Fix brave#916: Add pull to refresh (brave#3769)

BraveShared/BraveStrings.swift

@@ -484,6 +484,9 @@ extension Strings {
     public static let defaultBrowserCalloutCloseAccesabilityLabel =
         NSLocalizedString("defaultBrowserCalloutCloseAccesabilityLabel", tableName: "BraveShared",
                           bundle: .braveShared, value: "Close default browser callout", comment: "")
+    public static let enablePullToRefresh =
+        NSLocalizedString("enablePullToRefresh", tableName: "BraveShared",
+                          bundle: .braveShared, value: "Enable Pull-to-refresh", comment: "Describes whether or not the feature that allows the user to pull down from the top of a web page a certain amount before it triggers a page refresh")
 }
 
 extension Strings {

Client/Application/ClientPreferences.swift

@@ -101,6 +101,9 @@ extension Preferences {
 
         /// Whether or not the app (in regular browsing mode) will follow universal links
         static let followUniversalLinks = Option<Bool>(key: "general.follow-universal-links", default: true)
+
+        /// Whether or not the pull-to-refresh control is added to web views
+        static let enablePullToRefresh = Option<Bool>(key: "general.enable-pull-to-refresh", default: true)
     }
 
     final class DefaultBrowserIntro {

Client/Assets/Images.xcassets/Settings/settings-pull-to-refresh.imageset/Contents.json

@@ -0,0 +1,22 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
+      "filename" : "[email protected]",
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "filename" : "[email protected]",
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

Client/Frontend/Browser/BrowserViewController.swift

@@ -351,6 +351,7 @@ class BrowserViewController: UIViewController {
         Preferences.Privacy.privateBrowsingOnly.observe(from: self)
         Preferences.General.tabBarVisibility.observe(from: self)
         Preferences.General.alwaysRequestDesktopSite.observe(from: self)
+        Preferences.General.enablePullToRefresh.observe(from: self)
         Preferences.Shields.allShields.forEach { $0.observe(from: self) }
         Preferences.Privacy.blockAllCookies.observe(from: self)
         Preferences.Rewards.hideRewardsIcon.observe(from: self)
@@ -2162,7 +2163,8 @@ extension BrowserViewController: TabManagerDelegate {
 
         updateFindInPageVisibility(visible: false, tab: previous)
         updateTabsBarVisibility()
-
+        selected?.updatePullToRefreshVisibility()
+
         topToolbar.locationView.loading = selected?.loading ?? false
         navigationToolbar.updateBackStatus(selected?.canGoBack ?? false)
         navigationToolbar.updateForwardStatus(selected?.canGoForward ?? false)
@@ -2758,6 +2760,8 @@ extension BrowserViewController: PreferencesObserver {
         case Preferences.General.alwaysRequestDesktopSite.key:
             tabManager.reset()
             self.tabManager.reloadSelectedTab()
+        case Preferences.General.enablePullToRefresh.key:
+            tabManager.selectedTab?.updatePullToRefreshVisibility()
         case Preferences.Shields.blockAdsAndTracking.key,
              Preferences.Shields.httpsEverywhere.key,
              Preferences.Shields.blockScripts.key,

Client/Frontend/Browser/Tab.swift

@@ -185,6 +185,10 @@ class Tab: NSObject {
 
     /// A helper property that handles native to Brave Search communication.
     var braveSearchManager: BraveSearchManager?
+
+    private lazy var refreshControl = UIRefreshControl().then {
+        $0.addTarget(self, action: #selector(reload), for: .valueChanged)
+    }
 
     func createWebview() {
         if webView == nil {
@@ -417,13 +421,20 @@ class Tab: NSObject {
         webView?.stopLoading()
     }
 
-    func reload() {
+    @objc func reload() {
         // Clear the user agent before further navigation.
         // Proper User Agent setting happens in BVC's WKNavigationDelegate.
         // This prevents a bug with back-forward list, going back or forward and reloading the tab
         // loaded wrong user agent.
         webView?.customUserAgent = nil
 
+        defer {
+            if let refreshControl = webView?.scrollView.refreshControl,
+               refreshControl.isRefreshing {
+                refreshControl.endRefreshing()
+            }
+        }
+
         // Refreshing error, safe browsing warning pages.
         if let originalUrlFromErrorUrl = webView?.url?.originalURLFromErrorURL {
             webView?.load(URLRequest(url: originalUrlFromErrorUrl))
@@ -548,8 +559,15 @@ class Tab: NSObject {
             return
         }
 
+        updatePullToRefreshVisibility()
+
         self.urlDidChangeDelegate?.tab(self, urlDidChangeTo: url)
     }
+
+    func updatePullToRefreshVisibility() {
+        guard let url = webView?.url, let webView = webView else { return }
+        webView.scrollView.refreshControl = url.isLocalUtility || !Preferences.General.enablePullToRefresh.value ? nil : refreshControl
+    }
 
     func isDescendentOf(_ ancestor: Tab) -> Bool {
         return sequence(first: parent) { $0?.parent }.contains { $0 == ancestor }

Client/Frontend/Settings/SettingsViewController.swift

@@ -249,6 +249,12 @@ class SettingsViewController: TableViewController {
             }, cellClass: MultilineButtonCell.self))
         }
 
+        general.rows.append(
+            .boolRow(title: Strings.enablePullToRefresh,
+                     option: Preferences.General.enablePullToRefresh,
+                     image: #imageLiteral(resourceName: "settings-pull-to-refresh").template)
+        )
+
         return general
     }()