fix(chat): arm the reply swipe only where the bubble is

FlipcashTests/Chat/ChatSwipeToReplyTests.swift

@@ -186,9 +186,9 @@ struct ChatColumnCellSwipeOffsetTests {
     }
 }
 
-@Suite("The author gutter and the reply swipe")
+@Suite("The leading strip and the reply swipe")
 @MainActor
-struct ChatColumnCellAuthorGutterTests {
+struct ChatColumnCellLeadingStripTests {
 
     private func cell(for message: ChatMessage) -> ChatMessageCell {
         let cell = ChatMessageCell(frame: CGRect(x: 0, y: 0, width: 320, height: 60))
@@ -200,7 +200,7 @@ struct ChatColumnCellAuthorGutterTests {
     private func incomingGroupMessage() -> ChatMessage {
         ChatMessage(
             id: "1",
-            text: "hi",
+            text: "hi there",
             sender: .other,
             actions: [.reply],
             author: ChatAuthor(id: UserID(), name: "KT"),
@@ -209,63 +209,71 @@ struct ChatColumnCellAuthorGutterTests {
     }
 
     /// The strip the face sits in: the row's own margin plus the gutter it gives up.
-    private var insideGutter: CGPoint {
+    private var insideStrip: CGPoint {
         CGPoint(x: ChatColumnCell.rowInset + ChatColumnCell.authorGutterWidth - 1, y: 30)
     }
 
-    private var beyondGutter: CGPoint {
+    private var beyondStrip: CGPoint {
         CGPoint(x: ChatColumnCell.rowInset + ChatColumnCell.authorGutterWidth + 1, y: 30)
     }
 
     @Test("A point in an attributed incoming row's gutter starts no reply swipe")
     func attributedIncoming_gutterIsExcluded() {
         let cell = cell(for: incomingGroupMessage())
-        #expect(cell.isInAuthorGutter(insideGutter))
-        #expect(cell.isInAuthorGutter(CGPoint(x: 0, y: 30)))
+        #expect(cell.allowsReplySwipe(at: insideStrip) == false)
+        #expect(cell.allowsReplySwipe(at: CGPoint(x: 0, y: 30)) == false)
     }
 
     @Test("The rest of an attributed incoming row still swipes")
     func attributedIncoming_bubbleSideIsIncluded() {
         let cell = cell(for: incomingGroupMessage())
-        #expect(cell.isInAuthorGutter(beyondGutter) == false)
-        #expect(cell.isInAuthorGutter(CGPoint(x: 200, y: 30)) == false)
+        #expect(cell.allowsReplySwipe(at: beyondStrip))
+        #expect(cell.allowsReplySwipe(at: CGPoint(x: 200, y: 30)))
     }
 
-    @Test("A row that draws no face but holds the gutter open excludes it too")
-    func attributedIncoming_midRunExcludesGutter() {
+    @Test("A row that draws no face but holds the gutter open excludes the strip too")
+    func attributedIncoming_midRunExcludesStrip() {
         // The middle of a run hides the avatar; the gutter is the transcript's, so the strip is
         // still the face's and still off limits.
         let message = ChatMessage(
             id: "1",
-            text: "hi",
+            text: "hi there",
             sender: .other,
             isContinuedByNext: true,
             actions: [.reply],
             author: ChatAuthor(id: UserID(), name: "KT"),
             isAttributedTranscript: true
         )
-        #expect(cell(for: message).isInAuthorGutter(insideGutter))
+        #expect(cell(for: message).allowsReplySwipe(at: insideStrip) == false)
     }
 
-    @Test("A DM row reserves no gutter, so its leading edge swipes")
-    func dm_hasNoGutter() {
-        let cell = cell(for: ChatMessage(id: "1", text: "hi", sender: .other, actions: [.reply]))
-        #expect(cell.isInAuthorGutter(insideGutter) == false)
+    @Test("A DM row swipes in the strip, because that is where its bubble starts")
+    func dmIncoming_bubbleFillsTheStrip() {
+        let cell = cell(for: ChatMessage(id: "1", text: "hi there", sender: .other, actions: [.reply]))
+        #expect(cell.allowsReplySwipe(at: insideStrip))
+        #expect(cell.allowsReplySwipe(at: beyondStrip))
     }
 
-    @Test("The viewer's own row in a group reserves no gutter")
-    func ownRowInGroup_hasNoGutter() {
-        let message = ChatMessage(
-            id: "1", text: "hi", sender: .me, actions: [.reply], isAttributedTranscript: true
-        )
-        #expect(cell(for: message).isInAuthorGutter(insideGutter) == false)
+    @Test("The strip beside the viewer's own bubble starts no reply swipe, DM or group")
+    func ownRow_excludesTheStrip() {
+        let dm = cell(for: ChatMessage(id: "1", text: "hi there", sender: .me, actions: [.reply]))
+        #expect(dm.allowsReplySwipe(at: insideStrip) == false)
+        #expect(dm.allowsReplySwipe(at: beyondStrip))
+
+        let group = cell(for: ChatMessage(
+            id: "1", text: "hi there", sender: .me, actions: [.reply], isAttributedTranscript: true
+        ))
+        #expect(group.allowsReplySwipe(at: insideStrip) == false)
     }
 
-    @Test("Reuse clears the gutter")
-    func reuse_clearsTheGutter() {
+    @Test("The rule follows the bubble when a recycled cell is reconfigured")
+    func reuse_followsTheNewBubble() {
         let cell = cell(for: incomingGroupMessage())
+        #expect(cell.allowsReplySwipe(at: insideStrip) == false)
         cell.prepareForReuse()
-        #expect(cell.isInAuthorGutter(insideGutter) == false)
+        cell.configure(with: ChatMessage(id: "2", text: "hi there", sender: .other, actions: [.reply]), maxWidth: 250)
+        cell.layoutIfNeeded()
+        #expect(cell.allowsReplySwipe(at: insideStrip))
     }
 }
 

FlipcashUI/Sources/FlipcashUI/Chat/ChatColumnCell.swift

@@ -49,9 +49,6 @@ public class ChatColumnCell: UICollectionViewCell {
     /// Who the gutter face currently belongs to, so the tap knows whose profile to open. Nil on
     /// every row that draws no face.
     private var authorID: UserID?
-    /// Whether this row holds the leading gutter open — every incoming row of an attributed
-    /// transcript, whether or not it draws a face there.
-    private var reservesAuthorGutter = false
     /// The message's stable id while this row is failed and tappable; nil otherwise.
     private var retryID: String?
     /// Tap-to-retry recognizer, enabled only while this row is failed so non-failed bubbles don't
@@ -168,12 +165,18 @@ public class ChatColumnCell: UICollectionViewCell {
     /// the space the row actually has.
     public static let authorGutterWidth = ChatAuthorAvatarView.size + 8
 
-    /// Whether a point in this cell's coordinates falls in the author gutter. The reply swipe asks
-    /// before it starts: the gutter is the face's own tap target, so a drag beginning there is
-    /// someone reaching for a profile rather than for reply.
-    func isInAuthorGutter(_ point: CGPoint) -> Bool {
-        guard reservesAuthorGutter else { return false }
-        return point.x < Self.rowInset + Self.authorGutterWidth
+    /// Whether a drag starting at this point, in the cell's own coordinates, may reply to the row.
+    ///
+    /// The bubble always answers yes, wherever it sits. The strip beside it at the row's leading
+    /// edge does not: in an attributed transcript that strip is the author's face, whose own tap
+    /// target it must stay, and on every other row it is empty transcript beside a bubble that hugs
+    /// the far edge — nothing the finger was reaching for, in the band the screen-edge back gesture
+    /// also starts in. One rule covers both, because where the bubble sits is what tells them apart.
+    func allowsReplySwipe(at point: CGPoint) -> Bool {
+        guard point.x < Self.rowInset + Self.authorGutterWidth else { return true }
+        guard let content else { return false }
+        let bubble = content.convert(content.bounds, to: self)
+        return point.x >= bubble.minX && point.x <= bubble.maxX
     }
 
     /// How far the row's content is dragged towards the trailing edge by the reply swipe.
@@ -229,7 +232,6 @@ public class ChatColumnCell: UICollectionViewCell {
         authorAvatar.isHidden = true
         authorAvatar.reset()
         authorID = nil
-        reservesAuthorGutter = false
         columnLeading?.constant = Self.rowInset
     }
 
@@ -270,7 +272,7 @@ public class ChatColumnCell: UICollectionViewCell {
         // held open for every incoming row of a group chat — the middle of a run, and a row whose
         // sender no roster could name — so the bubbles share one leading edge instead of stepping
         // in and out as faces come and go.
-        reservesAuthorGutter = message.isAttributedTranscript && message.sender != .me
+        let reservesAuthorGutter = message.isAttributedTranscript && message.sender != .me
         columnLeading?.constant = reservesAuthorGutter ? Self.rowInset + Self.authorGutterWidth : Self.rowInset
 
         guard let author = message.author, message.sender != .me else {

FlipcashUI/Sources/FlipcashUI/Chat/ChatSwipeToReply.swift

@@ -34,8 +34,8 @@ final class ChatSwipeToReply: NSObject {
     let recognizer = UIPanGestureRecognizer()
 
     /// The row a drag from this point may reply to, or nil where no reply starts — a row that
-    /// offers no Reply, and the author gutter, whose face is its own target. The transcript answers
-    /// this; the gesture does not know what a message is.
+    /// offers no Reply, and the strip at the row's leading edge wherever the bubble isn't. The
+    /// transcript answers this; the gesture does not know what a message is.
     var rowForSwipe: ((CGPoint) -> (cell: ChatColumnCell, stableID: String)?)?
     /// Whether the transcript is busy — mid-update, or showing a context menu.
     var isBlocked: (() -> Bool)?

FlipcashUI/Sources/FlipcashUI/Chat/ChatViewController.swift

@@ -241,9 +241,9 @@ public final class ChatViewController: UICollectionViewController {
             guard let self,
                   let indexPath = self.collectionView.indexPathForItem(at: point),
                   let cell = self.collectionView.cellForItem(at: indexPath) as? ChatColumnCell,
-                  // A drag that starts on an author's face belongs to the face — see
-                  // `ChatColumnCell.isInAuthorGutter`.
-                  !cell.isInAuthorGutter(cell.convert(point, from: self.collectionView)),
+                  // The strip at the row's leading edge is the author's face, or empty transcript
+                  // — see `ChatColumnCell.allowsReplySwipe(at:)`.
+                  cell.allowsReplySwipe(at: cell.convert(point, from: self.collectionView)),
                   case .message(let message) = self.items[indexPath.item],
                   message.actions.contains(.reply)
             else { return nil }