feat(options): set default save format

Avoid false data-loss warnings when preserving the source format.\n\nCloses #529

src/app/mod.rs

@@ -789,6 +789,8 @@ pub(super) struct OpenCADStudio {
     save_dialog_filename: String,
     /// True when triggered from the unsaved-changes flow.
     save_dialog_for_unsaved: bool,
+    /// User preference for the first save of a new/unsaved drawing.
+    default_save_format: String,
 
     // ── DimStyle Dialog ───────────────────────────────────────────────────
     /// Name of the style currently shown in the dialog.
@@ -1298,6 +1300,7 @@ pub enum ModalKind {
     DimStyle,
     Unsaved,
     SaveDialog,
+    Options,
     AecDropWarning,
     #[cfg(not(target_arch = "wasm32"))]
     FileInUse,
@@ -1468,6 +1471,10 @@ pub enum Message {
     SaveDialogCancel,
     /// Destination picked in the native OS save dialog (`None` = cancelled).
     SaveDialogPathPicked(Option<std::path::PathBuf>),
+    /// Open the application-wide Options dialog.
+    OptionsOpen,
+    /// Set the default type/version used when first saving a new drawing.
+    DefaultSaveFormatChanged(String),
     ClearScene,
     SetWireframe(bool),
     /// Set the active tab's render mode (one of acadrust's seven visual
@@ -2618,9 +2625,10 @@ impl OpenCADStudio {
             pending_save_failure: None,
             #[cfg(not(target_arch = "wasm32"))]
             pending_external_change: None,
-            save_dialog_format: "DWG 2018".to_string(),
+            save_dialog_format: crate::io::DEFAULT_SAVE_FORMAT.to_string(),
             save_dialog_filename: "drawing.dwg".to_string(),
             save_dialog_for_unsaved: false,
+            default_save_format: crate::io::DEFAULT_SAVE_FORMAT.to_string(),
             // Plot style
             active_plot_style: None,
             // Color scheme (default: dark CAD-style)

src/app/settings.rs

@@ -135,6 +135,9 @@ pub struct UserSettings {
     /// Minutes between autosaves to a `.sv$` recovery file (SAVETIME command).
     /// 0 disables autosave.
     pub savetime_min: i32,
+    /// File type and version used when a new/unsaved drawing is first saved.
+    /// Existing drawings keep their own type and version.
+    pub default_save_format: String,
     /// PICKADD (#226): `true` (default) = a plain click ADDS to the selection
     /// (Shift removes); `false` = OS-style — a click REPLACES the selection
     /// and Shift+click toggles membership.
@@ -169,6 +172,7 @@ impl Default for UserSettings {
             backup_on_save: true,
             file_assoc_enabled: true,
             savetime_min: 10,
+            default_save_format: crate::io::DEFAULT_SAVE_FORMAT.to_string(),
             pick_add: true,
             pick_drag_rect: false,
             bg_color: None,

src/app/update/dialog.rs

@@ -26,18 +26,24 @@ impl OpenCADStudio {
         // Default the format dropdown to the loaded file's own format — its
         // DWG-vs-DXF kind (from the extension) and its version (from the parsed
         // document) — so Save-As round-trips the format instead of silently
-        // re-targeting the latest. A new/unsaved drawing has no path, so it
-        // keeps its document default version and DWG. The user can still pick
-        // any other version explicitly.
-        let is_dxf = self.tabs[tab_idx]
-            .current_path
-            .as_ref()
-            .and_then(|p| p.extension())
-            .and_then(|e| e.to_str())
-            .map(|e| e.eq_ignore_ascii_case("dxf"))
-            .unwrap_or(false);
-        let version = self.tabs[tab_idx].scene.document.version;
-        self.save_dialog_format = crate::io::format_for_version(version, is_dxf);
+        // re-targeting it. A new/unsaved drawing has no source format, so it
+        // uses the application-wide default chosen in Options (#529).
+        self.save_dialog_format = if let Some(path) = &self.tabs[tab_idx].current_path {
+            let is_dxf = path
+                .extension()
+                .and_then(|e| e.to_str())
+                .map(|e| e.eq_ignore_ascii_case("dxf"))
+                .unwrap_or(false);
+            let document = &self.tabs[tab_idx].scene.document;
+            let version = if is_dxf {
+                document.version
+            } else {
+                document.dwg_source_version.unwrap_or(document.version)
+            };
+            crate::io::format_for_version(version, is_dxf)
+        } else {
+            self.default_save_format.clone()
+        };
 
         // Pre-fill the default file name from the current path or the tab name;
         // the destination folder comes from the native OS dialog that follows.
@@ -280,7 +286,7 @@ pub(super) fn on_ribbon_tool_click(&mut self, tool_id: String, event: ModuleEven
             self.active_tab = idx;
             self.save_dialog_for_unsaved = true;
             let close = self.close_unsaved_dialog_window();
-            let save = self.save_default_dwg2018(idx);
+            let save = self.save_with_default_format(idx);
             return Task::batch([close, save]);
         }
 
@@ -291,7 +297,7 @@ pub(super) fn on_ribbon_tool_click(&mut self, tool_id: String, event: ModuleEven
                     self.pending_close = Some(crate::app::PendingClose::Tab(idx));
                     self.save_dialog_for_unsaved = true;
                     let close = self.close_unsaved_dialog_window();
-                    let save = self.save_default_dwg2018(idx);
+                    let save = self.save_with_default_format(idx);
                     Task::batch([close, save])
                 }
                 Some(crate::app::PendingClose::Quit) => {
@@ -300,7 +306,7 @@ pub(super) fn on_ribbon_tool_click(&mut self, tool_id: String, event: ModuleEven
                         self.pending_close = Some(crate::app::PendingClose::Quit);
                         self.save_dialog_for_unsaved = true;
                         let close = self.close_unsaved_dialog_window();
-                        let save = self.save_default_dwg2018(idx);
+                        let save = self.save_with_default_format(idx);
                         Task::batch([close, save])
                     } else {
                         Task::batch([

src/app/update/file.rs

@@ -118,6 +118,7 @@ impl OpenCADStudio {
             backup_on_save: self.backup_on_save,
             file_assoc_enabled: self.file_assoc_enabled,
             savetime_min: self.savetime_min,
+            default_save_format: self.default_save_format.clone(),
             pick_add: self.pick_add,
             pick_drag_rect: self.pick_drag_rect,
             bg_color: self.default_bg_color.map(f4_to_u3),
@@ -145,6 +146,8 @@ impl OpenCADStudio {
         self.backup_on_save = s.backup_on_save;
         self.file_assoc_enabled = s.file_assoc_enabled;
         self.savetime_min = s.savetime_min;
+        self.default_save_format =
+            crate::io::canonical_save_format(&s.default_save_format).to_string();
         self.pick_add = s.pick_add;
         self.pick_drag_rect = s.pick_drag_rect;
         self.default_bg_color = s.bg_color.map(u3_to_f4);
@@ -1307,6 +1310,7 @@ pub(super) fn on_open_file(&mut self) -> Task<Message> {
                 }
                 if outcome.set_current_path {
                     self.tabs[i].current_path = Some(outcome.path.clone());
+                    self.tabs[i].scene.document.version = outcome.version;
                     tasks.push(self.push_recent(outcome.path.clone()));
                 }
                 self.refresh_native_edit_guard_after_save(
@@ -1528,22 +1532,23 @@ pub(super) fn on_open_file(&mut self) -> Task<Message> {
                     );
                 }
                 self.save_dialog_for_unsaved = false;
-                self.save_default_dwg2018(i)
+                self.save_with_default_format(i)
     }
 
-    /// Save without the version picker: default to DWG 2018 and go straight to
+    /// Save without the version picker: use the configured default and go straight to
     /// the native destination dialog (native) or the browser download (web).
     /// Used by plain Save (QSAVE) on an as-yet-unsaved drawing and by the
     /// save-before-close flow — the version picker is reserved for Save As.
-    pub(in crate::app) fn save_default_dwg2018(&mut self, tab_idx: usize) -> Task<Message> {
+    pub(in crate::app) fn save_with_default_format(&mut self, tab_idx: usize) -> Task<Message> {
         self.active_tab = tab_idx;
-        self.save_dialog_format = "DWG 2018".to_string();
+        self.save_dialog_format = self.default_save_format.clone();
+        let (ext, _) = crate::io::parse_save_format(&self.save_dialog_format);
         self.save_dialog_filename = self.tabs[tab_idx]
             .current_path
             .as_ref()
             .and_then(|p| p.file_name())
             .map(|n| n.to_string_lossy().into_owned())
-            .unwrap_or_else(|| format!("{}.dwg", self.tabs[tab_idx].tab_display_name()));
+            .unwrap_or_else(|| format!("{}.{ext}", self.tabs[tab_idx].tab_display_name()));
         self.aec_drop_acknowledged = false;
         self.on_save_dialog_confirm()
     }
@@ -1625,6 +1630,7 @@ pub(super) fn on_open_file(&mut self) -> Task<Message> {
                         match crate::io::save_to_bytes(&self.tabs[i].scene.document, ext, version) {
                         Ok(bytes) => {
                             crate::sys::download_bytes(&filename, &bytes);
+                            self.tabs[i].scene.document.version = version;
                             self.tabs[i].dirty = false;
                             self.command_line.push_output(&format!("Saved: {filename}"));
                             true
@@ -1700,12 +1706,24 @@ pub(super) fn on_open_file(&mut self) -> Task<Message> {
     }
 
     /// AEC-drop warning → "Save in source version": switch the target to the
-    /// document's own DWG version (where the unsupported objects round-trip as
-    /// verbatim bytes), then save.
+    /// document's source type and version, then save.
     pub(super) fn on_aec_drop_same_version(&mut self) -> Task<Message> {
-        let src = self.tabs[self.active_tab].scene.document.version;
-        self.save_dialog_format = crate::io::format_for_version(src, false);
-        // Strip any extension (e.g. .dxf) so the confirm path appends .dwg.
+        let tab = &self.tabs[self.active_tab];
+        let is_dxf = tab
+            .current_path
+            .as_ref()
+            .and_then(|path| path.extension())
+            .and_then(|extension| extension.to_str())
+            .map(|extension| extension.eq_ignore_ascii_case("dxf"))
+            .unwrap_or(false);
+        let document = &tab.scene.document;
+        let src = if is_dxf {
+            document.version
+        } else {
+            document.dwg_source_version.unwrap_or(document.version)
+        };
+        self.save_dialog_format = crate::io::format_for_version(src, is_dxf);
+        // Strip the old extension so the confirm path appends the source type.
         let stem = std::path::Path::new(&self.save_dialog_filename)
             .file_stem()
             .map(|s| s.to_string_lossy().into_owned())

src/app/update/mod.rs

@@ -3663,7 +3663,18 @@ impl OpenCADStudio {
                 Task::none()
             }
 
-            // ── About window ──────────────────────────────────────────────
+            // ── Options / About windows ───────────────────────────────────
+            Message::OptionsOpen => {
+                self.active_modal = Some(super::ModalKind::Options);
+                Task::none()
+            }
+
+            Message::DefaultSaveFormatChanged(format) => {
+                self.default_save_format =
+                    crate::io::canonical_save_format(&format).to_string();
+                Task::none()
+            }
+
             Message::AboutOpen => {
                 self.active_modal = Some(super::ModalKind::About);
                 Task::none()

src/app/view/mod.rs

@@ -1708,6 +1708,7 @@ impl OpenCADStudio {
         let (w, h) = match self.active_modal? {
             About => (440, 360),
             Shortcuts => (720, 520),
+            Options => (480, 190),
             PluginManager => (520, 460),
             UpdateNotice => (560, 460),
             Layers => (900, 360),
@@ -2524,6 +2525,7 @@ pub(super) fn start_page_view<'a>(
             },
         )
         .into(),
+        outline_btn("Options", Message::OptionsOpen).into(),
         outline_btn("Plugins", Message::PluginManagerOpen).into(),
     ];
     // The web build is already in the browser, so only the desktop offers a

src/app/view/modal.rs

@@ -11,6 +11,7 @@ impl OpenCADStudio {
             Some(K::About) => "About",
             Some(K::Shortcuts) => "Keyboard Shortcuts",
             Some(K::Aliases) => "Command Aliases",
+            Some(K::Options) => "Options",
             Some(K::PluginManager) => "Plugin Manager",
             Some(K::UpdateNotice) => "Update Available",
             Some(K::Layers) => "Layer Manager",
@@ -61,6 +62,11 @@ impl OpenCADStudio {
             super::super::ModalKind::Aliases => {
                 sized(crate::ui::window::alias_editor::view_window(&self.alias_editor_rows), 480, 520)
             }
+            super::super::ModalKind::Options => sized(
+                crate::ui::window::options::view_window(&self.default_save_format),
+                480,
+                190,
+            ),
             super::super::ModalKind::PluginManager => sized(
                 crate::ui::window::plugin_manager::view_window(
                     &self.disabled_plugins,
@@ -574,7 +580,24 @@ impl OpenCADStudio {
                 let src_label = self
                     .tabs
                     .get(self.active_tab)
-                    .map(|t| crate::io::format_for_version(t.scene.document.version, false))
+                    .map(|t| {
+                        let is_dxf = t
+                            .current_path
+                            .as_ref()
+                            .and_then(|path| path.extension())
+                            .and_then(|extension| extension.to_str())
+                            .map(|extension| extension.eq_ignore_ascii_case("dxf"))
+                            .unwrap_or(false);
+                        let version = if is_dxf {
+                            t.scene.document.version
+                        } else {
+                            t.scene
+                                .document
+                                .dwg_source_version
+                                .unwrap_or(t.scene.document.version)
+                        };
+                        crate::io::format_for_version(version, is_dxf)
+                    })
                     .unwrap_or_else(|| "DWG".to_string());
                 sized(
                     aec_drop_dialog_window(
@@ -689,11 +712,6 @@ impl OpenCADStudio {
     }
 }
 
-const SAVE_FORMAT_OPTIONS: &[&str] = &[
-    "DWG 2018", "DWG 2013", "DWG 2010", "DWG 2007", "DWG 2004", "DWG 2000", "DWG R14", "DXF 2018",
-    "DXF 2013", "DXF 2010", "DXF 2007", "DXF 2004", "DXF 2000", "DXF R14",
-];
-
 /// Compact Save-As options dialog: pick the format/version and a default file
 /// name. The destination folder and overwrite confirmation come from the
 /// native OS save dialog (native) or the browser download (web) that follows.
@@ -769,7 +787,10 @@ fn save_as_dialog_window<'a>(filename: &'a str, format: &'a str) -> Element<'a,
             .padding([4, 12])
     };
 
-    let sel_fmt = SAVE_FORMAT_OPTIONS.iter().copied().find(|&s| s == format);
+    let sel_fmt = crate::io::SAVE_FORMAT_OPTIONS
+        .iter()
+        .copied()
+        .find(|&s| s == format);
     let label = |s: &'static str| text(s).size(11).color(DIM);
 
     let mut items: Vec<Element<'a, Message>> = Vec::new();
@@ -826,7 +847,7 @@ fn save_as_dialog_window<'a>(filename: &'a str, format: &'a str) -> Element<'a,
     items.push(
         row![
             label("Format:").width(70),
-            pick_list(SAVE_FORMAT_OPTIONS, sel_fmt, |s: &str| {
+            pick_list(crate::io::SAVE_FORMAT_OPTIONS, sel_fmt, |s: &str| {
                 Message::SaveDialogFormatChanged(s.to_string())
             })
             .width(Fill),

src/io/mod.rs

@@ -432,6 +432,21 @@ pub(crate) fn resolve_image_file(raw: &str, base_dir: Option<&Path>) -> Option<S
 
 // ── Save ──────────────────────────────────────────────────────────────────
 
+pub const DEFAULT_SAVE_FORMAT: &str = "DWG 2018";
+
+pub const SAVE_FORMAT_OPTIONS: &[&str] = &[
+    "DWG 2018", "DWG 2013", "DWG 2010", "DWG 2007", "DWG 2004", "DWG 2000", "DWG R14", "DXF 2018",
+    "DXF 2013", "DXF 2010", "DXF 2007", "DXF 2004", "DXF 2000", "DXF R14",
+];
+
+pub fn canonical_save_format(format: &str) -> &'static str {
+    SAVE_FORMAT_OPTIONS
+        .iter()
+        .copied()
+        .find(|candidate| candidate.eq_ignore_ascii_case(format))
+        .unwrap_or(DEFAULT_SAVE_FORMAT)
+}
+
 /// Parse a format string like "DWG 2013" or "DXF 2007" into
 /// `(extension, DxfVersion)`.  Falls back to ("dwg", AC1032) for unknown strings.
 pub fn parse_save_format(format: &str) -> (&'static str, acadrust::DxfVersion) {
@@ -486,6 +501,10 @@ pub fn dropped_on_save_count(
     target_version: acadrust::DxfVersion,
     is_dxf: bool,
 ) -> usize {
+    if !is_dxf && doc.dwg_source_version == Some(target_version) {
+        return 0;
+    }
+
     let mut n = doc
         .objects
         .values()
@@ -503,10 +522,6 @@ pub fn dropped_on_save_count(
                         || raw_dwg_version.is_some_and(|source| source != target_version)
                 }
             }
-            acadrust::objects::ObjectType::GeoData(_)
-            | acadrust::objects::ObjectType::VisualStyle(_)
-            | acadrust::objects::ObjectType::Material(_)
-            | acadrust::objects::ObjectType::TableStyle(_) => !is_dxf,
             _ => false,
         })
         .count();
@@ -522,20 +537,6 @@ pub fn dropped_on_save_count(
                             .is_some_and(|source| source != target_version)
                 }
             }
-            acadrust::EntityType::Surface(entity) => {
-                is_dxf
-                    || entity.raw_dwg_data.is_none()
-                    || entity
-                        .dwg_source_version
-                        .is_some_and(|source| source != target_version)
-            }
-            acadrust::EntityType::Light(entity) => {
-                is_dxf
-                    || entity.raw_dwg_data.is_none()
-                    || entity
-                        .dwg_source_version
-                        .is_some_and(|source| source != target_version)
-            }
             _ => false,
         };
         if dropped {

src/ui/window/mod.rs

@@ -6,5 +6,6 @@ pub mod shortcuts;
 pub mod layers;
 pub mod update_notice;
 pub mod open_progress;
+pub mod options;
 pub mod attribute_editor;
 pub mod alias_editor;

src/ui/window/options.rs

@@ -0,0 +1,98 @@
+use crate::app::Message;
+use iced::widget::{button, column, container, pick_list, row, text, Space};
+use iced::{Background, Border, Color, Element, Fill, Theme};
+
+pub fn view_window<'a>(default_save_format: &'a str) -> Element<'a, Message> {
+    const BG: Color = Color {
+        r: 0.15,
+        g: 0.15,
+        b: 0.17,
+        a: 1.0,
+    };
+    const BORDER: Color = Color {
+        r: 0.32,
+        g: 0.32,
+        b: 0.36,
+        a: 1.0,
+    };
+    const TEXT: Color = Color {
+        r: 0.90,
+        g: 0.90,
+        b: 0.90,
+        a: 1.0,
+    };
+    const DIM: Color = Color {
+        r: 0.60,
+        g: 0.60,
+        b: 0.64,
+        a: 1.0,
+    };
+
+    let selected = crate::io::SAVE_FORMAT_OPTIONS
+        .iter()
+        .copied()
+        .find(|candidate| *candidate == default_save_format);
+
+    let close = button(text("Close").size(12).color(TEXT))
+        .on_press(Message::CloseModal)
+        .padding([5, 16])
+        .style(|_: &Theme, status| button::Style {
+            background: Some(Background::Color(match status {
+                button::Status::Hovered | button::Status::Pressed => Color {
+                    r: 0.34,
+                    g: 0.34,
+                    b: 0.38,
+                    a: 1.0,
+                },
+                _ => Color {
+                    r: 0.26,
+                    g: 0.26,
+                    b: 0.29,
+                    a: 1.0,
+                },
+            })),
+            text_color: TEXT,
+            border: Border {
+                color: BORDER,
+                width: 1.0,
+                radius: 4.0.into(),
+            },
+            ..Default::default()
+        });
+
+    let body = column![
+        text("Open and Save").size(15).color(TEXT),
+        Space::new().height(16),
+        row![
+            text("Default save format:").size(12).color(TEXT).width(150),
+            pick_list(crate::io::SAVE_FORMAT_OPTIONS, selected, |format: &str| {
+                Message::DefaultSaveFormatChanged(format.to_string())
+            })
+            .width(Fill),
+        ]
+        .spacing(12)
+        .align_y(iced::Center),
+        Space::new().height(10),
+        text(
+            "Used when a new drawing is saved for the first time. Existing drawings keep their current file type and version."
+        )
+        .size(11)
+        .color(DIM)
+        .width(Fill),
+        Space::new().height(Fill),
+        row![Space::new().width(Fill), close],
+    ]
+    .spacing(0)
+    .width(Fill)
+    .height(Fill);
+
+    container(body)
+        .style(|_: &Theme| container::Style {
+            background: Some(Background::Color(BG)),
+            ..Default::default()
+        })
+        .padding([16, 18])
+        .width(Fill)
+        .height(Fill)
+        .into()
+}