Update MigrationCenterView, make it a reusable view for notifications and done screens

Author: Giorgio Ruscigno

WordPress/Jetpack/Classes/ViewRelated/WordPress-to-Jetpack Migration/Common/Views/MigrationCenterView.swift

@@ -0,0 +1,61 @@
+import UIKit
+
+/// A view with an injected content and a description withl highlighted words
+class MigrationCenterView: UIView {
+
+    private let contentView: UIView
+
+    private let descriptionText: String
+
+    private let highlightedDescriptionText: String
+
+    private lazy var descriptionLabel: UILabel = {
+        let label = UILabel()
+        label.font = WPStyleGuide.fontForTextStyle(.footnote, fontWeight: .regular)
+        label.attributedText = Appearance.highlightString(highlightedDescriptionText, inString: descriptionText)
+        label.textColor = Appearance.descriptionTextColor
+        label.numberOfLines = 0
+        return label
+    }()
+
+    private lazy var mainStackView: UIStackView = {
+        let stackView = UIStackView(arrangedSubviews: [contentView, descriptionLabel])
+        stackView.axis = .vertical
+        stackView.alignment = .center
+        stackView.setCustomSpacing(Appearance.fakeAlertToDescriptionSpacing, after: contentView)
+        stackView.translatesAutoresizingMaskIntoConstraints = false
+        return stackView
+    }()
+
+    init(contentView: UIView, descriptionText: String, highlightedDescriptionText: String) {
+        self.contentView = contentView
+        self.descriptionText = descriptionText
+        self.highlightedDescriptionText = highlightedDescriptionText
+        super.init(frame: .zero)
+        addSubview(mainStackView)
+        pinSubviewToAllEdges(mainStackView)
+    }
+
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+
+    private enum Appearance {
+
+        static func highlightString(_ subString: String, inString: String) -> NSAttributedString {
+            let attributedString = NSMutableAttributedString(string: inString)
+
+            guard let subStringRange = inString.nsRange(of: subString) else {
+                return attributedString
+            }
+
+            attributedString.addAttributes([.font: WPStyleGuide.fontForTextStyle(.footnote, fontWeight: .bold)],
+                                           range: subStringRange)
+            return attributedString
+        }
+
+        static let fakeAlertToDescriptionSpacing: CGFloat = 20
+
+        static let descriptionTextColor = UIColor(light: .muriel(color: .gray, .shade50), dark: .muriel(color: .gray, .shade10))
+    }
+}