Efficiency of grid generated by for-in loop

Question

I've spend the last several hours working on a loop designed to take items in an array and arrange them as a so to speak "gird" of UIButtons. As far as I've been able to see through testing this code works perfectly.

However, I am new to creating loops and I was wondering if anyone could give me any pointers on how I could make this code cleaner/more efficient for future coding purposes.

I know my question is very similar to Optimize sorting of Array according to Distance (CLLocation), but I'm really hoping to get some tips on a "per case" basis. Thank you for your time.

- (void)myMethod
{
 NSArray *array = [[NSArray alloc] initWithObjects:@"Item #1", @"Item #2", @"Item #3", @"Item #4", @"Item #5", @"Item #6", @"Item #7", @"Item #8", nil];
 BOOL leftOkay = NO;
 BOOL centerOkay = NO;
 BOOL rightOkay = NO;
 int left = 0;
 int center = 1;
 int right = 2;
 int yOrigin = 0;
 int spaceBetweenItems = 5;
 UIButton *leftButton;
 UIButton *centerButton;
 UIButton *rightButton;
 for (int i = 0; i < [array count]; i++)
 {
 if (left < [array count]) {
 leftButton = [[UIButton alloc] initWithFrame:CGRectMake(spaceBetweenItems, yOrigin + spaceBetweenItems, 100, 150)];
 [leftButton setTitle:[array objectAtIndex:left] forState:UIControlStateNormal];
 [leftButton setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
 [leftButton setBackgroundColor:[UIColor cyanColor]];
 [myScrollView addSubview:leftButton];
 leftOkay = YES;
 }
 if (center < [array count]) {
 centerButton = [[UIButton alloc] initWithFrame:CGRectMake(110, yOrigin + spaceBetweenItems, 100, 150)];
 [centerButton setTitle:[array objectAtIndex:center] forState:UIControlStateNormal];
 [centerButton setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];
 [centerButton setBackgroundColor:[UIColor yellowColor]];
 [myScrollView addSubview:centerButton];
 centerOkay = YES;
 }
 if (right < [array count]) {
 rightButton = [[UIButton alloc] initWithFrame:CGRectMake(215, yOrigin + spaceBetweenItems, 100, 150)];
 [rightButton setTitle:[array objectAtIndex:right] forState:UIControlStateNormal];
 [rightButton setTitleColor:[UIColor greenColor] forState:UIControlStateNormal];
 [rightButton setBackgroundColor:[UIColor purpleColor]];
 [myScrollView addSubview:rightButton];
 rightOkay = YES;
 }
 if (leftOkay == YES && centerOkay == YES && rightOkay == YES) {
 yOrigin = yOrigin + leftButton.frame.size.height + (spaceBetweenItems * 2);
 leftOkay = NO;
 centerOkay = NO;
 rightOkay = NO;
 }
 left = left + 3;
 center = center + 3;
 right = right + 3;
 }
 myScrollView.contentSize = CGSizeMake(myScrollView.frame.size.width, yOrigin + leftButton.frame.size.height + (spaceBetweenItems * 2));
}

Answer 1

you can write this code dramatically shorter like

self.view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
NSArray *array = [[NSArray alloc] initWithObjects:@"Item #1", @"Item #2", @"Item #3", @"Item #4", @"Item #5", @"Item #6", @"Item #7", @"Item #8", nil];
NSUInteger buttonWidth = 100;
NSUInteger buttonHight = 100;
NSUInteger spacer = 5;
NSUInteger leftOffset = 5;
NSUInteger topOffset = 5;
[array enumerateObjectsUsingBlock:^(NSString *obj, NSUInteger idx, BOOL *stop) {
 int row = idx / 3;
 int column = idx %3;
 UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
 button.frame = CGRectMake((buttonWidth + spacer)*column+leftOffset, (buttonHight+spacer)*row +topOffset , buttonWidth , buttonHight);
 [button setTitle:obj forState:UIControlStateNormal];
 [self.view addSubview:button];
}];

_{Note: ARC enabled}

• vikingosegundo: edited to have central defined variables
• vikingosegundo: If you'd like to have some explanations, just go ahead and ask :)
• Mick MacCallum: I appreciate it, my implementation of this is fairly simple, the array is actually a list of image file names 0 to x in NSDocumentsDirectory which .jpg is later appended to. So then I'm linking all the buttons to a void with a UIButton argument so I can pass the currently selected images frame property in order to animate the button/image growing to full screen when it is selected. Would you say this is a good way of doing this?
• vikingosegundo: sounds reasonable to me.