autoindent

autoindent.uc.js

// ==UserScript==
// @name    autoindent
// @desc    Performs basic auto-indentation on ENTER.
// @include main
// @include chrome://xqjs/content/xqjs.xul
// @include chrome://stylish/content/edit.xul
// @include chrome://keyconfig/content/edit.xul
// @include chrome://firegestures/content/edit.xul
// @compat  Fx3.6+
// @author  satyr
// ==/UserScript==
autoindent.chars = /^[ \t\u3000]*([ \t\u3000#@>=|*/+-])\1*[ \t\u3000]{0,}/
function autoindent(ev){
  if(ev.shiftKey || ev.ctrlKey || ev.altKey || ev.metaKey ||
     ev.keyCode != ev.DOM_VK_RETURN) return
  var tb = ev.originalTarget
  if(!(tb instanceof HTMLTextAreaElement)) return
  var {value, selectionStart: pos} = tb = XPCNativeWrapper(tb)
  var line = value.slice(value.lastIndexOf('\n', pos - 1) + 1, pos)
  if(!autoindent.chars.test(line)) return
  var indent = RegExp.lastMatch
  tb.selectionStart -= /\s*$/.exec(RegExp.rightContext)[0].length
  tb instanceof Ci.nsIDOMNSEditableElement
  tb.editor.QueryInterface(Ci.nsIPlaintextEditor).insertText('\n'+ indent)
  ev.preventDefault()
  ev.stopPropagation()
}
addEventListener('keypress', autoindent, false)