apply last character font size to the attachment

ElementX/Sources/Other/Pills/MessageText.swift

@@ -102,14 +102,34 @@ struct MessageText: UIViewRepresentable {
                                        size: CGSize(width: trailingReservedSize.width,
                                                     height: max(trailingReservedSize.height, 1)))
 
+            // Inherit the font from the preceding character so the appended runs
+            // (newline and attachment) carry the same line metrics as the surrounding
+            // text — otherwise a small default font on those characters can shrink the
+            // line height and clip e.g. a font-boosted lone emoji.
+            let trailingFont = baseText.length > 0
+                ? baseText.attribute(.font, at: baseText.length - 1, effectiveRange: nil)
+                : nil
+
             // When the last paragraph's natural text direction doesn't match the layout
             // direction, the inline attachment would land on the wrong side and overlap the
             // overlaid timestamp. Force it onto its own line so the bubble just grows taller.
             if !lastParagraphDirectionMatchesLayout(in: combined) {
-                combined.append(NSAttributedString(string: "\n"))
+                let newlineString = NSMutableAttributedString(string: "\n")
+                if let trailingFont {
+                    newlineString.addAttribute(.font,
+                                               value: trailingFont,
+                                               range: NSRange(location: 0, length: newlineString.length))
+                }
+                combined.append(newlineString)
             }
 
-            combined.append(NSAttributedString(attachment: attachment))
+            let attachmentString = NSMutableAttributedString(attachment: attachment)
+            if let trailingFont {
+                attachmentString.addAttribute(.font,
+                                              value: trailingFont,
+                                              range: NSRange(location: 0, length: attachmentString.length))
+            }
+            combined.append(attachmentString)
         }
 
         return combined

ElementX/Sources/Screens/Timeline/View/Style/TimelineStyler.swift

@@ -152,6 +152,15 @@ struct TimelineItemStyler_Previews: PreviewProvider, TestablePreview {
                                                                  canBeRepliedTo: true,
                                                                  sender: .test,
                                                                  content: .init(body: "באמת! -- house!"))
+    
+    static let bigEmoji = TextRoomTimelineItem(id: .randomEvent,
+                                               timestamp: .mock,
+                                               isOutgoing: true,
+                                               isEditable: false,
+                                               canBeRepliedTo: true,
+                                               shouldBoost: true,
+                                               sender: .test,
+                                               content: .init(body: "😮"))
 
     static var testView: some View {
         VStack(spacing: 0) {
@@ -172,6 +181,7 @@ struct TimelineItemStyler_Previews: PreviewProvider, TestablePreview {
             TextRoomTimelineView(timelineItem: rtlStringThatContainsLtr)
             TextRoomTimelineView(timelineItem: ltrStringThatFinishesInRtl)
             TextRoomTimelineView(timelineItem: rtlStringThatFinishesInLtr)
+            TextRoomTimelineView(timelineItem: bigEmoji)
         }
     }
 

ElementX/Sources/Screens/Timeline/View/TimelineItemViews/FormattedBodyText.swift

@@ -24,7 +24,7 @@ struct FormattedBodyText: View {
     private var attributedComponents: [AttributedStringBuilderComponent] {
         var adjustedAttributedString = attributedString
         
-        // Required to allow the underlying TextView to use  body font when no font is specifie in the AttributedString.
+        // Required to allow the underlying TextView to use  body font when no font is specified in the AttributedString.
         adjustedAttributedString.mergeAttributes(defaultAttributesContainer, mergePolicy: .keepCurrent)
         
         let string = String(attributedString.characters)

PreviewTests/Sources/__Snapshots__/PreviewTests/timelineItemStyler.Bubbles-LTR-with-different-layout-languages-iPad-en-GB.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:4d9ea384798ed026735ed3d875f55bcfb56f329957e87ff51c101d723985bdaf
-size 105891
+oid sha256:daa12b1efbc92c4dccf9a562a65389f75cc4fe3d85841d657f7a16d47f06a07b
+size 126617

PreviewTests/Sources/__Snapshots__/PreviewTests/timelineItemStyler.Bubbles-LTR-with-different-layout-languages-iPad-pseudo.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:c7b7852f0ba84a9692db2943eafd77517e40d22de0b82347ccde0e316ed6b299
-size 110670
+oid sha256:0cb0b55bd81599cae6dc6074f7b063ca541ebbd1703873339d6e44e23a93509d
+size 132787

PreviewTests/Sources/__Snapshots__/PreviewTests/timelineItemStyler.Bubbles-LTR-with-different-layout-languages-iPhone-en-GB.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:f9054993c31c97deb1e8830fb7e3ec5b056b0422434c8f0ca98249542c952f8f
-size 62340
+oid sha256:61f1b79a8425e639afbbe3b6b508d4f7e0c3282e513a3a39eed365c6dacc63bc
+size 82269

PreviewTests/Sources/__Snapshots__/PreviewTests/timelineItemStyler.Bubbles-LTR-with-different-layout-languages-iPhone-pseudo.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:855838858b0c0cffe293175bc327172abd136e83f09843e156c87ec11fc2418a
-size 65773
+oid sha256:773e8b830d6874356aa538d88b5ab6d7ffa08852a5a8539fa491cfeddb88275c
+size 86925

PreviewTests/Sources/__Snapshots__/PreviewTests/timelineItemStyler.Bubbles-RTL-with-different-layout-languages-iPad-en-GB.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:5668b46725738b0818b93e354d3f82fd9d61eeae86a057112e378a406666bbba
-size 104283
+oid sha256:499bf1736192faf92378530ef2da344088a842587ccd3bb33cd943faf3a65d43
+size 124605

PreviewTests/Sources/__Snapshots__/PreviewTests/timelineItemStyler.Bubbles-RTL-with-different-layout-languages-iPad-pseudo.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:62565ccd3424d2e0d0f04823b3a36d2d6a98e793f172b4fa149536a02683c318
-size 109345
+oid sha256:15a353e80323637bd0fe1037c82fa1d68ee6ff438050c6ef7aad61e1648cd19f
+size 130697

PreviewTests/Sources/__Snapshots__/PreviewTests/timelineItemStyler.Bubbles-RTL-with-different-layout-languages-iPhone-en-GB.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:cc85f143df29944f9da45f8afa556c97034308ec6be9db427b90bec6ec820743
-size 60347
+oid sha256:8d6b9aeb5a9ba5120a473a1c1458d6be66a42ec18f8688e999fb25a00ac01980
+size 80042

PreviewTests/Sources/__Snapshots__/PreviewTests/timelineItemStyler.Bubbles-RTL-with-different-layout-languages-iPhone-pseudo.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:0d0728ba0ca764a8beb2a46f813707f9505ee7d02ac5610a101913e7d8868924
-size 64053
+oid sha256:f184da565bdea14e33c8e65ae8dc8f69049cce7ab833e33fd3136f2d5069cd23
+size 84843