分类:
mui
我们经常遇到，在手机浏览图片时，图片会进行放大。看起来的效果很舒服。
我们就来实践一番吧：
第一：引进css:
```csharp
<link rel="stylesheet" type="text/css" href="css/preimg.css"/>
```
第二： 引进js:
```csharp
<script src="js/mui.zoom.js" type="text/javascript" charset="utf-8"></script>
<script src="js/mui.previewimage.js" type="text/javascript" charset="utf-8"></script>
```
第三：使用图片标签：
```handlebars
<img src="images/cbd.jpg" data-preview-src="" data-preview-group="1">
```
注意：`data-preview-src="" data-preview-group="1"`必须加入到img标签里
基本这样就可以了。
看效果：
图片可以进行手动放大缩小。
可以扩展一些东西，
如果图片标签是存在字符串里呢？
比如：
你可以用全部替换方法实现：
```csharp
var str="<img src=''/><img src=''/>";
alert(str.replace(/<img/g,'<img data-preview-src="" data-preview-group="1"'))
```
输出效果：
实例：
不懂的，可以咨询我哦！
提供的css:
**preimg.css:**
```css
.mui-preview-image.mui-fullscreen {
position: fixed;
z-index: 20;
background-color: #000;
}
.mui-preview-header,
.mui-preview-footer {
position: absolute;
width: 100%;
left: 0;
z-index: 10;
}
.mui-preview-header {
height: 44px;
top: 0;
}
.mui-preview-footer {
height: 50px;
bottom: 0px;
}
.mui-preview-header .mui-preview-indicator {
display: block;
line-height: 25px;
color: #fff;
text-align: center;
margin: 15px auto 4;
width: 70px;
background-color: rgba(0, 0, 0, 0.4);
border-radius: 12px;
font-size: 16px;
}
.mui-preview-image {
display: none;
-webkit-animation-duration: 0.5s;
animation-duration: 0.5s;
-webkit-animation-fill-mode: both;
animation-fill-mode: both;
}
.mui-preview-image.mui-preview-in {
-webkit-animation-name: fadeIn;
animation-name: fadeIn;
}
.mui-preview-image.mui-preview-out {
background: none;
-webkit-animation-name: fadeOut;
animation-name: fadeOut;
}
.mui-preview-image.mui-preview-out .mui-preview-header,
.mui-preview-image.mui-preview-out .mui-preview-footer {
display: none;
}
.mui-zoom-scroller {
position: absolute;
display: -webkit-box;
display: -webkit-flex;
display: flex;
-webkit-box-align: center;
-webkit-align-items: center;
align-items: center;
-webkit-box-pack: center;
-webkit-justify-content: center;
justify-content: center;
left: 0;
right: 0;
bottom: 0;
top: 0;
width: 100%;
height: 100%;
margin: 0;
-webkit-backface-visibility: hidden;
}
.mui-zoom {
-webkit-transform-style: preserve-3d;
transform-style: preserve-3d;
}
.mui-slider .mui-slider-group .mui-slider-item img {
width: auto;
height: auto;
max-width: 100%;
max-height: 100%;
}
.mui-android-4-1 .mui-slider .mui-slider-group .mui-slider-item img {
width: 100%;
}
.mui-android-4-1 .mui-slider.mui-preview-image .mui-slider-group .mui-slider-item {
display: inline-table;
}
.mui-android-4-1 .mui-slider.mui-preview-image .mui-zoom-scroller img {
display: table-cell;
vertical-align: middle;
}
.mui-preview-loading {
position: absolute;
width: 100%;
height: 100%;
top: 0;
left: 0;
display: none;
}
.mui-preview-loading.mui-active {
display: block;
}
.mui-preview-loading .mui-spinner-white {
position: absolute;
top: 50%;
left: 50%;
margin-left: -25px;
margin-top: -25px;
height: 50px;
width: 50px;
}
.mui-preview-image img.mui-transitioning {
-webkit-transition: -webkit-transform 0.5s ease, opacity 0.5s ease;
transition: transform 0.5s ease, opacity 0.5s ease;
}
@-webkit-keyframes fadeIn {
0% {
opacity: 0;
}
100% {
opacity: 1;
}
}
@keyframes fadeIn {
0% {
opacity: 0;
}
100% {
opacity: 1;
}
}
@-webkit-keyframes fadeOut {
0% {
opacity: 1;
}
100% {
opacity: 0;
}
}
@keyframes fadeOut {
0% {
opacity: 1;
}
100% {
opacity: 0;
}
}
p img {
max-width: 100%;
height: auto;
}
```
提供的js:
**mui.zoom.js**
```clike
(function($, window) {
var CLASS_ZOOM = $.className('zoom');
var CLASS_ZOOM_SCROLLER = $.className('zoom-scroller');
var SELECTOR_ZOOM = '.' + CLASS_ZOOM;
var SELECTOR_ZOOM_SCROLLER = '.' + CLASS_ZOOM_SCROLLER;
var EVENT_PINCH_START = 'pinchstart';
var EVENT_PINCH = 'pinch';
var EVENT_PINCH_END = 'pinchend';
if ('ongesturestart' in window) {
EVENT_PINCH_START = 'gesturestart';
EVENT_PINCH = 'gesturechange';
EVENT_PINCH_END = 'gestureend';
}
$.Zoom = function(element, options) {
var zoom = this;
zoom.options = $.extend($.Zoom.defaults, options);
zoom.wrapper = zoom.element = element;
zoom.scroller = element.querySelector(SELECTOR_ZOOM_SCROLLER);
zoom.scrollerStyle = zoom.scroller && zoom.scroller.style;
zoom.zoomer = element.querySelector(SELECTOR_ZOOM);
zoom.zoomerStyle = zoom.zoomer && zoom.zoomer.style;
zoom.init = function() {
//自动启用
$.options.gestureConfig.pinch = true;
$.options.gestureConfig.doubletap = true;
zoom.initEvents();
};
zoom.initEvents = function(detach) {
var action = detach ? 'removeEventListener' : 'addEventListener';
var target = zoom.scroller;
target[action](EVENT_PINCH_START, zoom.onPinchstart);
target[action](EVENT_PINCH, zoom.onPinch);
target[action](EVENT_PINCH_END, zoom.onPinchend);
target[action]($.EVENT_START, zoom.onTouchstart);
target[action]($.EVENT_MOVE, zoom.onTouchMove);
target[action]($.EVENT_CANCEL, zoom.onTouchEnd);
target[action]($.EVENT_END, zoom.onTouchEnd);
target[action]('drag', zoom.dragEvent);
target[action]('doubletap', zoom.doubleTapEvent);
};
zoom.dragEvent = function(e) {
if (imageIsMoved || isGesturing) {
e.stopPropagation();
}
};
zoom.doubleTapEvent = function(e) {
zoom.toggleZoom(e.detail.center);
};
zoom.transition = function(style, time) {
time = time || 0;
style['webkitTransitionDuration'] = time + 'ms';
return zoom;
};
zoom.translate = function(style, x, y) {
x = x || 0;
y = y || 0;
style['webkitTransform'] = 'translate3d(' + x + 'px,' + y + 'px,0px)';
return zoom;
};
zoom.scale = function(style, scale) {
scale = scale || 1;
style['webkitTransform'] = 'translate3d(0,0,0) scale(' + scale + ')';
return zoom;
};
zoom.scrollerTransition = function(time) {
return zoom.transition(zoom.scrollerStyle, time);
};
zoom.scrollerTransform = function(x, y) {
return zoom.translate(zoom.scrollerStyle, x, y);
};
zoom.zoomerTransition = function(time) {
return zoom.transition(zoom.zoomerStyle, time);
};
zoom.zoomerTransform = function(scale) {
return zoom.scale(zoom.zoomerStyle, scale);
};
// Gestures
var scale = 1,
currentScale = 1,
isScaling = false,
isGesturing = false;
zoom.onPinchstart = function(e) {
isGesturing = true;
};
zoom.onPinch = function(e) {
if (!isScaling) {
zoom.zoomerTransition(0);
isScaling = true;
}
scale = (e.detail ? e.detail.scale : e.scale) * currentScale;
if (scale > zoom.options.maxZoom) {
scale = zoom.options.maxZoom - 1 + Math.pow((scale - zoom.options.maxZoom + 1), 0.5);
}
if (scale < zoom.options.minZoom) {
scale = zoom.options.minZoom + 1 - Math.pow((zoom.options.minZoom - scale + 1), 0.5);
}
zoom.zoomerTransform(scale);
};
zoom.onPinchend = function(e) {
scale = Math.max(Math.min(scale, zoom.options.maxZoom), zoom.options.minZoom);
zoom.zoomerTransition(zoom.options.speed).zoomerTransform(scale);
currentScale = scale;
isScaling = false;
};
zoom.setZoom = function(newScale) {
scale = currentScale = newScale;
zoom.scrollerTransition(zoom.options.speed).scrollerTransform(0, 0);
zoom.zoomerTransition(zoom.options.speed).zoomerTransform(scale);
};
zoom.toggleZoom = function(position, speed) {
if (typeof position === 'number') {
speed = position;
position = undefined;
}
speed = typeof speed === 'undefined' ? zoom.options.speed : speed;
if (scale && scale !== 1) {
scale = currentScale = 1;
zoom.scrollerTransition(speed).scrollerTransform(0, 0);
} else {
scale = currentScale = zoom.options.maxZoom;
if (position) {
var offset = $.offset(zoom.zoomer);
var top = offset.top;
var left = offset.left;
var offsetX = (position.x - left) * scale;
var offsetY = (position.y - top) * scale;
this._cal();
if (offsetX >= imageMaxX && offsetX <= (imageMaxX + wrapperWidth)) { //center
offsetX = imageMaxX - offsetX + wrapperWidth / 2;
} else if (offsetX < imageMaxX) { //left
offsetX = imageMaxX - offsetX + wrapperWidth / 2;
} else if (offsetX > (imageMaxX + wrapperWidth)) { //right
offsetX = imageMaxX + wrapperWidth - offsetX - wrapperWidth / 2;
}
if (offsetY >= imageMaxY && offsetY <= (imageMaxY + wrapperHeight)) { //middle
offsetY = imageMaxY - offsetY + wrapperHeight / 2;
} else if (offsetY < imageMaxY) { //top
offsetY = imageMaxY - offsetY + wrapperHeight / 2;
} else if (offsetY > (imageMaxY + wrapperHeight)) { //bottom
offsetY = imageMaxY + wrapperHeight - offsetY - wrapperHeight / 2;
}
offsetX = Math.min(Math.max(offsetX, imageMinX), imageMaxX);
offsetY = Math.min(Math.max(offsetY, imageMinY), imageMaxY);
zoom.scrollerTransition(speed).scrollerTransform(offsetX, offsetY);
} else {
zoom.scrollerTransition(speed).scrollerTransform(0, 0);
}
}
zoom.zoomerTransition(speed).zoomerTransform(scale);
};
zoom._cal = function() {
wrapperWidth = zoom.wrapper.offsetWidth;
wrapperHeight = zoom.wrapper.offsetHeight;
imageWidth = zoom.zoomer.offsetWidth;
imageHeight = zoom.zoomer.offsetHeight;
var scaledWidth = imageWidth * scale;
var scaledHeight = imageHeight * scale;
imageMinX = Math.min((wrapperWidth / 2 - scaledWidth / 2), 0);
imageMaxX = -imageMinX;
imageMinY = Math.min((wrapperHeight / 2 - scaledHeight / 2), 0);
imageMaxY = -imageMinY;
};
var wrapperWidth, wrapperHeight, imageIsTouched, imageIsMoved, imageCurrentX, imageCurrentY, imageMinX, imageMinY, imageMaxX, imageMaxY, imageWidth, imageHeight, imageTouchesStart = {},
imageTouchesCurrent = {},
imageStartX, imageStartY, velocityPrevPositionX, velocityPrevTime, velocityX, velocityPrevPositionY, velocityY;
zoom.onTouchstart = function(e) {
e.preventDefault();
imageIsTouched = true;
imageTouchesStart.x = e.type === $.EVENT_START ? e.targetTouches[0].pageX : e.pageX;
imageTouchesStart.y = e.type === $.EVENT_START ? e.targetTouches[0].pageY : e.pageY;
};
zoom.onTouchMove = function(e) {
e.preventDefault();
if (!imageIsTouched) return;
if (!imageIsMoved) {
wrapperWidth = zoom.wrapper.offsetWidth;
wrapperHeight = zoom.wrapper.offsetHeight;
imageWidth = zoom.zoomer.offsetWidth;
imageHeight = zoom.zoomer.offsetHeight;
var translate = $.parseTranslateMatrix($.getStyles(zoom.scroller, 'webkitTransform'));
imageStartX = translate.x || 0;
imageStartY = translate.y || 0;
zoom.scrollerTransition(0);
}
var scaledWidth = imageWidth * scale;
var scaledHeight = imageHeight * scale;
if (scaledWidth < wrapperWidth && scaledHeight < wrapperHeight) return;
imageMinX = Math.min((wrapperWidth / 2 - scaledWidth / 2), 0);
imageMaxX = -imageMinX;
imageMinY = Math.min((wrapperHeight / 2 - scaledHeight / 2), 0);
imageMaxY = -imageMinY;
imageTouchesCurrent.x = e.type === $.EVENT_MOVE ? e.targetTouches[0].pageX : e.pageX;
imageTouchesCurrent.y = e.type === $.EVENT_MOVE ? e.targetTouches[0].pageY : e.pageY;
if (!imageIsMoved && !isScaling) {
// if (Math.abs(imageTouchesCurrent.y - imageTouchesStart.y) < Math.abs(imageTouchesCurrent.x - imageTouchesStart.x)) {
//TODO 此处需要优化，当遇到长图，需要上下滚动时，下列判断会导致滚动不流畅
if (
(Math.floor(imageMinX) === Math.floor(imageStartX) && imageTouchesCurrent.x < imageTouchesStart.x) ||
(Math.floor(imageMaxX) === Math.floor(imageStartX) && imageTouchesCurrent.x > imageTouchesStart.x)
) {
imageIsTouched = false;
return;
}
// }
}
imageIsMoved = true;
imageCurrentX = imageTouchesCurrent.x - imageTouchesStart.x + imageStartX;
imageCurrentY = imageTouchesCurrent.y - imageTouchesStart.y + imageStartY;
if (imageCurrentX < imageMinX) {
imageCurrentX = imageMinX + 1 - Math.pow((imageMinX - imageCurrentX + 1), 0.8);
}
if (imageCurrentX > imageMaxX) {
imageCurrentX = imageMaxX - 1 + Math.pow((imageCurrentX - imageMaxX + 1), 0.8);
}
if (imageCurrentY < imageMinY) {
imageCurrentY = imageMinY + 1 - Math.pow((imageMinY - imageCurrentY + 1), 0.8);
}
if (imageCurrentY > imageMaxY) {
imageCurrentY = imageMaxY - 1 + Math.pow((imageCurrentY - imageMaxY + 1), 0.8);
}
//Velocity
if (!velocityPrevPositionX) velocityPrevPositionX = imageTouchesCurrent.x;
if (!velocityPrevPositionY) velocityPrevPositionY = imageTouchesCurrent.y;
if (!velocityPrevTime) velocityPrevTime = $.now();
velocityX = (imageTouchesCurrent.x - velocityPrevPositionX) / ($.now() - velocityPrevTime) / 2;
velocityY = (imageTouchesCurrent.y - velocityPrevPositionY) / ($.now() - velocityPrevTime) / 2;
if (Math.abs(imageTouchesCurrent.x - velocityPrevPositionX) < 2) velocityX = 0;
if (Math.abs(imageTouchesCurrent.y - velocityPrevPositionY) < 2) velocityY = 0;
velocityPrevPositionX = imageTouchesCurrent.x;
velocityPrevPositionY = imageTouchesCurrent.y;
velocityPrevTime = $.now();
zoom.scrollerTransform(imageCurrentX, imageCurrentY);
};
zoom.onTouchEnd = function(e) {
if (!e.touches.length) {
isGesturing = false;
}
if (!imageIsTouched || !imageIsMoved) {
imageIsTouched = false;
imageIsMoved = false;
return;
}
imageIsTouched = false;
imageIsMoved = false;
var momentumDurationX = 300;
var momentumDurationY = 300;
var momentumDistanceX = velocityX * momentumDurationX;
var newPositionX = imageCurrentX + momentumDistanceX;
var momentumDistanceY = velocityY * momentumDurationY;
var newPositionY = imageCurrentY + momentumDistanceY;
if (velocityX !== 0) momentumDurationX = Math.abs((newPositionX - imageCurrentX) / velocityX);
if (velocityY !== 0) momentumDurationY = Math.abs((newPositionY - imageCurrentY) / velocityY);
var momentumDuration = Math.max(momentumDurationX, momentumDurationY);
imageCurrentX = newPositionX;
imageCurrentY = newPositionY;
var scaledWidth = imageWidth * scale;
var scaledHeight = imageHeight * scale;
imageMinX = Math.min((wrapperWidth / 2 - scaledWidth / 2), 0);
imageMaxX = -imageMinX;
imageMinY = Math.min((wrapperHeight / 2 - scaledHeight / 2), 0);
imageMaxY = -imageMinY;
imageCurrentX = Math.max(Math.min(imageCurrentX, imageMaxX), imageMinX);
imageCurrentY = Math.max(Math.min(imageCurrentY, imageMaxY), imageMinY);
zoom.scrollerTransition(momentumDuration).scrollerTransform(imageCurrentX, imageCurrentY);
};
zoom.destroy = function() {
zoom.initEvents(true); //detach
delete $.data[zoom.wrapper.getAttribute('data-zoomer')];
zoom.wrapper.setAttribute('data-zoomer', '');
}
zoom.init();
return zoom;
};
$.Zoom.defaults = {
speed: 300,
maxZoom: 3,
minZoom: 1,
};
$.fn.zoom = function(options) {
var zoomApis = [];
this.each(function() {
var zoomApi = null;
var self = this;
var id = self.getAttribute('data-zoomer');
if (!id) {
id = ++$.uuid;
$.data[id] = zoomApi = new $.Zoom(self, options);
self.setAttribute('data-zoomer', id);
} else {
zoomApi = $.data[id];
}
zoomApis.push(zoomApi);
});
return zoomApis.length === 1 ? zoomApis[0] : zoomApis;
};
})(mui, window);
```
**mui.previewimage.js**
```csharp
(function($, window) {
var template = '<div id="{{id}}" class="mui-slider mui-preview-image mui-fullscreen"><div class="mui-preview-header">{{header}}</div><div class="mui-slider-group"></div><div class="mui-preview-footer mui-hidden">{{footer}}</div><div class="mui-preview-loading"><span class="mui-spinner mui-spinner-white"></span></div></div>';
var itemTemplate = '<div class="mui-slider-item mui-zoom-wrapper {{className}}"><div class="mui-zoom-scroller"><img src="{{src}}" data-preview-lazyload="{{lazyload}}" style="{{style}}" class="mui-zoom"></div></div>';
var defaultGroupName = '__DEFAULT';
var div = document.createElement('div');
var imgId = 0;
var PreviewImage = function(options) {
this.options = $.extend(true, {
id: '__MUI_PREVIEWIMAGE',
zoom: true,
header: '<span class="mui-preview-indicator"></span>',
footer: ''
}, options || {});
this.init();
this.initEvent();
};
var proto = PreviewImage.prototype;
proto.init = function() {
var options = this.options;
var el = document.getElementById(this.options.id);
if (!el) {
div.innerHTML = template.replace(/\{\{id\}\}/g, this.options.id).replace('{{header}}', options.header).replace('{{footer}}', options.footer);
document.body.appendChild(div.firstElementChild);
el = document.getElementById(this.options.id);
}
this.element = el;
this.scroller = this.element.querySelector($.classSelector('.slider-group'));
this.indicator = this.element.querySelector($.classSelector('.preview-indicator'));
this.loader = this.element.querySelector($.classSelector('.preview-loading'));
if (options.footer) {
this.element.querySelector($.classSelector('.preview-footer')).classList.remove($.className('hidden'));
}
this.addImages();
};
proto.initEvent = function() {
var self = this;
$(document.body).on('tap', 'img[data-preview-src]', function() {
self.open(this);
return false;
});
var laterClose = null;
var laterCloseEvent = function() {
!laterClose && (laterClose = $.later(function() {
self.loader.removeEventListener('tap', laterCloseEvent);
self.scroller.removeEventListener('tap', laterCloseEvent);
self.close();
}, 300));
};
this.scroller.addEventListener('doubletap', function() {
if (laterClose) {
laterClose.cancel();
laterClose = null;
}
});
this.element.addEventListener('webkitAnimationEnd', function() {
if (self.element.classList.contains($.className('preview-out'))) { //close
self.element.style.display = 'none';
self.element.classList.remove($.className('preview-out'));
self.element.classList.remove($.className('preview-in'));
laterClose = null;
} else { //open
self.loader.addEventListener('tap', laterCloseEvent);
self.scroller.addEventListener('tap', laterCloseEvent);
}
});
this.element.addEventListener('slide', function(e) {
if (self.options.zoom) {
var lastZoomerEl = self.element.querySelector('.mui-zoom-wrapper:nth-child(' + (self.lastIndex + 1) + ')');
if (lastZoomerEl) {
$(lastZoomerEl).zoom().setZoom(1);
}
}
var slideNumber = e.detail.slideNumber;
self.lastIndex = slideNumber;
self.indicator && (self.indicator.innerText = (slideNumber + 1) + '/' + self.currentGroup.length);
self._loadItem(slideNumber);
});
};
proto.addImages = function(group, index) {
this.groups = {};
var imgs = [];
if (group) {
if (group === defaultGroupName) {
imgs = document.querySelectorAll("img[data-preview-src]:not([data-preview-group])");
} else {
imgs = document.querySelectorAll("img[data-preview-src][data-preview-group='" + group + "']");
}
} else {
imgs = document.querySelectorAll("img[data-preview-src]");
}
if (imgs.length) {
for (var i = 0, len = imgs.length; i < len; i++) {
this.addImage(imgs[i]);
}
}
};
proto.addImage = function(img) {
var group = img.getAttribute('data-preview-group');
group = group || defaultGroupName;
if (!this.groups[group]) {
this.groups[group] = [];
}
var src = img.getAttribute('src');
if (img.__mui_img_data && img.__mui_img_data.src === src) { //已缓存且图片未变化
this.groups[group].push(img.__mui_img_data);
} else {
var lazyload = img.getAttribute('data-preview-src');
if (!lazyload) {
lazyload = src;
}
var imgObj = {
src: src,
lazyload: src === lazyload ? '' : lazyload,
loaded: src === lazyload ? true : false,
sWidth: 0,
sHeight: 0,
sTop: 0,
sLeft: 0,
sScale: 1,
el: img
};
this.groups[group].push(imgObj);
img.__mui_img_data = imgObj;
}
};
proto.empty = function() {
this.scroller.innerHTML = '';
};
proto._initImgData = function(itemData, imgEl) {
if (!itemData.sWidth) {
var img = itemData.el;
itemData.sWidth = img.offsetWidth;
itemData.sHeight = img.offsetHeight;
var offset = $.offset(img);
itemData.sTop = offset.top;
itemData.sLeft = offset.left;
itemData.sScale = Math.max(itemData.sWidth / window.innerWidth, itemData.sHeight / window.innerHeight);
}
imgEl.style.webkitTransform = 'translate3d(0,0,0) scale(' + itemData.sScale + ')';
};
proto._getScale = function(from, to) {
var scaleX = from.width / to.width;
var scaleY = from.height / to.height;
var scale = 1;
if (scaleX <= scaleY) {
scale = from.height / (to.height * scaleX);
} else {
scale = from.width / (to.width * scaleY);
}
return scale;
};
proto._imgTransitionEnd = function(e) {
var img = e.target;
img.classList.remove($.className('transitioning'));
img.removeEventListener('webkitTransitionEnd', this._imgTransitionEnd.bind(this));
};
proto._loadItem = function(index, isOpening) { //TODO 暂时仅支持img
var itemEl = this.scroller.querySelector($.classSelector('.slider-item:nth-child(' + (index + 1) + ')'));
var itemData = this.currentGroup[index];
var imgEl = itemEl.querySelector('img');
this._initImgData(itemData, imgEl);
if (isOpening) {
var posi = this._getPosition(itemData);
imgEl.style.webkitTransitionDuration = '0ms';
imgEl.style.webkitTransform = 'translate3d(' + posi.x + 'px,' + posi.y + 'px,0) scale(' + itemData.sScale + ')';
imgEl.offsetHeight;
}
if (!itemData.loaded && imgEl.getAttribute('data-preview-lazyload')) {
var self = this;
self.loader.classList.add($.className('active'));
//移动位置动画
imgEl.style.webkitTransitionDuration = '0.5s';
imgEl.addEventListener('webkitTransitionEnd', self._imgTransitionEnd.bind(self));
imgEl.style.webkitTransform = 'translate3d(0,0,0) scale(' + itemData.sScale + ')';
this.loadImage(imgEl, function() {
itemData.loaded = true;
imgEl.src = itemData.lazyload;
self._initZoom(itemEl, this.width, this.height);
imgEl.classList.add($.className('transitioning'));
imgEl.addEventListener('webkitTransitionEnd', self._imgTransitionEnd.bind(self));
imgEl.setAttribute('style', '');
imgEl.offsetHeight;
self.loader.classList.remove($.className('active'));
});
} else {
itemData.lazyload && (imgEl.src = itemData.lazyload);
this._initZoom(itemEl, imgEl.width, imgEl.height);
imgEl.classList.add($.className('transitioning'));
imgEl.addEventListener('webkitTransitionEnd', this._imgTransitionEnd.bind(this));
imgEl.setAttribute('style', '');
imgEl.offsetHeight;
}
this._preloadItem(index + 1);
this._preloadItem(index - 1);
};
proto._preloadItem = function(index) {
var itemEl = this.scroller.querySelector($.classSelector('.slider-item:nth-child(' + (index + 1) + ')'));
if (itemEl) {
var itemData = this.currentGroup[index];
if (!itemData.sWidth) {
var imgEl = itemEl.querySelector('img');
this._initImgData(itemData, imgEl);
}
}
};
proto._initZoom = function(zoomWrapperEl, zoomerWidth, zoomerHeight) {
if (!this.options.zoom) {
return;
}
if (zoomWrapperEl.getAttribute('data-zoomer')) {
return;
}
var zoomEl = zoomWrapperEl.querySelector($.classSelector('.zoom'));
if (zoomEl.tagName === 'IMG') {
var self = this;
var maxZoom = self._getScale({
width: zoomWrapperEl.offsetWidth,
height: zoomWrapperEl.offsetHeight
}, {
width: zoomerWidth,
height: zoomerHeight
});
$(zoomWrapperEl).zoom({
maxZoom: Math.max(maxZoom, 1)
});
} else {
$(zoomWrapperEl).zoom();
}
};
proto.loadImage = function(imgEl, callback) {
var onReady = function() {
callback && callback.call(this);
};
var img = new Image();
img.onload = onReady;
img.onerror = onReady;
img.src = imgEl.getAttribute('data-preview-lazyload');
};
proto.getRangeByIndex = function(index, length) {
return {
from: 0,
to: length - 1
};
// var from = Math.max(index - 1, 0);
// var to = Math.min(index + 1, length);
// if (index === length - 1) {
// from = Math.max(length - 3, 0);
// to = length - 1;
// }
// if (index === 0) {
// from = 0;
// to = Math.min(2, length - 1);
// }
// return {
// from: from,
// to: to
// };
};
proto._getPosition = function(itemData) {
var sLeft = itemData.sLeft - window.pageXOffset;
var sTop = itemData.sTop - window.pageYOffset;
var left = (window.innerWidth - itemData.sWidth) / 2;
var top = (window.innerHeight - itemData.sHeight) / 2;
return {
left: sLeft,
top: sTop,
x: sLeft - left,
y: sTop - top
};
};
proto.refresh = function(index, groupArray) {
this.currentGroup = groupArray;
//重新生成slider
var length = groupArray.length;
var itemHtml = [];
var currentRange = this.getRangeByIndex(index, length);
var from = currentRange.from;
var to = currentRange.to + 1;
var currentIndex = index;
var className = '';
var itemStr = '';
var wWidth = window.innerWidth;
var wHeight = window.innerHeight;
for (var i = 0; from < to; from++, i++) {
var itemData = groupArray[from];
var style = '';
if (itemData.sWidth) {
style = '-webkit-transform:translate3d(0,0,0) scale(' + itemData.sScale + ');transform:translate3d(0,0,0) scale(' + itemData.sScale + ')';
}
itemStr = itemTemplate.replace('{{src}}', itemData.src).replace('{{lazyload}}', itemData.lazyload).replace('{{style}}', style);
if (from === index) {
currentIndex = i;
className = $.className('active');
} else {
className = '';
}
itemHtml.push(itemStr.replace('{{className}}', className));
}
this.scroller.innerHTML = itemHtml.join('');
this.element.style.display = 'block';
this.element.classList.add($.className('preview-in'));
this.lastIndex = currentIndex;
this.element.offsetHeight;
$(this.element).slider().gotoItem(currentIndex, 0);
this.indicator && (this.indicator.innerText = (currentIndex + 1) + '/' + this.currentGroup.length);
this._loadItem(currentIndex, true);
};
proto.openByGroup = function(index, group) {
index = Math.min(Math.max(0, index), this.groups[group].length - 1);
this.refresh(index, this.groups[group]);
};
proto.open = function(index, group) {
if (this.isShown()) {
return;
}
if (typeof index === "number") {
group = group || defaultGroupName;
this.addImages(group, index); //刷新当前group
this.openByGroup(index, group);
} else {
group = index.getAttribute('data-preview-group');
group = group || defaultGroupName;
this.addImages(group, index); //刷新当前group
this.openByGroup(this.groups[group].indexOf(index.__mui_img_data), group);
}
};
proto.close = function(index, group) {
if (!this.isShown()) {
return;
}
this.element.classList.remove($.className('preview-in'));
this.element.classList.add($.className('preview-out'));
var itemEl = this.scroller.querySelector($.classSelector('.slider-item:nth-child(' + (this.lastIndex + 1) + ')'));
var imgEl = itemEl.querySelector('img');
if (imgEl) {
imgEl.classList.add($.className('transitioning'));
var itemData = this.currentGroup[this.lastIndex];
var posi = this._getPosition(itemData);
var sLeft = posi.left;
var sTop = posi.top;
if (sTop > window.innerHeight || sLeft > window.innerWidth || sTop < 0 || sLeft < 0) { //out viewport
imgEl.style.opacity = 0;
imgEl.style.webkitTransitionDuration = '0.5s';
imgEl.style.webkitTransform = 'scale(' + itemData.sScale + ')';
} else {
if (this.options.zoom) {
$(imgEl.parentNode.parentNode).zoom().toggleZoom(0);
}
imgEl.style.webkitTransitionDuration = '0.5s';
imgEl.style.webkitTransform = 'translate3d(' + posi.x + 'px,' + posi.y + 'px,0) scale(' + itemData.sScale + ')';
}
}
var zoomers = this.element.querySelectorAll($.classSelector('.zoom-wrapper'));
for (var i = 0, len = zoomers.length; i < len; i++) {
$(zoomers[i]).zoom().destroy();
}
$(this.element).slider().destroy();
// this.empty();
};
proto.isShown = function() {
return this.element.classList.contains($.className('preview-in'));
};
var previewImageApi = null;
$.previewImage = function(options) {
if (!previewImageApi) {
previewImageApi = new PreviewImage(options);
}
return previewImageApi;
};
$.getPreviewImage = function() {
return previewImageApi;
}
})(mui, window);
mui.previewImage();
```
