欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  web前端

JQuery 实现的页面滚动时浮动窗口控件_jquery

程序员文章站 2022-05-12 15:00:59
...
JQuery 实现的页面滚动时浮动窗口控件_jquery
JQuery 实现的页面滚动时浮动窗口控件_jquery
1. Introduction:
这个控件能够实现的效果是当你的页面滚动时,某个DIV永远停留在你需要它停留的位置。同时可以为这个DIV设定个容器,当滚动条已经超过了这个容器,那么这个DIV就不再滚动了。
JQuery 实现的页面滚动时浮动窗口控件_jquery
有时候如果需要做个比较好用的导航条,使用这个控件挺不错的。
2. Code & Properties:
这个js文件是在jQuery和JQeury UI的核心上扩展的。所以使用它前你必须到JQuery的官网下载那两个js文件,jquery.js和ui.core.js。
整个javascript如下:
复制代码 代码如下:

( function( $ ) {

$.scrollFollow = function ( box, options )
{
// Convert box into a jQuery object
box = $( box );

// 'box' is the object to be animated
var position = box.css( 'position' );

function ani()
{
// The script runs on every scroll which really means many times during a scroll.
// We don't want multiple slides to queue up.
box.queue( [ ] );

// A bunch of values we need to determine where to animate to
var viewportHeight = parseInt( $( window ).height() );
var pageScroll = parseInt( $( document ).scrollTop() );
var parentTop = parseInt( box.cont.offset().top );
var parentHeight = parseInt( box.cont.attr( 'offsetHeight' ) );
var boxHeight = parseInt( box.attr( 'offsetHeight' ) + ( parseInt( box.css( 'marginTop' ) ) || 0 ) + ( parseInt( box.css( 'marginBottom' ) ) || 0 ) );
var aniTop;

// Make sure the user wants the animation to happen
if ( isActive )
{
// If the box should animate relative to the top of the window
if ( options.relativeTo == 'top' )
{
// Don't animate until the top of the window is close enough to the top of the box
if ( box.initialOffsetTop >= ( pageScroll + options.offset ) )
{
aniTop = box.initialTop;
}
else
{
aniTop = Math.min( ( Math.max( ( -parentTop ), ( pageScroll - box.initialOffsetTop + box.initialTop ) ) + options.offset ), ( parentHeight - boxHeight - box.paddingAdjustment ) );
}
}
// If the box should animate relative to the bottom of the window
else if ( options.relativeTo == 'bottom' )
{
// Don't animate until the bottom of the window is close enough to the bottom of the box
if ( ( box.initialOffsetTop + boxHeight ) >= ( pageScroll + options.offset + viewportHeight ) )
{
aniTop = box.initialTop;
}
else
{
aniTop = Math.min( ( pageScroll + viewportHeight - boxHeight - options.offset ), ( parentHeight - boxHeight ) );
}
}

// Checks to see if the relevant scroll was the last one
// "-20" is to account for inaccuracy in the timeout
if ( ( new Date().getTime() - box.lastScroll ) >= ( options.delay - 20 ) )
{
box.animate(
{
top: aniTop
}, options.speed, options.easing
);
}
}
};

// For user-initiated stopping of the slide
var isActive = true;

if ( $.cookie != undefined )
{
if( $.cookie( 'scrollFollowSetting' + box.attr( 'id' ) ) == 'false' )
{
var isActive = false;

$( '#' + options.killSwitch ).text( options.offText )
.toggle(
function ()
{
isActive = true;

$( this ).text( options.onText );

$.cookie( 'scrollFollowSetting' + box.attr( 'id' ), true, { expires: 365, path: '/'} );

ani();
},
function ()
{
isActive = false;

$( this ).text( options.offText );

box.animate(
{
top: box.initialTop
}, options.speed, options.easing
);

$.cookie( 'scrollFollowSetting' + box.attr( 'id' ), false, { expires: 365, path: '/'} );
}
);
}
else
{
$( '#' + options.killSwitch ).text( options.onText )
.toggle(
function ()
{
isActive = false;

$( this ).text( options.offText );

box.animate(
{
top: box.initialTop
}, 0
);

$.cookie( 'scrollFollowSetting' + box.attr( 'id' ), false, { expires: 365, path: '/'} );
},
function ()
{
isActive = true;

$( this ).text( options.onText );

$.cookie( 'scrollFollowSetting' + box.attr( 'id' ), true, { expires: 365, path: '/'} );

ani();
}
);
}
}

// If no parent ID was specified, and the immediate parent does not have an ID
// options.container will be undefined. So we need to figure out the parent element.
if ( options.container == '')
{
box.cont = box.parent();
}
else
{
box.cont = $( '#' + options.container );
}

// Finds the default positioning of the box.
box.initialOffsetTop = parseInt( box.offset().top );
box.initialTop = parseInt( box.css( 'top' ) ) || 0;

// Hack to fix different treatment of boxes positioned 'absolute' and 'relative'
if ( box.css( 'position' ) == 'relative' )
{
box.paddingAdjustment = parseInt( box.cont.css( 'paddingTop' ) ) + parseInt( box.cont.css( 'paddingBottom' ) );
}
else
{
box.paddingAdjustment = 0;
}

// Animate the box when the page is scrolled
$( window ).scroll( function ()
{
// Sets up the delay of the animation
$.fn.scrollFollow.interval = setTimeout( function(){ ani();} , options.delay );

// To check against right before setting the animation
box.lastScroll = new Date().getTime();
}
);

// Animate the box when the page is resized
$( window ).resize( function ()
{
// Sets up the delay of the animation
$.fn.scrollFollow.interval = setTimeout( function(){ ani();} , options.delay );

// To check against right before setting the animation
box.lastScroll = new Date().getTime();
}
);
// Run an initial animation on page load
box.lastScroll = 0;

ani();
};

$.fn.scrollFollow = function ( options )
{
options = options || {};
options.relativeTo = options.relativeTo || 'top';
options.speed = options.speed || 1;
options.offset = options.offset || 0;
options.easing = options.easing || 'swing';
options.container = options.container || this.parent().attr( 'id' );
options.killSwitch = options.killSwitch || 'killSwitch';
options.onText = options.onText || 'Turn Slide Off';
options.offText = options.offText || 'Turn Slide On';
options.delay = options.delay || 0;

this.each( function()
{
new $.scrollFollow( this, options );
}
);

return this;
};
})( jQuery );

这里面有几个参数可以设置效果:
JQuery 实现的页面滚动时浮动窗口控件_jquery
上面图示是用来设定这个DIV在滚动后的位置会在哪里。
而所有的动画效果参数设置如下:
JQuery 实现的页面滚动时浮动窗口控件_jquery
那么如何在HTML或者是其它的页面中使用呢?
复制代码 代码如下:



最后是设置ID为example这个DIV的Css样式,需要注意的是position必须设定为relative,如下例:
复制代码 代码如下:

#example {
position: relative;
width: 220px;
margin: 5px;
padding: 10px;
background: #DDDDDD;
border: 1px solid #42CBDC;
}