/**
 * Skroll
 *
 * @version      0.84
 * @author       nori (norimania@gmail.com)
 * @copyright    5509 (http://5509.me/)
 * @license      The MIT License
 * @link         https://github.com/5509/skroll
 *
 * 2011-08-04 11:47
 */
;(function($, window, document, undefined) {

	// CONST
	var MOBILE = "ontouchstart" in window,
		MOUSEWHEEL = "onmousewheel" in document ? "mousewheel" : "DOMMouseScroll",
		MATRIX = "matrix(1,0,0,1,0,0)",
		$document = $(document),
		$html = $("html");

	// jQuery plugin
	$.fn.skroll = function(option) {
		new Skroll(this, option);
		return this;
	};
	// enable using Skroll methods
	$.skroll = function(elm, option) {
		return new Skroll($(elm), option);
	};

	// Skroll
	function Skroll(elm, option) {
		var _borderRadius = undefined,
			_this = this,
			_opt;
		// Option
		_opt = this.option = $.extend({
			margin             : 0,
			width              : "auto",
			height             : parseInt(elm.css("height"), 10),
			inSpeed            : 0.05,
			outSpeed           : 0.2,
			delayTime          : 0.4,
			scrollBarBorder    : 1,
			scrollBarWidth     : 6,
			scrollBarHeight    : 6,
			scrollBarSpace     : 3,
			scrollBarColor     : "#000",
			scrollBarZIndex    : 100,
			opacity            : .5,
			scrollBarBg        : false,
			scrollBarBgColor   : "#666",
			scrollBarBgOpacity : .5,
			scrollBarGrowth    : "0 0 2px #fff",
			cursor             : {
				grab     : "url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABUAAAAVCAMAAACeyVWkAAAACVBMVEX///8AAAD///9+749PAAAAA3RSTlP//wDXyg1BAAAASUlEQVR42qXNQQqAQAxD0cT7H3qQj/MVKi4MXb3SJscUtX0o0qTtTZHknBetHyCWHTTo1UVUDnfUqLtNUuVJRVRWYRGVv3XKf13yEgJFXOqs0wAAAABJRU5ErkJggg==') 6 6, default",
				grabbing : "url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABUAAAAVCAMAAACeyVWkAAAACVBMVEX///8AAAD///9+749PAAAAA3RSTlP//wDXyg1BAAAAOklEQVR42sXQMQ4AIAxCUb73P7SDDNI03YyE6S2k1eryReE0FMkl1EFYg2+lU6RZc61qMHkbo7795AZ/8gKwxSMcDgAAAABJRU5ErkJggg==') 6 6, default"
			},
			scrollCancel       : 80,
			cubicBezier        : "cubic-bezier(0.20,0.71,0.30,0.87)",
			cubicBezierBounce  : "cubic-bezier(0.11,0.74,0.15,0.80)",
			cubicBezierBar     : "cubic-bazier(0.42,0,1,1)",
			scrollBarHide      : true
		}, option);

		// 古いブラウザはcursorのdataURLは無視する
		if ( !$.support.opacity ) {
			_opt.cursor = {
				grab: "move",
				grabbing: "move"
			}
		}

		_borderRadius = (_opt.scrollBarWidth + _opt.scrollBarBorder * 2) / 2 + "px";

		this.$elm = elm;
		this.$outer = $("<div class='scrollOuter'></div>");
		this.$bar = $("<div class='scrollbar'></div>").css({
			position           : "absolute",
			borderRadius       : _borderRadius,
			WebkitBorderRadius : _borderRadius,
			MozBorderRadius    : _borderRadius,
			cursor             : this.option.cursor.grab,
			backgroundColor    : this.option.scrollBarColor,
			opacity            : 0,
			WebkitTransform    : MATRIX,
			boxShadow          : this.option.scrollBarGrowth,
			MozBoxShadow       : this.option.scrollBarGrowth,
			WebkitBoxShadow    : this.option.scrollBarGrowth
		});
		this.$images = $("img", elm);
		this.scrollingBase = { x: 0, y: 0 };
		// 値を保持しておくためのやつ
		this.enteringCursor = false;
		this.transitioning = false;
		this.dragging = false;
		this.draggingX = false;
		this.scrolling = false;
		this.dragTop = 0;
		this.innerWidth = elm.get(0).offsetWidth,
		this.id = ".skrl" + (Math.floor(Math.random() * 1000) * 5);
		// イベント識別子
		this.mousedown = "mousedown" + this.id;
		this.mousemove = "mousemove" + this.id;
		this.mouseup = "mouseup" + this.id;
		this.outerHeight = undefined;
		this.diff = undefined;
		this.scrollBarWidth = undefined;
		this.scrollBarHeight = undefined;
		this.innerScrollVal = undefined;
		this.setUp = undefined;
		this.imgLoaded = 0;
		this.imgLength = 0;
		this.sideScroll = false;
		this.$scrollBarBg = undefined;

		if ( _opt.scrollBarBg ) {
			this.$scrollBarBg = $("<div class='scrollbarbg'></div>")
				.css({
					position           : "absolute",
					borderRadius       : _borderRadius,
					WebkitBorderRadius : _borderRadius,
					MozBorderRadius    : _borderRadius,
					backgroundColor    : _opt.scrollBarBgColor,
					opacity            : _opt.scrollBarBgOpacity
				});
		}

		elm.css("height", "auto");
		this.innerHeight = elm.get(0).offsetHeight;
		// Init
		this.setUpSkroll();
		if ( !MOBILE ) {
			this.eventBind();
		// Mobile init
		} else {
			this.evnetBindMobile();
		}

		if ( this.noScrollBar ) {
			this.$bar.css("opacity", 0);
			this.$scrollBarBg.css("opacity", 0);
		} else
		if ( _opt.scrollBarHide ) {
			if ( MOBILE ) {
				this.barFadeIn(_opt.delayTime);
				setTimeout(function() {
					_this.barFadeOut(0);
				}, _opt.delayTime*1000);
			} else {
				this.$bar
					.fadeIn(_opt.inSpeed*1000)
					.delay(_opt.delayTime*1000)
					.fadeOut(_opt.outSpeed*1000*2);
				if ( _opt.scrollBarBg ) {
					this.$scrollBarBg
						.fadeIn(_opt.inSpeed*1000)
						.delay(_opt.delayTime*1000)
						.fadeOut(_opt.outSpeed*1000*2);
				}
			}
		} else {
			this.barFadeIn();
		}
	}
	Skroll.prototype = {
		refresh: function() {
			var _opt = this.option;
			// コンテンツの高さを取得し直す
			_opt.height = parseInt(this.$elm.css("height"), 10);
			this.$outer.css({
				height: _opt.height
			});
			this.$elm.css("height", "auto");
			this.innerHeight = this.$elm.get(0).offsetHeight;
			// コンテンツアウターの高さを取得し直す
			this.outerHeight = this.$outer.get(0).offsetHeight;
			// スクロールバーの高さを取得し直す
			this.scrollBarHeight = Math.pow(parseInt(this.$outer.height(), 10), 2) / this.innerHeight;
			// スクロールバーが20より小さい場合は20で固定
			this.scrollBarHeight = this.scrollBarHeight < 20 ? 20 : this.scrollBarHeight;
			this.$bar.css({
				height: this.scrollBarHeight
			});
			// スクロールバーの背景がある場合は高さを取得し直す
			if ( this.$scrollBarBg ) {
				this.$scrollBarBg.css({
					height: this.outerHeight - _opt.scrollBarSpace*2
				});
			}
			// スクロール量を更新
			this.diff = this.innerHeight - this.outerHeight;
			this.innerScrollVal = this.diff / (this.outerHeight - this.scrollBarHeight - this.option.scrollBarSpace*2);
			// スクロールバーの有無
			this.noScrollBar = this.scrollBarHeight > this.outerHeight;

			this.scrollingBase = { x: 0, y: 0 };
			this.innerScrolling();

			if ( this.noScrollBar ) {
				this.$bar.css("opacity", 0);
				this.$scrollBarBg.css("opacity", 0);
			} else {
				this.$bar.css("opacity", _opt.opacity);
				this.$scrollBarBg.css("opacity", _opt.scrollBarBgOpacity);
			}
		},
		setUpSkroll: function() {
			var _this = this,
				_opt = this.option,
				$elm = this.$elm,
				$bar = this.$bar,
				$images = this.$images,
				$outer = this.$outer,
				$scrollBarBg = this.$scrollBarBg,
				$barX = this.$barX ? this.$barX : undefined,
				_barHeight = Math.pow(parseInt(_opt.height, 10), 2) / _this.innerHeight;

			// スクロールバーが20より小さい場合は20で固定する
			_barHeight = _barHeight < 20 ? 20 : _barHeight;

			this.$outer = $elm
				.css({
					margin          : 0,
					height          : "auto",
					overflow        : "auto",
					position        : MOBILE ? "static" : "relative",
					opacity         : 1,
					WebkitTransform : MATRIX
				})
				.wrap(
					$outer
						.css({
							margin        : _opt.margin,
							width         : _opt.width,
							height        : parseInt(_opt.height, 10),
							position      : "relative",
							overflow      : "hidden"
						})
				)
				.parent()
				.append($scrollBarBg ?
					$scrollBarBg
						.css({
							width   : _opt.scrollBarWidth,
							height  : parseInt(_opt.height, 10) - _opt.scrollBarSpace*2,
							top     : _opt.scrollBarSpace,
							right   : _opt.scrollBarSpace,
							opacity : _opt.scrollBarBgOpacity
						})
					: undefined
				)
				.append(
					$bar
						.css({
							width   : _opt.scrollBarWidth,
							height  : _barHeight,
							top     : _opt.scrollBarSpace,
							right   : _opt.scrollBarSpace,
							opacity : _opt.opacity,
							zIndex  : _opt.scrollBarZIndex
						})
				);

			this.scrollBarHeight = _barHeight;
			this.innerHeight = $elm.get(0).offsetHeight;
			this.diff = this.innerHeight - this.outerHeight;

			// スクロールバーの有無
			this.noScrollBar = this.scrollBarHeight > _opt.height;

			// 画像がある場合は画像の読み込み完了を待つ
			if ( $images.length ) {
				_this.imgLength = $images.length;
				$images.each(function() {
					$(this).m5ImgLoad(function() {
						_this.imgLoaded = _this.imgLoaded + 1;
					})
				});

				(function() {
					if ( _this.imgLoaded === _this.imgLength ) {
						_this.innerHeight = $elm.get(0).offsetHeight;
						return;
					}
					setTimeout(arguments.callee, 30);
				}());
			}
		},
		barFadeIn: function(delay) {
			var _opt = this.option;
			if ( this.noScrollBar ) return;
			if ( !MOBILE ) {
				this.$bar.stop(true, true).fadeIn(_opt.inSpeed*1000);
				if ( _opt.scrollBarBg ) {
					this.$scrollBarBg.stop(true, true).fadeIn(_opt.inSpeed*1000);
				}
			} else {
				this.$bar
					.css({
						WebkitTransitionDuration: _opt.inSpeed + "s",
						WebkitTransitionDelay: delay + "s",
						WebkitTransitionProperty: "opacity",
						opacity: _opt.opacity
					});
				if ( _opt.scrollBarBg ) {
					this.$scrollBarBg
						.css({
							WebkitTransitionDuration: _opt.inSpeed + "s",
							WebkitTransitionDelay: delay + "s",
							WebkitTransitionProperty: "opacity",
							opacity: _opt.scrollBarBgOpacity
						});
				}
			}
		},
		barFadeOut: function(delay) {
			var _opt = this.option;
			if ( this.noScrollBar ) return;
			if ( !_opt.scrollBarHide ) return;

			if ( !MOBILE ) {
				this.$bar.fadeOut(_opt.outSpeed*1000);
				if ( _opt.scrollBarBg ) {
					this.$scrollBarBg.fadeOut(_opt.outSpeed*1000);
				}
			} else {
				this.$bar
					.css({
						WebkitTransitionDuration: _opt.outSpeed + "s",
						WebkitTransitionDelay: delay + "s",
						WebkitTransitionProperty: "opacity",
						opacity: 0
					});
				if ( _opt.scrollBarBg ) {
					this.$scrollBarBg
						.css({
							WebkitTransitionDuration: _opt.outSpeed + "s",
							WebkitTransitionDelay: delay + "s",
							WebkitTransitionProperty: "opacity",
							opacity: 0
						});
				}
			}
		},
		getCurrent: function($el) {
			if ( MOBILE ) {
				var _matrix =  $el.css("WebkitTransform")
						.replace(/matrix\(([^\(\)]*)\)/, "$1")
						.split(",");
				return {
					x: parseInt(_matrix[4], 10),
					y: parseInt(_matrix[5], 10)
				}
			} else {
				return {
					x: parseInt($el.css("left"), 10),
					y: parseInt($el.css("top"),  10)
				}
			}
		},
		// for Transition
		setNext: function($el, val, bar, to) { // val: {x: valX, y: valY}
			var _this = this,
				_barDiff = this.outerHeight - this.scrollBarHeight - this.option.scrollBarSpace,
				_defaultVal = { x: 0, y: 0 };
			if ( val.y === 0 ) {
				val.y = "0";
			}
			if ( val.x === 0 ) {
				val.x = "0";
			}
			if ( !val.x || !val.y ) {
				_defaultVal = this.getCurrent($el);
			}
			val.x = 0;
			// モバイル環境のelmのみ
			// 含む要素が多いためmatrixで移動する
			if ( MOBILE && !bar ) {
				$el.css({
					WebkitTransform : "matrix(1,0,0,1," + (val.x || _defaultVal.x) + "," + (val.y || _defaultVal.y) + ")"
				});
			} else {
				// barのときのみ、barが下へ移動するときはbottomで移動する
				if ( to ) {
					$el.css({
						WebkitTransitionProperty: "height, bottom",
						top: "auto",
						bottom: (_barDiff + _this.option.scrollBarSpace) - val.y
					});
				// elmとbar共通、barは上へ移動するときのみ
				} else {
					$el.css({
						top: val.y || _defaultVal.y,
						bottom: "auto"
					});
				}
			}
		},
		setUpBeforeScrolling: function(e) {
			var $outer = this.$outer;
			if ( this.noScrollBar ) return;
			if ( !this.setUp ) {
				this.setUp = true;
			} else {
				return;
			}
			this.outerHeight = $outer.height();
			this.diff = this.innerHeight - this.outerHeight;
			this.innerScrollVal = this.diff / (this.outerHeight - this.scrollBarHeight - this.option.scrollBarSpace*2);
			this.dragTop = e ? e.clientY : 0;
			this.scrolling = this.dragging ? false : true;
		},
		innerScrolling: function(_to) {
			var _this = this,
				_opt = _this.option,
				_current = this.scrollingBase,
				_next = {},
				_innerNext = {},
				_barDiff = _this.outerHeight - _this.scrollBarHeight - _opt.scrollBarSpace,
				_innerScrolling = _current.y >= _barDiff,
				_maxInnerTop = -_barDiff * _this.innerScrollVal,
				_scrollBounceCapacity = _this.outerHeight*7/10,
				_scrollBarHeight = undefined,
				$bar = _this.$bar,
				$elm = _this.$elm;

			if ( this.noScrollBar ) return;

			if ( MOBILE ) {
				_next.y = _current.y <= 0
					? 0 : _innerScrolling
						? _barDiff : _current.y;
				_innerNext.y = _current.y * _this.innerScrollVal <= -_scrollBounceCapacity
					? _scrollBounceCapacity :
						-_current.y * _this.innerScrollVal <= _maxInnerTop - _scrollBounceCapacity
							? _maxInnerTop - _scrollBounceCapacity
								: -_current.y * _this.innerScrollVal;

				// スクロールバーが縮む
				if ( _innerNext.y > 0 ) {
					_scrollBarHeight = _this.scrollBarHeight * (1 - (_innerNext.y / 100)/2);
					$bar.css({
						height: _scrollBarHeight < 10 ?
							10 : _scrollBarHeight
					});
				} else
				if ( _innerNext.y < _maxInnerTop ) {
					_scrollBarHeight = _this.scrollBarHeight * (1 - (-(_innerNext.y - _maxInnerTop) / 100)/2);
					$bar.css({
						height: _scrollBarHeight < 10 ?
							10 : _scrollBarHeight
					});
				}

				_this.setNext($bar, {
					y: _next.y < 0 ? 0 :
							// 一番下よりさらに下になった場合
							_next.y + _opt.scrollBarSpace >= _barDiff ? _barDiff :
								// 上〜下の場合
								_next.y + _opt.scrollBarSpace
				}, true, _innerNext.y > _opt.scrollBarSpace ? false : _innerNext.y < _maxInnerTop ? true : _to);
				// 0を超えたときは常にtop、_maxInnerTop以下のときは常にbottom
			} else {
				if ( _current.y > _barDiff ) {
					_current.y = _barDiff;
				} else
				if ( _opt.scrollBarSpace > _current.y ) {
					_current.y = _opt.scrollBarSpace;
				}
				_innerNext.y = (_current.y - _opt.scrollBarSpace) * _this.innerScrollVal <= 0
					? 0 :
						-(_current.y - _opt.scrollBarSpace) * _this.innerScrollVal <= _maxInnerTop
							? _maxInnerTop
								: -(_current.y - _opt.scrollBarSpace) * _this.innerScrollVal;
				_this.setNext($bar, {
					y: _current.y <= _opt.scrollBarSpace
						? _opt.scrollBarSpace : _innerScrolling
							? _barDiff : _current.y
				});
			}
			_this.setNext($elm, {
				y: _innerNext.y
			});
		},
		css: function(elm, styles) {
			for ( var i = 0; i < elm.length; i++ ) {
				elm[i].css(styles);
			}
		},
		transioningFunc: function(callback) {
			var _this = this;
			this.transitioning = true;
			(function() {
				if ( !_this.transitioning ) return;
				callback();
				setTimeout(arguments.callee, 10);
			}());
		},
		bounceEffect: function($bar, $elm) {
			var _this = this,
				_opt = this.option,
				_barDiff = _this.outerHeight - _this.scrollBarHeight - _opt.scrollBarSpace*2,
				_maxInnerTop = -_barDiff * _this.innerScrollVal,
				_current = _this.scrollingBase;

			// 範囲を超えた場合のボイン戻し
			if ( _current.y > _barDiff ) {
				_current.y = _barDiff;
				_this.css([$elm, $bar], {
					WebkitTransitionDuration: "0.4s",
					WebkitTransitionTimingFunction: _opt.cubicBezierBounce
				});
				_this.setNext($elm, {
					y: _maxInnerTop
				});
			} else
			if ( 0 > _current.y ) {
				_current.y = 0;
				_this.css([$elm, $bar], {
					WebkitTransitionDuration: "0.4s",
					WebkitTransitionTimingFunction: _opt.cubicBezierBounce
				});
				$bar.css("height", _this.scrollBarHeight);
				_this.setNext($elm, {
					y: 0
				});
			} else {
				_this.css([$elm, $bar], {
					WebkitTransitionDuration: "0s",
					WebkitTransitionTimingFunction: _opt.cubicBezier
				});
				_this.barFadeOut(_opt.delayTime);
			}
			$bar.css("height", _this.scrollBarHeight);
		},
		eventBind: function() {
			var _this = this,
				_opt = this.option,
				$bar = this.$bar,
				$outer = this.$outer;

			$outer
				.bind("mouseover", function() {
					_this.enteringCursor = true;
					_this.barFadeIn();
				})
				.bind("mouseleave", function() {
					_this.enteringCursor = false;
					if ( _this.dragging || _this.draggingX ) {
						return false;
					}
					_this.setUp = false;
					_this.scrolling = false;
					if ( !_opt.scrollBarHide ) return;
					_this.barFadeOut();
				})
				.bind(MOUSEWHEEL, function(e) {
					e = e || window.event;
					// detailはwheelDeltaと正負が逆になり
					// 値もwheelDeltaの1/10
					var _delta = Math.round(e.wheelDelta/10) || -e.detail,
						_current = _this.scrollingBase;

					_current.y = _this.scrollingBase.y - _delta;
					if ( !_this.setUp ) _this.setUpBeforeScrolling();
					_this.innerScrolling();
					e.preventDefault();
				});

			$bar.bind(_this.mousedown, function(e) {
				var _current = _this.scrollingBase;

				this.dragTop = e.clientY;
				//_this.setUp = false;
				_this.dragging = true;
				_this.scrolling = false;
				if ( !_this.setUp) _this.setUpBeforeScrolling(e);

				_this.css([$html, $bar], {cursor: _opt.cursor.grabbing});

				$document
					.bind(_this.mousemove, function(e) {
						if ( _this.dragging ) {
							_current.y = _current.y + (e.clientY - _this.dragTop);
							_this.dragTop = e.clientY;
							_this.innerScrolling();
						}
						return false;
					})
					.bind(_this.mouseup, function() {
						_this.dragging = false;
						_this.setUp = false;
						$document
							.unbind(_this.mousemove)
							.unbind(_this.mouseup);
						$html.css("cursor", "default");
						$bar.css("cursor", _opt.cursor.grab);
						if ( !_this.enteringCursor && _opt.scrollBarHide ) {
							_this.barFadeOut();
						}
					});
				return false;
			});
		},
		evnetBindMobile: function() {
			var _this = this,
				_opt = this.option,
				$bar = this.$bar,
				$outer = this.$outer,
				$elm = this.$elm,
				outer = $outer.get(0),
				touching = false,
				touchStartPos = undefined,
				touchEndPosPrev = undefined,
				touchEndPos = undefined,
				acceleration = undefined,
				touchStartTime = undefined,
				touchMoveEndTime = undefined,
				touchEndTime = undefined,
				touchSpeed = 0;

			_this.css([$bar, $elm], {
				WebkitTransitionProperty       : "all",
				WebkitTransitionTimingFunction : _opt.cubicBezier,
				// GPUレンダリングをONにしておく
				WebkitTransformStyle           : "preserve-3d",
				WebkitTransitionDuration       : "0s"
			});

			$("a", $outer).each(function() {
				var $this = $(this),
					anchor = $this.get(0);

				anchor.addEventListener("touchend", function(e) {
					$this.click();
					e.stopPropagation();
				}, true);
			});
			outer.addEventListener("touchstart", function(e) {
				if ( e.touches[1] ) return;
				var _t = e.touches[0];

				this.scrolling = false;

				// touchstart時のタイムスタンプ
				touchStartTime = +new Date;
				touching = true;
				touchSpeed = 0;

				_this.enteringCursor = true;
				touchStartPos = {
					x: _t.pageX,
					y: _t.pageY
				};
			}, true);
			outer.addEventListener("touchmove", function(e) {
				if ( e.touches[1] ) return;
				else if ( !touching ) return;
				var _t = e.touches[0],
					_diffY = undefined,
					_current = _this.scrollingBase,
					_to = undefined;

				touchEndPosPrev = touchEndPos || touchStartPos;
				touchEndPos = {
					y: _t.pageY
				};

				// 一度折り返した場合は、touchStartPosを折り返した地点に置き換える
				if ( touchEndPos.y > touchStartPos.y && touchEndPos.y < touchEndPosPrev.y
				  || touchEndPos.y < touchStartPos.y && touchEndPos.y > touchEndPosPrev.y ) {
					touchStartPos = touchEndPosPrev;
				}
				// 最後にtouchmoveしたタイムスタンプ
				touchMoveEndTime = +new Date;

				_diffY = (touchEndPosPrev.y - touchEndPos.y) * (1 / 5);
				// 移動距離が気持ち短い方がなめらかにみえる
				_current.y = _current.y + _diffY;
				// 進む方向 down: true, up: false
				_to = _diffY > 0;

				_this.css([$elm, $bar], {
					WebkitTransitionDuration       : "0s",
					WebkitTransitionTimingFunction : _opt.cubicBezier
				});
				_this.$bar.css({
					WebkitTransitionProperty: "all",
					WebkitTransitionDelay: "0s",
					height: _this.scrollBarHeight
				});

				// vertical scrolling
				if ( !_this.setUp ) {
					$bar.css("opacity", _opt.opacity);
					if ( _opt.scrollBarBg ) {
						_this.$scrollBarBg.css({
							WebkitTransitionDuration: "0s",
							WebkitTransitionDelay: "0s",
							opacity: _opt.scrollBarBgOpacity
						});
					}
					_this.setUpBeforeScrolling();
				}
				_this.innerScrolling(_to);
				e.preventDefault();
			}, true);
			outer.addEventListener("touchend", function(e) {
				if ( e.touches[1] && touching ) return;
				if ( !touchEndPos ) return;
				var _diffY = (touchEndPos.y - touchStartPos.y), // タッチの移動距離
					_stepY = undefined, // 慣性でバーが進む距離
					_nextInnerY = undefined, // 慣性でインナーが進んだ後
					_barDiff = _this.outerHeight - _this.scrollBarHeight - _opt.scrollBarSpace*2,
					_maxInnerTop = -_barDiff * _this.innerScrollVal,
					_scrollBounceCapacity = _this.outerHeight/4,
					_duration = undefined,
					// 進む方向 down: false, up: true
					// moveのときとは逆
					_to = _diffY < 0,
					_current = _this.scrollingBase;

				// touchendのタイムスタンプ
				touchEndTime = +new Date;

				// モーメンタムスクロール
				if ( _current.y > 0 // 指を離したときに最低値を下回っていなければ
				  && _current.y < _barDiff // 指を離したときに最大値を上回っていなければ
				  // 最後のtouchmoveとひとつ前のtouchmoveのタイムスタンプの差を確認する
				  && touchEndTime - touchMoveEndTime < _opt.scrollCancel
				  // ひとつ手前のtouchEndPosとの差があまりない場合のみ
				  && (Math.abs(touchEndPosPrev.y - touchEndPos.y) > 15
				  || Math.abs(touchEndPosPrev.x - touchEndPos.x) > 15) ) {

					// スクロールする余裕がある場合
					acceleration = touchEndTime - touchStartTime; // 加速度として使う

					// スクロールする量と速度は
					// タッチしていた時間とタッチの距離による
					_stepY = -_diffY / 300 * acceleration; // 慣性でバーが進む距離
					// 現在位置の更新
					_current.y = _current.y + _stepY;
					// 現在位置からインナーの位置を決定する
					_nextInnerY = -_current.y * _this.innerScrollVal;

					// スクロール速度はタッチしていた時間による
					_duration = 0.7 > acceleration / 200 ? acceleration / 200 : 0.7;
					_this.css([$elm, $bar], {
						WebkitTransitionDuration: _duration + "s"
					});

					_this.setNext($elm, {
						y: _nextInnerY > _scrollBounceCapacity ? _scrollBounceCapacity :
							_nextInnerY < _maxInnerTop - _scrollBounceCapacity ? _maxInnerTop - _scrollBounceCapacity : _nextInnerY
					});

					// バーが縮むやつ
					// ここはbounceのtransitionが呼ばれているときだけ
					_this.transioningFunc(function() {
						var __current = _this.getCurrent($elm),
							__scrollBarHeight = undefined;
						if ( __current.y > 0 ) {
							__scrollBarHeight = _this.scrollBarHeight * (1 - (__current.y / 100)/2);
						} else
						if ( __current.y < _maxInnerTop ) {
							__scrollBarHeight = _this.scrollBarHeight * (1 - (-(__current.y - _maxInnerTop) / 100)/2);
						}
						$bar.css({
							height: __scrollBarHeight < 10 ?
								10 : __scrollBarHeight
						});
					});

					// 執着地点によってスクロールバーのtiming-functionが切り替わる
					if ( _current.y < _opt.scrollBarSpace
					  || _current.y >= _barDiff ) {
						$bar.css({
							WebkitTransitionTimingFunction: _opt.cubicBezierBar
						});
					}
					// スクロールバーの最終地点
					_this.setNext($bar, {
						// 一番上よりさらに上になった場合
						y: _current.y < _opt.scrollBarSpace ? _opt.scrollBarSpace :
							// 一番下よりさらに下になった場合
							_current.y >= _barDiff + _opt.scrollBarSpace ? _barDiff + _opt.scrollBarSpace :
								// 上〜下の場合
								_current.y
					}, true, _to);

				// モーメンタムスクロールなしで指を離したとき
				} else {
					// スクロールバーの最終地点
					// 一番上（下）よりさらに上（上）になった場合
					if ( _current.y < 0
					  || _current.y >= _barDiff ) {
						_this.bounceEffect($bar, $elm);
					} else {
						_this.barFadeOut(_opt.delayTime);
					}
					// 上〜下の場合は何もしない
				}

				touching = false;
				touchStartPos = touchEndPos = 0;

				_this.enteringCursor = false;
				_this.setUp = false;
				_this.scrolling = false;
				e.preventDefault();
			}, true);

			$elm.get(0).addEventListener("webkitTransitionEnd", function() {
				_this.transitioning = false;
				_this.bounceEffect($bar, $elm);
				$bar.css({
					WebkitTransitionProperty: "all"
				});
			}, false);
		}
	};

	/**
	 * m5ImgLoad
	 *
	 * @version      0.2
	 * @author       nori (norimania@gmail.com)
	 * @copyright    5509 (http://5509.me/)
	 * @license      The MIT License
	 * @link         https://github.com/5509/m5ImgLoad
	 *
	 * 2011-02-08 15:41
	 */
	$.fn.m5ImgLoad = function(callback, interval) {
		var _img = $(this).get(0),
			newImg = new Image();

		newImg.src = _img.src;

		(function() {
			if ( newImg.complete ) {
				callback.call($(newImg));
				return;
			}
			setTimeout(arguments.callee, interval || 20);
		}());
		return this;
	};

}(jQuery, this, this.document));