Object-oriented drag (subclass inheritance)

Drag (parent Class)

functionDrag (ID) {var_this = This;  This. DISX = 0;  This. Disy = 0;  This. Odiv =document.getElementById (ID);  This. Odiv.onmousedown =function(EV) {_this.fndown (EV); return false; };} Drag.prototype.fnDown=function(EV) {var_this = This; varoevent = EV | |event;  This. DISX = oevent.clientx- This. Odiv.offsetleft;  This. Disy = oevent.clienty- This. Odiv.offsettop; Document.onmousemove=function(EV) {_this.fnmove (EV);        }; Document.onmouseup=function() {_this.fnup (); };} Drag.prototype.fnMove=function(EV) {varoevent = EV | |event;  This. ODiv.style.left = oevent.clientx- This. disx+ ' px ';  This. ODiv.style.top = oevent.clienty- This. disy+ ' px ';} Drag.prototype.fnUp=function() {Document.onmousemove=NULL; Document.onmouseup=NULL;}/*window.onload=function () {var odiv = document.getElementById (' Div1 ');        Odiv.onmousedown=function (EV) {var oevent = EV | | event;        var disx = Oevent.clientx-odiv.offsetleft;        var disy = oevent.clienty-odiv.offsettop;            Document.onmousemove = function (ev) {var oevent = EV | | event;            ODiv.style.left = oevent.clientx-disx+ ' px ';        ODiv.style.top = oevent.clienty-disy+ ' px ';        };            Document.onmouseup=function () {document.onmousemove=null;        Document.onmouseup=null;    }; }}*/

Limitdrag (Subclass)

functionLimitdrag (ID) {Drag.call ( This, id);} for(varIinchDrag.prototype) {Limitdrag.prototype[i]=drag.prototype[i];} LimitDrag.prototype.fnMove=function(EV) {varoevent = EV | |event; varL = oevent.clientx- This. Disx; vart = oevent.clienty- This. Disy; if(L < 0) {L=0; }Else if(L > document.documentelement.clientwidth- This. Odiv.offsetwidth) {L= document.documentelement.clientwidth- This. Odiv.offsetwidth; }     This. ODiv.style.left = l + ' px ';  This. ODiv.style.top = t + ' px ';}

Object-oriented drag (subclass inheritance)