yckart/LICENSE.txt

## README.md

      
    Raw
  

              README.md
            
          
    Undo and redo is a fairly interesting and surprisingly difficult concept to implement in an application. Thanks to the way javascript treats functions, it isn't too hard to come up with a general and powerful approach for javascript apps.
undone([
  function () {
    // undo
  },
  function () {
    // redo
  }
]);

undone(0); // => undo
undone(1); // => redo

  
## annotated.js
function (a, b) {
  a = [
    [], // undo stack
    []  // redo stack
  ];
  return function (c) {
    // it's an array
    c[0] ? (
      // reset the redo stack
      a[1] = [],

      // add the action to our undo stack
      a[0].push(c),

      // call the undo function
      c[0]()
    ) : (
      b = a[c] // assign undo/redo stack
        .pop() // and remove last stack from it
               // if it doesn't exist, stop here
    ) && (
      a[+!c] // negate `c`
      .push(b), // push the negated stack to its complementary stack
      b[+!c]() // call it
    )
  }
}()

## index.js
function(a,b){a=[[],[]];return function(c){c[0]?(a[1]=[],a[0].push(c),c[0]()):(b=a[c].pop())&&(a[+!c].push(b),b[+!c]())}}()

## LICENSE.txt
            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
                    Version 2, December 2004

 Copyright (C) 2011 YOUR_NAME_HERE <YOUR_URL_HERE>

 Everyone is permitted to copy and distribute verbatim or modified
 copies of this license document, and changing it is allowed as long
 as the name is changed.

            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

  0. You just DO WHAT THE FUCK YOU WANT TO.

## package.json
{
  "name": "undo / redo manager",

  "description": "A really simple command stack, with undo/redo functionality.",

  "keywords": [
    "undo",
    "redo",
    "command",
    "stack",
    "function"
  ]
}

## test.html
<!DOCTYPE html>
<title>Foo</title>
<div>CTRL + Z: <b>undo</b></div>
<div>CTRL + Y: <b>redo</b></div>
<script>
  var undone = function(a,b){a=[[],[]];return function(c){c[0]?(a[1]=[],a[0].push(c),c[0]()):(b=a[c].pop())&&(a[+!c].push(b),b[+!c]())}}()

  var css = function (elem, prop, value) {
    var redo = elem.style[prop];
    undone([
      // undo
      function () {
        elem.style[prop] = value;
      },
      // redo
      function () {
        elem.style[prop] = redo;
      }
    ]);
  };

  var body = document.body;
  css(body, 'background', 'gold');
  css(body, 'background', 'tomato');
  css(body, 'background', 'yellowgreen');
  css(body, 'background', 'darkturquoise');

  document.onkeydown = function (e) {
    if (!e.ctrlKey || e.which < 89 || e.which > 90) return;
    undone(90 - e.which);
  };
</script>
	function (a, b) {
	a = [
	[], // undo stack
	[] // redo stack
	];
	return function (c) {
	// it's an array
	c[0] ? (
	// reset the redo stack
	a[1] = [],

	// add the action to our undo stack
	a[0].push(c),

	// call the undo function
	c[0]()
	) : (
	b = a[c] // assign undo/redo stack
	.pop() // and remove last stack from it
	// if it doesn't exist, stop here
	) && (
	a[+!c] // negate `c`
	.push(b), // push the negated stack to its complementary stack
	b[+!c]() // call it
	)
	}
	}()
	DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
	Version 2, December 2004

	Copyright (C) 2011 YOUR_NAME_HERE <YOUR_URL_HERE>

	Everyone is permitted to copy and distribute verbatim or modified
	copies of this license document, and changing it is allowed as long
	as the name is changed.

	DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
	TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

	0. You just DO WHAT THE FUCK YOU WANT TO.
	{
	"name": "undo / redo manager",

	"description": "A really simple command stack, with undo/redo functionality.",

	"keywords": [
	"undo",
	"redo",
	"command",
	"stack",
	"function"
	]
	}
	<!DOCTYPE html>
	<title>Foo</title>
	<div>CTRL + Z: <b>undo</b></div>
	<div>CTRL + Y: <b>redo</b></div>
	<script>
	var undone = function(a,b){a=[[],[]];return function(c){c[0]?(a[1]=[],a[0].push(c),c[0]()):(b=a[c].pop())&&(a[+!c].push(b),b[+!c]())}}()

	var css = function (elem, prop, value) {
	var redo = elem.style[prop];
	undone([
	// undo
	function () {
	elem.style[prop] = value;
	},
	// redo
	function () {
	elem.style[prop] = redo;
	}
	]);
	};

	var body = document.body;
	css(body, 'background', 'gold');
	css(body, 'background', 'tomato');
	css(body, 'background', 'yellowgreen');
	css(body, 'background', 'darkturquoise');

	document.onkeydown = function (e) {
	if (!e.ctrlKey \|\| e.which < 89 \|\| e.which > 90) return;
	undone(90 - e.which);
	};
	</script>