Showing help tags for views and controls using tooltip interactions

At a glance

Project structure

Source bundle/
├── TooltipSample/
│   ├── AppDelegate.swift
│   ├── SceneDelegate.swift
│   ├── ViewController.swift
│   ├── TextViewWithTooltip.swift
│   ├── ViewWithBackgroundColorTooltip.swift
│   ├── ViewWithTooltipRegion.swift
│   ├── Base.lproj/
│   │   ├── LaunchScreen.storyboard
│   │   └── Main.storyboard
│   └── Info.plist
├── Configuration/
│   └── SampleCode.xcconfig
└── TooltipSample.xcodeproj/
    ├── .xcodesamplecode.plist
    └── project.pbxproj

Structure observations

• The feature is composed in ViewController, not in the app delegate.
• Default tooltips need only an interaction or toolTip value; dynamic and region-aware tooltips use delegate callbacks.
• Custom view files colocate geometry/color knowledge with the delegate that uses it.

Overall architecture

flowchart LR
    VC["ViewController"] --> VIEWS["Labels, buttons, text and custom views"]
    VIEWS --> INTERACTIONS["UIToolTipInteraction objects"]
    INTERACTIONS --> STATIC["Static tooltip text"]
    INTERACTIONS --> DELEGATES["Delegate configuration callbacks"]
    DELEGATES --> DYNAMIC["Cart count, text range, color, or hover region"]

Reference code

TooltipSample/ViewController.swift:99 — tooltip composition

    override func viewDidLoad() {
        super.viewDidLoad()
        containerStackView.addArrangedSubview(viewWithDefaultTooltip)
        containerStackView.addArrangedSubview(labelWithTooltip)
        containerStackView.addArrangedSubview(buttonWithTooltip)
        containerStackView.addArrangedSubview(viewWithBackgroundColorTooltip)
        containerStackView.addArrangedSubview(shoppingCartButtonWithTooltip)
        containerStackView.addArrangedSubview(viewWithTooltipRegion)
    }

Interpretation

The controller is a composition showcase. Each tooltip style is implemented at the narrowest useful boundary: static strings on views/interactions, controller state for the cart count, and view-local delegate logic when geometry or appearance belongs to a custom view.

Ownership and state

classDiagram
    ViewController *-- UILabel : labelWithTooltip
    ViewController *-- UIButton : buttonWithTooltip
    ViewController *-- ViewWithTooltipRegion : lazy view
    UIView *-- UIToolTipInteraction : addInteraction
    ViewWithTooltipRegion ..|> UIToolTipInteractionDelegate

Ownership evidence

TooltipSample/ViewController.swift:74 — custom view and interaction construction

    lazy var viewWithBackgroundColorTooltip: UIView = {
        let view = ViewWithBackgroundColorTooltip()
        view.backgroundColor = UIColor.systemYellow
        let tooltipInteraction = UIToolTipInteraction()
        tooltipInteraction.delegate = view
        view.addInteraction(tooltipInteraction)
        return view
    }()

Composition denotes source-visible construction and retained value state. Aggregation denotes a stored or injected collaborator whose exclusive lifetime the source does not prove.

Class and protocol design

TooltipSample/ViewWithTooltipRegion.swift:11 — region-specific tooltip delegate

class ViewWithTooltipRegion: UIView, UIToolTipInteractionDelegate {

    func toolTipInteraction(_ interaction: UIToolTipInteraction,
                            configurationAt point: CGPoint) -> UIToolTipConfiguration? {
        var topRect = self.bounds
        var bottomRect = self.bounds
        let partHeight = self.bounds.size.height / 3
        topRect.size.height = partHeight
    }
}

All capability protocols here are UIKit-defined. The separate conforming view types are useful delegation seams, but the sample does not define a local protocol abstraction.

Access control

Reference code

TooltipSample/ViewController.swift:10 — module-internal feature root

class ViewController: UIViewController {
    // ...
}

This sample has no meaningful public, open, or fileprivate feature boundary. Its unmodified declarations are internal, which fits a single application target; production code could make demo properties private if no tests or collaborators require them.

Logic ownership and placement

Design patterns

Naming conventions

• Custom views state both subject and behavior (TextViewWithTooltip, ViewWithTooltipRegion).
• Delegate callbacks keep UIKit’s toolTipInteraction(_:configurationAt:) vocabulary.
• Lazy property names describe each demonstrated variant instead of generic view1/view2 labels.
• Files follow their primary custom view type.

Architecture takeaways

• Use an interaction object for attachable behavior and a delegate only when content is dynamic.
• Put geometry- or appearance-dependent tooltip rules on the view that owns that knowledge.
• Treat the controller as a demo composer; app lifecycle delegates are not part of the feature architecture.

Source map

• Official Apple documentation