HTML5 Canvas Shape Events

To detect shape events with Konva, we can use the on() method to bind event handlers to a node.

The on() method requires an event type and a function to be executed when the event occurs.

Mouse events: mouseover, mouseout, mouseenter, mouseleave, mousemove, mousedown, mouseup, wheel, click, dblclick.

Touch events: touchstart, touchmove, touchend, tap, dbltap.

Pointer events: pointerdown, pointermove, pointereup, pointercancel, pointerover, pointerenter, pointerout,pointerleave, pointerclick, pointerdblclick.

Drag events: dragstart, dragmove, and dragend.

Transform events: transformstart, transform, transformend.

Instructions: Mouseover and mouseout of the triangle, and mouseover, mouseout, mousedown, and mouseup over the circle.

Konva Binding_Events Demoview raw
<!DOCTYPE html>
<html>
<head>
<script src="https://unpkg.com/[email protected]/konva.min.js"></script>
<meta charset="utf-8" />
<title>Konva Shape 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.text(message);
}

var stage = new Konva.Stage({
container: 'container',
width: window.innerWidth,
height: window.innerHeight,
});

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',
});

triangle.on('mouseout', function () {
writeMessage('Mouseout triangle');
});

triangle.on('mousemove', function () {
var mousePos = stage.getPointerPosition();
writeMessage('x: ' + mousePos.x + ', y: ' + mousePos.y);
});

var circle = new Konva.Circle({
x: 230,
y: 100,
radius: 60,
fill: 'red',
stroke: 'black',
strokeWidth: 4,
});

circle.on('mouseover', function () {
writeMessage('Mouseover circle');
});
circle.on('mouseout', function () {
writeMessage('Mouseout circle');
});
circle.on('mousedown', function () {
writeMessage('Mousedown circle');
});
circle.on('mouseup', function () {
writeMessage('Mouseup circle');
});

layer.add(triangle);
layer.add(circle);
layer.add(text);

// add the layer to the stage
stage.add(layer);
</script>
</body>
</html>
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