Object oriented code reuse in iOS and objective-c [closed]

Question

I have a viewController in my iOS class and in viewDidLoad, I create a gradient with CAGradient and add it to the layer of my view. I want this to appear in other views too, so what's the best way to do that? (New to objective-c and ios, I know how to do this in PHP and C#).

Answer 1

One way would be to make a category on CALayer, and add a method to create and add your custom gradient. Something like this:

@implementation CALayer (CustomGradient)

-(void)addCustomGradient {
CAGradientLayer *gradientLayer = [CAGradientLayer layer];
gradientLayer.frame = self.bounds;
gradientLayer.startPoint = CGPointMake(.25, 0);
gradientLayer.endPoint = CGPointMake(1, 1);
gradientLayer.colors = @[(id)[UIColor colorWithHue:.5 saturation:.6 brightness:1 alpha:1].CGColor,(id)[UIColor colorWithHue:.65 saturation:.6 brightness:1 alpha:.5].CGColor];
gradientLayer.locations = @[@0.0f,@1.00f];
[self insertSublayer:gradientLayer atIndex:0];
}

And you could use it like this:

#import "ViewController.h"
#import <QuartzCore/QuartzCore.h>
#import "CALayer+CustomGradient.h"


@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self.view.layer addCustomGradient];
}