sizer/sizer.js at master · int64/sizer · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
/**
 * Sizer
 * =====
 * Image sizer =) (c) Bond, James Bond
 * @author int64
 * @var source - source element
 * @var params:
 * 		padding - padding from window
 * 		closeOnScroll - will be close overlay by scroll
 */

function getOffset(elem) {
	if (elem.getBoundingClientRect) {
		// "правильный" вариант
		return getOffsetRect(elem)
	} else {
		// пусть работает хоть как-то
		return getOffsetSum(elem)
	}
}

function getOffsetSum(elem) {
	var top=0, left=0
	while(elem) {
		top = top + parseInt(elem.offsetTop)
		left = left + parseInt(elem.offsetLeft)
		elem = elem.offsetParent
	}

	return {top: top, left: left}
}

function getOffsetRect(elem) {
	// (1)
	var box = elem.getBoundingClientRect()

	// (2)
	var body = document.body
	var docElem = document.documentElement

	// (3)
	var scrollTop = window.pageYOffset || docElem.scrollTop || body.scrollTop
	var scrollLeft = window.pageXOffset || docElem.scrollLeft || body.scrollLeft

	// (4)
	var clientTop = docElem.clientTop || body.clientTop || 0
	var clientLeft = docElem.clientLeft || body.clientLeft || 0

	// (5)
	var top  = box.top +  scrollTop - clientTop
	var left = box.left + scrollLeft - clientLeft

	return { top: Math.round(top), left: Math.round(left) }
}

var sizer = function(source,params) {

	if (source.sizer) {
		return false;
	}

	source.sizer = true;

	var init = function(){

		var padding = (params.padding != undefined ? params.padding : 5) / 100;
		var overlay = document.createElement("div");
		var clone = document.createElement('img');

		var scrollFunc = function(){
			close();
		}

		var close = function(){
			overlay.style.backgroundColor = 'transparent';
			clone.style.width = origW + 'px';
			clone.style.height = origH + 'px';
			clone.style.left = offsetLeft + 'px';
			clone.style.top = (offsetTop - window.scrollY) + 'px';
			setTimeout(function(){
				source.style.opacity = 1;
				overlay.parentNode.removeChild(overlay);
			},300);
			if (params.closeOnScroll) {
				window.removeEventListener('scroll',scrollFunc);
			}
		}

		source.style.opacity = 0;

		overlay.style.top = 0;
		overlay.style.left = 0;
		overlay.style.position = 'fixed';
		overlay.style.width = '100%';
		overlay.style.height = '100%';
		overlay.style.backgroundColor = 'transparent';
		overlay.style.transition = '0.3s ease background-color';
		overlay.style.zIndex = 5000;
		document.body.appendChild(overlay);
		overlay.appendChild(clone);

		clone.src = source.src;
		clone.style.position = 'absolute';
		clone.style.transition = 'all 300ms';

		var origW = source.width;
		var origH = source.height;
		var imgW = source.naturalWidth;
		var imgH = source.naturalHeight;
		var winW = window.innerWidth;
		var winH = window.innerHeight;
		var offsetLeft = getOffset(source).left + parseInt(window.getComputedStyle(source, null).borderLeftWidth);
		var offsetTop = getOffset(source).top + parseInt(window.getComputedStyle(source, null).borderTopWidth);
		var dw = winW / imgW;
		var dh = winH / imgH;
		if (dw > dh) {
			var resultHeight = dh > 1 ? (imgH - imgH * padding) : (winH - winH * padding);
			var resultWidth = origW * (resultHeight / origH);
		} else {
			var resultWidth = dw > 1 ? (imgW - imgW * padding) : (winW - winW * padding);
			var resultHeight = origH * (resultWidth / origW);
		}

		var leftW = (winW - resultWidth) / 2;
		var topH = (winH - resultHeight) / 2;

		overlay.style.backgroundColor = '#fff';
		overlay.addEventListener('click',close)

		if (params.closeOnScroll) {
			window.addEventListener('scroll',scrollFunc);
		}

		clone.style.width = origW + 'px';
		clone.style.height = origH + 'px';
		clone.style.left = offsetLeft + 'px';
		clone.style.top = (offsetTop - window.scrollY) + 'px';

		setTimeout(function(){
			clone.style.width = resultWidth + 'px';
			clone.style.height = resultHeight + 'px';
			clone.style.left = leftW + 'px';
			clone.style.top = topH + 'px';
		},10);

		return false;
	}

	source.addEventListener('click',init);

	source.removeSizer = function() {
		delete source.sizer;
		source.removeEventListener('click',init);
	}
};