Creating UI elements programmatically in Objective-C

Question

I have been working on automating some aspects of creating UI elements and have created this method that seems to work:

    - (void) viewDidLoad
        {
            [super viewDidLoad];
            button = [self createButton:button xPos:30 yPos:100 width:100 height:30  caption:@"autoButton" textPos:NSTextAlignmentCenter textClr:[UIColor blackColor] backClr:[UIColor yellowColor]];
            [self.view addSubview: button];
        }

    - (UIButton *) createButton:(UIButton *)control xPos:(CGFloat)x yPos:(CGFloat)y width:(CGFloat)width height:(CGFloat)height caption:(NSString *)caption textPos:(NSTextAlignmentCenter)textPosition textClr:(UIColor *)textColor backClr:(UIColor *)backColor
        {
            control = [[UIButton alloc] initWithFrame: CGRectMake(x, y, width, height)];
            [control setTitle:caption forState:UIControlStateNormal];
            control.titleLabel.textAlignment = textPosition;
            control.backgroundColor = backColor;
            [control setTitleColor: textColor forState:UIControlStateNormal];
            return control;
        }

1. Is there anything wrong/bad with this implementation?

2. Instead of using methods, would it be possible to implement the same thing with just plain old functions? It's a little long-winded to have to indicate the parameter names, xPos:30 yPos:100 width:100 height:100, etc.

Would be nice to be able to just do something like:

button = createButton(30, 100, 100, 30, @"autoButton", NSTextAlignmentCenter, [UIColor blackColor], [UIColor yellowColor]);

Is this doable?

Answer 1

1. Fine except it makes no sense to pass in the button parameter. Just return a UIButton object.

    - (void) viewDidLoad { [super viewDidLoad]; button = [self createButtonWithxPos:30 yPos:100 width:100 height:30 caption:@"autoButton" textPos:NSTextAlignmentCenter textClr:[UIColor blackColor] backClr:[UIColor yellowColor]]; [self.view addSubview: button]; } - (UIButton *) createButtonWithxPos:(CGFloat)x yPos:(CGFloat)y width:(CGFloat)width height:(CGFloat)height caption:(NSString *)caption textPos:(NSTextAlignmentCenter)textPosition textClr:(UIColor *)textColor backClr:(UIColor *)backColor { UIButton *control = [[UIButton alloc] initWithFrame: CGRectMake(x, y, width, height)]; [control setTitle:caption forState:UIControlStateNormal]; control.titleLabel.textAlignment = textPosition; control.backgroundColor = backColor; [control setTitleColor: textColor forState:UIControlStateNormal]; return control; } 

2. Fine, use a function or a method. Up to you. As long as you don't need self involved, a function works.

    UIButton *createButton(CGFloat x, CGFloat y, CGFloat width, CGFloat height, NSString *caption, NSTextAlignmentCenter textPosition, UIColor *textColor, UIColor *backColor) { UIButton *control = [[UIButton alloc] initWithFrame: CGRectMake(x, y, width, height)]; [control setTitle:caption forState:UIControlStateNormal]; control.titleLabel.textAlignment = textPosition; control.backgroundColor = backColor; [control setTitleColor: textColor forState:UIControlStateNormal]; return control; } - (void) viewDidLoad { [super viewDidLoad]; button = createButton(30, 100, 100, 30, @"autoButton", NSTextAlignmentCenter, [UIColor blackColor], [UIColor yellowColor]); [self.view addSubview: button]; } 

Answer 2

You can use the category built-in feature in Objective-c :
1. Apple documentary for customising classes
2. Categories tutorial