Persist sketch parameters across app relaunch

crates/vsvg/src/color.rs

@@ -1,6 +1,6 @@
 use std::fmt;
 
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
 pub struct Color {
     pub r: u8,
     pub g: u8,

crates/vsvg/src/path/point.rs

@@ -1,4 +1,4 @@
-#[derive(Debug, Clone, Copy, PartialEq, Default)]
+#[derive(Debug, Clone, Copy, PartialEq, Default, serde::Serialize, serde::Deserialize)]
 pub struct Point {
     data: [f64; 2],
 }

crates/whiskers-derive/src/lib.rs

@@ -11,6 +11,46 @@ fn format_label(label: &str) -> String {
     format!("{}:", label.to_case(Case::Lower))
 }
 
+/// Attribute macro to automatically derive some of the required traits for a sketch app.
+///
+/// This is equivalent to:
+/// ```ignore
+/// #[derive(Sketch, serde::Serialize, serde::Deserialize)]
+/// #[serde(crate = "::whiskers::prelude::serde")]
+/// ```
+#[proc_macro_attribute]
+pub fn sketch_app(_attr: TokenStream, item: TokenStream) -> TokenStream {
+    let ast = parse_macro_input!(item as DeriveInput);
+
+    let expanded = quote! {
+        #[derive(Sketch, serde::Serialize, serde::Deserialize)]
+        #[serde(crate = "::whiskers::prelude::serde")]
+        #ast
+    };
+
+    TokenStream::from(expanded)
+}
+
+/// Attribute macro to automatically derive some of the required traits for a sketch widget.
+///
+/// This is equivalent to:
+/// ```ignore
+/// #[derive(Widget, serde::Serialize, serde::Deserialize)]
+/// #[serde(crate = "::whiskers::prelude::serde")]
+/// ```
+#[proc_macro_attribute]
+pub fn sketch_widget(_attr: TokenStream, item: TokenStream) -> TokenStream {
+    let ast = parse_macro_input!(item as DeriveInput);
+
+    let expanded = quote! {
+        #[derive(Widget, serde::Serialize, serde::Deserialize)]
+        #[serde(crate = "::whiskers::prelude::serde")]
+        #ast
+    };
+
+    TokenStream::from(expanded)
+}
+
 #[proc_macro_derive(Sketch, attributes(param, skip))]
 pub fn sketch_derive(input: TokenStream) -> TokenStream {
     let input: DeriveInput = parse_macro_input!(input);

crates/whiskers-web-demo/src/lib.rs

@@ -4,7 +4,7 @@
 use itertools::iproduct;
 use whiskers::prelude::*;
 
-#[derive(Sketch)]
+#[sketch_app]
 pub struct WhiskersDemoSketch {
     col_count: u32,
     row_count: u32,

crates/whiskers/README.md

@@ -28,7 +28,7 @@ Here is the code for a basic sketch:
 ```rust
 use whiskers::prelude::*;
 
-#[derive(Sketch)]  // <- this is the magic to make the sketch interactive
+#[sketch_app]  // <- this is the magic to make the sketch interactive
 struct HelloWorldSketch {
     width: f64,   // <- interactive UI is automagically built for these fields
     height: f64,
@@ -82,7 +82,7 @@ This is the result:
 - [x] Random Number Generator UI with seed control (see e.g. `asteroid` example).
 - [x] Integrated profiler (based on [puffin](https://github.com/EmbarkStudios/puffin)).
 - [x] `Grid` helper for grid-based sketches.
-- [x] `HexGrid` helper for hexagonal-grid-based sketches 
+- [x] `HexGrid` helper for hexagonal-grid-based sketches
 - [ ] Configuration handling (save/restore config, etc.).
 - [ ] Compiled sketches are *also* a flexible CLI utility with the capability to batch generate sketch outputs with parameter ranges.
 - [ ] Export to other format through templating (HPGL, g-code, etc. — for now, please use [*vpype*](https://github.com/abey79/vpype)).

crates/whiskers/examples/animation_demo.rs

@@ -4,7 +4,7 @@
 use std::f64::consts::TAU;
 use whiskers::prelude::*;
 
-#[derive(Sketch)]
+#[sketch_app]
 struct AnimationDemoSketch {
     #[param(min = 3, max = 15)]
     ngon_sides: usize,

crates/whiskers/examples/app_demo.rs

@@ -1,6 +1,6 @@
 use whiskers::prelude::*;
 
-#[derive(Sketch)]
+#[sketch_app]
 struct MySketch {
     #[param(slider, min = 0.0, max = 10.0, step = 2.0)]
     rate: f64,

crates/whiskers/examples/asteroid.rs

@@ -11,7 +11,7 @@ use rand_distr::{Distribution, Normal};
 use std::f64::consts::PI;
 use whiskers::prelude::*;
 
-#[derive(Sketch)]
+#[sketch_app]
 struct AsteroidSketch {
     #[param(slider, min = 0.1, max = 1.5)]
     irregularity: f64,

crates/whiskers/examples/bezpath.rs

@@ -5,7 +5,7 @@
 
 use whiskers::prelude::*;
 
-#[derive(Sketch)]
+#[sketch_app]
 struct BezpathSketch {
     // path 1
     move_to: Point,

crates/whiskers/examples/catmull_rom.rs

@@ -1,6 +1,6 @@
 use whiskers::prelude::*;
 
-#[derive(Sketch)]
+#[sketch_app]
 struct CatmullRomSketch {
     #[param(slider, min = 3, max = 1500)]
     num_points: usize,

crates/whiskers/examples/custom_ui.rs

@@ -2,7 +2,7 @@ use egui::Ui;
 use whiskers::prelude::*;
 
 /// Very custom data structure that is not supported by default
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, serde::Serialize, serde::Deserialize)]
 struct GrayRed {
     gray: f64,
     red: f64,
@@ -85,7 +85,7 @@ register_widget_ui!(GrayRed, GrayRedWidget);
 // =================================================================================
 // from here on, we're back to super standard  sketch code...
 
-#[derive(Sketch)]
+#[sketch_app]
 struct CustomUISketch {
     // these param key/value will call into the [`GrayRedWidget`]'s builder methods.
     #[param(underline, label_color = egui::Color32::BLUE)]

crates/whiskers/examples/grid.rs

@@ -2,7 +2,7 @@
 
 use whiskers::prelude::*;
 
-#[derive(Sketch)]
+#[sketch_app]
 struct GridSketch {
     #[param(slider, min = 20.0, max = 400.0)]
     width: f64,

crates/whiskers/examples/hello_world.rs

@@ -1,6 +1,6 @@
 use whiskers::prelude::*;
 
-#[derive(Sketch)]
+#[sketch_app]
 struct HelloWorldSketch {
     width: f64,
     height: f64,

crates/whiskers/examples/hex_grid.rs

@@ -1,7 +1,7 @@
 //! This example demonstrates the use of the [`HexGrid`] helper.
 use whiskers::prelude::*;
 
-#[derive(Sketch)]
+#[sketch_app]
 struct HexGridSketch {
     is_pointy_orientation: bool,
     #[param(slider, min = 2, max = 20)]

crates/whiskers/examples/noise.rs

@@ -4,7 +4,7 @@ use noise::{Fbm, NoiseFn, Perlin};
 use rayon::prelude::*;
 use whiskers::prelude::*;
 
-#[derive(Sketch)]
+#[sketch_app]
 struct NoiseSketch {
     #[param(slider, min = 0.0, max = 500.0)]
     margin: f64,

crates/whiskers/examples/rng.rs

@@ -2,7 +2,7 @@ use std::ops::Range;
 use vsvg::COLORS;
 use whiskers::prelude::*;
 
-#[derive(Sketch)]
+#[sketch_app]
 struct RngSketch {
     width: f64,
     height: f64,

crates/whiskers/examples/ui_demo.rs

@@ -3,7 +3,8 @@
 
 use whiskers::prelude::*;
 
-#[derive(Sketch, Default)]
+#[sketch_app]
+#[derive(Default)]
 struct UiDemoSketch {
     // all basic numerical types are supported
     int_64: i64,
@@ -40,7 +41,8 @@ struct UiDemoSketch {
 // the [`whiskers::widgets::WidgetMapper`] trait can be implemented manually, see the `custom_ui`
 // example.
 // Note: all types must implement [`Default`].
-#[derive(Widget, Default)]
+#[sketch_widget]
+#[derive(Default)]
 struct CustomStruct {
     #[param(min = 0.0)]
     some_float: f64,
@@ -53,7 +55,8 @@ struct CustomStruct {
 }
 
 // Tuple structs are supported too
-#[derive(Widget, Default)]
+#[sketch_widget]
+#[derive(Default)]
 struct CustomStructUnnamed(bool, String);
 
 impl App for UiDemoSketch {

crates/whiskers/src/lib.rs

@@ -14,7 +14,7 @@
 //! ```no_run
 //! use whiskers::prelude::*;
 //!
-//! #[derive(Sketch)]
+//! #[sketch_app]
 //! struct MySketch {
 //!     /* add sketch parameters here */
 //! }
@@ -60,7 +60,7 @@
 //! use whiskers::prelude::*;
 //! use whiskers::wasm_main;
 //!
-//! #[derive(Sketch)]
+//! #[sketch_app]
 //! struct MySketch { }
 //!
 //! impl Default for MySketch {
@@ -135,7 +135,7 @@ pub trait App {
 
 /// This trait is implemented by the [`whiskers_derive::Sketch`] derive macro and makes it possible
 /// for the [`Runner`] to execute your sketch.s
-pub trait SketchApp: App + Default {
+pub trait SketchApp: App + Default + serde::Serialize + serde::de::DeserializeOwned {
     /// Create a runner for this app.
     fn runner<'a>() -> Runner<'a, Self> {
         Runner::<Self>::new()

crates/whiskers/src/prelude.rs

@@ -4,11 +4,13 @@ pub use crate::{
     HexGridCell, InfoOptions, LayoutOptions, PageSizeOptions, Result, Runner, Sketch, SketchApp,
 };
 pub use vsvg::{Color, Draw, IntoBezPath, IntoBezPathTolerance, PageSize, Point, Transforms, Unit};
-pub use whiskers_derive::{Sketch, Widget};
+pub use whiskers_derive::{sketch_app, sketch_widget, Sketch, Widget};
 
 #[cfg(not(target_arch = "wasm32"))]
 pub use vsvg_viewer::show;
 
+// re-exports
+pub use ::serde;
 pub use anyhow;
 pub use egui;
 pub use rand::prelude::*;

crates/whiskers/src/runner/mod.rs

@@ -333,6 +333,10 @@ impl<A: crate::SketchApp> vsvg_viewer::ViewerApp for Runner<'_, A> {
     }
 
     fn load(&mut self, storage: &dyn Storage) {
+        if let Some(app) = eframe::get_value(storage, "whiskers-app") {
+            self.app = app;
+        }
+
         let save_ui: Option<SaveUI> = eframe::get_value(storage, "whiskers-runner-save-ui");
         #[allow(unused_mut)]
         if let Some(mut save_ui) = save_ui {
@@ -358,6 +362,7 @@ impl<A: crate::SketchApp> vsvg_viewer::ViewerApp for Runner<'_, A> {
     }
 
     fn save(&self, storage: &mut dyn Storage) {
+        eframe::set_value(storage, "whiskers-app", &self.app);
         eframe::set_value(storage, "whiskers-runner-save-ui", &self.save_ui);
         eframe::set_value(storage, "whiskers-layout-options", &self.layout_options);
         eframe::set_value(storage, "whiskers-page-size", &self.page_size_options);

crates/whiskers/src/widgets/mod.rs

@@ -73,7 +73,8 @@
 //! Now let's consider a hypothetical sketch:
 //! ```rust
 //! # use whiskers::prelude::*;
-//! #[derive(Sketch, Default)]
+//! #[sketch_app]
+//! #[derive(Default)]
 //! struct MySketch {
 //!     #[param(slider, step = 0.1)]
 //!     irregularity: f64,