Fix SwiftUI indentation issues (#154)

example/SwiftUIView.swift

@@ -0,0 +1,50 @@
+import SwiftUI
+import PlaygroundSupport
+
+struct ExampleView: View {
+    @State var isShowingSheet = false
+
+    var body: some View {
+        VStack {
+            Text("Hello, World!")
+            // comment
+                .font(.caption)
+                .monospaced()
+            // red font
+                .foregroundStyle(.red)
+            Button(action: { print("clicked") }) {
+                Text("click me")
+            }
+            .buttonStyle(.bordered)
+
+            Button(action: { isShowingSheet = true }) {
+                Text("show sheet")
+            }
+            Text("sample")
+                .overlay {
+                    Circle()
+                        .fill(.gray.opacity(0.25))
+                }
+                .lineLimit(2)
+            Text("sample2")
+            HStack {
+                ForEach(0...5, id: \.self) { n in
+                    if n % 2 == 0 {
+                        Text(n.description)
+                            .foregroundStyle(.green)
+                    }
+                    else {
+                        Text(n.description)
+                    }
+                }
+            }
+        }
+        .padding(12)
+        .frame(width: 200, height: 400)
+        .sheet(isPresented: $isShowingSheet) {
+            Text("sheet")
+        }
+    }
+}
+
+PlaygroundPage.current.setLiveView(ExampleView())

indent/swift.vim

@@ -147,6 +147,9 @@ function! SwiftIndent(...)
         call cursor(line, column)
         return openingParenCol
       endif
+      if numOpenParensBracketLine == 0 && numCloseParensBracketLine == 0
+        return indent(openingBracket) + shiftwidth()
+      endif
 
       return indent(openingBracket)
     elseif currentCloseBrackets > currentOpenBrackets
@@ -184,6 +187,16 @@ function! SwiftIndent(...)
       let openingParen = searchpair("(", "", ")", "bWn", "s:IsExcludedFromIndent()")
       call cursor(line, column)
       return indent(openingParen)
+    elseif line =~ '^\s*\.' && previous !~ '^\s*\.' && numOpenParens > 0
+      return previousIndent + shiftwidth()
+    elseif previous =~ '^\s*\.'
+      if s:IsCommentLine(clnum) != 0
+        return previousIndent - shiftwidth()
+      elseif line =~ '^\s*\.'
+        return previousIndent
+      else
+        return previousIndent - shiftwidth()
+      endif
     else
       " - Current line is blank, and the user presses 'o'
       return previousIndent