鼠标拖动控制页面滚动 (可运用于全屏触摸设备)

var
 flag 
=
 
false
; 
//
mouse is clicked




var
 moveValue 
=
 
10
; 
//
scroll threshold value




var
 mouseY 
=
 
0
; 
//
Y coordinate







$(

function

(){


disableSelection(document.body);


$('body').bind(

'
mousedown
'
,
function

(event){


flag

=
 
true

;


}).bind(

'
mouseup
'
,
function

(event){


flag

=
 
false

;


}).bind(

'
mousemove
'
,
function

(event){



if
(
!
flag) 
return

;



if

(
mouseY

<

event.clientY){


window.scrollTo(

0
, GetPageScroll().Y
 + 

moveValue
);


}

else

{


window.scrollTo(

0
, GetPageScroll().Y
 -

moveValue
);


}


mouseY

=

event.clientY;


});


});





function

GetPageScroll() {



var

x, y;



if

(window.pageYOffset) {



//
 all except IE




    y 
=

window.pageYOffset;


x

=

window.pageXOffset;


}

else
 
if

(document.documentElement



&&

document.documentElement.scrollTop) {



//
 IE 6 Strict




    y 
=

document.documentElement.scrollTop;


x

=

document.documentElement.scrollLeft;


}

else
 
if

(document.body) {



//
 all other IE




    y 
=

document.body.scrollTop;


x

=

document.body.scrollLeft;


}



return

{X:x, Y:y};


}





function

disableSelection(target){



if
 (
typeof
 target.onselectstart
!=
"
undefined
"
) 
//
IE 




    target.onselectstart
=
function
(){
return
 
false

;}



else
 
if
 (
typeof
 target.style.MozUserSelect
!=
"
undefined
"
) 
//
Firefox 




    target.style.MozUserSelect
=
"
none
"

;



else
 
//
All other ie: Opera




    target.onmousedown
=
function
(){
return
 
false

}


target.style.cursor

=
 
"
default
"



}