ng-keyboard-shortcuts

An Angular module that provides a declarative API using components/directive to manage Keyboard shortcuts in scalable way.

This documentation is for version 7.0.0+ (8,9) and any future versions. For older versions (2.0.0/6.0.0) please click here

See demo here:
demo

important note

We recommend to update to version 7.0.0 and above and use the new component API which has a better memory management than previous version.

Compatible with Angular 5+

Install:

npm install --save ng-keyboard-shortcuts

or yarn

yarn add ng-keyboard-shortcuts

Setup:

import { KeyboardShortcutsModule }     from 'ng-keyboard-shortcuts';  

@NgModule({  
    declarations: [  
    ],  
    imports: [  
        BrowserModule,  
        KeyboardShortcutsModule.forRoot()  
    ],  
    bootstrap: [AppComponent]  
})  
export class AppModule {  
}  

Usage:

Combinations

key combinations are used with meta keys like control, shift, command, etc... and are defined using plus(+) sign as a separator. there can be multiple combinations for the same command, so either of the key combination will trigger the callback. Since combinations uses the plus sign as a seperator, if you want to bind to the actual + charachater, you will need to use "plus" instead.

Examples:

   [
       {
            key: ["cmd + a"],
            command: (output: ShortcutEventOutput) => console.log("command + a", output),
        },
        {
            key: "ctrl + a",
            preventDefault: true,
            command: (output: ShortcutEventOutput) => console.log("control + a", output),

        },
        {
            key: "ctrl + plus",
            preventDefault: true,
            command: (output: ShortcutEventOutput) => console.log("control + plus key", output),
        }
    ]

Sequences

Sequences can be used to support gmail like actions where you click "g" then "a", or "g" then "o" to perform certain actions.

Important note

The library can get very confused if you have a single key handler that uses the same key that a sequence starts with. This is because it can't tell if you are starting the sequence or if you are pressing that key on its own.

To counter this, there is a 500ms delay(only when single key is used in the beginning of another sequence, so it won't affect performance) . This gives the library time to wait for a more complete sequence, otherwise the single sequence will be triggered.

for example: binding both "? a" and "?", then clicking "?" will trigger the "?" callback, but only after 500ms delay. However, in all other cases there's no delay in execution of the callback (unless debounceTime is provided)

Examples:

This library supports gmail style sequences:

   [{
        key: ["g a"],
        command: (output: ShortcutEventOutput) => console.log("? a", output),
    }]

konami code:

    [{
         key: ["up up down down left right left right b a enter"],
         label: "Sequences",
         description: "Konami code!",
         command: (output: ShortcutEventOutput) => console.log("Konami code!!!", output),
    }]

Sequences can be used inside components or directives and are declared without the plus(+) sign, for example: key: ["a b c"] will require clicking, a, then b, then c.

Components:

ng-keyboard-shortcuts

Component that can be used across the app to bind to various shortcuts

Inputs:

Name Type Default Description
shortcuts ShortcutInput / ShortcutInput[] [] List of shortcut inputs types see types
disabled boolean false disable the shortcuts for the component

Methods:

Name Input Return Description
select string - key to listen to events (example: 'cmd + e') Observable<ShortcutEventOutput> Listen to specific key events (will only work for registered keys)

import { AfterViewInit, Component, ElementRef, OnInit, ViewChild } from "@angular/core";  
import { ShortcutInput, ShortcutEventOutput, KeyboardShortcutsComponent } from "ng-keyboard-shortcuts";  

@Component({  
    selector: 'demo-component',  
    template: "<ng-keyboard-shortcuts [shortcuts]="shortcuts"></ng-keyboard-shortcuts>"  
})  
export class DemoComponent implements AfterViewInit {  

    shortcuts: ShortcutInput[] = [];  
    @ViewChild('input') input: ElementRef;  

    ngAfterViewInit(): void {  
        this.shortcuts.push(  
            {  
                key: "ctrl + t",  
                preventDefault: true,  
                allowIn: [AllowIn.Textarea, AllowIn.Input],  
                command: e => console.log("clicked " , e.key)  
            },
           {
                key: ["? a"],
                label: "Sequences",
                description: "Sequence ? and a",
                command: (output: ShortcutEventOutput) => console.log("? a", output),
                preventDefault: true
            },            
            {
                key: ["up up down down left right left right b a enter"],
                label: "Sequences",
                description: "Konami code!",
                command: (output: ShortcutEventOutput) => console.log("Konami code!!!", output),
            },
            {  
                key: "cmd + shift + f",  
                command: (output: ShortcutEventOutput) => console.log(output),  
                preventDefault: true,  
                throttleTime: 250,  
                target: this.input.nativeElement  
            },  
            {  
                key: ["cmd + =", "cmd + z"],  
                command: (output: ShortcutEventOutput) => console.log(output),  
                preventDefault: true  
            },  
            {  
                key: "cmd + f",  
                command: (output: ShortcutEventOutput) => console.log(output),  
                preventDefault: true  
            }  
        );  

        this.keyboard.select("cmd + f").subscribe(e => console.log(e));  
    }  

    @ViewChild(KeyboardShortcutsComponent) private keyboard: KeyboardShortcutsComponent;  

}  

ng-keyboard-shortcuts-help

  1. Make sure to install @angular/animations ( npm install --save @angular/animations or yarn add @angular/animations
  2. Add BrowserAnimationsModule to your app.module imports

Can be used to show an help screen ( will be attached to body and be shown as a modal)

Should be placed in the root of your app, preferably in app.component.html

Inputs

Name Type default description
key string none The key to show/hide the help modal
keyDescription string none Description to show in the menu shortcut list for the toggle shortcut
keyLabel string none Label that can be used to group shortcuts together in the help menu
closeKey string none Close key to be used to close the modal
closeKeyDescription string none Description to show in the menu shortcut list for closing the modal shortcut
closeKeyLabel string none Label that can be used to group shortcuts together in the help menu
title string "Keyboard shortcuts" The title of the help screen
emptyMessage string "No shortcuts available" What message to show when no commands are registered when help modal is opened.
disableScrolling boolean true Whether to disable body scrolling when modal help screen is opened.

Methods:

Name Input Return Description
hide void KeyboardShortcutsHelpComponent Programmatically hide the modal
reveal void KeyboardShortcutsHelpComponent Programmatically hide the modal
visible void boolean Check whether the modal is visible or not.
toggle void KeyboardShortcutsHelpComponent Programmatically toggle the modal visibility

Methods:

Name Input Return Description
select string - key to listen to events (example: 'cmd + e') Observable<ShortcutEventOutput> Listen to specific key events (will only work for registered keys)

app.component.ts

import { Component } from "@angular/core";  

@Component({  
  selector: "app-root",  
  template: "./app.component.html",  
  styleUrls: ["./app.component.css"]  
})  
export class AppComponent {  
  title = "Hello";  
}  

app.component.html

<div style="text-align:center">  
   <h1>  
      Welcome to {{ title }}!  
   </h1>  
   <ng-keyboard-shortcuts-help [key]="'f1'" [closeKey]="'escape'" [title]="Help"></ng-keyboard-shortcut-help>  
</div>  

Directive

ngKeyboardShortcut

Directive that can only be used for focusable elements, such as textarea, select, input, etc...

Inputs

Name Type default description
ngKeyboardShortcut Shortcut / Shortcut [] List of shortcuts see types
disabled boolean false disable the shortcuts for the directive
disableScrolling boolean true disable body scrolling while modal is open

Example

import { AfterViewInit, Component, ElementRef, OnInit, ViewChild } from "@angular/core";  
import { ShortcutInput, ShortcutEventOutput, KeyboardShortcutsComponent } from "ng-keyboard-shortcuts";  

@Component({  
    selector: 'demo-component',  
    template: "<input [ngKeyboardShortcut]="shortcuts" />"  
})  
export class DemoComponent implements AfterViewInit {  

    shortcuts: ShortcutInput[] = [];  
    @ViewChild('input') input: ElementRef;  

    ngAfterViewInit(): void {  
        this.shortcuts.push({  
            key: "cmd + e",  
            label: "test",  
            description: "hello world",  
            command: () => console.log('directive cmd + e'),  
            preventDefault: true  
        });  

        this.keyboard.select("cmd + f").subscribe(e => console.log(e));  
    }  

    @ViewChild(KeyboardShortcutsComponent) private keyboard: KeyboardShortcutsComponent;  

}  

Service

KeyboardShortcutsHelpService

Singleton service that can be used to render a custom help screen. (used to build the Built in help component) Provides access to all registered shortcuts in the app using Observable that updates on shortcuts changes.
Since shortcuts can be added or removed during the lifecycle of the app, an observable data structure needed to be used.

properties type description
shortcuts$ Observable<{ key: string, label: string, description: string }[]> Array of registered shortcuts across the whole app

KeyboardShortcutsSelectService

A singleton service that can be used globally to listen to any registered shortcut: | Name | Input | Return | Description |
|----------|:------|:------:|:-------------:|
| select | string - key to listen to events (example: 'cmd + e') | Observable<ShortcutEventOutput> |Listen to specific key events (will only work for registered keys) |

API:

Types:

AllowIn

export enum AllowIn {  
    Textarea = 'TEXTAREA',  
    Input = 'INPUT',  
    Select = "SELECT"  
}  

Shortcut

Used for Directive input

export interface Shortcut {  

    key: string | string[];  

    /**  
     * callback to be called when shortcut is pressed.  
     * @param event - the event out  
     */  
    command(event: ShortcutEventOutput): any;  

    /**  
     * Description for the command can be used for rendering help menu.  
     */  
    description?: string;  

    /**  
     * How much time to throttle in ms.  
     */  
    throttleTime?: number;  

    /**  
     * Label, can be used for grouping commands.  
     */  
    label?: string;  

    /**  
     * Prevent browser default, default: false  
     */  
    preventDefault?: boolean;  
}  

ShortcutInput

Used for the component as input.

export interface ShortcutInput extends Shortcut {  
    /**  
     * textarea, select and input are ignored by default, this is used to override  
     * this behavior.  
     * allow in node names, accepts: ["TEXTAREA", "SELECT", "INPUT]  
     */  
    allowIn?: AllowIn[];  
    /**  
     * Only trigger the command when the target is in focus.  
     */  
    target?: HTMLElement;  
}  

ShortcutEventOutput

type = ShortcutEventOutput {  
    event: KeyboardEvent;  
    key: string | string[];  
}  

Building

npm run build-lib

Publishing

  1. npm run build-lib
  2. npm publish dist/ng-keyboard-shortcuts

License

This project is licensed under the MIT License - see the LICENSE.md file for details

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