Fix compilation of `egui_extras` without `serde` feature (#5014)

* Closes https://github.com/emilk/egui/issues/4771

.github/workflows/rust.yml

@@ -57,6 +57,10 @@ jobs:
       - name: check epaint --no-default-features
         run: cargo check --locked --no-default-features --lib -p epaint
 
+      # Regression test for https://github.com/emilk/egui/issues/4771
+      - name: cargo check -p test_egui_extras_compilation
+        run: cargo check -p test_egui_extras_compilation
+
       - name: Test doc-tests
         run: cargo test --doc --all-features
 

Cargo.lock

@@ -3804,6 +3804,14 @@ dependencies = [
  "winapi-util",
 ]
 
+[[package]]
+name = "test_egui_extras_compilation"
+version = "0.1.0"
+dependencies = [
+ "eframe",
+ "egui_extras",
+]
+
 [[package]]
 name = "test_inline_glow_paint"
 version = "0.1.0"

crates/egui_extras/Cargo.toml

@@ -27,7 +27,7 @@ all-features = true
 
 
 [features]
-default = ["dep:mime_guess2", "serde"]
+default = ["dep:mime_guess2"]
 
 ## Shorthand for enabling the different types of image loaders (`file`, `http`, `image`, `svg`).
 all_loaders = ["file", "http", "image", "svg", "gif"]

crates/egui_extras/src/syntax_highlighting.rs

@@ -153,16 +153,22 @@ impl CodeTheme {
     ///
     /// There is one dark and one light theme stored at any one time.
     pub fn from_memory(ctx: &egui::Context) -> Self {
-        if ctx.style().visuals.dark_mode {
-            ctx.data_mut(|d| {
-                d.get_persisted(egui::Id::new("dark"))
-                    .unwrap_or_else(Self::dark)
-            })
+        #![allow(clippy::needless_return)]
+
+        let (id, default) = if ctx.style().visuals.dark_mode {
+            (egui::Id::new("dark"), Self::dark as fn() -> Self)
         } else {
-            ctx.data_mut(|d| {
-                d.get_persisted(egui::Id::new("light"))
-                    .unwrap_or_else(Self::light)
-            })
+            (egui::Id::new("light"), Self::light as fn() -> Self)
+        };
+
+        #[cfg(feature = "serde")]
+        {
+            return ctx.data_mut(|d| d.get_persisted(id).unwrap_or_else(default));
+        }
+
+        #[cfg(not(feature = "serde"))]
+        {
+            return ctx.data_mut(|d| d.get_temp(id).unwrap_or_else(default));
         }
     }
 
@@ -170,11 +176,17 @@ impl CodeTheme {
     ///
     /// There is one dark and one light theme stored at any one time.
     pub fn store_in_memory(self, ctx: &egui::Context) {
-        if self.dark_mode {
-            ctx.data_mut(|d| d.insert_persisted(egui::Id::new("dark"), self));
+        let id = if ctx.style().visuals.dark_mode {
+            egui::Id::new("dark")
         } else {
-            ctx.data_mut(|d| d.insert_persisted(egui::Id::new("light"), self));
-        }
+            egui::Id::new("light")
+        };
+
+        #[cfg(feature = "serde")]
+        ctx.data_mut(|d| d.insert_persisted(id, self));
+
+        #[cfg(not(feature = "serde"))]
+        ctx.data_mut(|d| d.insert_temp(id, self));
     }
 }
 
@@ -245,9 +257,15 @@ impl CodeTheme {
     pub fn ui(&mut self, ui: &mut egui::Ui) {
         ui.horizontal_top(|ui| {
             let selected_id = egui::Id::NULL;
+
+            #[cfg(feature = "serde")]
             let mut selected_tt: TokenType =
                 ui.data_mut(|d| *d.get_persisted_mut_or(selected_id, TokenType::Comment));
 
+            #[cfg(not(feature = "serde"))]
+            let mut selected_tt: TokenType =
+                ui.data_mut(|d| *d.get_temp_mut_or(selected_id, TokenType::Comment));
+
             ui.vertical(|ui| {
                 ui.set_width(150.0);
                 egui::widgets::global_dark_light_mode_buttons(ui);
@@ -288,7 +306,10 @@ impl CodeTheme {
 
             ui.add_space(16.0);
 
+            #[cfg(feature = "serde")]
             ui.data_mut(|d| d.insert_persisted(selected_id, selected_tt));
+            #[cfg(not(feature = "serde"))]
+            ui.data_mut(|d| d.insert_temp(selected_id, selected_tt));
 
             egui::Frame::group(ui.style())
                 .inner_margin(egui::Vec2::splat(2.0))

crates/egui_extras/src/table.rs

@@ -543,12 +543,13 @@ impl TableState {
         let rect = Rect::from_min_size(ui.available_rect_before_wrap().min, Vec2::ZERO);
         ui.ctx().check_for_id_clash(state_id, rect, "Table");
 
-        let state = ui
-            .data_mut(|d| d.get_persisted::<Self>(state_id))
-            .filter(|state| {
-                // make sure that the stored widths aren't out-dated
-                state.column_widths.len() == columns.len()
-            });
+        #[cfg(feature = "serde")]
+        let state = ui.data_mut(|d| d.get_persisted::<Self>(state_id));
+        #[cfg(not(feature = "serde"))]
+        let state = ui.data_mut(|d| d.get_temp::<Self>(state_id));
+
+        // Make sure that the stored widths aren't out-dated:
+        let state = state.filter(|state| state.column_widths.len() == columns.len());
 
         let is_sizing_pass =
             ui.is_sizing_pass() || state.is_none() && columns.iter().any(|c| c.is_auto());
@@ -597,7 +598,15 @@ impl TableState {
     }
 
     fn store(self, ui: &egui::Ui, state_id: egui::Id) {
-        ui.data_mut(|d| d.insert_persisted(state_id, self));
+        #![allow(clippy::needless_return)]
+        #[cfg(feature = "serde")]
+        {
+            return ui.data_mut(|d| d.insert_persisted(state_id, self));
+        }
+        #[cfg(not(feature = "serde"))]
+        {
+            return ui.data_mut(|d| d.insert_temp(state_id, self));
+        }
     }
 
     fn reset(ui: &egui::Ui, state_id: egui::Id) {

tests/test_egui_extras_compilation/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "test_egui_extras_compilation"
+version = "0.1.0"
+license = "MIT OR Apache-2.0"
+edition = "2021"
+rust-version = "1.76"
+publish = false
+
+[lints]
+workspace = true
+
+
+[dependencies]
+eframe = { workspace = true, features = ["default", "persistence"] }
+egui_extras = { workspace = true }

tests/test_egui_extras_compilation/README.md

@@ -0,0 +1 @@
+Regression test for <https://github.com/emilk/egui/issues/4771>

tests/test_egui_extras_compilation/src/main.rs

@@ -0,0 +1,3 @@
+//! Regression test for <https://github.com/emilk/egui/issues/4771>
+
+fn main() {}