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Flash messages – or toasts, in Android parlance – are discrete, non-modal alerts designed to notify users without completely capturing their focus. For example, you might use a flash message to let the user know that new data has finished loading, that a document has been saved, or that a non-critical error has occurred.

Flash.swift makes displaying these kinds of messages easy, and gives you flexibility to custom their appearance and behaviour.

Screenshots

Installation

Flash.swift is available through the Swift Package Manager. To use Flash.swift with SPM, add https://github.com/conmulligan/Flash.swift.git as a dependency.

Getting Started

For an interactive example that you can build and run, check out the Xcode project in the Example directory.

Basic example

Showing a flash message can be as simple as creating a FlashView instance and calling the show() function:

let flash = FlashView(text: "Hello!")
flash.show()

You can also pass an image:

let star = UIImage(systemName: "star.fill")
let flash = FlashView(text: "Hello!", image: star)
flash.show()

By default, flash views are added directly to the active window’s view heirarchy. Adding the flash view direct to the window has some advantages; for example, doing so allows the flash view to survive changes to the view heirarchy, like a view controller being popped from a navigation stack.

If you want to show a flash message in a specific view, pass a UIView instance to the show() method:

flash.show(in: view)

By default, flash messages are visible for 2 seconds. You can change the duration by passing a TimeInterval value:

flash.show(duration: 5) // seconds

If you want the flash message to appear indefinitely, pass a duration of 0:

flash.show(duration: 0)

The flash message will be visible until the user taps on it (if tap-to-dismiss is enabled), or until dismissed programatically:

flash.hide()

Customization

The FlashView.Configuration struct allows you to customize the flash view’s alignment, background color, text color and more. In most cases, the default configuration should be used as a baseline:

var configuration = FlashView.Configuration.defaultConfiguration()
configuration.titleProperties.textColor = .red

You can also create a configuration from scratch using the default initializer:

let configuration = FlashView.Configuration(alignment: .bottom,
                                            playsHaptics: false,
                                            tapToDismiss: false)

Once you have created a configuration, pass it to the flash view’s initializer:

let flash = FlashView(text: "Hello!", configuration: configuration)
flash.show()

If you want to change the configuration for all flash views, use the shared static property:

FlashView.Configuration.shared.titleProperties.textColor = .white
FlashView.Configuration.shared.backgroundProperties.color = .systemBlue

Configuration Properties

Property	Description
alignment	The flash view’s vertical alignment.
spacing	The image-text spacing.
insets	The flash view’s layout insets, relative to its parent view.
contentInsets	The flash view’s inner content insets.
backgroundProperties	The background properties. Use this to change the background color and corner radius.
imageProperties	The image view properties. Use this to change the image tint color.
titleProperties	The title text properties. Use this to change the text color, font and number of lines.
playsHaptics	A Boolean value that determines whether the flash view plays haptic feedback when shown.
tapToDismiss	A Boolean value that determines whether the flash view is dismissed when tapped.
appliesAdditionalInsetsAutomatically	A Boolean value that determines whether the flash view attempts to inset automatically to avoid overlapping navigation UI.
animator	The flash view animator. Use this to customize the DefaultAnimator, or to supply a custom FlashAnimator type.

Animation

You can customize flash view animations using the DefaultAnimator.Configuration struct:

var configuration = DefaultAnimator.Configuration.defaultConfiguration()
configuration.duration = 0.5 
configuration.scaleCoefficient = 0.75

let animator = DefaultAnimator(configuration: configuration)
FlashView.Configuration.shared.animator = animator

For finer control over animations, create a custom type that conforms to FlashAnimator.

Configuration Properties

Property	Description
duration	The animation duration in seconds.
dampingRatio	The spring damping ratio to apply when animating in.
initialVelocity	The initial velocity of the flash view when animating in.
translateAmount	The distance in points the view is translated along the y axis when animating.
scaleCoefficient	The amount, between 0 and 1, to scale the view when animating in and out. A value of 1 will not scale the view.

SwiftUI

Flash.swift does not yet expose a native SwiftUI interface, but you can show a flash message as a side effect:

struct ExampleView: View {
    private func showFlash() {
        let flash = FlashView(text: "Hello!")
        flash.show()
    }

    var body: some View {
        Button("Show Flash") {
            showFlash()
        }
    }
}

License

Flash.swift is available under the MIT license. See the LICENSE file for more info.