library for defining and dispatching keyboard shortcuts
npm install keymasterKeymaster is a simple micro-library for defining and
dispatching keyboard shortcuts in web applications.
It has no dependencies.
*It’s a work in progress (e.g. beta), so spare me your nerdrage and instead
contribute! Patches are welcome, but they are not guaranteed to make
it in.*
Include keymaster.js in your web app*, by loading it as usual:
``html`
Keymaster has no dependencies and can be used completely standalone.
It should not interfere with any JavaScript libraries or frameworks.
_*Preferably use a minified version that fits your workflow. You can
run make to have UglifyJS (if you have it installed) create akeymaster.min.js file for you._
One global method is exposed, key which defines shortcuts when
called directly.
`javascript
// define short of 'a'
key('a', function(){ alert('you pressed a!') });
// returning false stops the event and prevents default browser events
key('ctrl+r', function(){ alert('stopped reload!'); return false });
// multiple shortcuts that do the same thing
key('⌘+r, ctrl+r', function(){ });
`
The handler method is called with two arguments set, the keydown event fired, and
an object containing, among others, the following two properties:
shortcut: a string that contains the shortcut used, e.g. ctrl+r: a string describing the scope (or all)
`javascript
key('⌘+r, ctrl+r', function(event, handler){
console.log(handler.shortcut, handler.scope);
});
// "ctrl+r", "all"
`
Keymaster understands the following modifiers:
⇧, shift, option, ⌥, alt, ctrl, control, command, and ⌘.
The following special keys can be used for shortcuts:
backspace, tab, clear, enter, return, esc, escape, space,up, down, left, right, home, end, pageup, pagedown, del, delete
and through f19.
At any point in time (even in code other than key shortcut handlers),
you can query the key object for the state of any keys. Thiskey.shift
allows easy implementation of things like shift+click handlers. For example, is true if the shift key is currently pressed.
`javascript`
if(key.shift) alert('shift is pressed, OMGZ!');
At any point in time (even in code other than key shortcut handlers),
you can query the key object for the state of any key. Thiskey.isPressed(77)
is very helpful for game development using a game loop. For example, is true if the M key is currently pressed.
`javascript`
if(key.isPressed("M")) alert('M key is pressed, can ya believe it!?');
if(key.isPressed(77)) alert('M key is pressed, can ya believe it!?');
You can also get these as an array using...
`javascript`
key.getPressedKeyCodes() // returns an array of key codes currently pressed
If you want to reuse the same shortcut for separate areas in your single page app,
Keymaster supports switching between scopes. Use the key.setScope method to set scope.
`javascript
// define shortcuts with a scope
key('o, enter', 'issues', function(){ / do something / });
key('o, enter', 'files', function(){ / do something else / });
// set the scope (only 'all' and 'issues' shortcuts will be honored)
key.setScope('issues'); // default scope is 'all'
`
By default, when an INPUT, SELECT or TEXTAREA element is focused, Keymaster doesn't process any shortcuts.
You can change this by overwriting key.filter with a new function. This function is called before
Keymaster processes shortcuts, with the keydown event as argument.
If your function returns false, then the no shortcuts will be processed.
Here's the default implementation for reference:
`javascript`
function filter(event){
var tagName = (event.target || event.srcElement).tagName;
return !(tagName == 'INPUT' || tagName == 'SELECT' || tagName == 'TEXTAREA');
}
If you only want _some_ shortcuts to work while in an input element, you can change the scope in the
key.filter function. Here's an example implementation, setting the scope to either 'input' or 'other'.true
Don't forget to return so the any shortcuts get processed.
`javascript`
key.filter = function(event){
var tagName = (event.target || event.srcElement).tagName;
key.setScope(/^(INPUT|TEXTAREA|SELECT)$/.test(tagName) ? 'input' : 'other');
return true;
}
However a more robust way to handle this is to use proper
focus and blur event handlers on your input element, and change scopes there as you see fit.
You can call `key.noConflict` to remove the `key` function from global scope and restore whatever `key` was defined to before Keymaster was loaded. Calling `key.noConflict` will return the Keymaster `key` function.
`javascript
var k = key.noConflict();
k('a', function() { / ... / });
key()
// --> TypeError: 'undefined' is not a function
`
Similar to defining shortcuts, they can be unbound using key.unbind.
`javascript
// unbind 'a' handler
key.unbind('a');
// unbind a key only for a single scope
// when no scope is specified it defaults to the current scope (key.getScope())
key.unbind('o, enter', 'issues');
key.unbind('o, enter', 'files');
`
Keymaster should work with any browser that fires keyup and keydown events,
and is tested with IE (6+), Safari, Firefox and Chrome.
See http://madrobby.github.com/keymaster/ for a live demo.
If you're using CoffeeScript, configuring key shortcuts couldn't be simpler:
`coffeescript
key 'a', -> alert('you pressed a!')
key '⌘+r, ctrl+r', ->
alert 'stopped reload!'
off
key 'o, enter', 'issues', ->
whatevs()
alert 'shift is pressed, OMGZ!' if key.shift
`
To contribute, please fork Keymaster, add your patch and tests for it (in the test/ folder) and
submit a pull request.
* Finish test suite
Keymaster is (c) 2011-2013 Thomas Fuchs and may be freely distributed under the MIT license.
See the MIT-LICENSE` file.