FKeymaster

FKeymaster is a simple library for defining and dispatching keyboard shortcuts. It has no dependencies. It's a fork of keymaster.js.

Demonstration

See live demo.

Basic concept

One global method is exposed, key which assign keys when called directly.

At any point in time (even in code other than key handlers), you can query the key object for the state of modifier keys. This allows easy implementation of things like shift+click handlers. For example, key.shift is true if the shift key is currently pressed.

FKeymaster understands the following modifiers:

⇧, shift, option, ⌥, alt, ctrl, control, command, and ⌘.

The following special keys can be used for keys:

backspace, tab, clear, enter, return, esc, escape, space, up, down, left, right, home, end, pageup, pagedown, del, delete and f1 through f19.

Scope

Scope is an important concept in FKeymaster. The default scope is 'all'. You can assign a key with scope or without. When you don't assign with scope, which mean that key will be activated in any scope.

Use key.setScope for switching current scope.

Assigning keys to handler function

The key assignment function has the syntax as follows:

key(KEY, [TARGET_SPEC,] HANDLER_FUNC);

Where

• KEY is the key(s) you want to bind,
• TARGET_SPEC has more complex structure please read "TARGET_SPEC" subsection below,
• HANDLER_FUNC is the handler when KEY is pressed.

Here are some quick examples:

// define short of 'a'
key('a', func);

// returning false stops the event and prevents default browser events
key('ctrl+r', function(){ alert('stopped reload!'); return false });

// multiple keys
key('command+r, ctrl+r', func);

// key with a scope
key('o, enter', 'issues', func);
key('o, enter', 'files', func);
key.setScope('issues'); // default scope is 'all'

// sequence key
key(['g', 's'], func);

// query modifier keys
if (key.shift)
  alert('shift is pressed, OMGZ!');

Assigning keys !, @, ?, ...

For keys like those, you need to use

• ! → shift+1
• @ → shift+2
• ? → shift+/

TARGET_SPEC

TARGET_SPEC can be one of

• string scope,
• array list of HTML elements for matching,
• HTML Element for matching,
• function for custom matching function,
• targetSpec an object, see below.

targetSpec is simple JavaScript object and FKeymaster stores/converts TARGET_SPEC as/to targetSpec.

It has these properties:

• scope
• match for matching, it can be one of
  • string CSS selector, FKeymaster has its own CSS selector match function, it uses this to perform matching,
  • HTML Element for matching, you can specify one element, but it will automatically be put into an array when FKeymaster processes key assignments.
  • array list of HTML elements for matching,
  • function for custom matching function, you can specify your own matching function and returns true or false to indicate if it's a match, see below for custom match function.

Here are some examples:

key('t', { match: '#elem_id' }, func);
key('t', { match: '#elem_id', scope: 'issues' }, func);
key('t', { match: '.class_name' }, func);
key('t', { match: 'textarea' }, func);
key(['t', 'd'], { match: 'input.class_name' }, func);

Handler function

The handler function is called with argument keydown event fired.

You can access more via this:

• this.key: string the triggered key, e.g. "ctrl+r"
• this.targetSpec:
  • this.targetSpec.scope: string the scope, e.g. "all".
  • this.targetSpec.match: string the CSS selector, e.g. "#issues".

For example:

key('j', { match: '.issues' }, function(event){
    // since match is a CSS selector, you can easily pass it to your favorite
    // library to select elements. This would be help when you need to do
    // something to ALL matched elements, in this case, it is elements with
    // 'issues' class.
    var $elements = $(this.targetSpec.match);

    // or you can get the target only
    var $just_target = $(event.target);

    console.log(this.key, this.targetSpec.scope);

    // ...
});

Custom match function

This works similar to handler function. A custom function should be implemented as

function myOwnMatch (event, handler) {
  // handler.targetSpec === this is true.

  // ...

  return match_or_not;
}

CoffeeScript

If you're using CoffeeScript, configuring key shortcuts couldn't be simpler:

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

Ender support

Add keymaster as a top level method to your Ender compilation.

$ ender add keymaster

Use it:

$.key('⌘+r', function () {
  alert('reload!')
})

License

• FKeymaster is (c) 2011 FKeymaster contributers and may be freely distributed under the MIT license.
• Keymaster is (c) 2011 Thomas Fuchs and may be freely distributed under the MIT license.

See the MIT-LICENSE file.