element-ios/Riot/Modules/Room/VoiceMessages/VoiceMessageWaveformView.swift

114 lines
3.7 KiB
Swift

//
// Copyright 2021-2024 New Vector Ltd.
//
// SPDX-License-Identifier: AGPL-3.0-only
// Please see LICENSE in the repository root for full details.
//
import UIKit
class VoiceMessageWaveformView: UIView {
private let lineWidth: CGFloat = 2.0
private let linePadding: CGFloat = 2.0
private let renderingQueue: DispatchQueue = DispatchQueue(label: "io.element.VoiceMessageWaveformView.queue", qos: .userInitiated)
var samples: [Float] = [] {
didSet {
computeWaveForm()
}
}
var primaryLineColor = UIColor.lightGray {
didSet {
backgroundLayer.strokeColor = primaryLineColor.cgColor
backgroundLayer.fillColor = primaryLineColor.cgColor
}
}
var secondaryLineColor = UIColor.darkGray {
didSet {
progressLayer.strokeColor = secondaryLineColor.cgColor
progressLayer.fillColor = secondaryLineColor.cgColor
}
}
private let backgroundLayer = CAShapeLayer()
private let progressLayer = CAShapeLayer()
var progress = 0.0 {
didSet {
CATransaction.begin()
CATransaction.setDisableActions(true)
progressLayer.frame = CGRect(origin: self.bounds.origin, size: CGSize(width: self.bounds.width * CGFloat(self.progress), height: self.bounds.height))
CATransaction.commit()
}
}
var requiredNumberOfSamples: Int {
return Int(self.bounds.size.width / (lineWidth + linePadding))
}
override init(frame: CGRect) {
super.init(frame: frame)
setupAndAdd(backgroundLayer, with: primaryLineColor)
setupAndAdd(progressLayer, with: secondaryLineColor)
progressLayer.masksToBounds = true
computeWaveForm()
}
required init?(coder: NSCoder) {
fatalError()
}
override func layoutSubviews() {
super.layoutSubviews()
backgroundLayer.frame = self.bounds
progressLayer.frame = CGRect(origin: self.bounds.origin, size: CGSize(width: self.bounds.width * CGFloat(self.progress), height: self.bounds.height))
computeWaveForm()
}
// MARK: - Private
private func computeWaveForm() {
renderingQueue.async { [samples] in // Capture the current samples as a way to provide atomicity
let path = UIBezierPath()
let drawMappingFactor = self.bounds.size.height
let minimumGraphAmplitude: CGFloat = 1
var xOffset: CGFloat = self.lineWidth / 2
var index = 0
while xOffset < self.bounds.width - self.lineWidth {
let sample = CGFloat(index >= samples.count ? 1 : samples[index])
let invertedDbSample = 1 - sample // sample is in dB, linearly normalized to [0, 1] (1 -> -50 dB)
let drawingAmplitude = max(minimumGraphAmplitude, invertedDbSample * drawMappingFactor)
path.move(to: CGPoint(x: xOffset, y: self.bounds.midY - drawingAmplitude / 2))
path.addLine(to: CGPoint(x: xOffset, y: self.bounds.midY + drawingAmplitude / 2))
xOffset += self.lineWidth + self.linePadding
index += 1
}
DispatchQueue.main.async {
self.backgroundLayer.path = path.cgPath
self.progressLayer.path = path.cgPath
}
}
}
private func setupAndAdd(_ shapeLayer: CAShapeLayer, with color: UIColor) {
shapeLayer.frame = self.bounds
shapeLayer.strokeColor = color.cgColor
shapeLayer.fillColor = color.cgColor
shapeLayer.lineCap = .round
shapeLayer.lineWidth = lineWidth
self.layer.addSublayer(shapeLayer)
}
}