Component:
<aura:component>
    
    <aura:handler name="init" value="{!this}" action="{!c.doInit}" />
    <aura:attribute name="intervalId" type="Integer" default="0"/>
    
    <div id="parentDIV" style="overflow:hidden">
        <p style="position:relative;" id="tofloat">
            <b><span style="color:red">Important Note : </span>
            I am Floating (Left to Right) Imformation...</b>
        </p>
    </div>
    
</aura:component>

Controller :
({
    doInit : function(component, event, helper) {
        var lWidth = window.innerWidth ;//Get the window's width
        //The setInterval() method calls a function or
        //evaluates an expression at specified intervals (in milliseconds).
        window.setInterval($A.getCallback(function() {
            helper.shiftDiv(component, event,lWidth);
        } ), 100);
    },
})

Helper :
({
    shiftDiv: function(component, event,lWidth) {
        var changeposition = component.get("v.intervalId");
        var floatElement = document.getElementById('tofloat');   
        if(changeposition < lWidth){
            floatElement.style.left = changeposition+'px';
            changeposition = changeposition + 5;
            component.set("v.intervalId",changeposition);
        }
        //reset the left to 0
        else{
            component.set("v.intervalId",0);
            floatElement.style.left = "0px";
            changeposition = component.get("v.intervalId");//resetting so as to hit the if block again
        }
    }
})

Can someone advise how can i achieve this. I used onmouseover in div tag but getting stuck at what function should be used?
PS : Have copied this code from sfdcmonkey