Bookmarklet to hide DOM elements

hide-dom-elements.js

/*
Bookmarklet to hide DOM elements
Left-click: hide element
Right-click: undo last hide
Middle-click: stop altering document

JSBin: http://jsbin.com/nimilu/
Convert to a bookmarklet here: http://ted.mielczarek.org/code/mozilla/bookmarklet.html
*/

(function(){
  var doc = document.querySelector('html');
  var originalState = [];
  
  function hide(e){
    switch (e.button) {
      case 0: // Left
        if (e.target !== doc) { // Don't hide the main document
          originalState.push({el: e.target, display: e.target.style.display});
          e.target.style.display = 'none';
        }
        break;
      case 1: // Middle
        doc.removeEventListener('mouseup',hide, false);
        doc.removeEventListener('contextmenu', prevent, false);
        break;
      case 2: // Right
        if (originalState.length > 0) {
          var state = originalState.pop();
          state.el.style.display = state.display;
        }
        break;
    }
    e.preventDefault();
  }
  
  function prevent(e){
    e.preventDefault();
    return false;
  }
  
  doc.addEventListener('mouseup',hide, false);  
  doc.addEventListener('contextmenu', prevent, false);
})();