Archive for November, 2008

Creating UIColor objects from hex values

November 27, 2008 at 12:29 pm · Comments (20)

It’s pretty inconvenient to create UIColor objects while developing apps for the iPhone, as you need to specific separate values for the RGB parts: red, green, blue.

I found a trick online a few weeks ago on how to automatically generate that code, by simply using a macro:

#define UIColorFromRGB(rgbValue) [UIColor \
    colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 \
    green:((float)((rgbValue & 0xFF00) >> 8))/255.0 \
    blue:((float)(rgbValue & 0xFF))/255.0 alpha:1.0]

The usage looks something like this:

- (UITableViewCell *)tableView:(UITableView *)tv cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell"];
    if (nil == cell) {
        cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:@"cell"] autorelease];
    }
    cell.textColor = UIColorFromRGB(0x333333);
    cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
    cell.text = @"Testing 1 2 3";
}

Hope that’s useful to someone.