[Idea] Make `referenceSize(in bounds:)` returns nil by default

[Ryo Aoyama]

Checklist

• Reviewed the README and documents.
• Searched existing issues for ensure not duplicated.

Description

Make referenceSize(in bounds:) returns nil by default in Component.
The table view and collection view are use their own size setting by default.
e.g.

• UITableView uses UITableView.rowHeight, default is UITableViewAutomaticDimenstion.
• UICollectionView(flow layout) uses UICollectionViewFlowLayout.itemSize, default is CGSize(width: 50, height: 50).

struct Label: Component, Equitable {
    var text: String

    func renderContent() -> UILabel {
        return UILabel()
    }

    func render(in content: UILabel) {
        content.text = text
    }

-    // Default is nil, it fallback to `UITableView.rowHeight`.
-    func referenceSize(in bounds: CGRect) -> CGSize? {
-        return CGSize(width: bounds.width, height: 44)
-    }
}

Motivation and Context

Wants to simplify the creation of Component like as List in SwiftUI.

Proposed Solution

Make Component.referenceSize returns nil by default.

Discussion

Agree 👍 or Disagree 👎