((window, electron) => { const X_OFFSET = 0 const NATURAL_KEY_WIDTH = 16; const ACCIDENTAL_KEY_WIDTH = 11; const accidental_key_x_offsets = [ 10.0 / 112.0, 28.0 / 112.0, 57.0 / 112.0, 75.0 / 112.0, 93.0 / 112.0, ] const { ipcRenderer, } = electron const renderKeys = () => { let midi_note = 12 const elements = {} let element const keyboard = window.document.getElementById('keyboard') for (let octave = 0; octave < 9; octave += 1) { for (let natural_key = 0; natural_key < 7; natural_key += 1) { element = window.document.createElement('div') element.classList.add('natural') element.classList.add('key') element.style.position = 'absolute' element.style.top = 0 element.style.left = X_OFFSET + (octave * NATURAL_KEY_WIDTH * 7) + (natural_key * NATURAL_KEY_WIDTH) + 'px' element.style.width = NATURAL_KEY_WIDTH + 'px' element.appendChild(window.document.createElement('div')) elements[midi_note] = element keyboard.appendChild(element) switch (natural_key) { case 0: case 1: case 3: case 4: case 5: midi_note += 2; break; case 2: case 6: midi_note += 1; break; default: break; } } midi_note -= 11; for (let accidental_key = 0; accidental_key < 5; accidental_key += 1) { element = window.document.createElement('div') element.classList.add('accidental') element.classList.add('key') element.style.position = 'absolute' element.style.top = 0 element.style.left = X_OFFSET + (octave * NATURAL_KEY_WIDTH * 7) + (NATURAL_KEY_WIDTH * 7 * accidental_key_x_offsets[accidental_key]) + 'px' element.style.width = ACCIDENTAL_KEY_WIDTH + 'px' element.appendChild(window.document.createElement('div')) elements[midi_note] = element keyboard.appendChild(element) switch (accidental_key) { case 0: case 2: case 3: midi_note += 2; break; case 1: case 4: midi_note += 3; break; default: break; } } midi_note -= 1; } return elements } const elements = renderKeys(null, null) ipcRenderer.on('note', (event, message) => { const [key, value, ] = message.split(':') if (value > 0) { elements[key].classList.add('pressed') } else { elements[key].classList.remove('pressed') } }) ipcRenderer.on('pedal', (event, message) => { console.log(message) const [which, value, ] = message.split(':') const pedalIds = { 64: 'sustain', 66: 'sostenuto', 67: 'unacorda', } console.log(window.document.getElementById(pedalIds[which])) window.document.getElementById(pedalIds[which]).style.opacity = value / 127 * 0.75 + 0.25 }) })(window, require('electron'))