https://almerecity.nl/wp-content/themes/Impreza/common/js/base/parallax-ver.js?ver=8.46.1

1/*
2 Plugin: jQuery Parallax
3 Version 1.1.3
4 Author: Ian Lunn
5 Twitter: @IanLunn
6 Author URL: http://www.ianlunn.co.uk/
7 Plugin URL: http://www.ianlunn.co.uk/plugins/jquery-parallax/
8
9 (Contains lots of UpSolution's modifications)
10
11 Dual licensed under the MIT and GPL licenses:
12 http://www.opensource.org/licenses/mit-license.php
13 http://www.gnu.org/licenses/gpl.html
14 */
15
16( function( $ ) {
17	var $window = $( window ),
18		windowHeight = $window.height();
19
20	$.fn.parallax = function( xposParam ) {
21		this.each( function() {
22			var $container = $( this ),
23				$this = $container.children( '.l-section-img' ),
24				speedFactor,
25				offsetFactor = 0,
26				getHeight,
27				topOffset = 0,
28				containerHeight = 0,
29				containerWidth = 0,
30				// Disable parallax on certain screen/img ratios
31				disableParallax = false,
32				parallaxIsDisabled = false,
33				// Base image width and height (if can be achieved)
34				baseImgHeight = 0,
35				baseImgWidth = 0,
36				// Background-size cover? and current image size (counted)
37				isBgCover = ( $this.css( 'background-size' ) == 'cover' ),
38				originalBgPos = $this.css( 'background-position' ),
39				curImgHeight = 0,
40				reversed = $container.hasClass( 'parallaxdir_reversed' ),
41				baseSpeedFactor = reversed ? - 0.1 : 0.61,
42				xpos,
43				outerHeight = true;
44			if ( $this.length == 0 ) {
45				return;
46			}
47
48			// setup defaults if arguments aren't specified
49			if ( xposParam === undefined ) {
50				xpos = "50%";
51			} else {
52				xpos = xposParam;
53			}
54
55			if ( $container.hasClass( 'parallax_xpos_right' ) ) {
56				xpos = "100%";
57			} else if ( $container.hasClass( 'parallax_xpos_left' ) ) {
58				xpos = "0%";
59			}
60
61			if ( outerHeight ) {
62				getHeight = function( jqo ) {
63					return jqo.outerHeight( true );
64				};
65			} else {
66				getHeight = function( jqo ) {
67					return jqo.height();
68				};
69			}
70
71			// Count background image size
72			function getBackgroundSize( callback ) {
73				var img = new Image(),
74					// here we will place image's width and height
75					width, height,
76					// here we get the size of the background and split it to array
77					backgroundSize = ( $this.css( 'background-size' ) || ' ' ).split( ' ' ),
78					backgroundWidthAttr = $this.attr( 'data-img-width' ),
79					backgroundHeightAttr = $this.attr( 'data-img-height' );
80
81				if ( backgroundWidthAttr != '' ) {
82					width = parseInt( backgroundWidthAttr );
83				}
84				if ( backgroundHeightAttr != '' ) {
85					height = parseInt( backgroundHeightAttr );
86				}
87
88				if ( width !== undefined && height !== undefined ) {
89					// Image is not needed
90					return callback( { width: width, height: height } );
91				}
92
93				// checking if width was set to pixel value
94				if ( /px/.test( backgroundSize[ 0 ] ) ) {
95					width = parseInt( backgroundSize[ 0 ] );
96				}
97				// checking if width was set to percent value
98				if ( /%/.test( backgroundSize[ 0 ] ) ) {
99					width = $this.parent().width() * ( parseInt( backgroundSize[ 0 ] ) / 100 );
100				}
101				// checking if height was set to pixel value
102				if ( /px/.test( backgroundSize[ 1 ] ) ) {
103					height = parseInt( backgroundSize[ 1 ] );
104				}
105				// checking if height was set to percent value
106				if ( /%/.test( backgroundSize[ 1 ] ) ) {
107					height = $this.parent().height() * ( parseInt( backgroundSize[ 0 ] ) / 100 );
108				}
109
110				if ( width !== undefined && height !== undefined ) {
111					// Image is not needed
112					return callback( { width: width, height: height } );
113				}
114
115				// Image is needed
116				img.onload = function() {
117					// check if width was set earlier, if not then set it now
118					if ( typeof width == 'undefined' ) {
119						width = this.width;
120					}
121					// do the same with height
122					if ( typeof height == 'undefined' ) {
123						height = this.height;
124					}
125					// call the callback
126					callback( { width: width, height: height } );
127				};
128				// extract image source from css using one, simple regex
129				// src should be set AFTER onload handler
130				img.src = ( $this.css( 'background-image' ) || '' ).replace( /url\(['"]*(.*?)['"]*\)/g, '$1' );
131			}
132

133			function update() {
134				// Force parallax off for iPad, no correct support for `background-attachment: fixed`;
135				// https://forums.developer.apple.com/forums/thread/99883
136				if( $us.$html.hasClass( 'ios-touch' ) ) {
137					return;
138				}
139				if ( disableParallax ) {
140					if ( ! parallaxIsDisabled ) {
141						$this.css( 'backgroundPosition', originalBgPos );
142						$container.usMod( 'parallax', 'fixed' );
143						parallaxIsDisabled = true;
144					}
145					return;
146				} else {
147					if ( parallaxIsDisabled ) {
148						$container.usMod( 'parallax', 'ver' );
149						parallaxIsDisabled = false;
150					}
151				}
152				if ( isNaN( speedFactor ) ) {
153					return;
154				}
155
156				var pos = $window.scrollTop();
157				// Check if totally above or totally below viewport
158				if ( ( topOffset + containerHeight < pos ) || ( pos < topOffset - windowHeight ) ) {
159					return;
160				}
161				$this.css( 'backgroundPosition', xpos + " " + ( offsetFactor + speedFactor * ( topOffset - pos ) ) + "px" );
162
163			}
164
165			function resize() {
166				$ush.timeout( function() {
167					windowHeight = $window.height();
168					containerHeight = getHeight( $this );
169					containerWidth = $this.width();
170
171
172					if ( $window.width() < $us.canvasOptions.disableEffectsWidth ) {
173						disableParallax = true;
174					} else {
175						disableParallax = false;
176						if ( isBgCover ) {
177							if ( baseImgWidth / baseImgHeight <= containerWidth / containerHeight ) {
178								// Resizing by width
179								curImgHeight = baseImgHeight * ( $this.width() / baseImgWidth );
180								disableParallax = false;
181							}
182							else {
183								disableParallax = true;
184							}
185						}
186					}
187
188					// Improving speed factor to prevent showing image limits
189					if ( curImgHeight !== 0 ) {
190						if ( baseSpeedFactor >= 0 ) {
191							speedFactor = Math.min( baseSpeedFactor, curImgHeight / windowHeight );
192							offsetFactor = .5 * ( windowHeight - curImgHeight - speedFactor * ( windowHeight - containerHeight ) );
193							// offsetFactor = Math.min( 0, offsetFactor );
194							if ( offsetFactor > 0 ) {
195								offsetFactor = -offsetFactor;
196							}
197						} else {
198							speedFactor = Math.min( baseSpeedFactor, ( windowHeight - containerHeight ) / ( windowHeight + containerHeight ) );
199							offsetFactor = Math.max( 0, speedFactor * containerHeight );
200						}
201					} else {
202						speedFactor = baseSpeedFactor;
203						offsetFactor = 0;
204					}
205					topOffset = $this.offset().top;
206					update();
207				}, 10 );
208			}
209
210			getBackgroundSize( function( sz ) {
211				curImgHeight = baseImgHeight = sz.height;
212				baseImgWidth = sz.width;
213				resize();
214			} );
215
216			$window.bind( { 'scroll.noPreventDefault': update, load: resize, resize: resize } );
217			resize();
218		} );
219	};
220
221	jQuery( '.parallax_ver' ).parallax( '50%' );
222
223} )( jQuery );