Don't duck Compose screen when the draft is empty

See #369

Packages/Duckable/Sources/Duckable/API.swift

@@ -10,7 +10,7 @@ import UIKit
 public protocol DuckableViewController: UIViewController {
     var duckableDelegate: DuckableViewControllerDelegate? { get set }
     
-    func duckableViewControllerShouldDuck() -> Bool
+    func duckableViewControllerShouldDuck() -> DuckAttemptAction
     
     func duckableViewControllerMayAttemptToDuck()
     
@@ -20,7 +20,7 @@ public protocol DuckableViewController: UIViewController {
 }
 
 extension DuckableViewController {
-    public func duckableViewControllerShouldDuck() -> Bool { true }
+    public func duckableViewControllerShouldDuck() -> DuckAttemptAction { .duck }
     public func duckableViewControllerMayAttemptToDuck() {}
     public func duckableViewControllerWillAnimateDuck(withDuration duration: CGFloat, afterDelay delay: CGFloat) {}
     public func duckableViewControllerDidFinishAnimatingDuck() {}
@@ -30,6 +30,12 @@ public protocol DuckableViewControllerDelegate: AnyObject {
     func duckableViewControllerWillDismiss(animated: Bool)
 }
 
+public enum DuckAttemptAction {
+    case duck
+    case dismiss
+    case block
+}
+
 extension UIViewController {
     @available(iOS 16.0, *)
     public func presentDuckable(_ viewController: DuckableViewController, animated: Bool, isDucked: Bool = false) -> Bool {

Packages/Duckable/Sources/Duckable/DuckableContainerViewController.swift

@@ -135,14 +135,18 @@ public class DuckableContainerViewController: UIViewController, DuckableViewCont
         guard case .presentingDucked(let viewController, isFirstPresentation: _) = state else {
             return
         }
-        guard viewController.duckableViewControllerShouldDuck() else {
-            viewController.sheetPresentationController!.selectedDetentIdentifier = .large
-            return
-        }
+        switch viewController.duckableViewControllerShouldDuck() {
+        case .duck:
             let placeholder = createPlaceholderForDuckedViewController(viewController)
             state = .ducked(viewController, placeholder: placeholder)
             configureChildForDuckedPlaceholder()
             dismiss(animated: true)
+        case .block:
+            viewController.sheetPresentationController!.selectedDetentIdentifier = .large
+        case .dismiss:
+            duckableViewControllerWillDismiss(animated: true)
+            dismiss(animated: true)
+        }
     }
     
     private func configureChildForDuckedPlaceholder() {

Tusker/Screens/Compose/ComposeHostingController.swift

@@ -138,6 +138,14 @@ class ComposeHostingController: UIHostingController<ComposeHostingController.Vie
     
     // MARK: Duckable
     
+    func duckableViewControllerShouldDuck() -> DuckAttemptAction {
+        if controller.draft.hasContent {
+            return .duck
+        } else {
+            return .dismiss
+        }
+    }
+    
     func duckableViewControllerWillAnimateDuck(withDuration duration: CGFloat, afterDelay delay: CGFloat) {
         controller.deleteDraftOnDisappear = false