Merge pull request #195 from KevinGriffin-new/feat/persist-background

feat(background): persist viewport background across sessions (#188)

src/app/commands.rs

@@ -108,6 +108,9 @@ impl OpenCADStudio {
             // ── Background color ───────────────────────────────────────────
             // Usage:  BACKGROUND <r> <g> <b>   (0–255 each)
             //         BACKGROUND RESET          (restore default)
+            // The chosen colour is also stored as the persisted default
+            // (`default_bg_color` / `default_paper_bg_color`) so it survives
+            // restarts and applies to new drawings (#188).
             cmd if cmd == "BACKGROUND" || cmd.starts_with("BACKGROUND ") => {
                 let args = cmd.split_whitespace().skip(1).collect::<Vec<_>>();
                 let is_paper = self.tabs[i].scene.current_layout != "Model";
@@ -119,9 +122,11 @@ impl OpenCADStudio {
                     if is_paper {
                         self.tabs[i].paper_bg_color = None;
                         self.tabs[i].scene.paper_bg_color = [1.0, 1.0, 1.0, 1.0];
+                        self.default_paper_bg_color = None;
                     } else {
                         self.tabs[i].bg_color = None;
                         self.tabs[i].scene.bg_color = [0.11, 0.11, 0.11, 1.0];
+                        self.default_bg_color = None;
                     }
                     // Wire colour adaptation (`adapt_to_bg`) reads the bg
                     // at tessellation time, so the cached wires need to
@@ -139,12 +144,15 @@ impl OpenCADStudio {
                     let r = args[0].parse::<u8>().unwrap_or(0) as f32 / 255.0;
                     let g = args[1].parse::<u8>().unwrap_or(0) as f32 / 255.0;
                     let b = args[2].parse::<u8>().unwrap_or(0) as f32 / 255.0;
+                    let rgba = [r, g, b, 1.0];
                     if is_paper {
-                        self.tabs[i].paper_bg_color = Some([r, g, b, 1.0]);
-                        self.tabs[i].scene.paper_bg_color = [r, g, b, 1.0];
+                        self.tabs[i].paper_bg_color = Some(rgba);
+                        self.tabs[i].scene.paper_bg_color = rgba;
+                        self.default_paper_bg_color = Some(rgba);
                     } else {
-                        self.tabs[i].bg_color = Some([r, g, b, 1.0]);
-                        self.tabs[i].scene.bg_color = [r, g, b, 1.0];
+                        self.tabs[i].bg_color = Some(rgba);
+                        self.tabs[i].scene.bg_color = rgba;
+                        self.default_bg_color = Some(rgba);
                     }
                     self.tabs[i].scene.recolor_meshes();
                     self.tabs[i].scene.bump_geometry();
@@ -152,6 +160,8 @@ impl OpenCADStudio {
                         "Background: rgb({}, {}, {})",
                         args[0], args[1], args[2]
                     ));
+                    // Persisted centrally after this message via
+                    // `persist_settings_if_changed()`.
                 } else {
                     self.command_line
                         .push_info("Usage: BACKGROUND <r> <g> <b>  (0–255)  |  BACKGROUND RESET");

src/app/mod.rs

@@ -245,6 +245,12 @@ pub(super) struct OpenCADStudio {
     dyn_input: bool,
     /// Controls whether the TEXTEDIT command repeats automatically (0 = Multiple, 1 = Single).
     pub texteditmode: bool,
+    /// Persisted default viewport background, restored from settings and applied
+    /// to every drawing tab (new and opened) so a chosen background survives
+    /// restarts (#188). `None` = the built-in dark-grey / off-white defaults.
+    /// The `a` channel is always 1.0.
+    default_bg_color: Option<[f32; 4]>,
+    default_paper_bg_color: Option<[f32; 4]>,
     /// `true` after a bare `VPORTS` in model space — the next command-line
     /// entry is treated as the tiled-config option (SIngle/2H/2V/4).
     awaiting_vports: bool,
@@ -1770,6 +1776,8 @@ impl OpenCADStudio {
             show_grid: false,
             dyn_input: true,
             texteditmode: false,
+            default_bg_color: None,
+            default_paper_bg_color: None,
             awaiting_vports: false,
             tile_drag: None,
             dyn_user_reshaped: false,

src/app/settings.rs

@@ -58,6 +58,25 @@ fn snap_from_id(s: &str) -> Option<SnapType> {
     SNAP_ORDER.iter().copied().find(|t| snap_id(*t) == s)
 }
 
+/// Parse a persisted `r,g,b` background triplet (each 0–255). Returns `None`
+/// for an empty or malformed value so a missing/garbage key falls back to the
+/// app default rather than a wrong colour.
+fn parse_rgb(val: &str) -> Option<[u8; 3]> {
+    let mut it = val.split(',').map(|t| t.trim().parse::<u8>());
+    let r = it.next()?.ok()?;
+    let g = it.next()?.ok()?;
+    let b = it.next()?.ok()?;
+    if it.next().is_some() {
+        return None;
+    }
+    Some([r, g, b])
+}
+
+/// Serialize an optional background triplet back to `r,g,b`, or empty when unset.
+fn rgb_to_str(c: Option<[u8; 3]>) -> String {
+    c.map(|[r, g, b]| format!("{r},{g},{b}")).unwrap_or_default()
+}
+
 /// A snapshot of the persisted preferences. Field defaults mirror the app's
 /// in-code defaults so a missing key restores the same value the app boots
 /// with.
@@ -84,6 +103,12 @@ pub struct UserSettings {
     pub plugin_repos: Vec<String>,
     /// Controls whether the TEXTEDIT command repeats automatically (0 = Multiple, 1 = Single).
     pub texteditmode: bool,
+    /// Persisted viewport background colours (0–255 RGB); `None` = app default
+    /// (dark grey model / off-white paper). Applied to every drawing tab on
+    /// launch and to tabs opened later, so a chosen background survives restarts
+    /// (#188).
+    pub bg_color: Option<[u8; 3]>,
+    pub paper_bg_color: Option<[u8; 3]>,
 }
 
 impl Default for UserSettings {
@@ -108,6 +133,8 @@ impl Default for UserSettings {
             disabled_plugins: Vec::new(),
             plugin_repos: Vec::new(),
             texteditmode: false,
+            bg_color: None,
+            paper_bg_color: None,
         }
     }
 }
@@ -140,6 +167,8 @@ impl UserSettings {
                 }
                 "osnap" => s.snap_enabled = val == "1",
                 "otrack" => s.otrack = val == "1",
+                "bg_color" => s.bg_color = parse_rgb(val),
+                "paper_bg_color" => s.paper_bg_color = parse_rgb(val),
                 "default_assoc_prompted" => s.default_assoc_prompted = val == "1",
                 "texteditmode" => {
                     if let Some(v) =
@@ -189,7 +218,7 @@ impl UserSettings {
             .collect::<Vec<_>>()
             .join(",");
         let body = format!(
-            "dyn={}\northo={}\npolar={}\npolar_increment_deg={}\nosnap={}\notrack={}\ndefault_assoc_prompted={}\nsnap_modes={}\ndisabled_plugins={}\nplugin_repos={}\ntexteditmode={}\n",
+            "dyn={}\northo={}\npolar={}\npolar_increment_deg={}\nosnap={}\notrack={}\ndefault_assoc_prompted={}\nsnap_modes={}\ndisabled_plugins={}\nplugin_repos={}\ntexteditmode={}\nbg_color={}\npaper_bg_color={}\n",
             b(self.dyn_input),
             b(self.ortho),
             b(self.polar),
@@ -201,6 +230,8 @@ impl UserSettings {
             self.disabled_plugins.join(","),
             self.plugin_repos.join(","),
             self.texteditmode,
+            rgb_to_str(self.bg_color),
+            rgb_to_str(self.paper_bg_color),
         );
         let _ = std::fs::write(path, body);
     }

src/app/update.rs

@@ -196,6 +196,8 @@ impl OpenCADStudio {
             },
             plugin_repos: self.plugin_repos.clone(),
             texteditmode: self.texteditmode,
+            bg_color: self.default_bg_color.map(f4_to_u3),
+            paper_bg_color: self.default_paper_bg_color.map(f4_to_u3),
         }
     }
 
@@ -212,9 +214,42 @@ impl OpenCADStudio {
         self.disabled_plugins = s.disabled_plugins.iter().cloned().collect();
         self.plugin_repos = s.plugin_repos.clone();
         self.texteditmode = s.texteditmode;
+        self.default_bg_color = s.bg_color.map(u3_to_f4);
+        self.default_paper_bg_color = s.paper_bg_color.map(u3_to_f4);
+        // Push the restored background onto every drawing tab that exists now
+        // (the start tab and any initial drawing). Tabs created later pick it
+        // up via `apply_bg_default` at their construction site.
+        for idx in 0..self.tabs.len() {
+            self.apply_bg_default(idx);
+        }
         self.rebuild_ribbon_modules();
     }
 
+    /// Apply the persisted default background(s) to tab `idx`. No-op for the
+    /// start tab or when no default is set. Refreshes the tab's cached wires
+    /// and meshes so background-adaptive colours pick up the change.
+    pub(super) fn apply_bg_default(&mut self, idx: usize) {
+        let bg = self.default_bg_color;
+        let paper_bg = self.default_paper_bg_color;
+        if bg.is_none() && paper_bg.is_none() {
+            return;
+        }
+        let tab = &mut self.tabs[idx];
+        if tab.is_start {
+            return;
+        }
+        if let Some(c) = bg {
+            tab.bg_color = Some(c);
+            tab.scene.bg_color = c;
+        }
+        if let Some(c) = paper_bg {
+            tab.paper_bg_color = Some(c);
+            tab.scene.paper_bg_color = c;
+        }
+        tab.scene.recolor_meshes();
+        tab.scene.bump_geometry();
+    }
+
     /// Check if a suspended command exists on the active tab and resume it
     /// with the outcome of the text editor.
     pub(super) fn post_editor_closed(&mut self, committed: bool) -> Task<Message> {
@@ -555,6 +590,7 @@ impl OpenCADStudio {
                     self.tabs.push(new_tab);
                     let idx = self.tabs.len() - 1;
                     self.active_tab = idx;
+                    self.apply_bg_default(idx);
                     idx
                 };
 
@@ -1346,6 +1382,8 @@ impl OpenCADStudio {
                 let new_tab = super::document::DocumentTab::new_drawing(self.tab_counter);
                 self.tabs.push(new_tab);
                 self.active_tab = self.tabs.len() - 1;
+                let idx = self.active_tab;
+                self.apply_bg_default(idx);
                 self.sync_ribbon_layers();
                 self.sync_ribbon_styles();
                 // #21: reset ribbon Color / Linetype / Lineweight to the
@@ -1397,6 +1435,7 @@ impl OpenCADStudio {
                     self.tab_counter += 1;
                     self.tabs[0] = super::document::DocumentTab::new_drawing(self.tab_counter);
                     self.active_tab = 0;
+                    self.apply_bg_default(0);
                 } else {
                     self.tabs.remove(idx);
                     if self.active_tab >= self.tabs.len() {
@@ -6474,6 +6513,7 @@ impl OpenCADStudio {
                             self.tabs[0] =
                                 super::document::DocumentTab::new_drawing(self.tab_counter);
                             self.active_tab = 0;
+                            self.apply_bg_default(0);
                         } else {
                             self.tabs.remove(idx);
                             if self.active_tab >= self.tabs.len() {
@@ -9591,3 +9631,19 @@ fn parse_plot_scale(s: &str) -> (f64, f64) {
     }
     (1.0, 1.0)
 }
+
+/// Convert an internal `[r,g,b,a]` colour (0.0–1.0) to a persisted 0–255 RGB
+/// triplet, dropping alpha (backgrounds are always opaque).
+fn f4_to_u3([r, g, b, _]: [f32; 4]) -> [u8; 3] {
+    [
+        (r * 255.0).round().clamp(0.0, 255.0) as u8,
+        (g * 255.0).round().clamp(0.0, 255.0) as u8,
+        (b * 255.0).round().clamp(0.0, 255.0) as u8,
+    ]
+}
+
+/// Inverse of [`f4_to_u3`]: a persisted 0–255 RGB triplet back to an opaque
+/// `[r,g,b,a]` colour.
+fn u3_to_f4([r, g, b]: [u8; 3]) -> [f32; 4] {
+    [r as f32 / 255.0, g as f32 / 255.0, b as f32 / 255.0, 1.0]
+}