Pro ASP.NET SignalR: Real-Time Communication in .NET with SignalR 2.1

Listing 10-116. User Input Capture Methods

function getDrawPosition(e) {    var canvasRect = document.getElementById('scratchCanvas').getBoundingClientRect();    var xPos = e.clientX - canvasRect.left;    var yPos = e.clientY - canvasRect.top;    return new Position(xPos, yPos);}function mouseMove(e) {    canvasBrushMove(getDrawPosition(e));}function mouseDown(e) {    canvasBrushDown(getDrawPosition(e));}function mouseUp(e) {    canvasBrushUp(getDrawPosition(e));}function msTouchStart(e) {    e.preventDefault();    if (firstTouch == null && e.buttons == 1) {        firstTouch = e.pointerId;        canvasBrushDown(new Position(e.clientX, e.clientY));    }}function msTouchMove(e) {    e.preventDefault();    if (firstTouch == e.pointerId) {         ...