session-ios/Session/Conversations/Input View/InputTextView.swift

106 lines
3.9 KiB
Swift

public final class InputTextView : UITextView, UITextViewDelegate {
private weak var snDelegate: InputTextViewDelegate?
private let maxWidth: CGFloat
private lazy var heightConstraint = self.set(.height, to: minHeight)
public override var text: String? { didSet { handleTextChanged() } }
// MARK: UI Components
private lazy var placeholderLabel: UILabel = {
let result = UILabel()
result.text = NSLocalizedString("vc_conversation_input_prompt", comment: "")
result.font = .systemFont(ofSize: Values.mediumFontSize)
result.textColor = Colors.text.withAlphaComponent(Values.mediumOpacity)
return result
}()
// MARK: Settings
private let minHeight: CGFloat = 22
private let maxHeight: CGFloat = 80
// MARK: Lifecycle
init(delegate: InputTextViewDelegate, maxWidth: CGFloat) {
snDelegate = delegate
self.maxWidth = maxWidth
super.init(frame: CGRect.zero, textContainer: nil)
setUpViewHierarchy()
self.delegate = self
self.isAccessibilityElement = true
self.accessibilityLabel = NSLocalizedString("vc_conversation_input_prompt", comment: "")
}
public override init(frame: CGRect, textContainer: NSTextContainer?) {
preconditionFailure("Use init(delegate:) instead.")
}
public required init?(coder: NSCoder) {
preconditionFailure("Use init(delegate:) instead.")
}
public override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
if action == #selector(paste(_:)) {
if let _ = UIPasteboard.general.image {
return true
}
}
return super.canPerformAction(action, withSender: sender)
}
public override func paste(_ sender: Any?) {
if let image = UIPasteboard.general.image {
snDelegate?.didPasteImageFromPasteboard(self, image: image)
}
super.paste(sender)
}
private func setUpViewHierarchy() {
showsHorizontalScrollIndicator = false
showsVerticalScrollIndicator = false
backgroundColor = .clear
textColor = Colors.text
font = .systemFont(ofSize: Values.mediumFontSize)
tintColor = Colors.accent
keyboardAppearance = isLightMode ? .light : .dark
heightConstraint.isActive = true
let horizontalInset: CGFloat = 2
textContainerInset = UIEdgeInsets(top: 0, left: horizontalInset, bottom: 0, right: horizontalInset)
addSubview(placeholderLabel)
placeholderLabel.pin(.leading, to: .leading, of: self, withInset: horizontalInset + 3) // Slight visual adjustment
placeholderLabel.pin(.top, to: .top, of: self)
pin(.trailing, to: .trailing, of: placeholderLabel, withInset: horizontalInset)
pin(.bottom, to: .bottom, of: placeholderLabel)
}
// MARK: Updating
public func textViewDidChange(_ textView: UITextView) {
handleTextChanged()
}
private func handleTextChanged() {
defer { snDelegate?.inputTextViewDidChangeContent(self) }
placeholderLabel.isHidden = !(text ?? "").isEmpty
let height = frame.height
let size = sizeThatFits(CGSize(width: maxWidth, height: .greatestFiniteMagnitude))
// `textView.contentSize` isn't accurate when restoring a multiline draft, so we set it here manually
self.contentSize = size
let newHeight = size.height.clamp(minHeight, maxHeight)
guard newHeight != height else { return }
heightConstraint.constant = newHeight
snDelegate?.inputTextViewDidChangeSize(self)
}
}
// MARK: - InputTextViewDelegate
protocol InputTextViewDelegate: AnyObject {
func inputTextViewDidChangeSize(_ inputTextView: InputTextView)
func inputTextViewDidChangeContent(_ inputTextView: InputTextView)
func didPasteImageFromPasteboard(_ inputTextView: InputTextView, image: UIImage)
}