alwaysTemplate

AlwaysTemplate is a rendering mode used in UIKit to treat an image as a template image. When an image is rendered in a view that supports tintColor, such as UIImageView, UIButton, or UIBarButtonItem, the non-transparent areas of the image are used as a mask and are drawn with the view’s tintColor rather than the image’s original colors. This enables consistent theming and icon coloring across an app.

Conceptually, a template image preserves only its alpha mask. The actual color comes from the tintColor applied by the hosting control or view. This is useful for icons that should adapt to different themes, states, or accessibility settings without creating multiple colored assets.

Usage in code typically involves creating or converting an image to template rendering mode, assigning it to a view, and then setting the tintColor. Example in Swift:

let icon = UIImage(named: "icon")?.withRenderingMode(.alwaysTemplate)

imageView.image = icon

imageView.tintColor = .systemBlue

In Interface Builder, you can set the image’s Rendering to Template Image and adjust the view’s Tint color to achieve the desired appearance. Template rendering is especially common for bar button items and tab bars where a single asset can adapt to different contexts and themes.

Notes and limitations: alwaysTemplate is appropriate for monochrome icons. If the source image contains multiple colors, they will be discarded in favor of the tintColor. To preserve original colors, use alwaysOriginal. SwiftUI offers a related approach with renderingMode(.template), which applies a similar templating concept to SwiftUI views. AlwaysTemplate is supported on iOS 7 and later.