aboutsummaryrefslogtreecommitdiffstats
path: root/src/offset.js
blob: 6a2fdc9934fdac3bb02e3840819b0d83ceb76a81 (plain)
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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
var rroot = /^(?:body|html)$/i;

jQuery.fn.offset = function( options ) {
	if ( arguments.length ) {
		return options === undefined ?
			this :
			this.each(function( i ) {
				jQuery.offset.setOffset( this, options, i );
			});
	}

	var docElem, body, win, clientTop, clientLeft, scrollTop, scrollLeft,
		box = { top: 0, left: 0 },
		elem = this[ 0 ],
		doc = elem && elem.ownerDocument;

	if ( !doc ) {
		return;
	}

	if ( (body = doc.body) === elem ) {
		return jQuery.offset.bodyOffset( elem );
	}

	docElem = doc.documentElement;

	// Make sure it's not a disconnected DOM node
	if ( !jQuery.contains( docElem, elem ) ) {
		return box;
	}

	// If we don't have gBCR, just use 0,0 rather than error
	// BlackBerry 5, iOS 3 (original iPhone)
	if ( typeof elem.getBoundingClientRect !== "undefined" ) {
		box = elem.getBoundingClientRect();
	}
	win = getWindow( doc );
	clientTop  = docElem.clientTop  || body.clientTop  || 0;
	clientLeft = docElem.clientLeft || body.clientLeft || 0;
	scrollTop  = win.pageYOffset || docElem.scrollTop;
	scrollLeft = win.pageXOffset || docElem.scrollLeft;
	return {
		top: box.top  + scrollTop  - clientTop,
		left: box.left + scrollLeft - clientLeft
	};
};

jQuery.offset = {

	bodyOffset: function( body ) {
		var top = body.offsetTop,
			left = body.offsetLeft;

		if ( jQuery.support.doesNotIncludeMarginInBodyOffset ) {
			top  += parseFloat( jQuery.css(body, "marginTop") ) || 0;
			left += parseFloat( jQuery.css(body, "marginLeft") ) || 0;
		}

		return { top: top, left: left };
	},

	setOffset: function( elem, options, i ) {
		var position = jQuery.css( elem, "position" );

		// set position first, in-case top/left are set even on static elem
		if ( position === "static" ) {
			elem.style.position = "relative";
		}

		var curElem = jQuery( elem ),
			curOffset = curElem.offset(),
			curCSSTop = jQuery.css( elem, "top" ),
			curCSSLeft = jQuery.css( elem, "left" ),
			calculatePosition = ( position === "absolute" || position === "fixed" ) && jQuery.inArray("auto", [curCSSTop, curCSSLeft]) > -1,
			props = {}, curPosition = {}, curTop, curLeft;

		// need to be able to calculate position if either top or left is auto and position is either absolute or fixed
		if ( calculatePosition ) {
			curPosition = curElem.position();
			curTop = curPosition.top;
			curLeft = curPosition.left;
		} else {
			curTop = parseFloat( curCSSTop ) || 0;
			curLeft = parseFloat( curCSSLeft ) || 0;
		}

		if ( jQuery.isFunction( options ) ) {
			options = options.call( elem, i, curOffset );
		}

		if ( options.top != null ) {
			props.top = ( options.top - curOffset.top ) + curTop;
		}
		if ( options.left != null ) {
			props.left = ( options.left - curOffset.left ) + curLeft;
		}

		if ( "using" in options ) {
			options.using.call( elem, props );
		} else {
			curElem.css( props );
		}
	}
};


jQuery.fn.extend({

	position: function() {
		if ( !this[ 0 ] ) {
			return;
		}

		var offsetParent, offset,
			parentOffset = { top: 0, left: 0 },
			elem = this[ 0 ];

		// fixed elements are offset from window (parentOffset = {top:0, left: 0}, because it is it's only offset parent
		if ( jQuery.css( elem, "position" ) === "fixed" ) {
			// we assume that getBoundingClientRect is available when computed position is fixed
			offset = elem.getBoundingClientRect();
		} else {
			// Get *real* offsetParent
			offsetParent = this.offsetParent();

			// Get correct offsets
			offset = this.offset();
			if ( !rroot.test( offsetParent[ 0 ].nodeName ) ) {
				parentOffset = offsetParent.offset();
			}

			// Add offsetParent borders
			parentOffset.top  += parseFloat( jQuery.css( offsetParent[ 0 ], "borderTopWidth" ) ) || 0;
			parentOffset.left += parseFloat( jQuery.css( offsetParent[ 0 ], "borderLeftWidth" ) ) || 0;
		}

		// Subtract parent offsets and element margins
		// note: when an element has margin: auto the offsetLeft and marginLeft
		// are the same in Safari causing offset.left to incorrectly be 0
		return {
			top:  offset.top  - parentOffset.top - ( parseFloat( jQuery.css( elem, "marginTop" ) ) || 0 ),
			left: offset.left - parentOffset.left - ( parseFloat( jQuery.css( elem, "marginLeft" ) ) || 0 )
		};
	},

	offsetParent: function() {
		return this.map(function() {
			var offsetParent = this.offsetParent || document.body;
			while ( offsetParent && (!rroot.test(offsetParent.nodeName) && jQuery.css(offsetParent, "position") === "static") ) {
				offsetParent = offsetParent.offsetParent;
			}
			return offsetParent || document.body;
		});
	}
});


// Create scrollLeft and scrollTop methods
jQuery.each( {scrollLeft: "pageXOffset", scrollTop: "pageYOffset"}, function( method, prop ) {
	var top = /Y/.test( prop );

	jQuery.fn[ method ] = function( val ) {
		return jQuery.access( this, function( elem, method, val ) {
			var win = getWindow( elem );

			if ( val === undefined ) {
				return win ? (prop in win) ? win[ prop ] :
					win.document.documentElement[ method ] :
					elem[ method ];
			}

			if ( win ) {
				win.scrollTo(
					!top ? val : jQuery( win ).scrollLeft(),
					 top ? val : jQuery( win ).scrollTop()
				);

			} else {
				elem[ method ] = val;
			}
		}, method, val, arguments.length, null );
	};
});

function getWindow( elem ) {
	return jQuery.isWindow( elem ) ?
		elem :
		elem.nodeType === 9 ?
			elem.defaultView || elem.parentWindow :
			false;
}