import { createMachine, assign, interpret } from "xstate"; const elBox = document.querySelector("#box"); const elBody = document.body; const assignPoint = assign({ px: (context, event) => event.clientX, py: (context, event) => event.clientY, }); const assignPosition = assign({ x: (context, event) => { return context.x + context.dx; }, y: (context, event) => { return context.y + context.dy; }, dx: 0, dy: 0, px: 0, py: 0, }); const assignDelta = assign({ dx: (context, event) => { return event.clientX - context.px; }, dy: (context, event) => { return event.clientY - context.py; }, }); const resetPosition = assign({ dx: 0, dy: 0, px: 0, py: 0, }); const dragDropMachine = createMachine( { initial: "idle", context: { x: 0, y: 0, dx: 0, dy: 0, px: 0, py: 0, }, states: { idle: { on: { mousedown: { actions: assignPoint, target: "dragging", }, }, }, dragging: { // cancel the dragging after 2 seconds after: { DRAGGING_TIMEOUT: { target: "idle",
actions: resetPosition }, }, on: { mousemove: { actions: assignDelta, internal: false, }, mouseup: { actions: [assignPosition], target: "idle", }, "keyup.escape": { target: "idle", actions: resetPosition, }, }, // Transition to 'idle' after 2 seconds // using a delayed transition. // ... }, }, }, { delays: { DRAGGING_TIMEOUT: 2000, }, } ); const service = interpret(dragDropMachine); service.onTransition((state) => { elBox.dataset.state = state.value; if (state.changed) { elBox.style.setProperty("--dx", state.context.dx); elBox.style.setProperty("--dy", state.context.dy); elBox.style.setProperty("--x", state.context.x); elBox.style.setProperty("--y", state.context.y); } }); service.start(); elBox.addEventListener("mousedown", (event) => { service.send(event); }); elBody.addEventListener("mousemove", (event) => { service.send(event); }); elBody.addEventListener("mouseup", (event) => { service.send(event); }); elBody.addEventListener("keyup", (e) => { if (e.key === "Escape") { service.send("keyup.escape"); } });