Add custom text field & text view

1 files changed, 124 insertions, 0 deletions

diff --git a/ios/MullvadVPN/CustomTextView.swift b/ios/MullvadVPN/CustomTextView.swift
new file mode 100644
index 0000000000..3ce1fa9466
--- /dev/null
+++ b/ios/MullvadVPN/CustomTextView.swift
@@ -0,0 +1,124 @@
+//
+//  CustomTextView.swift
+//  MullvadVPN
+//
+//  Created by pronebird on 16/09/2020.
+//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
+//
+
+import Foundation
+import UIKit
+
+private let kTextViewCornerRadius = CGFloat(4)
+
+class CustomTextView: UITextView {
+
+    var roundCorners: Bool = true {
+        didSet {
+            layer.cornerRadius = roundCorners ? kTextViewCornerRadius : 0
+        }
+    }
+
+    /// Placeholder string
+    var placeholder: String? {
+        set {
+            placeholderTextLabel.text = newValue
+        }
+        get {
+            return placeholderTextLabel.text
+        }
+    }
+
+    /// Placeholder text label
+    private let placeholderTextLabel = UILabel()
+
+    /// Placeholder label constraints
+    private var placeholderConstraints = [NSLayoutConstraint]()
+
+    override var textContainerInset: UIEdgeInsets {
+        didSet {
+            setNeedsUpdateConstraints()
+        }
+    }
+
+    override var font: UIFont? {
+        didSet {
+            placeholderTextLabel.font = self.font ?? UIFont.preferredFont(forTextStyle: .body)
+        }
+    }
+
+    /// Placeholder text inset derived from `textContainerInset`
+    private var placeholderTextInset: UIEdgeInsets {
+        var placeholderInset = textContainerInset
+
+        // Offset the placeholder label to match with text view rendering.
+        placeholderInset.top += 0.5
+
+        return placeholderInset
+    }
+
+    override init(frame: CGRect, textContainer: NSTextContainer?) {
+        super.init(frame: frame, textContainer: textContainer)
+
+        placeholderTextLabel.textColor = UIColor.TextField.placeholderTextColor
+        placeholderTextLabel.highlightedTextColor = UIColor.TextField.placeholderTextColor
+        placeholderTextLabel.translatesAutoresizingMaskIntoConstraints = false
+        addSubview(placeholderTextLabel)
+
+        // Create placeholder constraints
+        placeholderConstraints = [
+            placeholderTextLabel.topAnchor.constraint(equalTo: topAnchor),
+            placeholderTextLabel.leadingAnchor.constraint(equalTo: leadingAnchor),
+            placeholderTextLabel.trailingAnchor.constraint(equalTo: trailingAnchor)
+        ]
+        NSLayoutConstraint.activate(placeholderConstraints)
+
+        // Set visual appearance
+        textColor = UIColor.TextField.textColor
+        layer.cornerRadius = kTextViewCornerRadius
+        clipsToBounds = true
+
+        // Set content padding
+        contentInset = .zero
+        textContainerInset = UIEdgeInsets(top: 12, left: 14, bottom: 12, right: 14)
+        self.textContainer.lineFragmentPadding = 0
+
+        // Handle placeholder visibility
+        NotificationCenter.default.addObserver(
+            forName: NSTextStorage.didProcessEditingNotification,
+            object: textStorage,
+            queue: OperationQueue.main) { [weak self] (note) in
+                self?.updatePlaceholderVisibility()
+        }
+
+        updatePlaceholderVisibility()
+    }
+
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+
+    override func updateConstraints() {
+        let textInset = placeholderTextInset
+
+        for constraint in placeholderConstraints {
+            switch constraint.firstAttribute {
+            case .top:
+                constraint.constant = textInset.top
+            case .leading:
+                constraint.constant = textInset.left
+            case .trailing:
+                constraint.constant = textInset.right
+            default:
+                break
+            }
+        }
+
+        super.updateConstraints()
+    }
+
+    private func updatePlaceholderVisibility() {
+        placeholderTextLabel.isHidden = textStorage.length > 0
+    }
+
+}