Setting UISearchBar's search field background image changes the padding

Question

When I set a search field background image on a UIImage, the padding between the magnifying glass and placeholder text in the search bar when selected changes.

With the default background:

With a custom background:

This change is caused by these two lines:

UIImage *colorImage = [UIImage imageWithColor:[UIColor grayColor] size:CGSizeMake(28, 28)];
[self setSearchFieldBackgroundImage:[colorImage imageWithRoundedCorners:5] forState:UIControlStateNormal];

imageWithRoundedCorners: is a category method that simply draws the image onto a CALayer with a corner radius and then creates a UIImage from the graphics context.

Why is this and how can I avoid this? I tried passing an explicitly resizable image, but that had no effect.

Answer 1

Its odd that it resets it, however you can use something like this to set it to your liking after setting the background image. searchTextPositionAdjustment is a property on UISearchBar and works perfectly. 8.0 seems to be the default, but you could set it to whatever you like.

[self.searchBar setSearchFieldBackgroundImage:[self imageWithColor:[UIColor grayColor] andSize:CGSizeMake(28.0, 28.0)] forState:UIControlStateNormal];
[self.searchBar setSearchTextPositionAdjustment:UIOffsetMake(8.0, 0.0)];

Answer 2

For all those now using Swift, you can use the following code (works in Swift 2)

let searchBarBackground = UIImage.roundedImage(UIImage.imageWithColor(UIColor.whiteColor(), size: CGSize(width: 28, height: 28)),cornerRadius: 2)
searchBar.setSearchFieldBackgroundImage(searchBarBackground, forState: .Normal)
searchBar.searchTextPositionAdjustment = UIOffsetMake(8.0, 0.0)

Use this with an extension to UIImage:

extension UIImage {
     class func imageWithColor(color: UIColor, size: CGSize) -> UIImage {
        let rect: CGRect = CGRectMake(0, 0, size.width, size.height)
        UIGraphicsBeginImageContextWithOptions(size, false, 0)
        color.setFill()
        UIRectFill(rect)
        let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }
    class func roundedImage(image: UIImage, cornerRadius: Int) -> UIImage {
        let rect = CGRect(origin:CGPoint(x: 0, y: 0), size: image.size)
        UIGraphicsBeginImageContextWithOptions(image.size, false, 1)
        UIBezierPath(
            roundedRect: rect,
            cornerRadius: CGFloat(cornerRadius)
        ).addClip()
        image.drawInRect(rect)
        return UIGraphicsGetImageFromCurrentImageContext()
    }
}

To give something looking like this:

Answer 3

Updated solution for Swift 4

searchTextPositionAdjustment = UIOffset(horizontal: 8.0, vertical: 0.0)