Understanding the UIImagePicker Editing View

Overview of UIImagePickerController and Its Editing View

UIImagePickerController is a built-in iOS class used to manage image capture, editing, and sharing functionality. When an app uses UIImagePickerController, it presents a default camera or photo library view that allows users to take photos or select existing images.

However, this default editing view often comes with limitations in terms of customization. In our case, we’re looking to replace the standard ‘Retake’ and ‘Choose’ buttons with custom designs. To achieve this, we’ll need to create a custom ViewController and overlay it on top of the default picker’s editing view.

Understanding the Customization Process

To customize the UIImagePicker editing view, we must first understand how it works internally. When you create an instance of UIImagePickerController, it loads a default editing view that includes standard buttons for retaking photos or selecting existing images.

Our goal is to replace this default editing view with a custom one, which we can achieve by creating a separate ViewController and overlaying it on top of the default picker’s editing view. This process involves several steps:

1. Create a new ViewController that will serve as our custom editing view.
2. Designate this custom ViewController as the delegate for our UIImagePickerController.
3. Use a method to set the camera overlay view (a subview of the editing view) and make sure it is visible on top of the default picker’s editing view.

Creating the Custom Editing View

To start, let’s create a new ViewController class that we can use as our custom editing view. We’ll call this class CameraOverlayViewController.

// CameraOverlayViewController.h
#import <UIKit/UIKit.h>

@interface CameraOverlayViewController : UIViewController

@end

Next, we need to define the properties and methods for our custom ViewController. In this case, we only need a method to display the camera overlay view.

// CameraOverlayViewController.m
#import "CameraOverlayViewController.h"

@implementation CameraOverlayViewController

- (void)displayCameraOverlay {
    // Set up the camera overlay view here...
}

@end

Setting Up the Camera Overlay View

Now that we have our custom ViewController, let’s set it up as the delegate for our UIImagePickerController. We’ll also create an instance of UIImagePicker and configure its properties to use our custom editing view.

// startCameraControllerFromViewController
- (BOOL)startCameraControllerFromViewController:(UIViewController *)controller withAnimation:(BOOL)animated {
    // Set up camera overlay view...
    
    CameraOverlayViewController *cameraOverlay = [controller.storyboard instantiateViewControllerWithIdentifier:@"FuCameraOverlayID"];
    cameraOverlay.delegate = self;
    self.cameraOverlay = cameraOverlay;

    UIImagePickerController *cameraUI = [[UIImagePickerController alloc] init];
    cameraUI.sourceType = UIImagePickerControllerSourceTypeCamera;
    cameraUI.allowsEditing = NO;
    cameraUI.showsCameraControls = NO;
    cameraUI.delegate = self;
    [cameraUI setCameraOverlayView:self.cameraOverlay.view];
    self.imagePicker = cameraUI;

    // Present the picker view controller...
}

Setting Up the UI

Now that we have our UIImagePickerController configured to use a custom editing view, let’s set up the UI for this editing view. We’ll create a new ViewController class called EditPhotoViewController, which will serve as our custom editing view.

// EditPhotoViewController.h
#import <UIKit/UIKit.h>

@interface EditPhotoViewController : UIViewController

@end

Next, we need to define the properties and methods for our custom ViewController. In this case, we’ll have a button that allows users to retake photos or select existing images.

// EditPhotoViewController.m
#import "EditPhotoViewController.h"

@implementation EditPhotoViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    UIButton *retakeButton = [[UIButton alloc] initWithFrame:CGRectMake(10, 10, 100, 50)];
    retakeButton.backgroundColor = [UIColor redColor];
    retakeButton.setTitle(@"Retake", forState:UIControlStateNormal);
    [retakeButton addTarget:self action:@selector(retakePhoto:) forControlEvents:UIControlEventTouchUpInside];

    self.view.addSubview(retakeButton);

}

- (void)retakePhoto:(id)sender {
    // Handle the retake photo action...
}

@end

Integrating the Custom Editing View with the Default Picker

Now that we have our custom ViewController set up, let’s integrate it with the default picker. We’ll use a method to overlay our custom editing view on top of the default picker’s editing view.

// startCameraControllerFromViewController
- (BOOL)startCameraControllerFromViewController:(UIViewController *)controller withAnimation:(BOOL)animated {
    // Set up camera overlay view...

    UIImagePickerController *cameraUI = [[UIImagePickerController alloc] init];
    cameraUI.sourceType = UIImagePickerControllerSourceTypeCamera;
    cameraUI.allowsEditing = NO;
    cameraUI.showsCameraControls = NO;
    cameraUI.delegate = self;
    [cameraUI setCameraOverlayView:self.cameraOverlay.view];
    self.imagePicker = cameraUI;

    // Present the picker view controller...
}

Putting It All Together

To summarize, we’ve created a custom ViewController class called CameraOverlayViewController, which serves as our custom editing view. We’ve also configured our UIImagePickerController to use this custom editing view.

The final code block looks like this:

// startCameraControllerFromViewController
- (BOOL)startCameraControllerFromViewController:(UIViewController *)controller withAnimation:(BOOL)animated {
    // Set up camera overlay view...

    CameraOverlayViewController *cameraOverlay = [controller.storyboard instantiateViewControllerWithIdentifier:@"FuCameraOverlayID"];
    cameraOverlay.delegate = self;
    self.cameraOverlay = cameraOverlay;

    UIImagePickerController *cameraUI = [[UIImagePickerController alloc] init];
    cameraUI.sourceType = UIImagePickerControllerSourceTypeCamera;
    cameraUI.allowsEditing = NO;
    cameraUI.showsCameraControls = NO;
    cameraUI.delegate = self;
    [cameraUI setCameraOverlayView:self.cameraOverlay.view];
    self.imagePicker = cameraUI;

    // Present the picker view controller...
}

In this article, we have discussed how to customize the default UIImagePicker editing view. We covered creating a custom ViewController, setting up the camera overlay view, and integrating it with the default picker.

This approach can be used for various purposes such as replacing the standard buttons with custom designs or implementing additional functionality in your app’s photo editing section.

Last modified on 2024-01-10