HTML5 Canvas Mobile Touch Events Tutorial

To bind event handlers to shapes on a mobile device with Konva, we can use the on() method.
The on() method requires an event type and a function to be executed when the event occurs.
Konva supports touchstart, touchmove, touchend, tap, dbltap, dragstart, dragmove, and dragend mobile events.

Note: This example only works on iOS and Android mobile devices because it makes use of touch events rather than mouse events.

Instructions: move your finger across the triangle to see touch coordinates and touch start and touch end the circle.

Konva Mobile_Events Demoview raw
<!DOCTYPE html>
<html>
<head>
<script src="https://cdn.rawgit.com/konvajs/konva/1.7.2/konva.min.js"></script>
<meta charset="utf-8">
<title>Konva Mobile Touch Events Demo</title>
<style>
body {
margin: 0;
padding: 0;
overflow: hidden;
background-color: #F0F0F0;
}
</style>
</head>
<body>
<div id="container"></div>
<script>
function writeMessage(message) {
text.setText(message);
layer.draw();
}
var stage = new Konva.Stage({
container: 'container',
width: 300,
height: 300
});
var layer = new Konva.Layer();
var triangle = new Konva.RegularPolygon({
x: 80,
y: 120,
sides: 3,
radius: 80,
fill: '#00D2FF',
stroke: 'black',
strokeWidth: 4
});
var text = new Konva.Text({
x: 10,
y: 10,
fontFamily: 'Calibri',
fontSize: 24,
text: '',
fill: 'black'
});
var circle = new Konva.Circle({
x: 230,
y: 100,
radius: 60,
fill: 'red',
stroke: 'black',
strokeWidth: 4
});
triangle.on('touchmove', function() {
var touchPos = stage.getPointerPosition();
var x = touchPos.x - 190;
var y = touchPos.y - 40;
writeMessage('x: ' + x + ', y: ' + y);
});
circle.on('touchstart', function() {
writeMessage('Touchstart circle');
});
circle.on('touchend', function() {
writeMessage('Touchend circle');
});
layer.add(triangle);
layer.add(circle);
layer.add(text);
// add the layer to the stage
stage.add(layer);
</script>
</body>
</html>