add a change indicator

glsl/files.js

@@ -143,18 +143,31 @@ Object.keys(localStorage).forEach(function(file) {
  }
});
var changeEl = document.createElement("span");
var editorEl = document.createElement("textarea");
editorEl.style  = "width: 70ex; height: 40em";
editorEl.onkeydown = function(ev) {
  if (ev.ctrlKey && ev.keyCode == 83) { // Ctrl-s
    ev.preventDefault();
    
    changeEl.textContent = "";
    files.save(files.current, editorEl.value);
  }
}
editorEl.onkeyup = function(ev) {
  if (!ev.altKey && !ev.ctrlKey) {
    if (editorEl.value != files.currentFile.content) {
      changeEl.textContent = "(changed)";
    } else {
      changeEl.textContent = "";
    }
  }
}
setFile(files.open(files.current), nameEl, editorEl);
document.body.appendChild(filesEl);
document.body.appendChild(nameEl);
document.body.appendChild(changeEl);
document.body.appendChild(editorEl);