JSFiddle - React, Tailwind, and code Playground
HTML
<canvas id="canvas" width="500" height="500"></canvas>
JavaScript
var canvas = document.getElementById('canvas'),
ctx = canvas.getContext('2d'),
rect = {
x: 150,
y: 100,
w: 123,
h: 58
},
handlesSize = 8,
currentHandle = false,
drag = false;
function init() {
canvas.addEventListener('mousedown', mouseDown, false);
canvas.addEventListener('mouseup', mouseUp, false);
canvas.addEventListener('mousemove', mouseMove, false);
}
function point(x, y) {
return {
x: x,
y: y
};
}
function dist(p1, p2) {
return Math.sqrt((p2.x - p1.x) * (p2.x - p1.x) + (p2.y - p1.y) * (p2.y - p1.y));
}
function getHandle(mouse) {
if (dist(mouse, point(rect.x, rect.y)) <= handlesSize) return 'topleft';
if (dist(mouse, point(rect.x + rect.w, rect.y)) <= handlesSize) return 'topright';
if (dist(mouse, point(rect.x, rect.y + rect.h)) <= handlesSize) return 'bottomleft';
if (dist(mouse, point(rect.x + rect.w, rect.y + rect.h)) <= handlesSize) return 'bottomright';
if (dist(mouse, point(rect.x + rect.w / 2, rect.y)) <= handlesSize) return 'top';
if (dist(mouse, point(rect.x, rect.y + rect.h / 2)) <= handlesSize) return 'left';
if (dist(mouse, point(rect.x + rect.w / 2, rect.y + rect.h)) <= handlesSize) return 'bottom';
if (dist(mouse, point(rect.x + rect.w, rect.y + rect.h / 2)) <= handlesSize) return 'right';
return false;
}
function mouseDown(e) {
if (currentHandle) drag = true;
draw();
}
function mouseUp() {
drag = false;
currentHandle = false;
draw();
}
function mouseMove(e) {
var previousHandle = currentHandle;
if (!drag) currentHandle = getHandle(point(e.pageX - this.offsetLeft, e.pageY - this.offsetTop));
if (currentHandle && drag) {
var mousePos = point(e.pageX - this.offsetLeft, e.pageY - this.offsetTop);
switch (currentHandle) {
case 'topleft':
rect.w += rect.x - mousePos.x;
rect.h += rect.y - mousePos.y;
...