// TODO: Rewrite to support more than one window per page.

const subwindow = document.getElementById("window");
const titlebar = document.getElementById("window-titlebar");

let dragging = false;
let prevPosX;
let prevPosY;

titlebar.addEventListener("mousedown", (event) => {
    dragging = true;
    prevPosX = event.clientX;
    prevPosY = event.clientY;
});

window.addEventListener("mousemove", (event) => {
    if (!dragging)
        return;
    const newPosX = subwindow.offsetLeft - (prevPosX - event.clientX);
    const newPosY = subwindow.offsetTop  - (prevPosY - event.clientY);
    subwindow.style.left = newPosX + "px";
    subwindow.style.top  = newPosY + "px";
    prevPosX = event.clientX;
    prevPosY = event.clientY;
});

window.addEventListener("mouseup", (_event) => {
    dragging = false;
});