Tab Bar: Adds tab bar view/view controller

App/Browser View/BrowserView.swift

@@ -21,6 +21,14 @@ class BrowserView: UIView
         didSet { addSubview(toolbarView!) }
     }
     
+    var tabBarView: TabBarView? {
+        didSet { addSubview(tabBarView!) }
+    }
+    
+    var tabBarViewVisible: Bool = true {
+        didSet { setNeedsLayout() }
+    }
+    
     var autocompleteView: UIView? {
         didSet {
             addSubview(autocompleteView!)
@@ -129,6 +137,25 @@ class BrowserView: UIView
             }
         }
         
+        if let tabBarView = tabBarView {
+            bringSubviewToFront(tabBarView)
+            
+            if tabBarViewVisible {
+                tabBarView.isHidden = false
+                
+                let tabViewSize = tabBarView.sizeThatFits(bounds.size)
+                
+                tabBarView.frame = CGRect(
+                    x: 0.0, y: webViewContentInset.top,
+                    width: bounds.width, height: tabViewSize.height
+                )
+                
+                webViewContentInset.top += tabBarView.frame.height
+            } else {
+                tabBarView.isHidden = true
+            }
+        }
+        
         // Fix web view content insets
         if let webView = webView {
             webView.scrollView.layer.masksToBounds = true
@@ -154,10 +181,15 @@ class BrowserView: UIView
                 autocompleteView.layer.shadowPath = shadowPath.cgPath
                 
                 if let toolbarView = toolbarView, let urlBar = toolbarView.urlBar {
+                    var yOffset = toolbarView.frame.maxY + 3.0
+                    if let tabBarView = tabBarView, tabBarViewVisible {
+                        yOffset += tabBarView.frame.height
+                    }
+                    
                     let urlFrame = self.convert(urlBar.frame, from: urlBar.superview)
                     autocompleteView.frame = CGRect(
                         x: urlFrame.minX,
-                        y: toolbarView.frame.maxY + 3.0,
+                        y: yOffset,
                         width: urlFrame.width,
                         height: bounds.height / 2.5
                     )

App/Browser View/BrowserViewController.swift

@@ -5,6 +5,7 @@
 //  Created by James Magahern on 7/21/20.
 //
 
+import Combine
 import UIKit
 import UniformTypeIdentifiers
 
@@ -18,6 +19,7 @@ class BrowserViewController: UIViewController, WKNavigationDelegate, WKUIDelegat
     var webView: WKWebView { tab.webView }
     
     private let tabController = TabController()
+    private let tabBarViewController: TabBarViewController
     private let toolbarController = ToolbarViewController()
     private let findOnPageController = FindOnPageViewController()
     
@@ -32,6 +34,7 @@ class BrowserViewController: UIViewController, WKNavigationDelegate, WKUIDelegat
     private var loadingObservation: NSKeyValueObservation?
     private var backButtonObservation: NSKeyValueObservation?
     private var forwardButtonObservation: NSKeyValueObservation?
+    private var activeTabObservation: AnyCancellable?
     
     private var loadError: Error?
     
@@ -39,10 +42,12 @@ class BrowserViewController: UIViewController, WKNavigationDelegate, WKUIDelegat
     
     init() {
         self.tab = tabController.tabs.first!
+        self.tabBarViewController = TabBarViewController(tabController: tabController)
         super.init(nibName: nil, bundle: nil)
         
         addChild(toolbarController)
         addChild(findOnPageController)
+        addChild(tabBarViewController)
         
         didChangeTab(tab)
     }
@@ -52,6 +57,7 @@ class BrowserViewController: UIViewController, WKNavigationDelegate, WKUIDelegat
     override func loadView() {
         browserView.toolbarView = toolbarController.toolbarView
         browserView.findOnPageView = findOnPageController.findOnPageView
+        browserView.tabBarView = tabBarViewController.tabBarView
         
         // Refresh button
         toolbarController.urlBar.refreshButton.addAction(UIAction(handler: { [unowned self] action in
@@ -215,6 +221,16 @@ class BrowserViewController: UIViewController, WKNavigationDelegate, WKUIDelegat
             browserView.setFindOnPageVisible(false, animated: true)
         }), for: .touchUpInside)
         
+        // Tab controller
+        activeTabObservation = tabController.$activeTabIndex
+            .receive(on: RunLoop.main)
+            .sink(receiveValue: { [unowned self] (activeTab: Int) in
+                let tab = tabController.tabs[activeTab]
+                if self.tab != tab {
+                    self.tab = tab
+                }
+        })
+        
         self.view = browserView
     }
     
@@ -236,9 +252,19 @@ class BrowserViewController: UIViewController, WKNavigationDelegate, WKUIDelegat
         } else {
             toolbarController.urlBar.textField.text = ""
         }
+        
+        // Figure out which tab this corresponds to
+        let tab = tabController.tabs.first { $0.webView == webView }
+        if let tab = tab, let tabIndex = tabController.tabs.firstIndex(of: tab) {
+            tabBarViewController.tabBarView.reloadTab(atIndex: tabIndex)
+        }
     }
     
     private func didChangeTab(_ tab: Tab) {
+        if let activeIndex = tabController.tabs.firstIndex(of: tab) {
+            tabController.activeTabIndex = activeIndex
+        }
+        
         tab.delegate = self
         
         let webView = tab.webView
@@ -253,6 +279,9 @@ class BrowserViewController: UIViewController, WKNavigationDelegate, WKUIDelegat
         // Autocomplete view
         browserView.autocompleteView = autocompleteViewController.view
         
+        // Show tab bar view?
+        browserView.tabBarViewVisible = tabController.tabs.count > 1
+        
         // Load progress
         updateLoadProgress(forWebView: webView)
         loadingObservation = webView.observe(\.estimatedProgress) { [unowned self] (webView, observedChange) in