piano-chart v1.5.0

piano-chart — JavaScript library to visualize musical notes on a piano keyboard

The purpose of piano-chart is to allow developers to include visual representation of musical notes on a piano keyboard.

Installation

npm install piano-chart

or

yarn add piano-chart

Usage

The basics

All you need to do to display your notes on a piano chart is create the instrument by specifying a container to render into, and then tell it what notes to "press". Here's how you would show a D Major chord in 4th octave:

import { Instrument } from "piano-chart";

const piano = new Instrument(document.getElementById('pianoContainer'));
piano.create();

piano.keyDown("D4");
piano.keyDown("F#4");
piano.keyDown("A4");

And you should get this:

Configuration

As you can see it's very easy to get a simple piano chart. But there are more things you can customize to your liking.

This examples changes the keyboard to smaller one and also highlights the notes in D Major scale.

import { Instrument } from "piano-chart";

const piano = new Instrument(document.getElementById('pianoContainer'), {
    startOctave: 3,
    endOctave: 5,
    highlightedNotes: ["D", "E", "F#", "G", "A", "B", "C#"],
    specialHighlightedNotes: [{ note: "D" }],
  }
);
piano.create();

piano.keyDown("D4");
piano.keyDown("F#4");
piano.keyDown("A4");

This is what you get as a result:

You pass configuration object as a second parameter to the Instrument constructor and you can also change most of them later by calling the applySettings() method.

Available settings:

• startOctave: number (default 2) - the first displayed octave;
• startNote: Note (default "C") - the first displayed note in the first displayed octave;
• endOctave: number (default 6) - the last displayed octave;
• endNote: Note (default "C") - the last displayed note in the last displayed octave;
• showNoteNames: NoteNameBehavior (default "onpress") - when to show note labels on the keys. Available values:
  • always - labels are always on;
  • onpress - labels are displayed when a key is pressed;
  • onhighlight - labels are displayed only on highlighted keys;
  • never - labels are never displayed.
• highlightedNotes: NoteValue[] (default []) - an array of notes to highlight (octave number can be omitted);
• highlightColor: string (default "#0c0") - the base color for the highlight bubble;
• specialHighlightedNotes: NoteValue[] (default []) - an array of notes to highlight in a special way (eg. root notes)
• specialHighlightColor: string (default "#f00") - the base color of the special highlight bubbles;
• showOctaveNumbers: boolean (default false) - whether to show octave numbers on the keyboard or not;
• keyPressStyle: KeyPressStyle (default "subtle") (new in v.1.5) - the style of key press visualization. Values:
  • subtle - fills keys with a subtle gradient;
  • vivid - fills keys with a color specified via vividKeyPressColor.
• vividKeyPressColor: string (default "#f33") (new in v.1.5) - key fill color for key presses when keyPressStyle is set to vivid.

Methods

• create() - create and show an instrument chart;
• keyDown(note: INoteValue | string) - press a key;
• keyUp(note: INoteValue | string) - release a key;
• applySettings(settings: IInstrumentSettings) - apply new settings (changes to start/end notes and octaves are not supported through this method - recreate the Instrument instead);
• rasterize(done: (dataUrl: string) => void, signature?: string)) (new in v.1.4) - creates a PNG screenshot of the current keyboard and calls the specified callback with the data URL that can be used as the src of a HTML image. If signature string is provided, it will be added at the bottom right corner of the screenshot.
• destroy() - perform cleanup;

Events

piano-chart can raise events when keys are clicked with a mouse. To handle these events you need to add listeners using addKeyMouseDownListener(), addKeyMouseUpListener() and remove them using removeKeyMouseDownListener() and removeKeyMouseUpListener() when no longer needed.

All handlers receive an argument of INoteValue type:

interface INoteValue {
  note: Note;
  accidental?: Accidetnal;
  octave?: number;
}

Note that you need to route this note back to the keyDown()/keyUp() methods if you want for these clicks to result in visible key presses.

License

piano-chart is distributed under the MIT License.

Copyright by Alan Mendelevich.