### Basic Auto Layout Constraint with SnapKit

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/Example/Pods/SnapKit/README.md

This example demonstrates how to add a view and set its constraints using SnapKit's DSL in Swift. Ensure SnapKit is imported.

```swift
import SnapKit

class MyViewController: UIViewController {

    lazy var box = UIView()

    override func viewDidLoad() {
        super.viewDidLoad()

        self.view.addSubview(box)
        box.snp.makeConstraints { (make) -> Void in
           make.width.height.equalTo(50)
           make.center.equalTo(self.view)
        }
    }

}
```

--------------------------------

### Install SnapKit with Carthage

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/Example/Pods/SnapKit/README.md

Integrate SnapKit into your Xcode project using Carthage by specifying the dependency in your Cartfile.

```ogdl
github "SnapKit/SnapKit" ~> 4.0.0
```

--------------------------------

### Install SnapKit with CocoaPods

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/Example/Pods/SnapKit/README.md

Integrate SnapKit into your Xcode project using CocoaPods by specifying the pod in your Podfile.

```ruby
source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '10.0'
use_frameworks!

target '<Your Target Name>' do
    pod 'SnapKit', '~> 4.0.0'
end
```

--------------------------------

### Install TZImagePickerController with CocoaPods

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/Example/Pods/TZImagePickerController/README.md

Use this command to install the TZImagePickerController library using CocoaPods for iOS 8 and later.

```bash
pod 'TZImagePickerController'
```

--------------------------------

### Creating a Root Navigation Controller

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/README.md

Instantiate a UINavigationController with a root view controller and enable the left-swipe push gesture by setting `gk_openScrollLeftPush` to true. This custom initializer simplifies the setup of the main navigation stack.

```swift
let nav = UINavigationController(rootVC: GKMainViewController())
nav.gk_openScrollLeftPush = true // 开启左滑push
```

--------------------------------

### Install TZImagePickerController for iOS 6/7 with CocoaPods

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/Example/Pods/TZImagePickerController/README.md

Use this command to install a specific version of TZImagePickerController using CocoaPods for compatibility with iOS 6 and iOS 7.

```bash
pod 'TZImagePickerController', '2.2.6'
```

--------------------------------

### Global Navigation Bar Configuration

Source: https://context7.com/quintgao/gknavigationbarswift/llms.txt

Configure default navigation bar appearance globally in your AppDelegate. Call this once during app launch to set consistent styling across your entire application. Supports basic setup or custom configurations for various elements like background, title, back button, shadow, status bar, item spacing, and gesture sensitivity.

```swift
// AppDelegate.swift
import GKNavigationBarSwift

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

    // Basic setup with default values (white background, black title)
    GKConfigure.setupDefault()

    // Or use custom configuration
    GKConfigure.setupCustom {
        configure in
        // Navigation bar appearance
        configure.backgroundColor = UIColor.systemBlue
        configure.titleColor = UIColor.white
        configure.titleFont = UIFont.boldSystemFont(ofSize: 18.0)

        // Back button style
        configure.backStyle = .white  // .black, .white, or .none
        configure.backImage = UIImage(named: "custom_back")  // Custom back image

        // Shadow line
        configure.lineHidden = false
        configure.lineColor = UIColor.lightGray

        // Status bar
        configure.statusBarStyle = .lightContent
        configure.statusBarHidden = false

        // Navigation bar item spacing
        configure.gk_navItemLeftSpace = 12.0
        configure.gk_navItemRightSpace = 12.0

        // Gesture sensitivity
        configure.gk_snapMovementSensitivity = 0.7
        configure.gk_popTransitionCriticalValue = 0.5
        configure.gk_pushTransitionCriticalValue = 0.3

        // Global UIScrollView gesture handling
        configure.gk_openScrollViewGestureHandle = true

        // Auto-hide tabbar when pushing
        configure.gk_hidesBottomBarWhenPushed = true
    }

    return true
}
```

--------------------------------

### Setting Status Bar Style on Initialization

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/README.md

Set the status bar style within the controller's initialization method to prevent potential flickering issues when switching view controllers. This ensures the status bar style is correctly applied from the start.

```swift
override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
    super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
    
    self.gk_statusBarStyle = .lightContent
}
```

--------------------------------

### Enable Gesture Handling for UIScrollView

Source: https://context7.com/quintgao/gknavigationbarswift/llms.txt

Enable gesture handling for individual UIScrollView instances to resolve conflicts with navigation pop gestures. This ensures smooth navigation when scroll views are at their content start position.

```swift
import UIKit
import GKNavigationBarSwift

class ScrollViewController: UIViewController {

    private let scrollView = UIScrollView()
    private let tableView = UITableView()

    override func viewDidLoad() {
        super.viewDidLoad()

        // Enable gesture handling for individual scroll views
        scrollView.gk_openGestureHandle = true
        tableView.gk_openGestureHandle = true

        // Setup views
        scrollView.frame = view.bounds
        scrollView.contentSize = CGSize(width: view.bounds.width * 3, height: view.bounds.height)
        scrollView.isPagingEnabled = true
        view.addSubview(scrollView)
    }
}

// Alternatively, enable globally in configuration
// GKConfigure.setupCustom {
//     configure.gk_openScrollViewGestureHandle = true
// }
```

--------------------------------

### Creating Navigation Controller

Source: https://context7.com/quintgao/gknavigationbarswift/llms.txt

Initialize a navigation controller with gesture handling support. Use the convenience initializers to enable full-screen pop gestures and optional scaling transition effects. You can also enable left-swipe to push functionality and control the scaling transition effect.

```swift
import GKNavigationBarSwift

// Basic navigation controller with gesture support
let rootViewController = HomeViewController()
let navigationController = UINavigationController(rootVC: rootViewController)

// Navigation controller with scaling transition effect (like Toutiao app)
let navWithScale = UINavigationController(rootVC: rootViewController, scale: true)

// Enable left-swipe to push functionality
navigationController.gk_openScrollLeftPush = true

// Enable/disable scaling transition
navigationController.gk_transitionScale = true

// Set as window's root
window?.rootViewController = navigationController
window?.makeKeyAndVisible()
```

--------------------------------

### Implement Custom Push and Pop Transitions

Source: https://context7.com/quintgao/gknavigationbarswift/llms.txt

Set custom push and pop transition animations per view controller for unique navigation experiences. Requires conforming to UIViewControllerAnimatedTransitioning.

```swift
import UIKit
import GKNavigationBarSwift

class CustomTransitionViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Set custom push transition
        self.gk_pushTransition = FadeInTransition()

        // Set custom pop transition
        self.gk_popTransition = FadeOutTransition()
    }
}

// Custom fade transition example
class FadeInTransition: NSObject, UIViewControllerAnimatedTransitioning {

    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return 0.35
    }

    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        guard let toView = transitionContext.view(forKey: .to) else { return }

        let containerView = transitionContext.containerView
        toView.alpha = 0
        containerView.addSubview(toView)

        UIView.animate(withDuration: transitionDuration(using: transitionContext), animations: {
            toView.alpha = 1
        }) { _ in
            transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
        }
    }
}

class FadeOutTransition: NSObject, UIViewControllerAnimatedTransitioning {

    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return 0.35
    }

    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        guard let fromView = transitionContext.view(forKey: .from),
              let toView = transitionContext.view(forKey: .to) else { return }

        let containerView = transitionContext.containerView
        containerView.insertSubview(toView, belowSubview: fromView)

        UIView.animate(withDuration: transitionDuration(using: transitionContext), animations: {
            fromView.alpha = 0
        }) { _ in
            transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
        }
    }
}
```

--------------------------------

### Initialize TZImagePickerController and present it

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/Example/Pods/TZImagePickerController/README.md

This Objective-C code initializes the TZImagePickerController with a maximum image count and a delegate. It then presents the picker view controller. You can optionally set a block to handle the selected photos.

```objective-c
TZImagePickerController *imagePickerVc = [[TZImagePickerController alloc] initWithMaxImagesCount:9 delegate:self];

    // You can get the photos by block, the same as by delegate.
    // 你可以通过block或者代理，来得到用户选择的照片.    
    [imagePickerVc setDidFinishPickingPhotosHandle:^(NSArray<UIImage *> *photos, NSArray *assets, BOOL isSelectOriginalPhoto) {
    
    }];
    [self presentViewController:imagePickerVc animated:YES completion:nil];
```

--------------------------------

### Configure TZImagePickerController for Max/Min Video Length and Photo Size

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/Example/Pods/TZImagePickerController/README.md

You can set maximum and minimum lengths for videos and minimum/maximum dimensions for photos. Assets that do not meet these requirements will not be displayed. For synchronous filtering, use `isAssetCanBeDisplayed`. For selection-time warnings, use `isAssetCanBeSelected`.

```swift
let imagePickerVc = TZImagePickerController()
imagePickerVc.maxImagesCount = 9
imagePickerVc.allowPickingVideo = true
imagePickerVc.allowPickingImage = true
imagePickerVc.allowTakeVideo = true
imagePickerVc.allowPickingOriginalPhoto = true

// To set max/min video length:
// imagePickerVc.videoMaximumDuration = 60.0 // seconds
// imagePickerVc.videoMinimumDuration = 5.0 // seconds

// To set min/max photo dimensions (requires custom implementation in isAssetCanBeDisplayed):
// imagePickerVc.photoWidth = 1000
// imagePickerVc.photoHeight = 1000
```

--------------------------------

### Default Navigation Configuration

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/README.md

Add this line in your AppDelegate to set up the default navigation configuration for the application. This is a required step for initializing the library's core settings.

```swift
GKConfigure.setupDefault()
```

--------------------------------

### Implement Custom Asset Filtering

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/Example/Pods/TZImagePickerController/README.md

To filter assets based on specific criteria (e.g., video duration, photo dimensions), implement the `isAssetCanBeDisplayed` method. This method is synchronous. For asynchronous information like video size or iCloud status, you'll need to modify the source code, which may impact album opening speed.

```swift
// Example of implementing isAssetCanBeDisplayed (synchronous filtering):
// func isAssetCanBeDisplayed(asset: PHAsset) -> Bool {
//     // Your filtering logic here
//     return true
// }
```

--------------------------------

### Implement GKViewControllerPopDelegate to Track Pop Progress

Source: https://context7.com/quintgao/gknavigationbarswift/llms.txt

Implement this protocol to receive callbacks during swipe-to-pop gestures. This is useful for coordinating animations or updating UI elements based on the gesture's progress.

```swift
import UIKit
import GKNavigationBarSwift

class AnimatedViewController: UIViewController, GKViewControllerPopDelegate {

    private let overlayView = UIView()

    override func viewDidLoad() {
        super.viewDidLoad()

        // Assign self as pop delegate
        self.gk_popDelegate = self

        // Setup overlay for animation
        overlayView.frame = view.bounds
        overlayView.backgroundColor = UIColor.black.withAlphaComponent(0.5)
        overlayView.alpha = 0
        view.addSubview(overlayView)
    }

    // MARK: - GKViewControllerPopDelegate

    // Called when pop gesture starts
    func viewControllerPopScrollBegan() {
        print("Pop gesture started")
        overlayView.alpha = 0.5
    }

    // Called during pop gesture - track progress (0.0 - 1.0)
    func viewControllerPopScrollUpdate(progress: CGFloat) {
        print("Pop progress: \(progress)")
        // Fade overlay based on progress
        overlayView.alpha = 0.5 * (1 - progress)
    }

    // Called when pop gesture ends
    func viewControllerPopScrollEnded(finished: Bool) {
        if finished {
            print("Pop completed - view will disappear")
        } else {
            print("Pop cancelled - returning to original state")
            UIView.animate(withDuration: 0.25) {
                self.overlayView.alpha = 0
            }
        }
    }
}
```

--------------------------------

### Implement GKViewControllerPushDelegate for Left Swipe to Push

Source: https://context7.com/quintgao/gknavigationbarswift/llms.txt

Implement this protocol to handle custom push transitions triggered by a left swipe. Assign the delegate and implement the required methods to define the push behavior.

```swift
import UIKit
import GKNavigationBarSwift

class ArticleViewController: UIViewController, GKViewControllerPushDelegate {

    var nextArticle: Article?

    override func viewDidLoad() {
        super.viewDidLoad()

        // Assign self as push delegate
        self.gk_pushDelegate = self
    }

    // MARK: - GKViewControllerPushDelegate

    // Called when left swipe completes - create and push the next controller
    func pushToNextViewController() {
        guard let article = nextArticle else { return }
        let nextVC = ArticleViewController()
        nextVC.configure(with: article)
        navigationController?.pushViewController(nextVC, animated: true)
    }

    // Called when push gesture starts
    func viewControllerPushScrollBegan() {
        print("Push gesture started")
        // Prepare next view controller or fetch data
    }

    // Called during push gesture - track progress (0.0 - 1.0)
    func viewControllerPushScrollUpdate(progress: CGFloat) {
        print("Push progress: \(progress)")
        // Update UI based on progress (e.g., preview indicator)
    }

    // Called when push gesture ends
    func viewControllerPushScrollEnded(finished: Bool) {
        if finished {
            print("Push completed")
        } else {
            print("Push cancelled")
        }
    }
}

// Don't forget to enable left swipe push on the navigation controller
// navigationController.gk_openScrollLeftPush = true
```

--------------------------------

### Optimize Video Export Performance

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/Example/Pods/TZImagePickerController/README.md

Video export involves two steps: obtaining an AVURLAsset (which can be slow for iCloud videos due to network requests) and saving the video to the sandbox. To provide user feedback for the slow first step, consider extracting the source code and implementing progress updates.

```swift
// To provide progress for the first step (getting AVURLAsset):
// 1. Copy the library's source code.
// 2. Implement progress tracking for the asset fetching process.
// 3. Display progress to the user.
```

--------------------------------

### Awake GKConfigure on App Launch

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/README.md

Call GKConfigure.awake() during application launch to resolve issues with awake methods not being automatically called in Xcode 11.4 during debugging. Note: Versions 1.4.6 and later may not require manual calling due to changes in loading timing.

```swift
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    
    GKConfigure.awake()
}
```

--------------------------------

### Obtain Image File Path for Uploads

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/Example/Pods/TZImagePickerController/README.md

When uploading photos, do not rely on `PHImageFileURLKey` as it's not always available and only accessible via the Photos framework. If an upload requires a path, save the `UIImage` to the sandbox first and use the sandbox path. For a name parameter, use the image's original name.

```swift
// To upload a photo by path:
// 1. Save the UIImage to the sandbox.
//    let imageData = UIImage.pngData()
//    let filePath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .userDomainMask, true)[0] as NSString
//    let fullPath = filePath.stringByAppendingPathComponent("myImage.png")
//    imageData?.writeToFile(fullPath, atomically: false)
//
// 2. Use the fullPath for uploads.
//
// For a name parameter, use the image's original name.
```

--------------------------------

### Configure Navigation Bar Appearance for TZImagePickerController

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/Example/Pods/TZImagePickerController/README.md

When using TZImagePickerController, if navigation bar color settings are ineffective, especially with WRNavigationBar integrated, ensure TZImagePickerController's controllers are added to WRNavigationBar's blacklist. If WRNavigationBar is not used, search issues for similar problems or provide a reproducible demo.

```objective-c
imagePickerVc.navigationBar.standardAppearance.configureWithOpaque background color:UIColor.whiteColor() foregroundColor:UIColor.blackColor() titleTextAttributes:nil
imagePickerVc.navigationBar.scrollEdgeAppearance.configureWithOpaque background color:UIColor.whiteColor() foregroundColor:UIColor.blackColor() titleTextAttributes:nil
```

--------------------------------

### Handle Asset Selection Constraints

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/Example/Pods/TZImagePickerController/README.md

To prevent users from selecting assets that don't meet certain criteria (e.g., maximum number of photos), implement the `isAssetCanBeSelected` method. This method is called when the user attempts to select an asset.

```swift
// Example of implementing isAssetCanBeSelected:
// func isAssetCanBeSelected(asset: PHAsset) -> Bool {
//     // Check if the asset meets selection criteria
//     return true
// }
```

--------------------------------

### Configure Navigation Bar for Dark Mode

Source: https://context7.com/quintgao/gknavigationbarswift/llms.txt

Set navigation bar appearance for both light and dark modes with automatic switching support. Images for background, shadow, and back button can be customized per mode.

```swift
import UIKit
import GKNavigationBarSwift

class DarkModeSupportViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        self.gk_navTitle = "Dark Mode Support"

        // Set light mode appearance
        self.gk_navBackgroundColor = UIColor.white
        self.gk_navBackgroundImage = UIImage(named: "nav_bg_light")
        self.gk_navShadowImage = UIImage(named: "nav_line_light")
        self.gk_backImage = UIImage(named: "back_black")

        // Set dark mode appearance (automatically used in dark mode)
        self.gk_darkNavBackgroundImage = UIImage(named: "nav_bg_dark")
        self.gk_darkNavShadowImage = UIImage(named: "nav_line_dark")
        self.gk_darkBackImage = UIImage(named: "back_white")
    }
}

// Global dark mode configuration
// GKConfigure.setupCustom {
//     configure in
//     configure.backgroundImage = UIImage(named: "nav_bg_light")
//     configure.darkBackgroundImage = UIImage(named: "nav_bg_dark")
//     configure.lineImage = UIImage(named: "nav_line_light")
//     configure.darkLineImage = UIImage(named: "nav_line_dark")
//     configure.backImage = UIImage(named: "back_black")
//     configure.darkBackImage = UIImage(named: "back_white")
// }
```

--------------------------------

### Access Device Metrics and Safe Area Information

Source: https://context7.com/quintgao/gknavigationbarswift/llms.txt

Use these static methods to retrieve device-specific layout information. Ensure UIKit and GKNavigationBarSwift are imported. This code is typically used within a UIViewController's lifecycle methods.

```swift
import UIKit
import GKNavigationBarSwift

class LayoutViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Navigation bar heights
        let navBarHeight = UIDevice.navBarHeight()           // Without status bar
        let fullNavHeight = UIDevice.navBarFullHeight()      // With status bar
        let portraitNavHeight = UIDevice.navBarFullHeightForPortrait()

        // Status bar heights
        let statusBarHeight = UIDevice.statusBarFullHeight()
        let portraitStatusBarHeight = UIDevice.statusBarHeightForPortrait()

        // Tab bar height
        let tabBarHeight = UIDevice.tabBarHeight()

        // Safe area insets
        let safeInsets = UIDevice.safeAreaInsets()

        // Screen detection
        let isNotched = UIDevice.isNotchedScreen           // iPhone X and later
        let isDynamicIsland = UIDevice.isDynamicIslandScreen()  // iPhone 14 Pro and later
        let isLandscape = UIDevice.isLandScape()

        // Device type
        let isIPad = UIDevice.isIPad
        let isIPhone = UIDevice.isIPhone
        let isMac = UIDevice.isMac                          // Mac Catalyst

        // Screen sizes
        let screenWidth = UIDevice.width
        let screenHeight = UIDevice.height

        // Liquid Glass support (iOS 26+)
        let isLiquidGlass = UIDevice.isLiquidGlass()

        // Example: Layout content below navigation bar
        let contentView = UIView()
        contentView.frame = CGRect(
            x: 0,
            y: fullNavHeight,
            width: view.bounds.width,
            height: view.bounds.height - fullNavHeight - tabBarHeight
        )
        view.addSubview(contentView)
    }
}
```

--------------------------------

### Dynamic Status Bar Visibility

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/README.md

Implement these methods in your base view controller to dynamically control the status bar's visibility. Ensure these are overridden in subclasses that require dynamic status bar behavior.

```swift
override var prefersStatusBarHidden: Bool {
    return self.gk_statusBarHidden
}

override var preferredStatusBarStyle: UIStatusBarStyle {
    return self.gk_statusBarStyle
}
```

--------------------------------

### Intercept Navigation Pop Behavior in Swift

Source: https://context7.com/quintgao/gknavigationbarswift/llms.txt

Implement `GKGesturePopHandlerProtocol` to intercept and control navigation pop behavior for both button clicks and swipe gestures. Return `true` to allow the pop action.

```swift
import UIKit
import GKNavigationBarSwift

class EditViewController: UIViewController {

    var hasChanges = false

    override func viewDidLoad() {
        super.viewDidLoad()
        self.gk_navTitle = "Edit Profile"
    }

    // Called for both button clicks and gestures
    // Return true to allow pop, false to prevent
    override func navigationShouldPop() -> Bool {
        if hasChanges {
            showUnsavedChangesAlert()
            return false
        }
        return true
    }

    // Optional: Control only gesture-based pop
    func navigationShouldPopOnGesture() -> Bool {
        return !hasChanges
    }

    // Optional: Control only button click pop
    func navigationShouldPopOnClick() -> Bool {
        if hasChanges {
            showUnsavedChangesAlert()
            return false
        }
        return true
    }

    // Optional: Handle gesture conflicts (e.g., with WKWebView)
    func popGestureRecognizer(_ gestureRecognizer: UIGestureRecognizer,
                              shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        // Return true to allow both gestures to work simultaneously
        return true
    }

    private func showUnsavedChangesAlert() {
        let alert = UIAlertController(
            title: "Unsaved Changes",
            message: "You have unsaved changes. Do you want to discard them?",
            preferredStyle: .alert
        )
        alert.addAction(UIAlertAction(title: "Cancel", style: .cancel))
        alert.addAction(UIAlertAction(title: "Discard", style: .destructive) { [weak self] _ in
            self?.hasChanges = false
            self?.navigationController?.popViewController(animated: true)
        })
        present(alert, animated: true)
    }
}
```

--------------------------------

### Adding Custom Navigation Bar Button Items

Source: https://context7.com/quintgao/gknavigationbarswift/llms.txt

Add custom left and right bar button items to the navigation bar using factory methods. Supports images, titles, custom colors, and fonts.

```swift
import UIKit
import GKNavigationBarSwift

class SettingsViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        self.gk_navTitle = "Settings"

        // Single right bar button with image
        self.gk_navRightBarButtonItem = UIBarButtonItem.gk_item(
            image: UIImage(named: "icon_more"),
            target: self,
            action: #selector(moreButtonTapped)
        )

        // Single right bar button with title
        self.gk_navRightBarButtonItem = UIBarButtonItem.gk_item(
            title: "Save",
            color: UIColor.systemBlue,
            font: UIFont.systemFont(ofSize: 16),
            target: self,
            action: #selector(saveButtonTapped)
        )

        // Multiple right bar buttons
        let searchItem = UIBarButtonItem.gk_item(
            image: UIImage(named: "icon_search"),
            target: self,
            action: #selector(searchTapped)
        )
        let shareItem = UIBarButtonItem.gk_item(
            image: UIImage(named: "icon_share"),
            target: self,
            action: #selector(shareTapped)
        )
        self.gk_navRightBarButtonItems = [shareItem, searchItem]

        // Custom left bar button (replaces back button)
        self.gk_navLeftBarButtonItem = UIBarButtonItem.gk_item(
            title: "Cancel",
            color: UIColor.red,
            target: self,
            action: #selector(cancelTapped)
        )

        // Bar button with image and custom color
        let coloredItem = UIBarButtonItem.gk_item(
            image: UIImage(named: "icon_star"),
            color: UIColor.systemYellow,
            target: self,
            action: #selector(starTapped)
        )
        self.gk_navRightBarButtonItem = coloredItem
    }

    @objc func moreButtonTapped() {
        print("More tapped")
    }

    @objc func saveButtonTapped() {
        print("Save tapped")
    }

    @objc func searchTapped() {
        print("Search tapped")
    }

    @objc func shareTapped() {
        print("Share tapped")
    }

    @objc func cancelTapped() {
        navigationController?.popViewController(animated: true)
    }

    @objc func starTapped() {
        print("Star tapped")
    }
}

```

--------------------------------

### Control Status Bar Appearance in Swift

Source: https://context7.com/quintgao/gknavigationbarswift/llms.txt

Set the status bar style and visibility per view controller. Ensure to override `prefersStatusBarHidden` and `preferredStatusBarStyle` for dynamic changes.

```swift
import UIKit
import GKNavigationBarSwift

class DarkModeViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        view.backgroundColor = UIColor.black

        // Set status bar style
        self.gk_statusBarStyle = .lightContent

        // Hide status bar
        self.gk_statusBarHidden = false
    }

    // REQUIRED: Override these methods for dynamic status bar changes
    override var prefersStatusBarHidden: Bool {
        return self.gk_statusBarHidden
    }

    override var preferredStatusBarStyle: UIStatusBarStyle {
        return self.gk_statusBarStyle
    }

    // Toggle status bar visibility
    func toggleStatusBar() {
        self.gk_statusBarHidden = !self.gk_statusBarHidden
    }

    // Change status bar style dynamically
    func setLightStatusBar() {
        self.gk_statusBarStyle = .lightContent
    }

    func setDarkStatusBar() {
        if #available(iOS 13.0, *) {
            self.gk_statusBarStyle = .darkContent
        } else {
            self.gk_statusBarStyle = .default
        }
    }
}
```

--------------------------------

### Handle Video Export Issues with TZImagePickerController

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/Example/Pods/TZImagePickerController/README.md

For video export failures, upgrade to version 2.2.6 or later. This version defaults to not correcting video orientation, which can resolve issues with videos from Android devices. If orientation correction is needed, set `needFixComposition` to YES, but be aware of potential failures with Android videos. Refer to the issue for more details.

```swift
let imagePickerVc = TZImagePickerController()
imagePickerVc.needFixComposition = true // Set to true if orientation correction is required, but be cautious with Android videos.
```

--------------------------------

### Dynamic Navigation Bar Transparency on Scroll

Source: https://context7.com/quintgao/gknavigationbarswift/llms.txt

Implement transparency effects for the navigation bar that change based on scroll position. Useful for detail pages with header images. Ensure the view controller conforms to UIScrollViewDelegate.

```swift
import UIKit
import GKNavigationBarSwift

class ScrollDetailViewController: UIViewController, UIScrollViewDelegate {

    private let scrollView = UIScrollView()
    private let headerHeight: CGFloat = 250

    override func viewDidLoad() {
        super.viewDidLoad()

        // Start with transparent navigation bar
        self.gk_navBarAlpha = 0.0
        self.gk_navBackgroundColor = UIColor.white
        self.gk_navLineHidden = true
        self.gk_navTitle = "Photo Detail"

        // Setup scroll view
        scrollView.delegate = self
        scrollView.frame = view.bounds
        scrollView.contentSize = CGSize(width: view.bounds.width, height: 1500)
        view.addSubview(scrollView)

        // Add header image view
        let headerView = UIImageView(frame: CGRect(x: 0, y: 0, width: view.bounds.width, height: headerHeight))
        headerView.image = UIImage(named: "header_bg")
        headerView.contentMode = .scaleAspectFill
        scrollView.addSubview(headerView)
    }

    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        let offsetY = scrollView.contentOffset.y

        // Calculate alpha based on scroll offset
        var alpha: CGFloat = 0
        if offsetY > 0 {
            alpha = min(1.0, offsetY / (headerHeight - 88))
        }

        // Update navigation bar transparency
        self.gk_navBarAlpha = alpha

        // Change title color based on alpha
        self.gk_navTitleColor = alpha > 0.5 ? .black : .white

        // Change back button style based on background
        self.gk_backStyle = alpha > 0.5 ? .black : .white

        // Show shadow line when fully opaque
        self.gk_navLineHidden = alpha < 1.0
    }
}
```

--------------------------------

### Per-Controller Navigation Bar Customization

Source: https://context7.com/quintgao/gknavigationbarswift/llms.txt

Customize the navigation bar appearance for individual view controllers. Each property automatically triggers the navigation bar to update when set. This includes setting the title, background color or image, title styling, shadow line, back button image and style, transparency, and more.

```swift
import UIKit
import GKNavigationBarSwift

class DetailViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad() // MARK: - Navigation Bar Customization

        // Set navigation bar title
        self.gk_navTitle = "Detail Page"

        // Or use custom title view
        let titleLabel = UILabel()
        titleLabel.text = "Custom Title"
        titleLabel.textColor = .white
        self.gk_navTitleView = titleLabel

        // Background color
        self.gk_navBackgroundColor = UIColor.systemIndigo

        // Or use background image
        self.gk_navBackgroundImage = UIImage(named: "nav_bg")

        // Title styling
        self.gk_navTitleColor = UIColor.white
        self.gk_navTitleFont = UIFont.boldSystemFont(ofSize: 20)

        // Shadow line
        self.gk_navShadowColor = UIColor.gray
        self.gk_navLineHidden = false  // Show/hide shadow line

        // Custom back button image
        self.gk_backImage = UIImage(named: "white_back")
        self.gk_backStyle = .white  // .black, .white, .none

        // Navigation bar transparency (0.0 - 1.0)
        self.gk_navBarAlpha = 1.0
    }

    // Hide/show shadow line dynamically
    func toggleShadowLine() {
        self.hideNavLine()  // Hide
        self.showNavLine()  // Show
    }
}
```

--------------------------------

### Control Swipe-to-Pop Gestures in Swift

Source: https://context7.com/quintgao/gknavigationbarswift/llms.txt

Manage swipe-to-pop gesture behavior per view controller. Options include disabling gestures, enabling edge-only pop, or customizing the swipe distance.

```swift
import UIKit
import GKNavigationBarSwift

class FormViewController: UIViewController {

    var hasUnsavedChanges = false

    override func viewDidLoad() {
        super.viewDidLoad()

        // Disable all pop gestures
        self.gk_interactivePopDisabled = true

        // Or disable full-screen pop, keep edge pop only
        self.gk_fullScreenPopDisabled = true

        // Set maximum distance from left edge for pop gesture (in points)
        self.gk_maxPopDistance = 100

        // Disable system gesture handling (for custom transitions)
        self.gk_systemGestureHandleDisabled = false
    }

    // Enable/disable gestures based on form state
    func updateGestureState() {
        if hasUnsavedChanges {
            self.gk_interactivePopDisabled = true
        } else {
            self.gk_interactivePopDisabled = false
        }
    }
}
```

--------------------------------

### Setting Navigation Bar Background Color

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/README.md

Set the background color of the navigation bar by assigning a UIColor to the `gk_navBackgroundColor` property. This property is available immediately after calling it, creating the navigation bar if it doesn't exist.

```swift
self.gk_navBackgroundColor = [UIColor red]
```

--------------------------------

### Fix Navigation Bar Issues with GKNavigationBarViewController

Source: https://github.com/quintgao/gknavigationbarswift/blob/master/Example/Pods/TZImagePickerController/README.md

If the navigation bar disappears when using GKNavigationBarViewController, ensure the library is updated to version 2.0.4 or later. Refer to the provided issue link for detailed information.

```swift
import GKNavigationBarViewController

// Ensure GKNavigationBarViewController is updated to 2.0.4 or later
```

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