fix: preference window tab icons adapt to dark mode (closes #498)

src/api-wrappers/HelperExtensions.swift

@@ -147,3 +147,11 @@ extension NSViewController {
         subview.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
     }
 }
+
+extension NSImage {
+    static func initTemplate(_ name: String) -> NSImage {
+        let image = NSImage(named: name)!
+        image.isTemplate = true
+        return image
+    }
+}

src/ui/preferences-window/tabs/AboutTab.swift

@@ -4,7 +4,7 @@ import Preferences
 class AboutTab: NSViewController, PreferencePane {
     let preferencePaneIdentifier = PreferencePane.Identifier("About")
     let preferencePaneTitle = NSLocalizedString("About", comment: "")
-    let toolbarItemIcon = NSImage(named: "about")!
+    let toolbarItemIcon = NSImage.initTemplate("about")
 
     override func loadView() {
         let appIcon = NSImageView(image: NSImage(named: "app-icon")!.resizedCopy(256, 256))

src/ui/preferences-window/tabs/AcknowledgmentsTab.swift

@@ -7,7 +7,7 @@ class AcknowledgmentsTab: NSViewController, PreferencePane {
     static let maxTabHeight = CGFloat(450)
     let preferencePaneIdentifier = PreferencePane.Identifier("Acknowledgments")
     let preferencePaneTitle = NSLocalizedString("Acknowledgments", comment: "")
-    let toolbarItemIcon = NSImage(named: "acknowledgments")!
+    let toolbarItemIcon = NSImage.initTemplate("acknowledgments")
 
     override func loadView() {
         let textViews: [TextField] = ["Contributors", "Acknowledgments"].map {

src/ui/preferences-window/tabs/AppearanceTab.swift

@@ -4,7 +4,7 @@ import Preferences
 class AppearanceTab: NSViewController, PreferencePane {
     let preferencePaneIdentifier = PreferencePane.Identifier("Appearance")
     let preferencePaneTitle = NSLocalizedString("Appearance", comment: "")
-    let toolbarItemIcon = NSImage(named: "appearance")!
+    let toolbarItemIcon = NSImage.initTemplate("appearance")
 
     override func loadView() {
         let grid = GridView([

src/ui/preferences-window/tabs/BlacklistsTab.swift

@@ -5,7 +5,7 @@ import Preferences
 class BlacklistsTab: NSViewController, PreferencePane {
     let preferencePaneIdentifier = PreferencePane.Identifier("Blacklists")
     let preferencePaneTitle = NSLocalizedString("Blacklists", comment: "")
-    let toolbarItemIcon = NSImage(named: "blacklists")!
+    let toolbarItemIcon = NSImage.initTemplate("blacklists")
 
     override func loadView() {
         let dontShowBlacklistLabel = NSTextField(labelWithString: NSLocalizedString("Don’t show windows from these apps", comment: ""))

src/ui/preferences-window/tabs/ControlsTab.swift

@@ -5,7 +5,7 @@ import Preferences
 class ControlsTab: NSViewController, PreferencePane {
     let preferencePaneIdentifier = PreferencePane.Identifier("Controls")
     let preferencePaneTitle = NSLocalizedString("Controls", comment: "")
-    let toolbarItemIcon = NSImage(named: "controls")!
+    let toolbarItemIcon = NSImage.initTemplate("controls")
 
     static var nextWindowShortcut: NSControl!
     static var nextWindowShortcut2: NSControl!

src/ui/preferences-window/tabs/GeneralTab.swift

@@ -4,7 +4,7 @@ import Preferences
 class GeneralTab: NSViewController, PreferencePane {
     let preferencePaneIdentifier = PreferencePane.Identifier("General")
     let preferencePaneTitle = NSLocalizedString("General", comment: "")
-    let toolbarItemIcon = NSImage(named: "general")!
+    let toolbarItemIcon = NSImage.initTemplate("general")
 
     override func loadView() {
         let startAtLogin = LabelAndControl.makeLabelWithCheckbox(NSLocalizedString("Start at login:", comment: ""), "startAtLogin", extraAction: startAtLoginCallback)

src/ui/preferences-window/tabs/PoliciesTab.swift

@@ -5,7 +5,7 @@ import Preferences
 class PoliciesTab: NSViewController, PreferencePane {
     let preferencePaneIdentifier = PreferencePane.Identifier("Policies")
     let preferencePaneTitle = NSLocalizedString("Policies", comment: "")
-    let toolbarItemIcon = NSImage(named: "policies")!
+    let toolbarItemIcon = NSImage.initTemplate("policies")
 
     static var updateButtons: [NSButton]!
     static var crashButtons: [NSButton]!