Reposition div according to window size-CodePudding

I have this draggable div which automatically positions correctly when window is being re-sized from left or top. I want it to do the same thing from right and bottom as well so it is still visible.

Can this be done with just css? or do I need to use javascript? can someone please show me how.

<head>
<style>
#box {
    position: fixed;
    background:  red;
    width: 10%;
    height: 10%;
}
</style>
    
</head>

<body>

    <div id="box"> </div>

    <script>
        //Make the DIV element draggagle:
        dragElement(document.getElementById("box"));
        
        function dragElement(elmnt) {
          var pos1 = 0, pos2 = 0, pos3 = 0, pos4 = 0;
          if (document.getElementById(elmnt.id   "header")) {
            /* if present, the header is where you move the DIV from:*/
            document.getElementById(elmnt.id   "header").onmousedown = dragMouseDown;
          } else {
            /* otherwise, move the DIV from anywhere inside the DIV:*/
            elmnt.onmousedown = dragMouseDown;
          }
        
          function dragMouseDown(e) {
            e = e || window.event;
            e.preventDefault();
            // get the mouse cursor position at startup:
            pos3 = e.clientX;
            pos4 = e.clientY;
            document.onmouseup = closeDragElement;
            // call a function whenever the cursor moves:
            document.onmousemove = elementDrag;
          }
        
          function elementDrag(e) {
            e = e || window.event;
            e.preventDefault();
            // calculate the new cursor position:
            pos1 = pos3 - e.clientX;
            pos2 = pos4 - e.clientY;
            pos3 = e.clientX;
            pos4 = e.clientY;
            // set the element's new position:
            elmnt.style.top = (elmnt.offsetTop - pos2)   "px";
            elmnt.style.left = (elmnt.offsetLeft - pos1)   "px";
          }
        
          function closeDragElement() {
            /* stop moving when mouse button is released:*/
            document.onmouseup = null;
            document.onmousemove = null;
          }
        }
        </script>
</body>

CodePudding user response：

you need to set position to sticky instead of fixed, that will work:)

position: sticky;

CodePudding user response：

You will need to use position as sticky and not use % for height. It might make the height to 0.

<head>
    <style>
    #box {
        position: sticky;
        background:  red;
        width: 10vw;
        height: 10vh;
    }
    </style>
        
</head>

<body>

    <div id="box"> </div>

    <script>
        //Make the DIV element draggagle:
        dragElement(document.getElementById("box"));

        function dragElement(elmnt) {
          var pos1 = 0, pos2 = 0, pos3 = 0, pos4 = 0;
          if (document.getElementById(elmnt.id   "header")) {
            /* if present, the header is where you move the DIV from:*/
            document.getElementById(elmnt.id   "header").onmousedown = dragMouseDown;
          } else {
            /* otherwise, move the DIV from anywhere inside the DIV:*/
            elmnt.onmousedown = dragMouseDown;
          }

          function dragMouseDown(e) {
            e = e || window.event;
            e.preventDefault();
            // get the mouse cursor position at startup:
            pos3 = e.clientX;
            pos4 = e.clientY;
            document.onmouseup = closeDragElement;
            // call a function whenever the cursor moves:
            document.onmousemove = elementDrag;
          }

          function elementDrag(e) {
            e = e || window.event;
            e.preventDefault();
            // calculate the new cursor position:
            pos1 = pos3 - e.clientX;
            pos2 = pos4 - e.clientY;
            pos3 = e.clientX;
            pos4 = e.clientY;
            // set the element's new position:
            elmnt.style.top = (elmnt.offsetTop - pos2)   "px";
            elmnt.style.left = (elmnt.offsetLeft - pos1)   "px";
          }

          function closeDragElement() {
            /* stop moving when mouse button is released:*/
            document.onmouseup = null;
            document.onmousemove = null;
          }
        }
        </script>
</body>