I am using Konva to drag and detect collision, that works, but what I want to do is prevent to be able to drag over an item when the collision has been detected, I am not able to.
I know about: dragBoundFunc, but that works with absolute positioning and the haveIntersection works with the relative positioning of the elements. So that is not handy.
Sample code:
<!DOCTYPE html>
<html>
<head>
<script src="https://unpkg.com/konva@9.3.15/konva.min.js"></script>
<meta charset="utf-8" />
<title>Konva Drag and Drop Collision Detection Demo</title>
<style>
body {
margin: 0;
padding: 0;
overflow: hidden;
background-color: #f0f0f0;
}
</style>
</head>
<body>
<div id="container"></div>
<script>
var width = window.innerWidth;
var height = window.innerHeight;
var stage = new Konva.Stage({
container: 'container',
width: width,
height: height,
});
var layer = new Konva.Layer();
stage.add(layer);
function createShape() {
var group = new Konva.Group({
x: Math.random() * width,
y: Math.random() * height,
draggable: true,
});
var shape = new Konva.Rect({
width: 30 + Math.random() * 30,
height: 30 + Math.random() * 30,
fill: 'grey',
rotation: 360 * Math.random(),
name: 'fillShape',
});
group.add(shape);
var boundingBox = shape.getClientRect({ relativeTo: group });
var box = new Konva.Rect({
x: boundingBox.x,
y: boundingBox.y,
width: boundingBox.width,
height: boundingBox.height,
stroke: 'red',
strokeWidth: 1,
});
group.add(box);
return group;
}
for (var i = 0; i < 10; i++) {
layer.add(createShape());
}
layer.on('dragmove', function (e) {
var target = e.target;
var targetRect = e.target.getClientRect();
layer.children.forEach(function (group) {
// do not check intersection with itself
if (group === target) {
return;
}
if (haveIntersection(group.getClientRect(), targetRect)) {
console.log('tar', target);
console.log('tarRec', targetRect);
group.findOne('.fillShape').fill('red');
target.attrs.x(target._lastPos.x);
} else {
group.findOne('.fillShape').fill('grey');
}
});
});
function haveIntersection(r1, r2) {
return !(
r2.x > r1.x + r1.width ||
r2.x + r2.width < r1.x ||
r2.y > r1.y + r1.height ||
r2.y + r2.height < r1.y
);
}
</script>
</body>
</html>