angular-hotkeys

Configuration-centric keyboard shortcuts for your Angular apps.

Requirements: Angular 1.2+

Features:

• Define hotkeys on an entire route, automatically binding and unbinding them as you navigate
• Automatic listing of shortcuts when users hit the ? key
• Super duper unit tests

Installation:

via bower:

$ bower install chieffancypants/angular-hotkeys --save

via npm:

$ npm install angular-hotkeys --save

please use either the minified or unminified file in the build directory

Why I made this:

Other projects out there rely too heavily on HTML markup for keyboard shortcuts. For example:

<div class="player">
  <div class="playPause-btn" shortcut="{space: playPause}"></div>
  <div class="mute-btn" shortcut="{'ctrl+down': mute}"></div>
</div>

While this is a great approach for many Angular apps, some applications do not have a 1 to 1 relationship between DOM elements and controller methods. In my case, many methods on the controller were only accessible through the keyboard.

Additionally, this only allows you to pass a function reference, you can't pass arguments to the function you intend to call. So instead of simply calling seek(currentTime + 30) and seek(currentTime + 60), I needed to create a ton of helper functions on the scope (such as forward30 and forward60), and litter my HTML like this:

<div class="player" shortcut="{space: playPause,
                              'alt+right': forward30,
                              'ctrl+right': forward60,
                              'left': back30,
                              'ctrl+left': back60,
                              up: volumeUp,
                              down: volumeDown,
                              'ctrl+down': mute,
                              'ctrl+up': unmute,
                              f: fullscreen,
                              h: showHelp}">
  <div class="playPause-btn"></div>
  <div class="mute-btn"></div>
</div>

With a few dozen shortcuts, this left the DOM really messy, and with multiple views and directive templates, it was next to impossible to remember where all the different shortcuts were. This became a maintenance nightmare.

Usage:

You can either define hotkeys in your Controller, or in your Route configuration (or both). To start, though, require the lib as a dependency for your angular app:

angular.module('myApp', ['ngRoute', 'cfp.hotkeys']);

Behind the scenes, I'm using the Mousetrap library to manage the key bindings. Check out the docs there for more information on what kind of key combinations can be used. This library is included in the files from the build directory, so there is no need to install and include Mousetrap separately.

Binding hotkeys in controllers:

It is important to note that by default, hotkeys bound using the hotkeys.add() method are persistent, meaning they will continue to exist through route changes, DOM manipulation, or anything else.

However, it is possible to bind the hotkey to a particular scope, and when that scope is destroyed, the hotkey is automatically removed. This should be considered the best practice when binding hotkeys from a controller. For this usage example, see the hotkeys.bindTo() method below:

angular.module('myApp').controller('NavbarCtrl', function($scope, hotkeys) {
  $scope.volume = 5;

  // You can pass it an object.  This hotkey will not be unbound unless manually removed
  // using the hotkeys.del() method
  hotkeys.add({
    combo: 'ctrl+up',
    description: 'This one goes to 11',
    callback: function() {
      $scope.volume += 1;
    }
  });

  // when you bind it to the controller's scope, it will automatically unbind
  // the hotkey when the scope is destroyed (due to ng-if or something that changes the DOM)
  hotkeys.bindTo($scope)
    .add({
      combo: 'w',
      description: 'blah blah',
      callback: function() {}
    })
    // you can chain these methods for ease of use:
    .add ({...});

});

Binding hotkeys in routes:

You can also define hotkeys on an entire route, and this lib will bind and unbind them as you navigate the app.

angular.module('myApp').config(function ($routeProvider) {
  $routeProvider.when('/', {
    controller: 'RestaurantsController',
    templateUrl: 'views/restaurants.html',
    hotkeys: [
      ['p', 'Sort by price', 'sort(price)']
    ]
  });
});

Binding hotkeys in directives:

Lastly, even though binding hotkeys in your templates/html tends to be a bad idea, it can be super useful for simple shortcuts. Think along the lines of a modal directive where you simply want to bind to the escape key or something equally simple. Accomplishing this within a controller is too much overhead, and it may lead to code-reuse.

Example of how directive-based hotkeys works:

<modal title="Modal Title" hotkey="{esc: close}">

Configuration

Disable the cheatsheet:

Disabling the cheatsheet can be accomplished by configuring the hotkeysProvider:

angular.module('myApp', ['cfp.hotkeys'])
  .config(function(hotkeysProvider) {
    hotkeysProvider.includeCheatSheet = false;
  })

Cheatsheet template:

angular.module('myApp', ['cfp.hotkeys'])
  .config(function(hotkeysProvider) {
    hotkeysProvider.template = '<div class="my-own-cheatsheet">...</div>';
  })

API

hotkeys.add(object)

object: An object with the following parameters:

• combo: They keyboard combo (shortcut) you want to bind to
• description: [OPTIONAL] The description for what the combo does and is only used for the Cheat Sheet. If it is not supplied, it will not show up, and in effect, allows you to have unlisted hotkeys.
• callback: The function to execute when the key(s) are pressed. Passes along two arguments, event and hotkey
• action: [OPTIONAL] The type of event to listen for, such as keypress, keydown or keyup. Usage of this parameter is discouraged as the underlying library will pick the most suitable option automatically. This should only be necessary in advanced situations.
• allowIn: [OPTIONAL] an array of tag names to allow this combo in ('INPUT', 'SELECT', and/or 'TEXTAREA')

hotkeys.add({
  combo: 'ctrl+w',
  description: 'Description goes here',
  callback: function(event, hotkey) {
    event.preventDefault();
  }
});

// this hotkey will not show up on the cheat sheet:
hotkeys.add({
  combo: 'ctrl+x',
  callback: function(event, hotkey) {...}
});

hotkeys.get(key)

Returns the Hotkey object

hotkeys.get('ctrl+w');
// -> Hotkey { combo: ['ctrl+w'], description: 'Description goes here', callback: function (event, hotkey) }

hotkeys.del(key)

Removes and unbinds a hotkey

hotkeys.del('ctrl+w');

Allowing hotkeys in form elements

By default, Mousetrap prevents hotkey callbacks from firing when their event originates from an input, select, or textarea element. To enable hotkeys in these elements, specify them in the allowIn parameter:

hotkeys.add({
  combo: 'ctrl+w',
  description: 'Description goes here',
  allowIn: ['INPUT', 'SELECT', 'TEXTAREA'],
  callback: function(event, hotkey) {
    event.preventDefault();
  }
});

Credits:

Muchas gracias to Craig Campbell for his Mousetrap library, which provides the underlying library for handling keyboard shortcuts.