Fix staging/unstaging of files in changes group checkbox

Sources/Lithe/Application/GitFeatureModel.swift

@@ -603,6 +603,24 @@ final class GitFeatureModel: ObservableObject {
         await refreshGit()
     }
 
+    /// Stages or unstages every file in a section (for example the "Changes" or
+    /// "Unversioned Files" group header checkbox). Mirrors the tri-state behavior
+    /// of the JetBrains changelist checkbox: if every file is already staged the
+    /// group is unstaged, otherwise the group is staged to completion.
+    func toggleStagingAll(_ changes: [GitChange]) async {
+        guard let gitRepositoryRoot, !changes.isEmpty else { return }
+        let shouldStage = !changes.allSatisfy(\.isStaged)
+        let paths = changes.flatMap(\.pathspecs)
+        let result = await withGitOperation {
+            shouldStage
+                ? await service.stage(paths: paths, at: gitRepositoryRoot)
+                : await service.unstage(paths: paths, at: gitRepositoryRoot)
+        }
+        let verb = shouldStage ? "Staged" : "Unstaged"
+        showResult(result, success: "\(verb) \(changes.count) file(s)")
+        await refreshGit()
+    }
+
     func stageAllChanges() async {
         guard let gitRepositoryRoot else { return }
         let result = await withGitOperation { await service.stageAll(at: gitRepositoryRoot) }

Sources/Lithe/Core/RustGitOperations.swift

@@ -89,6 +89,14 @@ struct RustGitOperations: GitOperations, GitCommandRunner, Sendable {
         write(at: change.repositoryRoot, operation: "unstage", paths: change.pathspecs)
     }
 
+    func stage(paths: [String], at rootURL: URL) -> ProcessResult? {
+        write(at: rootURL, operation: "stage", paths: paths)
+    }
+
+    func unstage(paths: [String], at rootURL: URL) -> ProcessResult? {
+        write(at: rootURL, operation: "unstage", paths: paths)
+    }
+
     func discard(_ change: GitChange) -> ProcessResult? {
         return write(at: change.repositoryRoot, operation: "discard", paths: change.pathspecs)
     }

Sources/Lithe/Models/AppModel.swift

@@ -1403,6 +1403,10 @@ final class AppModel: ObservableObject, Identifiable {
         await gitFeature.toggleStaging(change)
     }
 
+    func toggleStagingAll(_ changes: [GitChange]) async {
+        await gitFeature.toggleStagingAll(changes)
+    }
+
     func stageAllChanges() async {
         await gitFeature.stageAllChanges()
     }

Sources/Lithe/Services/GitService.swift

@@ -55,6 +55,8 @@ protocol GitOperations: Sendable {
 
     func stage(_ change: GitChange) -> ProcessResult?
     func unstage(_ change: GitChange) -> ProcessResult?
+    func stage(paths: [String], at rootURL: URL) -> ProcessResult?
+    func unstage(paths: [String], at rootURL: URL) -> ProcessResult?
     func discard(_ change: GitChange) -> ProcessResult?
     func discardAll(_ change: GitChange) -> ProcessResult?
     func commit(at rootURL: URL, message: String, amend: Bool) -> ProcessResult?
@@ -232,6 +234,14 @@ struct GitService: GitWatchContextProviding, Sendable {
         await command { $0.unstage(change) }
     }
 
+    func stage(paths: [String], at repositoryRoot: URL) async -> CommandResult {
+        await command { $0.stage(paths: paths, at: repositoryRoot) }
+    }
+
+    func unstage(paths: [String], at repositoryRoot: URL) async -> CommandResult {
+        await command { $0.unstage(paths: paths, at: repositoryRoot) }
+    }
+
     func discard(_ change: GitChange) async -> CommandResult {
         return await command { $0.discard(change) }
     }

Sources/Lithe/Views/ChangesSidebarView.swift

@@ -521,33 +521,47 @@ struct ChangesSidebarView: View {
         showsParentPaths: Bool
     ) -> some View {
         if !changes.isEmpty {
-            Button {
-                expanded.wrappedValue.toggle()
-            } label: {
-                HStack(spacing: 7) {
-                    Image(systemName: expanded.wrappedValue ? "chevron.down" : "chevron.right")
-                        .font(.system(size: 8, weight: .bold))
-                        .frame(width: 10)
-                    Image(systemName: "square")
+            HStack(spacing: 0) {
+                Button {
+                    Task { await model.toggleStagingAll(changes) }
+                } label: {
+                    Image(systemName: sectionStagingSymbol(changes))
                         .font(.system(size: 16))
-                        .foregroundStyle(LitheTheme.secondaryText)
-                    Text(LocalizedStringKey(title))
-                        .font(.system(size: 12.5, weight: .semibold))
-                        .foregroundStyle(LitheTheme.primaryText)
-                    Text(changes.count == 1 ? "1 file" : "\(changes.count) files")
-                        .font(.system(size: 11))
-                        .foregroundStyle(LitheTheme.secondaryText)
-                    Spacer()
+                        .foregroundStyle(sectionStagingColor(changes))
+                        .frame(width: 24, height: 30)
+                        .contentShape(Rectangle())
                 }
-                .padding(.horizontal, 7)
-                .frame(maxWidth: .infinity)
-                .frame(height: 30)
-                .background(LitheTheme.subtleSelection.opacity(0.72))
-                .clipShape(RoundedRectangle(cornerRadius: 4))
-                .contentShape(Rectangle())
+                .buttonStyle(.plain)
+                .lithePointer()
+                .help("Stage or unstage all files in this group")
+
+                Button {
+                    expanded.wrappedValue.toggle()
+                } label: {
+                    HStack(spacing: 7) {
+                        Image(systemName: expanded.wrappedValue ? "chevron.down" : "chevron.right")
+                            .font(.system(size: 8, weight: .bold))
+                            .frame(width: 10)
+                        Text(LocalizedStringKey(title))
+                            .font(.system(size: 12.5, weight: .semibold))
+                            .foregroundStyle(LitheTheme.primaryText)
+                        Text(changes.count == 1 ? "1 file" : "\(changes.count) files")
+                            .font(.system(size: 11))
+                            .foregroundStyle(LitheTheme.secondaryText)
+                        Spacer(minLength: 0)
+                    }
+                    .frame(maxWidth: .infinity)
+                    .frame(height: 30)
+                    .contentShape(Rectangle())
+                }
+                .buttonStyle(.plain)
+                .lithePointer()
             }
-            .buttonStyle(.plain)
-            .lithePointer()
+            .padding(.horizontal, 7)
+            .frame(maxWidth: .infinity)
+            .frame(height: 30)
+            .background(LitheTheme.subtleSelection.opacity(0.72))
+            .clipShape(RoundedRectangle(cornerRadius: 4))
 
             if expanded.wrappedValue {
                 ForEach(changes) { change in
@@ -557,6 +571,17 @@ struct ChangesSidebarView: View {
         }
     }
 
+    private func sectionStagingSymbol(_ changes: [GitChange]) -> String {
+        let staged = changes.filter(\.isStaged).count
+        if staged == changes.count { return "checkmark.square.fill" }
+        if staged == 0 { return "square" }
+        return "minus.square"
+    }
+
+    private func sectionStagingColor(_ changes: [GitChange]) -> Color {
+        changes.allSatisfy(\.isStaged) ? LitheTheme.accent : LitheTheme.secondaryText
+    }
+
     private func changeRow(_ change: GitChange, showsParentPath: Bool) -> some View {
         HStack(spacing: 6) {
             Button {