Creating self-sizing table view cells
At a glance
| Item | Summary |
|---|---|
| Purpose | Create table view cells that support Dynamic Type and use system spacing constraints to adjust the spacing surrounding text labels. |
| App architecture | A Swift sample with the source-visible chain AppDelegate → ViewController → UIKit APIs. |
| Main patterns | View-controller organization, Delegate or data-source callbacks |
| Project style | 4 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries. |
| Execution model | No structured execution marker indexed; callback threading requires source review. |
| State/event model | No structured observation or publisher-scheduling marker indexed. |
| Key frameworks/packages | UIKit; these are source dependencies, not architecture labels. |
Project structure
Source bundle/
├── SelfSizingCellsWithDynamicType/
│ ├── AppDelegate.swift
│ ├── CustomDataSource.swift
│ ├── ViewController.swift
│ ├── CustomCell.swift
│ ├── Base.lproj/
│ │ ├── LaunchScreen.storyboard
│ │ └── Main.storyboard
│ └── Info.plist
├── Configuration/
│ └── SampleCode.xcconfig
└── SelfSizingCellsWithDynamicType.xcodeproj/
├── .xcodesamplecode.plist
└── project.pbxproj
Structure observations
- Architecturally prominent files are ranked from entry points and role-named declarations; resource-only paths are omitted.
- Primary languages: Swift.
- The verified tree contains 6 project/configuration file(s) and 4 source declaration(s).
Overall architecture
flowchart LR
N1["AppDelegate"]
N2["ViewController"]
N3["UIKit APIs"]
N1 --> N2
N2 --> N3
Reference code
SelfSizingCellsWithDynamicType/AppDelegate.swift:12 — architecture anchor
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
}Interpretation
The arrows summarize the source-visible entry, role-named types or folders, and framework direction; when nodes come from structural folders, the sequence is a high-level interpretation rather than proof that every adjacent node calls the next. Ownership is claimed only where the next section cites a stored property or assignment. The diagram is intentionally limited to the dominant path into UIKit.
Ownership and state
classDiagram
AppDelegate o-- UIWindow : window
CustomDataSource *-- Dictionary : sampleData
ViewController o-- UITableView : tableView
ViewController *-- CustomDataSource : dataSource
Ownership evidence
SelfSizingCellsWithDynamicType/AppDelegate.swift:15 — stored dependency or nearest verified ownership anchor
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
}| Owner | Object or state | Relationship | Mutation authority |
|---|---|---|---|
AppDelegate |
UIWindow (window) |
stores or receives | App/module collaborators |
CustomDataSource |
Dictionary (sampleData) |
owns value state | Initialized by the owner; the binding is immutable |
ViewController |
UITableView (tableView) |
holds a non-owning reference | The referenced object’s lifecycle is owned elsewhere |
ViewController |
CustomDataSource (dataSource) |
creates and retains | Initialized by the owner; the binding is immutable |
Composition arrows indicate a source-visible construction expression or locally owned value state; aggregation means the owner stores or receives a dependency without proving exclusive lifetime ownership.
Concurrency, scheduling, and thread safety
Evidence limit: actor isolation, async/await, or Task creation does not by itself prove background-thread execution; Sendable conformance alone does not prove thread-safe mutation.
No source-visible execution, scheduling, or synchronization boundary was found in the indexed source.
@MainActor/MainActor.run, DispatchQueue.main, and RunLoop.main are reported as distinct isolation, queue, and event-loop mechanisms. A plain Task is kept separate from Task.detached; neither is labeled as a background thread.
State propagation, frameworks, and dependencies
Evidence limit: an import proves a source-level compilation dependency at the cited line; it does not prove runtime use, architectural adoption, or whether a Swift package is a direct application dependency.
| Category | Mechanism or module | Verified role | Evidence |
|---|---|---|---|
| Source import | UIKit |
The cited file imports this module; runtime use and architectural role are not inferred. | SelfSizingCellsWithDynamicType/AppDelegate.swift:8 |
receive(on:) describes downstream delivery scheduling, while subscribe(on:) describes upstream subscription/request/cancel scheduling. An import Combine alone establishes neither behavior nor a Store, reducer, Redux, or other application architecture.
Class and protocol design
SelfSizingCellsWithDynamicType/AppDelegate.swift:13 — representative type boundary
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
}| Type | Responsibility | Depends on or conforms to |
|---|---|---|
AppDelegate |
Receives callback-driven events | UIResponder, UIApplicationDelegate |
CustomDataSource |
Supplies data through a callback contract | NSObject, UITableViewDataSource |
ViewController |
View lifecycle, callbacks, and feature coordination | UIViewController |
CustomCell |
Owns feature behavior and collaborator lifecycle | UITableViewCell |
No local protocol conformance is claimed as protocol-oriented design; external framework conformances are listed only as dependencies.
Access control
| Symbol | Access | Verified effect | Likely rationale |
|---|---|---|---|
makeSampleLabel (SelfSizingCellsWithDynamicType/CustomCell.swift:37) |
private |
Use is restricted to the lexical declaration and same-file extensions allowed by Swift. | Inference: hide an implementation step that is not part of the collaboration surface. |
setUpLabelsAndConstraints (SelfSizingCellsWithDynamicType/CustomCell.swift:70) |
private |
Use is restricted to the lexical declaration and same-file extensions allowed by Swift. | Inference: hide an implementation step that is not part of the collaboration surface. |
dataSource (SelfSizingCellsWithDynamicType/ViewController.swift:18) |
private |
Use is restricted to the lexical declaration and same-file extensions allowed by Swift. | Inference: keep state mutation or dependency lifetime inside the owning implementation. |
CustomDataSource (SelfSizingCellsWithDynamicType/CustomDataSource.swift:8) |
implicit internal |
No explicit modifier means the Swift declaration is internal to the module. | Inference: app-target collaboration needs no exported library surface. |
Reference code
SelfSizingCellsWithDynamicType/CustomCell.swift:37 — representative boundary
private static func makeSampleLabel() -> UILabel {
let label = UILabel()
// ...
}Swift declarations without a modifier are internal; explicit private, fileprivate, private(set), public, or open entries above are interpreted by language semantics. Objective-C/C samples instead rely on header and implementation boundaries, which are not equivalent to Swift lexical privacy.
Logic ownership and placement
| Logic | Owning type or file | Placement rationale |
|---|---|---|
| View lifecycle, callbacks, and feature coordination | ViewController |
The source’s Controller suffix makes this role explicit. |
| Supplies data through a callback contract | CustomDataSource |
The source’s DataSource suffix makes this role explicit. |
| Receives callback-driven events | AppDelegate |
The source’s Delegate suffix makes this role explicit. |
Design patterns
| Pattern | Source evidence | Purpose or tradeoff |
|---|---|---|
| View-controller organization | SelfSizingCellsWithDynamicType/ViewController.swift:12 |
A controller is the verified coordination boundary; this is MVC-style only where a separate model is present. |
| Delegate or data-source callbacks | SelfSizingCellsWithDynamicType/AppDelegate.swift:13 |
Callback protocols invert event delivery back into the sample’s owner. |
Naming conventions
- Types: Controller: ViewController; DataSource: CustomDataSource; Delegate: AppDelegate.
- Protocols: no local protocol declaration in the scanned source.
- Methods:
registerCells,tableView,viewDidLoad,makeSampleLabel,setUpLabelsAndConstraints. - Files:
SelfSizingCellsWithDynamicType/AppDelegate.swift,SelfSizingCellsWithDynamicType/CustomDataSource.swift,SelfSizingCellsWithDynamicType/ViewController.swift,SelfSizingCellsWithDynamicType/CustomCell.swift.
Architecture takeaways
AppDelegateis the main source-visible entry or composition anchor for this sample.- Framework work reaches UIKit through a deliberately small high-level chain; the detailed API graph remains inside the cited implementation files.
- Stored-property evidence identifies lifecycle collaboration; it does not by itself prove exclusive object ownership.
- Access-control conclusions separate verified language visibility from the likely design rationale.
- The source does not justify labeling the design protocol-oriented.
Source map
| Source file | Relevant symbols |
|---|---|
SelfSizingCellsWithDynamicType/AppDelegate.swift |
Cited implementation, AppDelegate, UIKit |
SelfSizingCellsWithDynamicType/CustomCell.swift |
Cited implementation, CustomCell |
SelfSizingCellsWithDynamicType/ViewController.swift |
Cited implementation, ViewController |
SelfSizingCellsWithDynamicType/CustomDataSource.swift |
CustomDataSource |