argb))
-			colors[pos] = argb
-			return this
-		}
+		fun setPixel(argb : Int) = apply { colors[pos] = argb }
 		
 		fun setPixel(a : Int, r : Int, g : Int, b : Int) = setPixel(
 			((a and 255) shl 24) or
@@ -37,18 +33,14 @@ class ApngBitmap(var width : Int, var height : Int) {
 				(b and 255)
 		)
 		
-		fun setOffset(pos : Int = 0, step : Int = 1) : Pointer {
+		fun setOffset(pos : Int = 0, step : Int = 1) = apply {
 			this.pos = pos
 			this.step = step
-			return this
 		}
 		
 		fun setXY(x : Int, y : Int, step : Int = 1) = setOffset(x + y * width, step)
 		
-		fun plus(x : Int) : Pointer {
-			pos += x
-			return this
-		}
+		fun plus(x : Int) = apply { pos += x }
 		
 		fun next() = plus(step)
 		
diff --git a/apng/src/main/java/jp/juggler/apng/ApngChunk.kt b/apng/src/main/java/jp/juggler/apng/ApngChunk.kt
index e1d33f9b..d15702d5 100644
--- a/apng/src/main/java/jp/juggler/apng/ApngChunk.kt
+++ b/apng/src/main/java/jp/juggler/apng/ApngChunk.kt
@@ -5,35 +5,35 @@ package jp.juggler.apng
 import jp.juggler.apng.util.StreamTokenizer
 import java.util.zip.CRC32
 
-internal class ApngChunk(crc32:CRC32,tokenizer: StreamTokenizer) {
-    val size: Int
-    val type: String
-
-    init {
-        size = tokenizer.readInt32()
-        val typeBytes = tokenizer.readBytes(4)
-        type = typeBytes.toString(Charsets.UTF_8)
-
-        crc32.update(typeBytes)
-    }
-
-    fun readBody(crc32:CRC32,tokenizer: StreamTokenizer): ByteArray {
-        val bytes = tokenizer.readBytes(size)
-        val crcExpect = tokenizer.readUInt32()
-
-        crc32.update(bytes, 0, size)
-        val crcActual = crc32.value
-        if (crcActual != crcExpect) throw ParseError("CRC not match.")
-
-        return bytes
-    }
-
-    fun skipBody(tokenizer: StreamTokenizer) {
-        tokenizer.skipBytes((size + 4).toLong())
-    }
-
-    fun checkCRC(tokenizer: StreamTokenizer, crcActual: Long) {
-        val crcExpect = tokenizer.readUInt32()
-        if (crcActual != crcExpect) throw ParseError("CRC not match.")
-    }
+internal class ApngChunk(crc32 : CRC32, tokenizer : StreamTokenizer) {
+	val size : Int
+	val type : String
+	
+	init {
+		size = tokenizer.readInt32()
+		val typeBytes = tokenizer.readBytes(4)
+		type = typeBytes.toString(Charsets.UTF_8)
+		
+		crc32.update(typeBytes)
+	}
+	
+	fun readBody(crc32 : CRC32, tokenizer : StreamTokenizer) : ByteArray {
+		val bytes = tokenizer.readBytes(size)
+		val crcExpect = tokenizer.readUInt32()
+		
+		crc32.update(bytes, 0, size)
+		val crcActual = crc32.value
+		if(crcActual != crcExpect) throw ApngParseError("CRC not match.")
+		
+		return bytes
+	}
+	
+	fun skipBody(tokenizer : StreamTokenizer) =
+		tokenizer.skipBytes((size + 4).toLong())
+	
+	
+	fun checkCRC(tokenizer : StreamTokenizer, crcActual : Long) {
+		val crcExpect = tokenizer.readUInt32()
+		if(crcActual != crcExpect) throw ApngParseError("CRC not match.")
+	}
 }
diff --git a/apng/src/main/java/jp/juggler/apng/ApngDecoder.kt b/apng/src/main/java/jp/juggler/apng/ApngDecoder.kt
index 508dcd86..30e52a82 100644
--- a/apng/src/main/java/jp/juggler/apng/ApngDecoder.kt
+++ b/apng/src/main/java/jp/juggler/apng/ApngDecoder.kt
@@ -11,22 +11,22 @@ object ApngDecoder {
 	private val PNG_SIGNATURE = byteArrayOf(0x89.toByte(), 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0a)
 	
 	fun parseStream(
-		_inStream : InputStream,
+		inStream : InputStream,
 		callback : ApngDecoderCallback
 	) {
 		val apng = Apng()
-		val tokenizer = StreamTokenizer(_inStream)
+		val tokenizer = StreamTokenizer(inStream)
 		
 		val pngHeader = tokenizer.readBytes(8)
 		if(! pngHeader.contentEquals(PNG_SIGNATURE)) {
-			throw ParseError("header not match")
+			throw ApngParseError("header not match")
 		}
 		
 		var lastSequenceNumber : Int? = null
 		fun checkSequenceNumber(n : Int) {
 			val last = lastSequenceNumber
 			if(last != null && n <= last) {
-				throw ParseError("incorrect sequenceNumber. last=$lastSequenceNumber,current=$n")
+				throw ApngParseError("incorrect sequenceNumber. last=$lastSequenceNumber,current=$n")
 			}
 			lastSequenceNumber = n
 		}
@@ -56,7 +56,7 @@ object ApngDecoder {
 				"PLTE" -> apng.palette = ApngPalette(chunk.readBody(crc32, tokenizer))
 				
 				"bKGD" -> {
-					val header = apng.header ?: throw ParseError("missing IHDR")
+					val header = apng.header ?: throw ApngParseError("missing IHDR")
 					apng.background = ApngBackground(
 						header.colorType,
 						ByteSequence(chunk.readBody(crc32, tokenizer))
@@ -64,7 +64,7 @@ object ApngDecoder {
 				}
 				
 				"tRNS" -> {
-					val header = apng.header ?: throw ParseError("missing IHDR")
+					val header = apng.header ?: throw ApngParseError("missing IHDR")
 					val body = chunk.readBody(crc32, tokenizer)
 					when(header.colorType) {
 						ColorType.GREY -> apng.transparentColor =
@@ -72,15 +72,15 @@ object ApngDecoder {
 						ColorType.RGB -> apng.transparentColor =
 							ApngTransparentColor(false, ByteSequence(body))
 						ColorType.INDEX -> apng.palette?.parseTRNS(body)
-							?: throw ParseError("missing palette")
+							?: throw ApngParseError("missing palette")
 						else -> callback.onApngWarning("tRNS ignored. colorType =${header.colorType}")
 					}
 				}
 				
 				"IDAT" -> {
-					val header = apng.header ?: throw ParseError("missing IHDR")
+					val header = apng.header ?: throw ApngParseError("missing IHDR")
 					if(idatDecoder == null) {
-						bitmap ?: throw ParseError("missing bitmap")
+						bitmap ?: throw ApngParseError("missing bitmap")
 						bitmap.reset(header.width, header.height)
 						idatDecoder = IdatDecoder(
 							apng,
@@ -106,11 +106,11 @@ object ApngDecoder {
 				}
 				
 				"acTL" -> {
-					val header = apng.header ?: throw ParseError("missing IHDR")
+					val header = apng.header ?: throw ApngParseError("missing IHDR")
 					val animationControl =
 						ApngAnimationControl(ByteSequence(chunk.readBody(crc32, tokenizer)))
 					apng.animationControl = animationControl
-					callback.onAnimationInfo(apng, header,animationControl)
+					callback.onAnimationInfo(apng, header, animationControl)
 				}
 				
 				"fcTL" -> {
@@ -121,9 +121,9 @@ object ApngDecoder {
 				}
 				
 				"fdAT" -> {
-					val fctl = lastFctl ?: throw ParseError("missing fCTL before fdAT")
+					val fctl = lastFctl ?: throw ApngParseError("missing fCTL before fdAT")
 					if(fdatDecoder == null) {
-						bitmap ?: throw ParseError("missing bitmap")
+						bitmap ?: throw ApngParseError("missing bitmap")
 						bitmap.reset(fctl.width, fctl.height)
 						fdatDecoder = IdatDecoder(
 							apng,
diff --git a/apng/src/main/java/jp/juggler/apng/ApngDecoderCallback.kt b/apng/src/main/java/jp/juggler/apng/ApngDecoderCallback.kt
index ab1571d7..188f733c 100644
--- a/apng/src/main/java/jp/juggler/apng/ApngDecoderCallback.kt
+++ b/apng/src/main/java/jp/juggler/apng/ApngDecoderCallback.kt
@@ -8,7 +8,7 @@ interface ApngDecoderCallback {
 	// called for debug message
 	fun onApngDebug(message : String) {}
 	
-	fun canApngDebug():Boolean = false
+	fun canApngDebug() : Boolean = false
 	
 	// called when PNG image header is detected.
 	fun onHeader(apng : Apng, header : ApngImageHeader)
diff --git a/apng/src/main/java/jp/juggler/apng/ApngEnums.kt b/apng/src/main/java/jp/juggler/apng/ApngEnums.kt
index 55a07d75..67bd2900 100644
--- a/apng/src/main/java/jp/juggler/apng/ApngEnums.kt
+++ b/apng/src/main/java/jp/juggler/apng/ApngEnums.kt
@@ -1,41 +1,41 @@
 package jp.juggler.apng
 
-enum class ColorType(val num:Int ){
-    GREY(0),
-    RGB ( 2),
-    INDEX( 3),
-    GREY_ALPHA ( 4),
-    RGBA ( 6),
+enum class ColorType(val num : Int) {
+	GREY(0),
+	RGB(2),
+	INDEX(3),
+	GREY_ALPHA(4),
+	RGBA(6),
 }
 
-enum class CompressionMethod(val num:Int ){
-    Standard(0)
+enum class CompressionMethod(val num : Int) {
+	Standard(0)
 }
 
-enum class FilterMethod(val num:Int ){
-    Standard(0)
+enum class FilterMethod(val num : Int) {
+	Standard(0)
 }
 
-enum class InterlaceMethod(val num:Int ){
-    None(0),
-    Standard(1)
+enum class InterlaceMethod(val num : Int) {
+	None(0),
+	Standard(1)
 }
 
-enum class FilterType(val num:Int ){
-    None(0),
-    Sub(1),
-    Up(2),
-    Average(3),
-    Paeth(4)
+enum class FilterType(val num : Int) {
+	None(0),
+	Sub(1),
+	Up(2),
+	Average(3),
+	Paeth(4)
 }
 
-enum class DisposeOp(val num :Int){
-    None(0),
-    Background(1),
-    Previous(2)
+enum class DisposeOp(val num : Int) {
+	None(0),
+	Background(1),
+	Previous(2)
 }
 
-enum class BlendOp(val num :Int){
-    Source(0),
-    Over(1)
+enum class BlendOp(val num : Int) {
+	Source(0),
+	Over(1)
 }
diff --git a/apng/src/main/java/jp/juggler/apng/ApngFrameControl.kt b/apng/src/main/java/jp/juggler/apng/ApngFrameControl.kt
index 262211c8..1d53d22e 100644
--- a/apng/src/main/java/jp/juggler/apng/ApngFrameControl.kt
+++ b/apng/src/main/java/jp/juggler/apng/ApngFrameControl.kt
@@ -4,40 +4,40 @@ package jp.juggler.apng
 
 import jp.juggler.apng.util.ByteSequence
 
-
-class ApngFrameControl internal constructor(src: ByteSequence) {
-
-    val width: Int
-    val height: Int
-    val xOffset: Int
-    val yOffset: Int
-    val delayNum: Int
-    val delayDen: Int
-    val disposeOp: DisposeOp
-    val blendOp: BlendOp
-
-    init {
-        width = src.readInt32()
-        height = src.readInt32()
-        xOffset = src.readInt32()
-        yOffset = src.readInt32()
-        delayNum = src.readUInt16()
-        delayDen = src.readUInt16().let{ if(it==0) 100 else it}
-
-        var num:Int
-
-        num = src.readUInt8()
-        disposeOp = DisposeOp.values().first{it.num==num}
-
-        num = src.readUInt8()
-        blendOp = BlendOp.values().first{it.num==num}
-    }
-
-    override fun toString() ="ApngFrameControl(width=$width,height=$height,x=$xOffset,y=$yOffset,delayNum=$delayNum,delayDen=$delayDen,disposeOp=$disposeOp,blendOp=$blendOp)"
-    
-    val delayMilliseconds : Long
-        get() = when(delayDen) {
-	        1000 -> delayNum.toLong()
-	        else -> (1000f * delayNum.toFloat() / delayDen.toFloat() + 0.5f).toLong()
-        }
+class ApngFrameControl internal constructor(src : ByteSequence) {
+	
+	val width : Int
+	val height : Int
+	val xOffset : Int
+	val yOffset : Int
+	val delayNum : Int
+	val delayDen : Int
+	val disposeOp : DisposeOp
+	val blendOp : BlendOp
+	
+	init {
+		width = src.readInt32()
+		height = src.readInt32()
+		xOffset = src.readInt32()
+		yOffset = src.readInt32()
+		delayNum = src.readUInt16()
+		delayDen = src.readUInt16().let { if(it == 0) 100 else it }
+		
+		var num : Int
+		
+		num = src.readUInt8()
+		disposeOp = DisposeOp.values().first { it.num == num }
+		
+		num = src.readUInt8()
+		blendOp = BlendOp.values().first { it.num == num }
+	}
+	
+	override fun toString() =
+		"ApngFrameControl(width=$width,height=$height,x=$xOffset,y=$yOffset,delayNum=$delayNum,delayDen=$delayDen,disposeOp=$disposeOp,blendOp=$blendOp)"
+	
+	val delayMilliseconds : Long
+		get() = when(delayDen) {
+			1000 -> delayNum.toLong()
+			else -> (1000f * delayNum.toFloat() / delayDen.toFloat() + 0.5f).toLong()
+		}
 }
\ No newline at end of file
diff --git a/apng/src/main/java/jp/juggler/apng/ApngImageHeader.kt b/apng/src/main/java/jp/juggler/apng/ApngImageHeader.kt
index f524476d..57c63ccf 100644
--- a/apng/src/main/java/jp/juggler/apng/ApngImageHeader.kt
+++ b/apng/src/main/java/jp/juggler/apng/ApngImageHeader.kt
@@ -5,37 +5,39 @@ package jp.juggler.apng
 import jp.juggler.apng.util.ByteSequence
 
 // information from IHDR chunk.
-class ApngImageHeader internal constructor(src: ByteSequence) {
-    val width: Int
-    val height: Int
-    val bitDepth: Int
-    val colorType: ColorType
-    val compressionMethod: CompressionMethod
-    val filterMethod: FilterMethod
-    val interlaceMethod: InterlaceMethod
-
-    init {
-
-        width = src.readInt32()
-        height = src.readInt32()
-        if(width <=0 || height <=0 ) throw ParseError("w=$width,h=$height is too small")
-
-        bitDepth = src.readUInt8()
-
-        var num:Int
-        //
-        num =src.readUInt8()
-        colorType = ColorType.values().first { it.num==num }
-        //
-        num =src.readUInt8()
-        compressionMethod = CompressionMethod.values().first { it.num==num }
-        //
-        num =src.readUInt8()
-        filterMethod = FilterMethod.values().first { it.num==num }
-        //
-        num =src.readUInt8()
-        interlaceMethod = InterlaceMethod.values().first { it.num==num }
-    }
-
-    override fun toString() = "ApngImageHeader(w=$width,h=$height,bits=$bitDepth,color=$colorType,interlace=$interlaceMethod)"
+class ApngImageHeader internal constructor(src : ByteSequence) {
+	
+	val width : Int
+	val height : Int
+	val bitDepth : Int
+	val colorType : ColorType
+	val compressionMethod : CompressionMethod
+	val filterMethod : FilterMethod
+	val interlaceMethod : InterlaceMethod
+	
+	init {
+		
+		width = src.readInt32()
+		height = src.readInt32()
+		if(width <= 0 || height <= 0) throw ApngParseError("w=$width,h=$height is too small")
+		
+		bitDepth = src.readUInt8()
+		
+		var num : Int
+		//
+		num = src.readUInt8()
+		colorType = ColorType.values().first { it.num == num }
+		//
+		num = src.readUInt8()
+		compressionMethod = CompressionMethod.values().first { it.num == num }
+		//
+		num = src.readUInt8()
+		filterMethod = FilterMethod.values().first { it.num == num }
+		//
+		num = src.readUInt8()
+		interlaceMethod = InterlaceMethod.values().first { it.num == num }
+	}
+	
+	override fun toString() =
+		"ApngImageHeader(w=$width,h=$height,bits=$bitDepth,color=$colorType,interlace=$interlaceMethod)"
 }
diff --git a/apng/src/main/java/jp/juggler/apng/ApngPalette.kt b/apng/src/main/java/jp/juggler/apng/ApngPalette.kt
index 217d7fb6..b5454436 100644
--- a/apng/src/main/java/jp/juggler/apng/ApngPalette.kt
+++ b/apng/src/main/java/jp/juggler/apng/ApngPalette.kt
@@ -7,6 +7,7 @@ import jp.juggler.apng.util.getUInt8
 class ApngPalette(
 	src : ByteArray // repeat of R,G,B
 ) {
+	
 	companion object {
 		// full opaque black
 		const val OPAQUE = 255 shl 24
@@ -18,14 +19,14 @@ class ApngPalette(
 	
 	init {
 		val entryCount = src.size / 3
-		list = IntArray( entryCount)
+		list = IntArray(entryCount)
 		var pos = 0
 		for(i in 0 until entryCount) {
 			list[i] = OPAQUE or
 				(src.getUInt8(pos) shl 16) or
-				(src.getUInt8(pos+1) shl 8) or
-				src.getUInt8(pos+2)
-			pos+=3
+				(src.getUInt8(pos + 1) shl 8) or
+				src.getUInt8(pos + 2)
+			pos += 3
 		}
 	}
 	
diff --git a/apng/src/main/java/jp/juggler/apng/ApngParseError.kt b/apng/src/main/java/jp/juggler/apng/ApngParseError.kt
new file mode 100644
index 00000000..8bb66bae
--- /dev/null
+++ b/apng/src/main/java/jp/juggler/apng/ApngParseError.kt
@@ -0,0 +1,3 @@
+package jp.juggler.apng
+
+class ApngParseError(message: String) : IllegalArgumentException(message)
diff --git a/apng/src/main/java/jp/juggler/apng/ApngTransparentColor.kt b/apng/src/main/java/jp/juggler/apng/ApngTransparentColor.kt
index d10f58a2..1f910468 100644
--- a/apng/src/main/java/jp/juggler/apng/ApngTransparentColor.kt
+++ b/apng/src/main/java/jp/juggler/apng/ApngTransparentColor.kt
@@ -4,23 +4,24 @@ package jp.juggler.apng
 
 import jp.juggler.apng.util.ByteSequence
 
-class ApngTransparentColor internal constructor(isGreyScale:Boolean, src: ByteSequence) {
-    val red:Int
-    val green:Int
-    val blue:Int
-    init{
-        if( isGreyScale){
-            val v = src.readUInt16()
-            red =v
-            green =v
-            blue =v
-        }else{
-            red =src.readUInt16()
-            green =src.readUInt16()
-            blue =src.readUInt16()
-        }
-    }
-
-    fun match(grey:Int) = red == grey
-    fun match(r:Int,g:Int,b:Int) = (r==red && g == green && b == blue)
+class ApngTransparentColor internal constructor(isGreyScale : Boolean, src : ByteSequence) {
+	val red : Int
+	val green : Int
+	val blue : Int
+	
+	init {
+		if(isGreyScale) {
+			val v = src.readUInt16()
+			red = v
+			green = v
+			blue = v
+		} else {
+			red = src.readUInt16()
+			green = src.readUInt16()
+			blue = src.readUInt16()
+		}
+	}
+	
+	fun match(grey : Int) = red == grey
+	fun match(r : Int, g : Int, b : Int) = (r == red && g == green && b == blue)
 }
\ No newline at end of file
diff --git a/apng/src/main/java/jp/juggler/apng/IdatDecoder.kt b/apng/src/main/java/jp/juggler/apng/IdatDecoder.kt
index 58b1abd5..a2691069 100644
--- a/apng/src/main/java/jp/juggler/apng/IdatDecoder.kt
+++ b/apng/src/main/java/jp/juggler/apng/IdatDecoder.kt
@@ -4,7 +4,6 @@ package jp.juggler.apng
 
 import jp.juggler.apng.util.*
 import java.io.InputStream
-import java.util.*
 import java.util.zip.CRC32
 import java.util.zip.Inflater
 
@@ -33,7 +32,6 @@ internal class IdatDecoder(
 		
 		private val dummyPaletteData = IntArray(0)
 		
-
 		private fun abs(v : Int) = if(v >= 0) v else - v
 		
 		// a = left, b = above, c = upper left
@@ -51,8 +49,9 @@ internal class IdatDecoder(
 		
 		private inline fun scanLine1(baLine : ByteArray, pass_w : Int, block : (v : Int) -> Unit) {
 			var pos = 1
-			var x = 0
-			while(pass_w - x >= 8) {
+			var remain = pass_w
+			while(remain >= 8) {
+				remain -= 8
 				val v = baLine[pos ++].toInt()
 				block((v shr 7) and 1)
 				block((v shr 6) and 1)
@@ -62,9 +61,7 @@ internal class IdatDecoder(
 				block((v shr 2) and 1)
 				block((v shr 1) and 1)
 				block(v and 1)
-				x += 8
 			}
-			val remain = pass_w - x
 			if(remain > 0) {
 				val v = baLine[pos].toInt()
 				block((v shr 7) and 1)
@@ -79,16 +76,15 @@ internal class IdatDecoder(
 		
 		private inline fun scanLine2(baLine : ByteArray, pass_w : Int, block : (v : Int) -> Unit) {
 			var pos = 1
-			var x = 0
-			while(pass_w - x >= 4) {
+			var remain = pass_w
+			while(remain >= 4) {
+				remain -= 4
 				val v = baLine[pos ++].toInt()
 				block((v shr 6) and 3)
 				block((v shr 4) and 3)
 				block((v shr 2) and 3)
 				block(v and 3)
-				x += 4
 			}
-			val remain = pass_w - x
 			if(remain > 0) {
 				val v = baLine[pos].toInt()
 				block((v shr 6) and 3)
@@ -99,14 +95,13 @@ internal class IdatDecoder(
 		
 		private inline fun scanLine4(baLine : ByteArray, pass_w : Int, block : (v : Int) -> Unit) {
 			var pos = 1
-			var x = 0
-			while(pass_w - x >= 2) {
+			var remain = pass_w
+			while(remain >= 2) {
+				remain -= 2
 				val v = baLine[pos ++].toInt()
 				block((v shr 4) and 15)
 				block(v and 15)
-				x += 2
 			}
-			val remain = pass_w - x
 			if(remain > 0) {
 				val v = baLine[pos].toInt()
 				block((v shr 4) and 15)
@@ -115,14 +110,16 @@ internal class IdatDecoder(
 		
 		private inline fun scanLine8(baLine : ByteArray, pass_w : Int, block : (v : Int) -> Unit) {
 			var pos = 1
-			for(x in 0 until pass_w) {
+			var remain = pass_w
+			while(remain -- > 0) {
 				block(baLine.getUInt8(pos ++))
 			}
 		}
 		
 		private inline fun scanLine16(baLine : ByteArray, pass_w : Int, block : (v : Int) -> Unit) {
 			var pos = 1
-			for(x in 0 until pass_w) {
+			var remain = pass_w
+			while(remain -- > 0) {
 				block(baLine.getUInt16(pos))
 				pos += 2
 			}
@@ -134,7 +131,8 @@ internal class IdatDecoder(
 			block : (r : Int, g : Int, b : Int) -> Unit
 		) {
 			var pos = 1
-			for(x in 0 until pass_w) {
+			var remain = pass_w
+			while(remain -- > 0) {
 				block(
 					baLine.getUInt8(pos),
 					baLine.getUInt8(pos + 1),
@@ -150,7 +148,8 @@ internal class IdatDecoder(
 			block : (r : Int, g : Int, b : Int) -> Unit
 		) {
 			var pos = 1
-			for(x in 0 until pass_w) {
+			var remain = pass_w
+			while(remain -- > 0) {
 				block(
 					baLine.getUInt16(pos),
 					baLine.getUInt16(pos + 2),
@@ -166,7 +165,8 @@ internal class IdatDecoder(
 			block : (r : Int, g : Int, b : Int, a : Int) -> Unit
 		) {
 			var pos = 1
-			for(x in 0 until pass_w) {
+			var remain = pass_w
+			while(remain -- > 0) {
 				block(
 					baLine.getUInt8(pos),
 					baLine.getUInt8(pos + 1),
@@ -183,7 +183,8 @@ internal class IdatDecoder(
 			block : (r : Int, g : Int, b : Int, a : Int) -> Unit
 		) {
 			var pos = 1
-			for(x in 0 until pass_w) {
+			var remain = pass_w
+			while(remain -- > 0) {
 				block(
 					baLine.getUInt16(pos),
 					baLine.getUInt16(pos + 2),
@@ -200,7 +201,8 @@ internal class IdatDecoder(
 			block : (g : Int, a : Int) -> Unit
 		) {
 			var pos = 1
-			for(x in 0 until pass_w) {
+			var remain = pass_w
+			while(remain -- > 0) {
 				block(
 					baLine.getUInt8(pos),
 					baLine.getUInt8(pos + 1)
@@ -215,7 +217,8 @@ internal class IdatDecoder(
 			block : (g : Int, a : Int) -> Unit
 		) {
 			var pos = 1
-			for(x in 0 until pass_w) {
+			var remain = pass_w
+			while(remain -- > 0) {
 				block(
 					baLine.getUInt16(pos),
 					baLine.getUInt16(pos + 2)
@@ -233,7 +236,7 @@ internal class IdatDecoder(
 	private val sampleBits : Int
 	private val sampleBytes : Int
 	private val scanLineBytesMax : Int
-	private val linePool = LinkedList<ByteArray>()
+	private val scanLinePool : BufferPool
 	private val transparentCheckerGrey : (v : Int) -> Int
 	private val transparentCheckerRGB : (r : Int, g : Int, b : Int) -> Int
 	private val renderScanLineFunc : (baLine : ByteArray) -> Unit
@@ -250,15 +253,8 @@ internal class IdatDecoder(
 	
 	init {
 		val header = requireNotNull(apng.header)
-		this.colorType = header.colorType
-		this.bitDepth = header.bitDepth
-		
-		this.paletteData = if(colorType == ColorType.INDEX) {
-			apng.palette?.list
-				?: throw ParseError("missing ApngPalette for index color")
-		} else {
-			dummyPaletteData
-		}
+		colorType = header.colorType
+		bitDepth = header.bitDepth
 		
 		sampleBits = when(colorType) {
 			ColorType.GREY, ColorType.INDEX -> bitDepth
@@ -269,9 +265,14 @@ internal class IdatDecoder(
 		
 		sampleBytes = (sampleBits + 7) / 8
 		scanLineBytesMax = 1 + (bitmap.width * sampleBits + 7) / 8
+		scanLinePool = BufferPool(scanLineBytesMax)
 		
-		linePool.add(ByteArray(scanLineBytesMax))
-		linePool.add(ByteArray(scanLineBytesMax))
+		paletteData = if(colorType == ColorType.INDEX) {
+			apng.palette?.list
+				?: throw ApngParseError("missing ApngPalette for index color")
+		} else {
+			dummyPaletteData
+		}
 		
 		val transparentColor = apng.transparentColor
 		
@@ -358,7 +359,7 @@ internal class IdatDecoder(
 	
 	private fun renderIndex2(baLine : ByteArray) {
 		scanLine2(baLine, passWidth) { v ->
-			bitmapPointer.setPixel( paletteData[v] ).next()
+			bitmapPointer.setPixel(paletteData[v]).next()
 		}
 	}
 	
@@ -400,7 +401,7 @@ internal class IdatDecoder(
 	}
 	
 	private fun colorBitsNotSupported() : Nothing {
-		throw ParseError("bitDepth $bitDepth is not supported for $colorType")
+		throw ApngParseError("bitDepth $bitDepth is not supported for $colorType")
 	}
 	
 	private fun selectRenderFunc() = when(colorType) {
@@ -443,11 +444,11 @@ internal class IdatDecoder(
 		passY = 0
 		scanLineBytes = 1 + (passWidth * sampleBits + 7) / 8
 		
-		baPreviousLine?.let { linePool.add(it) }
+		scanLinePool.recycle(baPreviousLine)
 		baPreviousLine = null
 		
 		if(passWidth <= 0 || passHeight <= 0) {
-			if( callback.canApngDebug() ) callback.onApngDebug("pass $pass is empty. size=${passWidth}x${passHeight} ")
+			if(callback.canApngDebug()) callback.onApngDebug("pass $pass is empty. size=${passWidth}x${passHeight} ")
 			incrementPassOrComplete()
 		}
 	}
@@ -464,20 +465,20 @@ internal class IdatDecoder(
 	
 	// スキャンラインを読む。行を処理したらtrueを返す
 	private fun readScanLine() : Boolean {
-
-		if(inflateBufferQueue.remain < scanLineBytes){
+		
+		if(inflateBufferQueue.remain < scanLineBytes) {
 			// not yet enough data to process scanline
 			return false
 		}
 		
-		val baLine = linePool.removeFirst()
+		val baLine = scanLinePool.obtain()
 		inflateBufferQueue.readBytes(baLine, 0, scanLineBytes)
 		
 		val filterNum = baLine.getUInt8(0)
 		val filterType = FilterType.values().first { it.num == filterNum }
 		
-//		if( callback.canApngDebug() ) callback.onApngDebug("y=$passY/${passHeight},filterType=$filterType")
-
+		// if( callback.canApngDebug() ) callback.onApngDebug("y=$passY/${passHeight},filterType=$filterType")
+		
 		when(filterType) {
 			FilterType.None -> {
 			}
@@ -485,23 +486,22 @@ internal class IdatDecoder(
 			FilterType.Sub -> {
 				for(pos in 1 until scanLineBytes) {
 					val vCur = baLine.getUInt8(pos)
-					val leftPos = pos -sampleBytes
-					val vLeft = if(leftPos <=0 ) 0 else baLine.getUInt8(leftPos)
-					
+					val leftPos = pos - sampleBytes
+					val vLeft = if(leftPos <= 0) 0 else baLine.getUInt8(leftPos)
 					
 					baLine[pos] = (vCur + vLeft).toByte()
 					
-//					if( callback.canApngDebug() ){
-//						val x = passInfo.xStart + passInfo.xStep * ((pos-1)/sampleBytes)
-//						val y = passInfo.yStart + passInfo.yStep * passY
-//						callback.onApngDebug("sub pos=$pos,x=$x,y=$y,left=$vLeft,cur=$vCur,after=${baLine[pos].toInt() and 255}")
-//					}
-
+					// if( callback.canApngDebug() ){
+					//  val x = passInfo.xStart + passInfo.xStep * ((pos-1)/sampleBytes)
+					//  val y = passInfo.yStart + passInfo.yStep * passY
+					//  callback.onApngDebug("sub pos=$pos,x=$x,y=$y,left=$vLeft,cur=$vCur,after=${baLine[pos].toInt() and 255}")
+					// }
+					
 				}
 			}
 			
 			FilterType.Up -> {
-				val baPreviousLine=this.baPreviousLine
+				val baPreviousLine = this.baPreviousLine
 				for(pos in 1 until scanLineBytes) {
 					val vCur = baLine.getUInt8(pos)
 					val vUp = baPreviousLine?.getUInt8(pos) ?: 0
@@ -510,47 +510,47 @@ internal class IdatDecoder(
 			}
 			
 			FilterType.Average -> {
-				val baPreviousLine=this.baPreviousLine
+				val baPreviousLine = this.baPreviousLine
 				for(pos in 1 until scanLineBytes) {
 					val vCur = baLine.getUInt8(pos)
-					val leftPos = pos -sampleBytes
-					val vLeft = if(leftPos <=0 ) 0 else baLine.getUInt8(leftPos)
+					val leftPos = pos - sampleBytes
+					val vLeft = if(leftPos <= 0) 0 else baLine.getUInt8(leftPos)
 					val vUp = baPreviousLine?.getUInt8(pos) ?: 0
 					baLine[pos] = (vCur + ((vLeft + vUp) shr 1)).toByte()
 				}
 			}
 			
 			FilterType.Paeth -> {
-				val baPreviousLine=this.baPreviousLine
+				val baPreviousLine = this.baPreviousLine
 				for(pos in 1 until scanLineBytes) {
 					val vCur = baLine.getUInt8(pos)
-					val leftPos = pos -sampleBytes
-					val vLeft = if(leftPos <=0 ) 0 else baLine.getUInt8(leftPos)
+					val leftPos = pos - sampleBytes
+					val vLeft = if(leftPos <= 0) 0 else baLine.getUInt8(leftPos)
 					val vUp = baPreviousLine?.getUInt8(pos) ?: 0
-					val vUpperLeft = if(leftPos <=0 ) 0  else baPreviousLine?.getUInt8(leftPos) ?: 0
+					val vUpperLeft = if(leftPos <= 0) 0 else baPreviousLine?.getUInt8(leftPos) ?: 0
 					
 					baLine[pos] = (vCur + paeth(vLeft, vUp, vUpperLeft)).toByte()
 					
-//					if( callback.canApngDebug() ){
-//						val x = passInfo.xStart + passInfo.xStep * ((pos-1)/sampleBytes)
-//						val y = passInfo.yStart + passInfo.yStep * passY
-//						callback.onApngDebug("paeth pos=$pos,x=$x,y=$y,left=$vLeft,up=$vUp,ul=$vUpperLeft,cur=$vCur,paeth=${paeth(vLeft, vUp, vUpperLeft)}")
-//					}
-
+					//					if( callback.canApngDebug() ){
+					//						val x = passInfo.xStart + passInfo.xStep * ((pos-1)/sampleBytes)
+					//						val y = passInfo.yStart + passInfo.yStep * passY
+					//						callback.onApngDebug("paeth pos=$pos,x=$x,y=$y,left=$vLeft,up=$vUp,ul=$vUpperLeft,cur=$vCur,paeth=${paeth(vLeft, vUp, vUpperLeft)}")
+					//					}
+					
 				}
 			}
 		}
 		
 		// render scanline
 		bitmapPointer.setXY(
-			x=passInfo.xStart,
-			y=passInfo.yStart + passInfo.yStep * passY,
-			step=passInfo.xStep
+			x = passInfo.xStart,
+			y = passInfo.yStart + passInfo.yStep * passY,
+			step = passInfo.xStep
 		)
 		renderScanLineFunc(baLine)
 		
 		// save previous line
-		baPreviousLine?.let { linePool.add(it) }
+		scanLinePool.recycle(baPreviousLine)
 		baPreviousLine = baLine
 		
 		if(++ passY >= passHeight) {
@@ -607,14 +607,14 @@ internal class IdatDecoder(
 			while(! inflater.needsInput()) {
 				val buffer = inflateBufferPool.obtain()
 				val nInflated = inflater.inflate(buffer)
-				if( nInflated <= 0 ){
+				if(nInflated <= 0) {
 					inflateBufferPool.recycle(buffer)
-				}else{
+				} else {
 					inflateBufferQueue.add(ByteSequence(buffer, 0, nInflated))
 					// キューに追加したデータをScanLine単位で消費する
 					while(! isCompleted && readScanLine()) {
 					}
-					if(isCompleted){
+					if(isCompleted) {
 						inflateBufferQueue.clear()
 						break
 					}
diff --git a/apng/src/main/java/jp/juggler/apng/ParseError.kt b/apng/src/main/java/jp/juggler/apng/ParseError.kt
deleted file mode 100644
index 7b569c73..00000000
--- a/apng/src/main/java/jp/juggler/apng/ParseError.kt
+++ /dev/null
@@ -1,3 +0,0 @@
-package jp.juggler.apng
-
-class ParseError(message: String) : IllegalArgumentException(message)
diff --git a/apng/src/main/java/jp/juggler/apng/util/BufferPool.kt b/apng/src/main/java/jp/juggler/apng/util/BufferPool.kt
index a358ffd8..88b21052 100644
--- a/apng/src/main/java/jp/juggler/apng/util/BufferPool.kt
+++ b/apng/src/main/java/jp/juggler/apng/util/BufferPool.kt
@@ -2,14 +2,8 @@ package jp.juggler.apng.util
 
 import java.util.*
 
-internal class BufferPool(private val arraySize:Int){
-    private val list =LinkedList<ByteArray>()
-
-    fun recycle(array: ByteArray) {
-        list.add( array)
-    }
-
-    fun obtain(): ByteArray {
-        return if( list.isEmpty() ) ByteArray(arraySize) else list.removeFirst()
-    }
-}
\ No newline at end of file
+internal class BufferPool(private val arraySize : Int) {
+	private val list = LinkedList<ByteArray>()
+	fun obtain() : ByteArray = if(list.isEmpty()) ByteArray(arraySize) else list.removeFirst()
+	fun recycle(array : ByteArray?) = array?.let { list.add(it) }
+}
diff --git a/apng/src/main/java/jp/juggler/apng/util/ByteSequence.kt b/apng/src/main/java/jp/juggler/apng/util/ByteSequence.kt
index 8c1cf9d0..02b6ea64 100644
--- a/apng/src/main/java/jp/juggler/apng/util/ByteSequence.kt
+++ b/apng/src/main/java/jp/juggler/apng/util/ByteSequence.kt
@@ -1,6 +1,6 @@
 package jp.juggler.apng.util
 
-import jp.juggler.apng.ParseError
+import jp.juggler.apng.ApngParseError
 
 internal fun ByteArray.getUInt8(pos : Int) = get(pos).toInt() and 255
 
@@ -16,10 +16,11 @@ internal class ByteSequence(
 	var offset : Int,
 	var length : Int
 ) {
+	
 	constructor(ba : ByteArray) : this(ba, 0, ba.size)
 	
 	private inline fun <T> readX(dataSize : Int, block : () -> T) : T {
-		if(length < dataSize) throw ParseError("readX: unexpected end")
+		if(length < dataSize) throw ApngParseError("readX: unexpected end")
 		val v = block()
 		offset += dataSize
 		length -= dataSize
diff --git a/apng/src/main/java/jp/juggler/apng/util/ByteSequenceQueue.kt b/apng/src/main/java/jp/juggler/apng/util/ByteSequenceQueue.kt
index b5b63d6f..3c6bf57c 100644
--- a/apng/src/main/java/jp/juggler/apng/util/ByteSequenceQueue.kt
+++ b/apng/src/main/java/jp/juggler/apng/util/ByteSequenceQueue.kt
@@ -2,41 +2,34 @@ package jp.juggler.apng.util
 
 import java.util.*
 
-internal class ByteSequenceQueue(private val bufferRecycler :(ByteSequence)->Unit) {
-
-    private val list = LinkedList<ByteSequence>()
-
-    val remain: Int
-        get() = list.sumBy { it.length }
-
-    fun add(range: ByteSequence) {
-        list.add(range)
-    }
-
-    fun clear() {
-        for( item in list ){
-            bufferRecycler(item)
-        }
-        list.clear()
-    }
-
-    fun readBytes(dst: ByteArray, offset: Int, length: Int): Int {
-        var dstOffset = offset
-        var dstRemain = length
-        while (dstRemain > 0 && list.isNotEmpty()) {
-            val item = list.first()
-            if (item.length <= 0) {
-                bufferRecycler(item)
-                list.removeFirst()
-            }else {
-                val delta = Math.min(item.length, dstRemain)
-                System.arraycopy(item.array, item.offset, dst, dstOffset, delta)
-                dstOffset += delta
-                dstRemain -= delta
-                item.offset += delta
-                item.length -= delta
-            }
-        }
-        return length - dstRemain
-    }
+internal class ByteSequenceQueue(private val bufferRecycler : (ByteSequence) -> Unit) {
+	
+	private val list = LinkedList<ByteSequence>()
+	
+	val remain : Int
+		get() = list.sumBy { it.length }
+	
+	fun add(range : ByteSequence) =list.add(range)
+	
+	fun clear() = list.also{ it.forEach(bufferRecycler) }.clear()
+	
+	fun readBytes(dst : ByteArray, offset : Int, length : Int) : Int {
+		var dstOffset = offset
+		var dstRemain = length
+		while(dstRemain > 0 && list.isNotEmpty()) {
+			val item = list.first()
+			if(item.length <= 0) {
+				bufferRecycler(item)
+				list.removeFirst()
+			} else {
+				val delta = Math.min(item.length, dstRemain)
+				System.arraycopy(item.array, item.offset, dst, dstOffset, delta)
+				dstOffset += delta
+				dstRemain -= delta
+				item.offset += delta
+				item.length -= delta
+			}
+		}
+		return length - dstRemain
+	}
 }
diff --git a/apng/src/main/java/jp/juggler/apng/util/StreamTokenizer.kt b/apng/src/main/java/jp/juggler/apng/util/StreamTokenizer.kt
index c5e45500..dfd9eb5d 100644
--- a/apng/src/main/java/jp/juggler/apng/util/StreamTokenizer.kt
+++ b/apng/src/main/java/jp/juggler/apng/util/StreamTokenizer.kt
@@ -1,66 +1,66 @@
 package jp.juggler.apng.util
 
-import jp.juggler.apng.ParseError
+import jp.juggler.apng.ApngParseError
 import java.io.InputStream
 import java.util.zip.CRC32
 
-internal class StreamTokenizer(val inStream: InputStream) {
-
-    fun skipBytes(size: Long) {
-        var nRead = 0L
-        while (true) {
-            val remain = size - nRead
-            if (remain <= 0) break
-            val delta = inStream.skip(size - nRead)
-            if (delta <= 0) throw ParseError("skipBytes: unexpected EoS")
-            nRead += delta
-        }
-    }
-
-    fun readBytes(size: Int): ByteArray {
-        val dst = ByteArray(size)
-        var nRead = 0
-        while (true) {
-            val remain = size - nRead
-            if (remain <= 0) break
-            val delta = inStream.read(dst, nRead, size - nRead)
-            if (delta < 0) throw ParseError("readBytes: unexpected EoS")
-            nRead += delta
-        }
-        return dst
-    }
-
-    private fun readByte(): Int {
-        val b = inStream.read()
-        if( b == -1 ) throw ParseError("readBytes: unexpected EoS")
-        return b and 0xff
-    }
-
-    fun readInt32(): Int {
-        val b0 = readByte()
-        val b1 = readByte()
-        val b2 = readByte()
-        val b3 = readByte()
-
-        return (b0 shl 24) or (b1 shl 16) or (b2 shl 8) or b3
-    }
-
-    fun readInt32(crc32: CRC32): Int {
-        val ba = readBytes(4)
-        crc32.update(ba)
-        val b0 = ba[0].toInt() and 255
-        val b1 = ba[1].toInt() and 255
-        val b2 = ba[2].toInt() and 255
-        val b3 = ba[3].toInt() and 255
-
-        return (b0 shl 24) or (b1 shl 16) or (b2 shl 8) or b3
-    }
-
-    fun readUInt32(): Long {
-        val b0 = readByte()
-        val b1 = readByte()
-        val b2 = readByte()
-        val b3 = readByte()
-        return (b0.toLong() shl 24) or ((b1 shl 16) or (b2 shl 8) or b3).toLong()
-    }
+internal class StreamTokenizer(val inStream : InputStream) {
+	
+	fun skipBytes(size : Long) {
+		var nRead = 0L
+		while(true) {
+			val remain = size - nRead
+			if(remain <= 0) break
+			val delta = inStream.skip(size - nRead)
+			if(delta <= 0) throw ApngParseError("skipBytes: unexpected EoS")
+			nRead += delta
+		}
+	}
+	
+	fun readBytes(size : Int) : ByteArray {
+		val dst = ByteArray(size)
+		var nRead = 0
+		while(true) {
+			val remain = size - nRead
+			if(remain <= 0) break
+			val delta = inStream.read(dst, nRead, size - nRead)
+			if(delta < 0) throw ApngParseError("readBytes: unexpected EoS")
+			nRead += delta
+		}
+		return dst
+	}
+	
+	private fun readByte() : Int {
+		val b = inStream.read()
+		if(b == - 1) throw ApngParseError("readByte: unexpected EoS")
+		return b and 0xff
+	}
+	
+	fun readInt32() : Int {
+		val b0 = readByte()
+		val b1 = readByte()
+		val b2 = readByte()
+		val b3 = readByte()
+		
+		return (b0 shl 24) or (b1 shl 16) or (b2 shl 8) or b3
+	}
+	
+	fun readInt32(crc32 : CRC32) : Int {
+		val ba = readBytes(4)
+		crc32.update(ba)
+		val b0 = ba[0].toInt() and 255
+		val b1 = ba[1].toInt() and 255
+		val b2 = ba[2].toInt() and 255
+		val b3 = ba[3].toInt() and 255
+		
+		return (b0 shl 24) or (b1 shl 16) or (b2 shl 8) or b3
+	}
+	
+	fun readUInt32() : Long {
+		val b0 = readByte()
+		val b1 = readByte()
+		val b2 = readByte()
+		val b3 = readByte()
+		return (b0.toLong() shl 24) or ((b1 shl 16) or (b2 shl 8) or b3).toLong()
+	}
 }
\ No newline at end of file
diff --git a/apng_android/src/main/java/jp/juggler/apng/ApngFrames.kt b/apng_android/src/main/java/jp/juggler/apng/ApngFrames.kt
index 65a0cefa..9198d15d 100644
--- a/apng_android/src/main/java/jp/juggler/apng/ApngFrames.kt
+++ b/apng_android/src/main/java/jp/juggler/apng/ApngFrames.kt
@@ -24,11 +24,9 @@ class ApngFrames private constructor(
 		private const val DELAY_AFTER_END = 3000L
 		
 		// アニメーションフレームの描画に使う
-		private val sPaintDontBlend : Paint by lazy {
-			val paint = Paint()
-			paint.xfermode = PorterDuffXfermode(PorterDuff.Mode.SRC)
-			paint.isFilterBitmap = true
-			paint
+		private val sPaintDontBlend = Paint().apply {
+			xfermode = PorterDuffXfermode(PorterDuff.Mode.SRC)
+			isFilterBitmap = true
 		}
 		
 		private fun createBlankBitmap(w : Int, h : Int) =
@@ -45,7 +43,7 @@ class ApngFrames private constructor(
 			
 			val wSrc = src.width
 			val hSrc = src.height
-			if(size_max <= 0 || wSrc <= size_max && hSrc <= size_max) {
+			if(size_max <= 0 || (wSrc <= size_max && hSrc <= size_max)) {
 				return if(recycleSrc) {
 					src
 				} else {
@@ -75,8 +73,8 @@ class ApngFrames private constructor(
 			return b2
 		}
 		
-		private fun toAndroidBitmap(src : ApngBitmap) : Bitmap {
-			return Bitmap.createBitmap(
+		private fun toAndroidBitmap(src : ApngBitmap) =
+			Bitmap.createBitmap(
 				src.colors, // int[] 配列
 				0, // offset
 				src.width, //stride
@@ -84,7 +82,6 @@ class ApngFrames private constructor(
 				src.height, //height
 				Bitmap.Config.ARGB_8888
 			)
-		}
 		
 		private fun toAndroidBitmap(src : ApngBitmap, size_max : Int) =
 			scaleBitmap(size_max, toAndroidBitmap(src))
@@ -99,11 +96,8 @@ class ApngFrames private constructor(
 			try {
 				ApngDecoder.parseStream(inStream, result)
 				result.onParseComplete()
-				return if(result.defaultImage != null || result.frames?.isNotEmpty() == true) {
-					result
-				} else {
-					throw RuntimeException("APNG has no image")
-				}
+				return result.takeIf { result.defaultImage != null || result.frames?.isNotEmpty() == true }
+					?: throw RuntimeException("APNG has no image")
 			} catch(ex : Throwable) {
 				result.dispose()
 				throw ex