PhotoSwipe之API（4）

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API介绍

在这个页面上，列出的所有方法和属性都是公共的。如果你想看看API能做什么的例子，请进入PhotoSwipe默认UI源码页。

初始化后，你可以得到一个PhotoSwipe实例。

var photoswipeInstance = new PhotoSwipe(/*...*/);

方法

var pswp = new PhotoSwipe( /* ... */ );

// Initialize and open gallery
// (you can bind events before this method)
pswp.init();

// Go to slide by index
// @param {int} `index`
pswp.goTo(index);

// Go to the next slide
pswp.next();

// Go to the previous slide
pswp.prev();

// Update gallery size
// @param  {boolean} `force` If you set it to `true`, 
//                          size of the gallery will be updated 
//                          even if viewport size hasn't changed.
pswp.updateSize(force);

// Close gallery
pswp.close();

// Destroy gallery,
// automatically called after close() 
pswp.destroy()

// Zoom current slide to (optionally with animation)
// @param  {number}   `destZoomLevel` Destination scale number. 1 - original.  
//                                   pswp.currItem.fitRatio - image will fit into viewport.
// @param  {object}   `centerPoint`   Object of x and y coordinates, relative to viewport.
// @param  {int}      `speed`         Animation duration. Can be 0.
// @param  {function} `easingFn`      Easing function (optional). Set to false to use default easing.
// @param  {function} `updateFn`      Function will be called on each update frame. (optional)
//
// Example below will 2x zoom to center of slide:
// pswp.zoomTo(2, {x:pswp.viewportSize.x/2,y:pswp.viewportSize.y/2}, 2000, false, function(now) {
//      
// });
pswp.zoomTo(destZoomLevel, centerPoint, speed, easingFn, updateFn);

// Apply zoom and pan to the current slide
// 
// @param   {number} `zoomLevel`
// @param   {int}    `panX`
// @param   {int}    `panY`
// 
// For example: `pswp.applyZoomPan(1, 0, 0)`
// will zoom current image to the original size
// and will place it on top left corner
// 
// 
pswp.applyZoomPan(zoomLevel, panX, panY);

属性

// current slide object
pswp.currItem

// items array (slides, images)
pswp.items

// size of sliding viewport
pswp.viewportSize

// object holds all functions from framework
// framework-bridge.js
pswp.framework

// UI object (e.g. PhotoSwipeUI_Default instance)
pswp.ui

// background element (pswp__bg)
pswp.bg

// container element (pswp__container)
pswp.container

// options
pswp.options



// Even though methods below aren't technically properties, we list them here:

// current item index (int)
pswp.getCurrentIndex();

// total number of items
pswp.options.getNumItemsFn()

// current zoom level (number)
pswp.getZoomLevel();

// one (or more) pointer is used
pswp.isDragging();

// two (or more) pointers are used
pswp.isZooming();

// `true` when transition between is running (after swipe)
pswp.isMainScrollAnimating();

事件

PhotoSwipe使用了非常简单的事件/通讯系统。该系统有两个方法，第一个是shout用来触发事件（triggers event）,第二个是listen用来监听事件。没有解绑事件的方法，但是在PhotoSwipe被关闭时，所有这些都会被清除。

var pswp = new PhotoSwipe(/* ... */);

// Listen for "helloWorld" event
pswp.listen('helloWorld', function(name) {
    alert('Name is: ' + name);
});

// Trigger "helloWorld" event
pswp.shout('helloWorld', 'John' /* you may pass more arguments */);

可用的事件

// Before slides change
// (before the content is changed, but after navigation)
// Update UI here (like "1 of X" indicator)
pswp.listen('beforeChange', function() { });

// After slides change
// (after content changed)
pswp.listen('afterChange', function() { });

// Image loaded
pswp.listen('imageLoadComplete', function(index, item) { 
    // index - index of a slide that was loaded
    // item - slide object
});

// Viewport size changed
pswp.listen('resize', function() { });

// Triggers when PhotoSwipe "reads" slide object data,
// which happens before content is set, or before lazy-loading is initiated.
// Use it to dynamically change properties
pswp.listen('gettingData', function(index, item) {
    // index - index of a slide that was loaded
    // item - slide object

    // e.g. change path to the image based on `something`
    if( something ) {
        item.src = item.something;
    } else {
        item.src = item.somethingElse;
    }
});

// Mouse was used (triggers only once)
pswp.listen('mouseUsed', function() { });


// Opening zoom in animation starting
pswp.listen('initialZoomIn', function() { });

// Opening zoom in animation finished
pswp.listen('initialZoomInEnd', function() { });

// Closing zoom out animation started
pswp.listen('initialZoomOut', function() { });

// Closing zoom out animation finished
pswp.listen('initialZoomOutEnd', function() { });


// Allows overriding vertical margin for individual items
pswp.listen('parseVerticalMargin', function(item) { 
    // For example:
    var gap = item.vGap;

    gap.top = 50; // There will be 50px gap from top of viewport
    gap.bottom = 100; // and 100px gap from the bottom
})

// Gallery starts closing
pswp.listen('close', function() { });

// Gallery unbinds events
// (triggers before closing animation)
pswp.listen('unbindEvents', function() { });

// After gallery is closed and closing animation finished.
// Clean up your stuff here.
pswp.listen('destroy', function() { });

// Called when the page scrolls.
// The callback is passed an offset with properties {x: number, y: number}.
//
// PhotoSwipe uses the offset to determine the top-left of the template,
// which by default is the top-left of the viewport. When using modal: false,
// you should listen to this event (before calling .init()) and modify the offset
// with the template's getBoundingClientRect().
//
// Look at the "Implementing inline gallery display" FAQ section for more info.
pswp.listen('updateScrollOffset', function(_offset) {
    var r = gallery.template.getBoundingClientRect();
    _offset.x += r.left;
    _offset.y += r.top;
});

// PhotoSwipe has a special event called pswpTap.
// It's dispatched using default JavaScript event model.
// So you can, for example, call stopPropagation on it.
// pswp.framework.bind - is a shorthand for addEventListener
pswp.framework.bind( pswp.scrollWrap /* bind on any element of gallery */, 'pswpTap', function(e) {
    console.log('tap', e, e.detail);
    // e.detail.origEvent  // original event that finished tap (e.g. mouseup or touchend)
    // e.detail.target // e.target of original event
    // e.detail.releasePoint // object with x/y coordinates of tap
    // e.detail.pointerType // mouse, touch, or pen
});

// Allow to call preventDefault on down and up events
pswp.listen('preventDragEvent', function(e, isDown, preventObj) {
    // e - original event
    // isDown - true = drag start, false = drag release

    // Line below will force e.preventDefault() on:
    // touchstart/mousedown/pointerdown events
    // as well as on:
    // touchend/mouseup/pointerup events
    preventObj.prevent = true;
});



// Default UI events
// -------------------------

// Share link clicked
pswp.listen('shareLinkClick', function(e, target) { 
    // e - original click event
    // target - link that was clicked

    // If `target` has `href` attribute and 
    // does not have `download` attribute - 
    // share modal window will popup
});

动态添加图库项

在PhotoSwipe被打开后，如果你想添加，编辑或删除图库项，你只需要修改items数组。
例如：你可以创建一个新的slide对象push到items数组中。

pswp.items.push({
	src: "path/to/image.png",
	w: 1200,
	h: 500
})

如果你改变了当前/下一个/上一个图库项（应尽量避免这样做），你必须调用它们的内容更新方法

// sets a flag that slides should be updated
pswp.invalidateCurrItems();
// updates the content of slides
pswp.updateSize(true);

否则，你什么都不用做。除非你想部分默认UI更新，可以调用pswp.ui.update(),其他注意项：

• 你不能再分配整个数组，你只能修改它。（例如：使用splice去移除元素）
• 如果你要删除当前图库项，请在调用goto方法之前操作。
• 至少保留一个图库项
• 这种技术常常用来服务响应式图片