Tab picker: Allow multiple selection/deletion

App/Browser View/BrowserViewController.swift

@@ -251,9 +251,11 @@ class BrowserViewController: UIViewController, WKNavigationDelegate, WKUIDelegat
         activeTabObservation = tabController.$activeTabIndex
             .receive(on: RunLoop.main)
             .sink(receiveValue: { [unowned self] (activeTab: Int) in
-                let tab = tabController.tabs[activeTab]
+                if activeTab < tabController.tabs.count {
-                if self.tab != tab {
+                    let tab = tabController.tabs[activeTab]
-                    self.tab = tab
+                    if self.tab != tab {
+                        self.tab = tab
+                    }
                 }
         })
         

App/Script Policy UI/ScriptPolicyViewController.swift

@@ -7,7 +7,7 @@
 
 import UIKit
 
-protocol ScriptPolicyViewControllerDelegate: class {
+protocol ScriptPolicyViewControllerDelegate: AnyObject {
     func didChangeScriptPolicy()
     func setScriptsEnabledForTab(_ enabled: Bool)
 }
@@ -96,16 +96,7 @@ class ScriptPolicyViewController: UIViewController, UICollectionViewDelegate
     }
     
     override var traitCollection: UITraitCollection {
-        get {
+        get { return super.traitCollection.alwaysPadLike() }
-            let actualTraits = super.traitCollection
-            if actualTraits.userInterfaceIdiom == .mac {
-                // Override traits to be iPad like on mac. We dont want small list cells here.
-                let desiredTraits = UITraitCollection(userInterfaceIdiom: .pad)
-                return UITraitCollection(traitsFrom: [ actualTraits, desiredTraits ])
-            }
-            
-            return actualTraits
-        }
     }
     
     private static let enableScriptsForTabItem: String = "enableScriptsForTab"
@@ -229,6 +220,7 @@ class ScriptPolicyViewController: UIViewController, UICollectionViewDelegate
     
     override func loadView() {
         self.view = collectionView
+        self.view.backgroundColor = .systemGroupedBackground
     }
     
     // MARK: UICollectionViewDelegate

App/Tabs/TabPickerViewController.swift

@@ -7,7 +7,7 @@
 
 import UIKit
 
-protocol TabPickerViewControllerDelegate: class
+protocol TabPickerViewControllerDelegate: AnyObject
 {
     func tabPicker(_ picker: TabPickerViewController, didSelectTab tab: Tab)
     func tabPicker(_ picker: TabPickerViewController, willCloseTab tab: Tab)
@@ -22,9 +22,27 @@ class TabPickerViewController: UIViewController, UICollectionViewDelegate
     
     typealias TabID = UUID
     
+    private var selectedTabsForEditing: Set<Tab> = []
     private var collectionView: UICollectionView?
     private var dataSource: UICollectionViewDiffableDataSource<Int, TabID>?
     
+    override var traitCollection: UITraitCollection {
+        get { return super.traitCollection.alwaysPadLike() }
+    }
+    
+    private lazy var newTabButton: UIBarButtonItem = {
+        UIBarButtonItem(systemItem: .add, primaryAction: UIAction(handler: { [unowned self] _ in
+            let newTab = self.tabController.createNewTab(url: nil)
+            self.delegate?.tabPicker(self, didSelectTab: newTab)
+        }), menu: nil)
+    }()
+    
+    lazy var deleteTabButton: UIBarButtonItem = {
+        UIBarButtonItem(systemItem: .trash, primaryAction: UIAction(handler: { [unowned self] _ in
+            deleteSelectedTabs()
+        }), menu: nil)
+    }()
+    
     init(tabController: TabController) {
         self.tabController = tabController
         super.init(nibName: nil, bundle: nil)
@@ -58,6 +76,8 @@ class TabPickerViewController: UIViewController, UICollectionViewDelegate
         
         let listLayout = UICollectionViewCompositionalLayout.list(using: listConfig)
         let collectionView = UICollectionView(frame: .zero, collectionViewLayout: listLayout)
+        collectionView.allowsMultipleSelectionDuringEditing = true
+        collectionView.backgroundColor = .systemGroupedBackground
                 
         let registry = UICollectionView.CellRegistration<UICollectionViewListCell, TabID> { [unowned self] (listCell, indexPath, item) in
             var config = listCell.defaultContentConfiguration()
@@ -85,7 +105,7 @@ class TabPickerViewController: UIViewController, UICollectionViewDelegate
                 config.imageProperties.maximumSize = CGSize(width: 21.0, height: 21.0)
                 config.imageProperties.cornerRadius = 3.0
                 
-                if tab == self.selectedTab {
+                if self.selectedTab == tab {
                     listCell.accessories = [ .checkmark() ]
                 } else {
                     listCell.accessories = []
@@ -114,16 +134,68 @@ class TabPickerViewController: UIViewController, UICollectionViewDelegate
         self.collectionView = collectionView
         self.view = self.collectionView
         
-        let newTabButton = UIBarButtonItem(systemItem: .add, primaryAction: UIAction(handler: { [unowned self] _ in
+        configureNavigationButtons(forEditing: isEditing)
-            let newTab = self.tabController.createNewTab(url: nil)
+    }
-            self.delegate?.tabPicker(self, didSelectTab: newTab)
-        }), menu: nil)
     
-        navigationItem.rightBarButtonItem = newTabButton
+    private func configureNavigationButtons(forEditing: Bool) {
+        if !forEditing {
+            navigationItem.rightBarButtonItem = newTabButton
+        } else {
+            deleteTabButton.isEnabled = collectionView?.indexPathsForSelectedItems?.count ?? 0 > 0
+            navigationItem.rightBarButtonItem = deleteTabButton
+        }
+        
+        navigationItem.leftBarButtonItem = editButtonItem
+    }
+    
+    override func setEditing(_ editing: Bool, animated: Bool) {
+        super.setEditing(editing, animated: animated)
+        
+        if let collectionView = collectionView {
+            collectionView.isEditing = editing
+        }
+        
+        configureNavigationButtons(forEditing: editing)
+    }
+    
+    private func deleteSelectedTabs() {
+        guard let dataSource = dataSource else { return }
+        
+        var snapshot = dataSource.snapshot()
+        for tab in selectedTabsForEditing {
+            snapshot.deleteItems([ tab.identifier ])
+            self.delegate?.tabPicker(self, willCloseTab: tab)
+            self.tabController.closeTab(tab)
+        }
+        
+        dataSource.apply(snapshot, animatingDifferences: true)
     }
     
     func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
         let tab = tabController.tabs[indexPath.row]
-        delegate?.tabPicker(self, didSelectTab: tab)
+        
+        if !isEditing {
+            delegate?.tabPicker(self, didSelectTab: tab)
+        } else {
+            deleteTabButton.isEnabled = collectionView.indexPathsForSelectedItems?.count ?? 0 > 0
+            selectedTabsForEditing.update(with: tab)
+        }
+    }
+    
+    func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
+        if isEditing {
+            let tab = tabController.tabs[indexPath.row]
+            selectedTabsForEditing.remove(tab)
+            
+            deleteTabButton.isEnabled = collectionView.indexPathsForSelectedItems?.count ?? 0 > 0
+        }
+    }
+    
+    func collectionView(_ collectionView: UICollectionView, shouldBeginMultipleSelectionInteractionAt indexPath: IndexPath) -> Bool {
+        true
+    }
+    
+    func collectionView(_ collectionView: UICollectionView, didBeginMultipleSelectionInteractionAt indexPath: IndexPath) {
+        isEditing = true
     }
 }

App/Utilities/UITraitCollection+MacLike.swift

@@ -0,0 +1,20 @@
+//
+//  UITraitCollection+MacLike.swift
+//  App
+//
+//  Created by James Magahern on 2/11/21.
+//
+
+import UIKit
+
+extension UITraitCollection {
+    public func alwaysPadLike() -> UITraitCollection {
+        if self.userInterfaceIdiom == .mac {
+            // Override traits to be iPad like on mac. We dont want small list cells here.
+            let desiredTraits = UITraitCollection(userInterfaceIdiom: .pad)
+            return UITraitCollection(traitsFrom: [ self, desiredTraits ])
+        }
+        
+        return self
+    }
+}

SBrowser.xcodeproj/project.pbxproj

@@ -52,6 +52,7 @@
 		CDCE2664251AA80F007FE92A /* DocumentControlViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = CDCE2663251AA80F007FE92A /* DocumentControlViewController.swift */; };
 		CDCE2666251AA840007FE92A /* StackView.swift in Sources */ = {isa = PBXBuildFile; fileRef = CDCE2665251AA840007FE92A /* StackView.swift */; };
 		CDCE2668251AAA9A007FE92A /* FontSizeAdjustView.swift in Sources */ = {isa = PBXBuildFile; fileRef = CDCE2667251AAA9A007FE92A /* FontSizeAdjustView.swift */; };
+		CDEDD8AA25D62ADB00862605 /* UITraitCollection+MacLike.swift in Sources */ = {isa = PBXBuildFile; fileRef = CDEDD8A925D62ADB00862605 /* UITraitCollection+MacLike.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -133,6 +134,7 @@
 		CDCE2663251AA80F007FE92A /* DocumentControlViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DocumentControlViewController.swift; sourceTree = "<group>"; };
 		CDCE2665251AA840007FE92A /* StackView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StackView.swift; sourceTree = "<group>"; };
 		CDCE2667251AAA9A007FE92A /* FontSizeAdjustView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FontSizeAdjustView.swift; sourceTree = "<group>"; };
+		CDEDD8A925D62ADB00862605 /* UITraitCollection+MacLike.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UITraitCollection+MacLike.swift"; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -315,6 +317,7 @@
 				CD7A8918251989C90075991E /* UIKeyCommand+ConvInit.swift */,
 				1ADFF4C624CA6DEB006DC7AE /* UIEdgeInsets+Layout.swift */,
 				1AB88F0524D4D3A90006F850 /* UIGestureRecognizer+Actions.swift */,
+				CDEDD8A925D62ADB00862605 /* UITraitCollection+MacLike.swift */,
 			);
 			path = Utilities;
 			sourceTree = "<group>";
@@ -468,6 +471,7 @@
 				CDCE2666251AA840007FE92A /* StackView.swift in Sources */,
 				CD853BD124E778B800D2BDCC /* History.xcdatamodeld in Sources */,
 				1AD31040252545BF00A4A952 /* FindOnPageView.swift in Sources */,
+				CDEDD8AA25D62ADB00862605 /* UITraitCollection+MacLike.swift in Sources */,
 				CD7A8919251989C90075991E /* UIKeyCommand+ConvInit.swift in Sources */,
 				1ADFF4C724CA6DEB006DC7AE /* UIEdgeInsets+Layout.swift in Sources */,
 				1ADFF4AE24C8ED32006DC7AE /* ResourcePolicyManager.swift in Sources */,