Persist the default Git diff layout

src/app/git.rs

@@ -40,13 +40,6 @@ pub(super) struct GitWorktree {
     pub(super) files: Vec<GitFile>,
 }
 
-#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
-pub(crate) enum GitDiffMode {
-    #[default]
-    Unified,
-    Split,
-}
-
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub(super) enum GitDiffLineKind {
     Section,
@@ -186,6 +179,7 @@ impl App {
         match load_diff(&worktree.root, file, &self.config.git) {
             Ok(diff) => {
                 self.git_diff = Some(diff);
+                self.git_diff_layout = self.config.git.diff_layout;
                 self.error = None;
             }
             Err(error) => self.error = Some(error),
@@ -1113,6 +1107,7 @@ mod tests {
             .find(|file| file.display_path == "changed.txt")
             .unwrap();
         let settings = GitConfig {
+            diff_layout: GitDiffLayout::Unified,
             diff_algorithm: GitDiffAlgorithm::Patience,
             context_lines: 0,
             interhunk_lines: 0,

src/app/preferences.rs

@@ -12,6 +12,7 @@ pub(super) struct PreferenceDraft {
     pub(super) endpoint_cors: bool,
     pub(super) dev_brain_enabled: bool,
     pub(super) dev_brain_vault_path: String,
+    pub(super) git_diff_layout: GitDiffLayout,
     pub(super) git_diff_algorithm: GitDiffAlgorithm,
     pub(super) git_context_lines: String,
     pub(super) git_interhunk_lines: String,
@@ -70,6 +71,7 @@ impl PreferenceDraft {
             endpoint_cors: config.endpoint.cors,
             dev_brain_enabled: config.dev_brain.enabled,
             dev_brain_vault_path: config.dev_brain.vault_path.clone().unwrap_or_default(),
+            git_diff_layout: config.git.diff_layout,
             git_diff_algorithm: config.git.diff_algorithm,
             git_context_lines: config.git.context_lines.to_string(),
             git_interhunk_lines: config.git.interhunk_lines.to_string(),
@@ -140,6 +142,7 @@ impl PreferenceDraft {
 
     pub(super) fn git(&self) -> Result<GitConfig, String> {
         Ok(GitConfig {
+            diff_layout: self.git_diff_layout,
             diff_algorithm: self.git_diff_algorithm,
             context_lines: parse_u32("Git diff context lines", &self.git_context_lines)?,
             interhunk_lines: parse_u32("Git diff interhunk lines", &self.git_interhunk_lines)?,

src/app/view.rs

@@ -12,7 +12,7 @@ use super::{
     ModelDownload, ModelOperation, PreferenceSection, ProjectChoice, chat_scroll_id, composer_id,
     models_path, preferences_scroll_id,
 };
-use crate::config::{GIT_DIFF_ALGORITHMS, GIT_DIFF_WHITESPACE_MODES};
+use crate::config::{GIT_DIFF_ALGORITHMS, GIT_DIFF_LAYOUTS, GIT_DIFF_WHITESPACE_MODES};
 use crate::database::{ProjectWithSessions, Session, SessionState};
 use crate::model::{
     self, DownloadPhase, MODEL_CHOICES, ManagedArtifact, ManagedArtifactState, ModelChoice,

src/app/view/git.rs

@@ -1,6 +1,7 @@
 use super::*;
-use crate::app::git::{GitChangeKind, GitDiffLine, GitDiffLineKind, GitDiffMode, GitDiffRow};
+use crate::app::git::{GitChangeKind, GitDiffLine, GitDiffLineKind, GitDiffRow};
 use crate::app::{git_diff_new_scroll_id, git_diff_old_scroll_id};
+use crate::config::GitDiffLayout;
 use iced::widget::column;
 
 impl App {
@@ -230,13 +231,13 @@ impl App {
 
     pub(super) fn git_diff_panel(&self) -> Element<'_, Message> {
         let diff = self.git_diff.as_ref().unwrap();
-        let unified_active = self.git_diff_mode == GitDiffMode::Unified;
-        let split_active = self.git_diff_mode == GitDiffMode::Split;
+        let unified_active = self.git_diff_layout == GitDiffLayout::Unified;
+        let split_active = self.git_diff_layout == GitDiffLayout::Split;
         let mode = container(
             row![
                 button(text("1 column").size(12))
                     .padding([4, 10])
-                    .on_press(Message::SetGitDiffMode(GitDiffMode::Unified))
+                    .on_press(Message::SetGitDiffLayout(GitDiffLayout::Unified))
                     .style(move |theme, status| segmented_button_style(
                         theme,
                         status,
@@ -244,7 +245,7 @@ impl App {
                     )),
                 button(text("2 columns").size(12))
                     .padding([4, 10])
-                    .on_press(Message::SetGitDiffMode(GitDiffMode::Split))
+                    .on_press(Message::SetGitDiffLayout(GitDiffLayout::Split))
                     .style(move |theme, status| segmented_button_style(
                         theme,
                         status,

src/app/view/preferences.rs

@@ -199,6 +199,20 @@ impl App {
             PreferenceSection::Git,
             "GIT DIFFS",
             column![
+                row![
+                    hint(
+                        text("Default layout").size(13).width(Length::Fill),
+                        "Layout used whenever a file diff is opened. The control in the diff can still change that one view.",
+                    ),
+                    pick_list(
+                        &GIT_DIFF_LAYOUTS[..],
+                        Some(self.preference_draft.git_diff_layout),
+                        Message::PreferenceGitDiffLayoutChanged,
+                    )
+                    .width(240),
+                ]
+                .spacing(12)
+                .align_y(Alignment::Center),
                 row![
                     hint(
                         text("Algorithm").size(13).width(Length::Fill),