teach/public/js/app.js

/* teach - start: beeldgrootte, contrast, sessie-herstel */
/* =========================================================
   init
==========================================================*/
/* display size: scale the whole app up for pupils who need it (device setting) */
let ZOOM = 100;
const btnZoomIn = document.getElementById("btnZoomIn");
const btnZoomOut = document.getElementById("btnZoomOut");
const zoomPct = document.getElementById("zoomPct");
function setZoom(z){
  ZOOM = Math.max(100, Math.min(200, Math.round(z/10)*10));
  document.body.style.zoom = ZOOM/100;
  zoomPct.textContent = ZOOM+"%";
  zoomPct.classList.toggle("on", ZOOM!==100);
  btnZoomIn.title = btnZoomOut.title = zoomPct.title = T("zoomUI");
  btnZoomIn.disabled = ZOOM>=200;
  btnZoomOut.disabled = ZOOM<=100;
  try{ localStorage.setItem("teach.zoom", ZOOM); }catch(e){}
}
btnZoomIn.addEventListener("click", ()=>setZoom(ZOOM+10));
btnZoomOut.addEventListener("click", ()=>setZoom(ZOOM-10));
zoomPct.addEventListener("click", ()=>setZoom(100));   /* tap the % to reset */
document.addEventListener("langchange", ()=>{ btnZoomIn.title = btnZoomOut.title = zoomPct.title = T("zoomUI"); });
try{ const z = +localStorage.getItem("teach.zoom"); if(z>100) setZoom(z); else setZoom(100); }catch(e){ setZoom(100); }

/* weergave-instellingen (Instellingen → Weergave): apparaat-gebonden voorkeuren.
   Elke seg-groep: knopjes met data-v, keuze in localStorage, body-class toepassen. */
function initSeg(id, key, def, apply){
  const seg = document.getElementById(id);
  let val = def;
  try{ val = localStorage.getItem(key) || def; }catch(e){}
  if(![...seg.querySelectorAll("button")].some(b=>b.dataset.v===val)) val = def;
  const set = v=>{
    seg.querySelectorAll("button").forEach(b=>b.classList.toggle("active", b.dataset.v===v));
    apply(v);
    try{ localStorage.setItem(key, v); }catch(e){}
  };
  seg.querySelectorAll("button").forEach(b=>b.addEventListener("click", ()=>set(b.dataset.v)));
  set(val);
}
/* thema: licht / donker / automatisch (volgt het OS) */
const darkMq = window.matchMedia("(prefers-color-scheme: dark)");
const applyTheme = v=>{
  document.body.classList.toggle("dark", v==="dark" || (v==="auto" && darkMq.matches));
};
initSeg("segTheme", "teach.theme", "light", applyTheme);
darkMq.addEventListener("change", ()=>{
  try{ if((localStorage.getItem("teach.theme")||"light")==="auto") applyTheme("auto"); }catch(e){}
});
/* hoog contrast (voorheen de 👁-knop in de menubalk; zelfde localStorage-sleutel) */
(function(){
  let init = "off";
  try{ if(localStorage.getItem("teach.hc")==="1") init = "on"; }catch(e){}
  const seg = document.getElementById("segHC");
  const set = v=>{
    seg.querySelectorAll("button").forEach(b=>b.classList.toggle("active", b.dataset.v===v));
    document.body.classList.toggle("hc", v==="on");
    try{ localStorage.setItem("teach.hc", v==="on" ? "1" : ""); }catch(e){}
  };
  seg.querySelectorAll("button").forEach(b=>b.addEventListener("click", ()=>set(b.dataset.v)));
  set(init);
})();
/* menubalk-positie: boven / links / rechts */
initSeg("segTbar", "teach.tbar", "top", v=>{
  document.body.classList.toggle("tb-left", v==="left");
  document.body.classList.toggle("tb-right", v==="right");
});
/* minder beweging: standaard uit als het OS erom vraagt */
const motionDef = window.matchMedia("(prefers-reduced-motion: reduce)").matches ? "off" : "on";
initSeg("segMotion", "teach.motion", motionDef, v=>document.body.classList.toggle("no-motion", v==="off"));
/* glas-effect (transparantie/blur van widgets en balken) */
initSeg("segGlass", "teach.glass", "on", v=>document.body.classList.toggle("no-glass", v==="off"));

/* taalkeuze onthouden (de schakelaar staat nu onder Weergave) */
try{
  const l = localStorage.getItem("teach.lang");
  if(l && I18N[l]) LANG = l;
}catch(e){}

applyI18n();
updateEmptyHint();
/* sessie herstellen: geldig servertoken? dan opnieuw inloggen zonder wachtwoord */
(async function(){
  updateBoardsUI();
  if(!TOKEN) return;
  try{
    const me = await api("/auth/me");
    currentUser = me.user;
    updateUserUI();
    await hydrateFromServer();
  }catch(e){
    resetToGuest();
  }
})();