cloudgamer出品ImageZoom 图片放大效果(3)

var ImageZoom = function(image, viewer, options) {
this._initialize( image, viewer, options );
this._initMode( this.options.mode );
this._oninit();
this._initLoad();
};
ImageZoom.prototype = {
//初始化程序
_initialize: function(image, viewer, options) {
this._image = $$(image);//原图
this._zoom = document.createElement("img");//显示图
this._viewer = $$(viewer);//显示框
this._viewerWidth = 0;//显示框宽
this._viewerHeight = 0;//显示框高
this._preload = new Image();//预载对象
this._rect = null;//原图坐标
this._repairLeft = 0;//显示图x坐标修正
this._repairTop = 0;//显示图y坐标修正
this._rangeWidth = 0;//显示范围宽度
this._rangeHeight = 0;//显示范围高度
this._timer = null;//计时器
this._loaded = false;//是否加载
this._substitute = false;//是否替换
var opt = this._setOptions(options);
this._scale = opt.scale;
this._max = opt.max;
this._min = opt.min;
this._originPic = opt.originPic;
this._zoomPic = opt.zoomPic;
this._rangeWidth = opt.rangeWidth;
this._rangeHeight = opt.rangeHeight;
this.delay = opt.delay;
this.autoHide = opt.autoHide;
this.mouse = opt.mouse;
this.rate = opt.rate;
this.onLoad = opt.onLoad;
this.onStart = opt.onStart;
this.onMove = opt.onMove;
this.onEnd = opt.onEnd;
var oThis = this, END = function(){ oThis._end(); };
this._END = function(){ oThis._timer = setTimeout( END, oThis.delay ); };
this._START = $$F.bindAsEventListener( this._start, this );
this._MOVE = $$F.bindAsEventListener( this._move, this );
this._MOUSE = $$F.bindAsEventListener( this._mouse, this );
this._OUT = $$F.bindAsEventListener( function(e){
if ( !e.relatedTarget ) this._END();
}, this );
},
//设置默认属性
_setOptions: function(options) {
this.options = {//默认值
mode: "simple",//模式
scale: 0,//比例(大图/原图)
max: 10,//最大比例
min: 1.5,//最小比例
originPic: "",//原图地址
zoomPic: "",//大图地址
rangeWidth: 0,//显示范围宽度
rangeHeight:0,//显示范围高度
delay: 20,//延迟结束时间
autoHide: true,//是否自动隐藏
mouse: false,//鼠标缩放
rate: .2,//鼠标缩放比率
onLoad: $$.emptyFunction,//加载完成时执行
onStart: $$.emptyFunction,//开始放大时执行
onMove: $$.emptyFunction,//放大移动时执行
onEnd: $$.emptyFunction//放大结束时执行
};
return $$.extend(this.options, options || {});
},
//根据模式初始化函数属性
_initMode: function(mode) {
mode = $$.extend({
options:{},
init: $$.emptyFunction,
load: $$.emptyFunction,
start: $$.emptyFunction,
end: $$.emptyFunction,
move: $$.emptyFunction,
dispose:$$.emptyFunction
}, (ImageZoom._MODE || {})[ mode.toLowerCase() ] || {} );
this.options = $$.extend( mode.options, this.options );
this._oninit = mode.init;
this._onload = mode.load;
this._onstart = mode.start;
this._onend = mode.end;
this._onmove = mode.move;
this._ondispose = mode.dispose;
},
//初始化加载
_initLoad: function() {
var image = this._image, originPic = this._originPic,
useOrigin = !this._zoomPic && this._scale,
loadImage = $$F.bind( useOrigin ? this._loadOriginImage : this._loadImage, this );
//设置自动隐藏
if ( this.autoHide ) { this._viewer.style.display = "none"; }
//先加载原图
if ( originPic && originPic != image.src ) {//使用自定义地址
image.onload = loadImage;
image.src = originPic;
} else if ( image.src ) {//使用元素地址
if ( !image.complete ) {//未载入完
image.onload = loadImage;
} else {//已经载入
loadImage();
}
} else {
return;//没有原图地址
}
//加载大图
if ( !useOrigin ) {
var preload = this._preload, zoomPic = this._zoomPic || image.src,
loadPreload = $$F.bind( this._loadPreload, this );
if ( zoomPic != preload.src ) {//新地址重新加载
preload.onload = loadPreload;
preload.src = zoomPic;
} else {//正在加载
if ( !preload.complete ) {//未载入完
preload.onload = loadPreload;
} else {//已经载入
this._loadPreload();
}
}
}
},
//原图放大加载程序
_loadOriginImage: function() {
this._image.onload = null;
this._zoom.src = this._image.src;
this._initLoaded();
},
//原图加载程序
_loadImage: function() {
this._image.onload = null;
if ( this._loaded ) {//大图已经加载
this._initLoaded();
} else {
this._loaded = true;
if ( this._scale ) {//有自定义比例才用原图放大替换大图
this._substitute = true;
this._zoom.src = this._image.src;
this._initLoaded();
}
}
},
//大图预载程序
_loadPreload: function() {
this._preload.onload = null;
this._zoom.src = this._preload.src;
if ( this._loaded ) {//原图已经加载
//没有使用替换
if ( !this._substitute ) { this._initLoaded(); }
} else {
this._loaded = true;
}
},
//初始化加载设置
_initLoaded: function(src) {
//初始化显示图
this._initSize();
//初始化显示框
this._initViewer();
//初始化数据
this._initData();
//开始执行
this._onload();
this.onLoad();
this.start();
},
//初始化显示图尺寸
_initSize: function() {
var zoom = this._zoom, image = this._image, scale = this._scale;
if ( !scale ) { scale = this._preload.width / image.width; }
this._scale = scale = Math.min( Math.max( this._min, scale ), this._max );
//按比例设置显示图大小
zoom.width = Math.ceil( image.width * scale );
zoom.height = Math.ceil( image.height * scale );
},
//初始化显示框
_initViewer: function() {
var zoom = this._zoom, viewer = this._viewer;
//设置样式
var styles = { padding: 0, overflow: "hidden" }, p = $$D.getStyle( viewer, "position" );
if ( p != "relative" && p != "absolute" ){ styles.position = "relative"; };
$$D.setStyle( viewer, styles );
zoom.style.position = "absolute";
//插入显示图
if ( !$$D.contains( viewer, zoom ) ){ viewer.appendChild( zoom ); }
},
//初始化数据
_initData: function() {
var zoom = this._zoom, image = this._image, viewer = this._viewer,
scale = this._scale, rangeWidth = this._rangeWidth, rangeHeight = this._rangeHeight;
//原图坐标
this._rect = $$D.rect( image );
//修正参数
this._repairLeft = image.clientLeft + parseInt($$D.getStyle( image, "padding-left" ));
this._repairTop = image.clientTop + parseInt($$D.getStyle( image, "padding-top" ));
//设置范围参数和显示框大小
if ( rangeWidth > 0 && rangeHeight > 0 ) {
rangeWidth = Math.ceil( rangeWidth );
rangeHeight = Math.ceil( rangeHeight );
this._viewerWidth = Math.ceil( rangeWidth * scale );
this._viewerHeight = Math.ceil( rangeHeight * scale );
$$D.setStyle( viewer, {
width: this._viewerWidth + "px",
height: this._viewerHeight + "px"
});
} else {
var styles;
if ( !viewer.clientWidth ) {//隐藏
var style = viewer.style;
styles = {
display: style.display,
position: style.position,
visibility: style.visibility
};
$$D.setStyle( viewer, {
display: "block", position: "absolute", visibility: "hidden"
});
}
this._viewerWidth = viewer.clientWidth;
this._viewerHeight = viewer.clientHeight;
if ( styles ) { $$D.setStyle( viewer, styles ); }
rangeWidth = Math.ceil( this._viewerWidth / scale );
rangeHeight = Math.ceil( this._viewerHeight / scale );
}
this._rangeWidth = rangeWidth;
this._rangeHeight = rangeHeight;
},
//开始
_start: function() {
clearTimeout( this._timer );
var viewer = this._viewer, image = this._image, scale = this._scale;
viewer.style.display = "block";
this._onstart();
this.onStart();
$$E.removeEvent( image, "mouseover", this._START );
$$E.removeEvent( image, "mousemove", this._START );
$$E.addEvent( document, "mousemove", this._MOVE );
$$E.addEvent( document, "mouseout", this._OUT );
this.mouse && $$E.addEvent( document, $$B.firefox ? "DOMMouseScroll" : "mousewheel", this._MOUSE );
},
//移动
_move: function(e) {
clearTimeout( this._timer );
var x = e.pageX, y = e.pageY, rect = this._rect;
if ( x < rect.left || x > rect.right || y < rect.top || y > rect.bottom ) {
this._END();//移出原图范围
} else {
var zoom = this._zoom,
pos = this._repair(
x - rect.left - this._repairLeft,
y - rect.top - this._repairTop
);
this._onmove( e, pos );
//设置定位
zoom.style.left = pos.left + "px";
zoom.style.top = pos.top + "px";
this.onMove();
}
},
//修正坐标
_repair: function(x, y) {
var scale = this._scale, zoom = this._zoom,
viewerWidth = this._viewerWidth,
viewerHeight = this._viewerHeight;
//修正坐标
x = Math.ceil( viewerWidth / 2 - x * scale );
y = Math.ceil( viewerHeight / 2 - y * scale );
//范围限制
x = Math.min( Math.max( x, viewerWidth - zoom.width ), 0 );
y = Math.min( Math.max( y, viewerHeight - zoom.height ), 0 );
return { left: x, top: y };
},
//结束
_end: function() {
this._onend();
this.onEnd();
if ( this.autoHide ) { this._viewer.style.display = "none"; }
this.stop();
this.start();
},
//鼠标缩放
_mouse: function(e) {
this._scale += ( e.wheelDelta ? e.wheelDelta / (-120) : (e.detail || 0) / 3 ) * this.rate;
var opt = this.options;
this._rangeWidth = opt.rangeWidth;
this._rangeHeight = opt.rangeHeight;
this._initSize();
this._initData();
this._move(e);
e.preventDefault();
},
//开始
start: function() {
if ( this._viewerWidth && this._viewerHeight ) {
var image = this._image, START = this._START;
$$E.addEvent( image, "mouseover", START );
$$E.addEvent( image, "mousemove", START );
}
},
//停止
stop: function() {
clearTimeout( this._timer );
$$E.removeEvent( this._image, "mouseover", this._START );
$$E.removeEvent( this._image, "mousemove", this._START );
$$E.removeEvent( document, "mousemove", this._MOVE );
$$E.removeEvent( document, "mouseout", this._OUT );
$$E.removeEvent( document, $$B.firefox ? "DOMMouseScroll" : "mousewheel", this._MOUSE );
},
//修改设置
reset: function(options) {
this.stop();
var viewer = this._viewer, zoom = this._zoom;
if ( $$D.contains( viewer, zoom ) ) { viewer.removeChild( zoom ); }
var opt = $$.extend( this.options, options || {} );
this._scale = opt.scale;
this._max = opt.max;
this._min = opt.min;
this._originPic = opt.originPic;
this._zoomPic = opt.zoomPic;
this._rangeWidth = opt.rangeWidth;
this._rangeHeight = opt.rangeHeight;
//重置属性
this._loaded = this._substitute = false;
this._rect = null;
this._repairLeft = this._repairTop =
this._viewerWidth = this._viewerHeight = 0;
this._initLoad();
},
//销毁程序
dispose: function() {
this._ondispose();
this.stop();
if ( $$D.contains( this._viewer, this._zoom ) ) {
this._viewer.removeChild( this._zoom );
}
this._image.onload = this._preload.onload =
this._image = this._preload = this._zoom = this._viewer =
this.onLoad = this.onStart = this.onMove = this.onEnd =
this._START = this._MOVE = this._END = this._OUT = null
}
}