.gitignore

@@ -13,3 +13,4 @@ examples/demo/target/
 lvgl-sys/target/
 lvgl/target/
 lvgl-sys/src/bindings.rs
+lvgl/src/widgets/generated.rs

README.md

@@ -62,6 +62,14 @@ $ git submodule init
 $ git submodule update 
 ```
 
+Some parts of `lvgl-rs` are auto-generated. The package `lvgl-codegen` is responsible for the generated code.
+When building from source, we need to first compile the `lvgl-codegen` tool. The `lvgl-codegen` tool is used
+automatically in the [`lvgl` package build](./lvgl/build.rs).
+
+```bash
+$ DEP_LV_CONFIG_PATH=`pwd`/examples/include cargo build --package lvgl-codegen
+```
+
 Then run the `demo` example:
 
 ```shell
@@ -80,7 +88,7 @@ List of LVGL features that impacts the library usage in general.
       draw to the display. You can use `lvgl-rs` with any of the
       [`embedded_graphics` supported displays](https://docs.rs/embedded-graphics/0.6.2/embedded_graphics/#supported-displays).
 - [x] Events: You can listen and trigger events in widget objects.
-- [x] Styles: You can set styles in any exposed object. We are still missing the possibility of defining base styles.
+- [x] Styles: You can set styles in any exposed object. We are still missing the possibility of defining global base styles.
 - [ ] Input Devices
 - [ ] Fonts
 - [ ] Images
@@ -90,40 +98,5 @@ List of LVGL features that impacts the library usage in general.
 
 ### Widgets
 
-- [x] Base object (lv_obj)
-- [ ] Arc (lv_arc)
-- [x] Bar (lv_bar)
-- [x] Button (lv_btn)
-- [ ] Button matrix (lv_btnmatrix)
-- [ ] Calendar (lv_calendar)
-- [ ] Canvas (lv_canvas)
-- [ ] Checkbox (lv_cb)
-- [ ] Chart (lv_chart)
-- [ ] Container (lv_cont)
-- [ ] Color picker (lv_cpicker)
-- [ ] Drop-down list (lv_dropdown)
-- [x] Gauge (lv_gauge)
-- [ ] Image (lv_img)
-- [ ] Image button (lv_imgbtn)
-- [ ] Keyboard (lv_keyboard)
-- [x] Label (lv_label)
-- [ ] LED (lv_led)
-- [ ] Line (lv_line)
-- [ ] List (lv_list)
-- [ ] Line meter (lv_lmeter)
-- [ ] Message box (lv_msdbox)
-- [ ] Object mask (lv_objmask)
-- [ ] Page (lv_page)
-- [ ] Roller (lv_roller)
-- [ ] Slider (lv_slider)
-- [ ] Spinbox (lv_spinbox)
-- [ ] Spinner (lv_spinner)
-- [ ] Switch (lv_switch)
-- [ ] Table (lv_table)
-- [ ] Tabview (lv_tabview)
-- [ ] Text area (lv_textarea)
-- [ ] Tile view (lv_tileview)
-- [ ] Window (lv_win)
-
 Widgets currently implemented might have some missing features. If the widget you want to use is not exposed or
 is missing a feature you want to make use, please send a Pull Request or open an issue.

examples/button_click.rs

@@ -39,9 +39,18 @@ fn main() -> Result<(), LvError> {
     button.set_size(180, 80)?;
     let mut btn_lbl = Label::new(&mut button)?;
     btn_lbl.set_text("Click me!")?;
-    button.on_event(|_, event| {
+
+    let mut btn_state = false;
+    button.on_event(|mut btn, event| {
         if let lvgl::Event::Clicked = event {
+            if btn_state {
+                btn_lbl.set_text("Click me!").unwrap();
+            } else {
+                btn_lbl.set_text("Clicked!").unwrap();
+            }
+            btn_state = !btn_state;
             println!("Clicked!");
+            btn.toggle().unwrap();
         }
     })?;
 
@@ -83,7 +92,7 @@ fn main() -> Result<(), LvError> {
             }
         }
 
-        sleep(Duration::from_millis(25));
+        sleep(Duration::from_millis(5));
     }
 
     stop_ch.send(true).unwrap();

lvgl-codegen/Cargo.toml

@@ -1,12 +1,23 @@
 [package]
 name = "lvgl-codegen"
 version = "0.1.0"
+description = "Code generation based on LVGL source code"
 authors = ["Rafael Caricio <rafael@caricio.com>"]
 edition = "2018"
+license = "MIT"
 publish = false
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+build = "build.rs"
 
 [dependencies]
-tera = "1.3.0"
 regex = "1.3.9"
+quote = "1.0.7"
+lazy_static = "1.4.0"
+clang = { path = "../../clang-rs" }
+itertools = "0.9.0"
+proc-macro2 = "1.0.18"
+Inflector = "0.11.4"
+lang-c = "0.8.1"
+syn = "1.0.31"
+
+[build-dependencies]
+cc = "1.0.50"

lvgl-codegen/build.rs

@@ -0,0 +1,70 @@
+use cc::Build;
+use std::ffi::OsStr;
+use std::process::{Command, Stdio};
+use std::{env, fs, path::Path, path::PathBuf};
+
+static CONFIG_NAME: &str = "DEP_LV_CONFIG_PATH";
+
+fn main() {
+    let project_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap())
+        .canonicalize()
+        .unwrap();
+    let lvgl_sys = project_dir.join("..").join("lvgl-sys");
+    let vendor = lvgl_sys.join("vendor");
+    let lvgl_top_path = vendor.join("lvgl");
+    let lvgl_src_path = lvgl_top_path.join("src");
+    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
+
+    let lv_config_dir = {
+        let raw_path = env::var(CONFIG_NAME).unwrap_or_else(|_| {
+            panic!(
+                "The environment variable {} is required to be defined",
+                CONFIG_NAME
+            );
+        });
+        let conf_path = PathBuf::from(raw_path);
+
+        if !conf_path.exists() {
+            panic!(format!(
+                "Directory referenced by {} needs to exist",
+                CONFIG_NAME
+            ));
+        }
+        if !conf_path.is_dir() {
+            panic!(format!("{} needs to be a directory", CONFIG_NAME));
+        }
+        if !conf_path.join("lv_conf.h").exists() {
+            panic!(format!(
+                "Directory referenced by {} needs to contain a file called lv_conf.h",
+                CONFIG_NAME
+            ));
+        }
+
+        println!(
+            "cargo:rerun-if-changed={}",
+            conf_path.join("lv_conf.h").to_str().unwrap()
+        );
+        conf_path
+    };
+
+    let build = Build::new();
+    let tool = build.get_compiler();
+    let preprocessed = Command::new(tool.path().to_str().unwrap())
+        .args(&[
+            "-E",
+            "-std=c99",
+            "-DLV_CONF_INCLUDE_SIMPLE",
+            "-I",
+            lvgl_top_path.to_string_lossy().as_ref(),
+            "-I",
+            lvgl_src_path.to_string_lossy().as_ref(),
+            "-I",
+            lv_config_dir.to_string_lossy().as_ref(),
+            lvgl_top_path.join("lvgl.h").to_string_lossy().as_ref(),
+        ])
+        .output()
+        .unwrap();
+
+    let content = String::from_utf8(preprocessed.stdout).unwrap();
+    fs::write(out_path.join("lvgl_full.c"), content).unwrap();
+}

lvgl-codegen/src/lib.rs

@@ -0,0 +1,617 @@
+use clang::{Clang, Entity, EntityKind, Index, Linkage, Type};
+use inflector::cases::pascalcase::to_pascal_case;
+use lazy_static::lazy_static;
+use proc_macro2::{Ident, TokenStream};
+use quote::format_ident;
+use quote::quote;
+use regex::Regex;
+use std::collections::HashMap;
+use std::error::Error;
+
+type CGResult<T> = Result<T, Box<dyn Error>>;
+
+const LIB_PREFIX: &str = "lv_";
+
+lazy_static! {
+    static ref TYPE_MAPPINGS: HashMap<&'static str, &'static str> = [
+        ("uint16_t", "u16"),
+        ("int32_t", "i32"),
+        ("uint8_t", "u8"),
+        ("bool", "bool"),
+        ("_Bool", "bool"),
+        ("const char *", "&str"),
+    ]
+    .iter()
+    .cloned()
+    .collect();
+}
+
+#[derive(Debug, Copy, Clone)]
+pub enum WrapperError {
+    Skip,
+}
+
+pub type WrapperResult<T> = Result<T, WrapperError>;
+
+pub trait Rusty {
+    type Parent;
+
+    fn code(&self, parent: &Self::Parent) -> WrapperResult<TokenStream>;
+}
+
+#[derive(Clone, Eq, PartialEq)]
+pub struct LvWidget {
+    name: String,
+    methods: Vec<LvFunc>,
+}
+
+impl Rusty for LvWidget {
+    type Parent = ();
+
+    fn code(&self, _parent: &Self::Parent) -> WrapperResult<TokenStream> {
+        // We don't generate for the generic Obj
+        if self.name.eq("obj") {
+            return Err(WrapperError::Skip);
+        }
+
+        let widget_name = format_ident!("{}", to_pascal_case(self.name.as_str()));
+        let methods: Vec<TokenStream> = self.methods.iter().flat_map(|m| m.code(self)).collect();
+        Ok(quote! {
+            define_object!(#widget_name);
+
+            impl #widget_name {
+                #(#methods)*
+            }
+        })
+    }
+}
+
+#[derive(Clone, Eq, PartialEq)]
+pub struct LvFunc {
+    name: String,
+    args: Vec<LvArg>,
+    ret: Option<LvType>,
+}
+
+impl LvFunc {
+    pub fn new(name: String, args: Vec<LvArg>, ret: Option<LvType>) -> Self {
+        Self { name, args, ret }
+    }
+
+    pub fn is_method(&self) -> bool {
+        if self.args.len() > 0 {
+            let first_arg = &self.args[0];
+            return first_arg.typ.typ.contains("lv_obj_t");
+        }
+        false
+    }
+}
+
+impl Rusty for LvFunc {
+    type Parent = LvWidget;
+
+    fn code(&self, parent: &Self::Parent) -> WrapperResult<TokenStream> {
+        let templ = format!("{}{}_", LIB_PREFIX, parent.name.as_str());
+        let new_name = self.name.replace(templ.as_str(), "");
+        let func_name = format_ident!("{}", new_name);
+        let original_func_name = format_ident!("{}", self.name.as_str());
+
+        // generate constructor
+        if new_name.eq("create") {
+            return Ok(quote! {
+                pub fn new<C>(parent: &mut C) -> crate::LvResult<Self>
+                where
+                    C: crate::NativeObject,
+                {
+                    unsafe {
+                        let ptr = lvgl_sys::#original_func_name(parent.raw()?.as_mut(), core::ptr::null_mut());
+                        let raw = core::ptr::NonNull::new(ptr)?;
+                        let core = <crate::Obj as crate::Widget>::from_raw(raw);
+                        Ok(Self { core })
+                    }
+                }
+            });
+        }
+
+        // We don't deal with methods that return types yet
+        if self.ret.is_some() {
+            return Err(WrapperError::Skip);
+        }
+
+        // Make sure all arguments can be generated, skip the first arg (self)!
+        for arg in self.args.iter().skip(1) {
+            arg.code(self)?;
+        }
+
+        let args_decl = self
+            .args
+            .iter()
+            .enumerate()
+            .fold(quote!(), |args, (i, arg)| {
+                // if first arg is `const`, then it should be immutable
+                let next_arg = if i == 0 {
+                    if arg.get_type().is_const() {
+                        quote!(&self)
+                    } else {
+                        quote!(&mut self)
+                    }
+                } else {
+                    arg.code(self).unwrap()
+                };
+                if args.is_empty() {
+                    quote! {
+                        #next_arg
+                    }
+                } else {
+                    quote! {
+                        #args, #next_arg
+                    }
+                }
+            });
+
+        let args_processing = self
+            .args
+            .iter()
+            .enumerate()
+            .fold(quote!(), |args, (i, arg)| {
+                // if first arg is `const`, then it should be immutable
+                let next_arg = if i == 0 {
+                    quote!()
+                } else {
+                    let var = arg.get_processing();
+                    quote!(#var)
+                };
+                if args.is_empty() {
+                    quote! {
+                        #next_arg
+                    }
+                } else {
+                    quote! {
+                        #args
+                        #next_arg
+                    }
+                }
+            });
+
+        let args_call = self
+            .args
+            .iter()
+            .enumerate()
+            .fold(quote!(), |args, (i, arg)| {
+                // if first arg is `const`, then it should be immutable
+                let next_arg = if i == 0 {
+                    quote!(self.core.raw()?.as_mut())
+                } else {
+                    let var = arg.get_value_usage();
+                    quote!(#var)
+                };
+                if args.is_empty() {
+                    quote! {
+                        #next_arg
+                    }
+                } else {
+                    quote! {
+                        #args, #next_arg
+                    }
+                }
+            });
+
+        // TODO: Handle methods that return types
+        Ok(quote! {
+            pub fn #func_name(#args_decl) -> crate::LvResult<()> {
+                #args_processing
+                unsafe {
+                    lvgl_sys::#original_func_name(#args_call);
+                }
+                Ok(())
+            }
+        })
+    }
+}
+
+impl From<Entity<'_>> for LvFunc {
+    fn from(entity: Entity) -> Self {
+        let result = entity.get_result_type().unwrap().get_display_name();
+        let ret_type = match result.as_str() {
+            "void" => None,
+            _ => Some(LvType::new(result)),
+        };
+        Self::new(
+            entity.get_name().unwrap(),
+            entity
+                .get_arguments()
+                .unwrap()
+                .iter()
+                .map(|e| e.into())
+                .collect::<Vec<LvArg>>(),
+            ret_type,
+        )
+    }
+}
+
+#[derive(Clone, Eq, PartialEq)]
+pub struct LvArg {
+    name: String,
+    typ: LvType,
+}
+
+impl LvArg {
+    pub fn new(name: String, typ: LvType) -> Self {
+        Self { name, typ }
+    }
+
+    pub fn get_name_ident(&self) -> Ident {
+        // Filter Rust language keywords
+        syn::parse_str::<syn::Ident>(self.name.as_str())
+            .unwrap_or_else(|_| format_ident!("r#{}", self.name.as_str()))
+    }
+
+    pub fn get_processing(&self) -> TokenStream {
+        let ident = self.get_name_ident();
+        // TODO: A better way to handle this, instead of `is_sometype()`, is using the Rust
+        //       type system itself.
+        if self.typ.is_str() {
+            quote! {
+                let #ident = cstr_core::CString::new(#ident)?;
+            }
+        } else {
+            // No need to pre-process this type of argument
+            quote! {}
+        }
+    }
+
+    pub fn get_value_usage(&self) -> TokenStream {
+        let ident = self.get_name_ident();
+        if self.typ.is_str() {
+            quote! {
+                #ident.as_ptr()
+            }
+        } else {
+            quote! {
+                #ident
+            }
+        }
+    }
+
+    pub fn get_type(&self) -> &LvType {
+        &self.typ
+    }
+}
+
+impl Rusty for LvArg {
+    type Parent = LvFunc;
+
+    fn code(&self, _parent: &Self::Parent) -> WrapperResult<TokenStream> {
+        let name = self.get_name_ident();
+        let typ = self.typ.code(self)?;
+        Ok(quote! {
+            #name: #typ
+        })
+    }
+}
+
+impl From<&Entity<'_>> for LvArg {
+    fn from(entity: &Entity) -> Self {
+        Self::new(
+            entity.get_name().unwrap(),
+            entity.get_type().unwrap().into(),
+        )
+    }
+}
+
+#[derive(Clone, Eq, PartialEq)]
+pub struct LvType {
+    typ: String,
+}
+
+impl LvType {
+    pub fn new(typ: String) -> Self {
+        Self { typ }
+    }
+
+    pub fn is_const(&self) -> bool {
+        self.typ.starts_with("const ")
+    }
+
+    pub fn is_str(&self) -> bool {
+        self.typ.ends_with("char *")
+    }
+}
+
+impl Rusty for LvType {
+    type Parent = LvArg;
+
+    fn code(&self, _parent: &Self::Parent) -> WrapperResult<TokenStream> {
+        match TYPE_MAPPINGS.get(self.typ.as_str()) {
+            Some(name) => {
+                let val = if self.is_str() {
+                    quote!(&str)
+                } else {
+                    let ident = format_ident!("{}", name);
+                    quote!(#ident)
+                };
+                Ok(quote! {
+                    #val
+                })
+            }
+            None => Err(WrapperError::Skip),
+        }
+    }
+}
+
+impl From<Type<'_>> for LvType {
+    fn from(ty: Type) -> Self {
+        Self::new(ty.get_display_name())
+    }
+}
+
+pub struct CodeGen {
+    functions: Vec<LvFunc>,
+    widgets: Vec<LvWidget>,
+}
+
+impl CodeGen {
+    pub fn new() -> CGResult<Self> {
+        let functions = Self::load_function_definitions()?;
+        let widgets = Self::extract_widgets(&functions)?;
+        Ok(Self { functions, widgets })
+    }
+
+    pub fn get_widgets(&self) -> &Vec<LvWidget> {
+        &self.widgets
+    }
+
+    fn extract_widgets(functions: &Vec<LvFunc>) -> CGResult<Vec<LvWidget>> {
+        let widget_names = Self::get_widget_names(functions);
+
+        let widgets = functions.iter().fold(HashMap::new(), |mut ws, f| {
+            for widget_name in &widget_names {
+                if f.name
+                    .starts_with(format!("{}{}", LIB_PREFIX, widget_name).as_str())
+                    && f.is_method()
+                {
+                    ws.entry(widget_name.clone())
+                        .or_insert_with(|| LvWidget {
+                            name: widget_name.clone(),
+                            methods: Vec::new(),
+                        })
+                        .methods
+                        .push(f.clone())
+                }
+            }
+            ws
+        });
+
+        Ok(widgets.values().map(|v| v.clone()).collect())
+    }
+
+    fn get_widget_names(functions: &Vec<LvFunc>) -> Vec<String> {
+        let reg = format!("^{}([^_]+)_create$", LIB_PREFIX);
+        let create_func = Regex::new(reg.as_str()).unwrap();
+
+        functions
+            .iter()
+            .filter(|e| create_func.is_match(e.name.as_str()) && e.args.len() == 2)
+            .filter_map(|f| {
+                Some(String::from(
+                    create_func
+                        .captures(f.name.as_str())
+                        .unwrap()
+                        .get(1)
+                        .unwrap()
+                        .as_str(),
+                ))
+            })
+            .collect::<Vec<_>>()
+    }
+
+    pub fn load_function_definitions() -> CGResult<Vec<LvFunc>> {
+        let clang = Clang::new()?;
+        let index = Index::new(&clang, false, false);
+        let tu = index
+            .parser(concat!(env!("OUT_DIR"), "/lvgl_full.c"))
+            .parse()?;
+        let entities = tu
+            .get_entity()
+            .get_children()
+            .into_iter()
+            .filter(|e| e.get_kind() == EntityKind::FunctionDecl)
+            .filter(|e| e.get_name().is_some())
+            .filter(|e| e.get_linkage().unwrap() != Linkage::Internal)
+            .map(|e| e.into())
+            .filter(|e: &LvFunc| e.name.starts_with(LIB_PREFIX))
+            .collect::<Vec<_>>();
+        Ok(entities)
+    }
+
+    pub fn get_function_names(&self) -> CGResult<Vec<String>> {
+        Ok(self.functions.iter().map(|f| f.name.clone()).collect())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use crate::{CodeGen, LvArg, LvFunc, LvType, LvWidget, Rusty};
+    use quote::quote;
+
+    #[test]
+    fn can_list_functions() {
+        let lv = CodeGen::new().unwrap();
+        let func = String::from("lv_obj_create");
+        let func_names = lv.get_function_names().unwrap();
+        assert!(func_names.contains(&func));
+    }
+
+    #[test]
+    fn can_identify_widgets_from_function_names() {
+        let funcs = vec![
+            LvFunc::new(
+                "lv_obj_create".to_string(),
+                vec![
+                    LvArg::new("parent".to_string(), LvType::new("abc".to_string())),
+                    LvArg::new("copy_from".to_string(), LvType::new("bcf".to_string())),
+                ],
+                None,
+            ),
+            LvFunc::new(
+                "lv_btn_create".to_string(),
+                vec![
+                    LvArg::new("parent".to_string(), LvType::new("abc".to_string())),
+                    LvArg::new("copy_from".to_string(), LvType::new("bcf".to_string())),
+                ],
+                None,
+            ),
+            LvFunc::new(
+                "lv_do_something".to_string(),
+                vec![
+                    LvArg::new("parent".to_string(), LvType::new("abc".to_string())),
+                    LvArg::new("copy_from".to_string(), LvType::new("bcf".to_string())),
+                ],
+                None,
+            ),
+            LvFunc::new(
+                "lv_invalid_create".to_string(),
+                vec![LvArg::new(
+                    "parent".to_string(),
+                    LvType::new("abc".to_string()),
+                )],
+                None,
+            ),
+            LvFunc::new(
+                "lv_cb_create".to_string(),
+                vec![
+                    LvArg::new("parent".to_string(), LvType::new("abc".to_string())),
+                    LvArg::new("copy_from".to_string(), LvType::new("bcf".to_string())),
+                ],
+                None,
+            ),
+        ];
+
+        let widget_names = CodeGen::get_widget_names(&funcs);
+
+        assert_eq!(widget_names.len(), 3);
+    }
+
+    #[test]
+    fn generate_method_wrapper() {
+        // void lv_arc_set_bg_end_angle(lv_obj_t * arc, uint16_t end);
+        let arc_set_bg_end_angle = LvFunc::new(
+            "lv_arc_set_bg_end_angle".to_string(),
+            vec![
+                LvArg::new("arc".to_string(), LvType::new("lv_obj_t *".to_string())),
+                LvArg::new("end".to_string(), LvType::new("uint16_t".to_string())),
+            ],
+            None,
+        );
+        let arc_widget = LvWidget {
+            name: "arc".to_string(),
+            methods: vec![],
+        };
+
+        let code = arc_set_bg_end_angle.code(&arc_widget).unwrap();
+        let expected_code = quote! {
+            pub fn set_bg_end_angle(&mut self, end: u16) -> crate::LvResult<()> {
+                unsafe {
+                    lvgl_sys::lv_arc_set_bg_end_angle(self.core.raw()?.as_mut(), end);
+                }
+                Ok(())
+            }
+        };
+
+        assert_eq!(code.to_string(), expected_code.to_string());
+    }
+
+    #[test]
+    fn generate_method_wrapper_for_str_types_as_argument() {
+        // void lv_label_set_text(lv_obj_t * label, const char * text)
+        let label_set_text = LvFunc::new(
+            "lv_label_set_text".to_string(),
+            vec![
+                LvArg::new("label".to_string(), LvType::new("lv_obj_t *".to_string())),
+                LvArg::new("text".to_string(), LvType::new("const char *".to_string())),
+            ],
+            None,
+        );
+        let parent_widget = LvWidget {
+            name: "label".to_string(),
+            methods: vec![],
+        };
+
+        let code = label_set_text.code(&parent_widget).unwrap();
+        let expected_code = quote! {
+            pub fn set_text(&mut self, text: &str) -> crate::LvResult<()> {
+                let text = cstr_core::CString::new(text)?;
+                unsafe {
+                    lvgl_sys::lv_label_set_text(
+                        self.core.raw()?.as_mut(),
+                        text.as_ptr()
+                    );
+                }
+                Ok(())
+            }
+        };
+
+        assert_eq!(code.to_string(), expected_code.to_string());
+    }
+
+    #[test]
+    fn generate_basic_widget_code() {
+        let arc_widget = LvWidget {
+            name: "arc".to_string(),
+            methods: vec![],
+        };
+
+        let code = arc_widget.code(&()).unwrap();
+        let expected_code = quote! {
+            define_object!(Arc);
+
+            impl Arc {
+
+            }
+        };
+
+        assert_eq!(code.to_string(), expected_code.to_string());
+    }
+
+    #[test]
+    fn generate_widget_with_constructor_code() {
+        // lv_obj_t * lv_arc_create(lv_obj_t * par, const lv_obj_t * copy);
+        let arc_create = LvFunc::new(
+            "lv_arc_create".to_string(),
+            vec![
+                LvArg::new("par".to_string(), LvType::new("lv_obj_t *".to_string())),
+                LvArg::new(
+                    "copy".to_string(),
+                    LvType::new("const lv_obj_t *".to_string()),
+                ),
+            ],
+            Some(LvType::new("lv_obj_t *".to_string())),
+        );
+
+        let arc_widget = LvWidget {
+            name: "arc".to_string(),
+            methods: vec![arc_create],
+        };
+
+        let code = arc_widget.code(&()).unwrap();
+        let expected_code = quote! {
+            define_object!(Arc);
+
+            impl Arc {
+                pub fn new<C>(parent: &mut C) -> crate::LvResult<Self>
+                where
+                    C: crate::NativeObject,
+                {
+                    unsafe {
+                        let ptr = lvgl_sys::lv_arc_create(parent.raw()?.as_mut(), core::ptr::null_mut());
+                        let raw = core::ptr::NonNull::new(ptr)?;
+                        let core = <crate::Obj as crate::Widget>::from_raw(raw);
+                        Ok(Self { core })
+                    }
+                }
+            }
+        };
+
+        assert_eq!(code.to_string(), expected_code.to_string());
+    }
+}

lvgl-codegen/src/main.rs

@@ -1,35 +1,33 @@
-use regex::Regex;
-use tera::{Context, Tera};
+use lvgl_codegen::{CodeGen, Rusty};
+use proc_macro2::TokenStream;
+use quote::quote;
+use std::fs::File;
+use std::io::prelude::*;
+use std::path::Path;
 
 fn main() {
-    let re = Regex::new(r"\((?P<prop_name>[^,]+), (?P<func_name>[^,]+), (?P<value_type>[^,]+), (?P<style_type>[^)]+), [a-z]+\)").unwrap();
+    let rs = Path::new(concat!(
+        env!("CARGO_MANIFEST_DIR"),
+        "/../lvgl/src/widgets/generated.rs"
+    ));
 
-    let input = include_str!("../../lvgl-sys/vendor/lvgl/src/lv_core/lv_obj_style_dec.h");
+    let codegen = CodeGen::new().unwrap();
 
-    let mut tera = Tera::default();
-    tera.add_raw_template("styles.rs", include_str!("../templates/style.rs.j2"))
-        .unwrap();
+    let widgets_impl: Vec<TokenStream> = codegen
+        .get_widgets()
+        .iter()
+        .flat_map(|w| w.code(&()))
+        .collect();
 
-    for line in input.lines() {
-        if !line.starts_with("_LV_OBJ_STYLE_SET_GET_DECLARE") {
-            continue;
-        }
+    let code = quote! {
+        #(#widgets_impl)*
+    };
 
-        if let Some(cap) = re.captures(line) {
-            let style_type = cap.get(4).unwrap().as_str().to_string();
-            if style_type.eq("_ptr") {
-                // Just a few, we will take care of this manually.
-                continue;
-            }
-
-            let value_type = cap.get(3).unwrap().as_str().to_string();
-
-            let mut ctx = Context::new();
-            ctx.insert("prop_name", cap.get(1).unwrap().as_str());
-            ctx.insert("func_name", cap.get(2).unwrap().as_str());
-            ctx.insert("value_type", value_type.as_str());
-            ctx.insert("style_type", style_type.as_str());
-            println!("{}", tera.render("styles.rs", &ctx).unwrap());
-        }
-    }
+    let mut file = File::create(rs).unwrap();
+    writeln!(
+        file,
+        "/* automatically generated by lvgl-codegen */\n{}",
+        code
+    )
+    .unwrap();
 }

lvgl-codegen/templates/style.rs.j2

@@ -1,33 +0,0 @@
-pub fn set_{{func_name}}(&mut self, state: State,
-
-    {% if style_type == "_color" %}
-    value: Color
-    {% elif style_type == "_int" %}
-    value: i16
-    {% elif style_type == "_ptr" %}
-    value: Any
-    {% elif style_type == "_opa" %}
-    value: Opacity
-    {% endif %}
-
-) {
-    let native_state: u32 = state.get_bits();
-    unsafe {
-        lvgl_sys::_lv_style_set{{style_type}}(
-            self.raw.as_mut(),
-            (lvgl_sys::LV_STYLE_{{prop_name}}
-            | (native_state << lvgl_sys::LV_STYLE_STATE_POS as u32)) as u16,
-
-            {% if style_type == "_color" %}
-                value.raw,
-            {% elif style_type == "_int" %}
-                value
-            {% elif style_type == "_opa" %}
-                value.into()
-            {% elif style_type == "_ptr" %}
-                value.into()
-            {% endif %}
-
-        );
-    }
-}

lvgl-sys/Cargo.toml

@@ -21,4 +21,4 @@ cty = "0.2.1"
 
 [build-dependencies]
 cc = "1.0.50"
-bindgen = "0.53.2"
+bindgen = "0.54.0"

lvgl-sys/string.c

@@ -66,3 +66,18 @@ char *strcpy(char *dest, const char *src)
         /* nothing */;
     return tmp;
 }
+
+int strcmp(const char *cs, const char *ct)
+{
+    unsigned char c1, c2;
+
+    while (1) {
+        c1 = *cs++;
+        c2 = *ct++;
+        if (c1 != c2)
+            return c1 < c2 ? -1 : 1;
+        if (!c1)
+            break;
+    }
+    return 0;
+}

lvgl-sys/vendor/lvgl

@@ -1 +1 @@
-Subproject commit 91b997769e7a2b7eb410371725b1e3a7cb6ecde8
+Subproject commit 1ca1934dbe8e826ef1ed1690005fb678fea3a1f3

lvgl/Cargo.toml

@@ -9,6 +9,7 @@ license = "MIT"
 readme = "../README.md"
 categories = ["api-bindings", "embedded", "gui", "no-std"]
 keywords = ["littlevgl", "lvgl", "graphical_interfaces"]
+include = ["Cargo.toml", "src/**/*", "src/widgets/generated.rs"]
 
 [dependencies]
 lvgl-sys = { path = "../lvgl-sys", version = "0.2.0" }
@@ -16,3 +17,4 @@ cty = "0.2.1"
 embedded-graphics = "0.6.2"
 cstr_core = { version = "0.2.0", default-features = false, features = ["alloc"] }
 bitflags = "1.2.1"
+

lvgl/build.rs

@@ -0,0 +1,33 @@
+use std::env;
+use std::path::Path;
+use std::process::Command;
+
+fn main() {
+    let manifest_dir = Path::new(env!("CARGO_MANIFEST_DIR"));
+    let widgets_rs_path = manifest_dir.join("src/widgets/generated.rs");
+    let codegen_bin = manifest_dir
+        .join("..")
+        .join("target")
+        .join("debug")
+        .join("lvgl-codegen")
+        .canonicalize()
+        .unwrap();
+    println!("cargo:rerun-if-changed={}", codegen_bin.to_string_lossy());
+
+    if env::var("LVGL_FORCE_CODEGEN").is_ok() || !widgets_rs_path.exists() {
+        println!("Generating `src/widgets/generated.rs`");
+        let status = Command::new(codegen_bin)
+            .spawn()
+            .unwrap_or_else(|_| {
+                panic!(
+                    "Code generation failed because no codegen executable was found. \
+                     Please run `cargo build --package lvgl-codegen` and then try again.",
+                )
+            })
+            .wait()
+            .unwrap();
+        if !status.success() {
+            panic!("Code generation failed");
+        }
+    }
+}

lvgl/src/display.rs

@@ -16,32 +16,26 @@ impl DisplayDriver {
         C: PixelColor + From<Color>,
     {
         let disp_drv = unsafe {
-            // Create a display buffer for LittlevGL
-            let mut display_buffer = MaybeUninit::<lvgl_sys::lv_disp_buf_t>::uninit();
-
             // Declare a buffer for the refresh rate
             // TODO: Make this an external configuration
             const REFRESH_BUFFER_LEN: usize = 2;
-            let refresh_buffer1 = Box::new(
-                MaybeUninit::<
-                    [MaybeUninit<lvgl_sys::lv_color_t>;
-                        lvgl_sys::LV_HOR_RES_MAX as usize * REFRESH_BUFFER_LEN],
-                >::uninit()
-                .assume_init(),
-            );
-            let refresh_buffer2 = Box::new(
-                MaybeUninit::<
-                    [MaybeUninit<lvgl_sys::lv_color_t>;
-                        lvgl_sys::LV_HOR_RES_MAX as usize * REFRESH_BUFFER_LEN],
-                >::uninit()
-                .assume_init(),
-            );
+            let refresh_buffer1 = vec![
+                Color::from_rgb((0, 0, 0)).raw;
+                lvgl_sys::LV_HOR_RES_MAX as usize * REFRESH_BUFFER_LEN
+            ];
 
+            let refresh_buffer2 = vec![
+                Color::from_rgb((0, 0, 0)).raw;
+                lvgl_sys::LV_HOR_RES_MAX as usize * REFRESH_BUFFER_LEN
+            ];
+
+            // Create a display buffer for LittlevGL
+            let mut display_buffer = MaybeUninit::<lvgl_sys::lv_disp_buf_t>::uninit();
             // Initialize the display buffer
             lvgl_sys::lv_disp_buf_init(
                 display_buffer.as_mut_ptr(),
-                Box::into_raw(refresh_buffer1) as *mut cty::c_void,
-                Box::into_raw(refresh_buffer2) as *mut cty::c_void,
+                Box::into_raw(refresh_buffer1.into_boxed_slice()) as *mut cty::c_void,
+                Box::into_raw(refresh_buffer2.into_boxed_slice()) as *mut cty::c_void,
                 lvgl_sys::LV_HOR_RES_MAX * REFRESH_BUFFER_LEN as u32,
             );
             let display_buffer = Box::new(display_buffer.assume_init());
@@ -55,6 +49,7 @@ impl DisplayDriver {
             // Set your driver function
             disp_drv.flush_cb = Some(display_callback_wrapper::<T, C>);
             // TODO: DrawHandler type here
+            // Safety: `user_data` is set to NULL in C code.
             disp_drv.user_data = device as *mut _ as *mut cty::c_void;
             disp_drv
         };

lvgl/src/lib.rs

@@ -1,6 +1,7 @@
 #![feature(try_trait)]
 #![no_std]
 
+#[macro_use]
 extern crate alloc;
 #[macro_use]
 extern crate bitflags;

lvgl/src/lv_core/obj.rs

@@ -118,36 +118,26 @@ impl Default for Obj {
 }
 
 macro_rules! define_object {
-    ($item:ident, $create_fn:ident) => {
-        define_object!($item, $create_fn, event = (), part = $crate::Part);
+    ($item:ident) => {
+        define_object!($item, event = (), part = $crate::Part);
     };
-    ($item:ident, $create_fn:ident, event = $event_type:ty) => {
-        define_object!($item, $create_fn, event = $event_type, part = $crate::Part);
+    ($item:ident, event = $event_type:ty) => {
+        define_object!($item, event = $event_type, part = $crate::Part);
     };
-    ($item:ident, $create_fn:ident, part = $part_type:ty) => {
-        define_object!($item, $create_fn, event = (), part = $part_type);
+    ($item:ident, part = $part_type:ty) => {
+        define_object!($item, event = (), part = $part_type);
     };
-    ($item:ident, $create_fn:ident, part = $part_type:ty, event = $event_type:ty) => {
-        define_object!($item, $create_fn, event = $event_type, part = $part_type);
+    ($item:ident, part = $part_type:ty, event = $event_type:ty) => {
+        define_object!($item, event = $event_type, part = $part_type);
     };
-    ($item:ident, $create_fn:ident, event = $event_type:ty, part = $part_type:ty) => {
+    ($item:ident, event = $event_type:ty, part = $part_type:ty) => {
         pub struct $item {
             core: $crate::Obj,
         }
 
-        impl $item {
-            pub fn new<C>(parent: &mut C) -> $crate::LvResult<Self>
-            where
-                C: $crate::NativeObject,
-            {
-                unsafe {
-                    let ptr = lvgl_sys::$create_fn(parent.raw()?.as_mut(), core::ptr::null_mut());
-                    let raw = core::ptr::NonNull::new(ptr)?;
-                    let core = <$crate::Obj as $crate::Widget>::from_raw(raw);
-                    Ok(Self { core })
-                }
-            }
+        unsafe impl Send for $item {}
 
+        impl $item {
             pub fn on_event<F>(&mut self, f: F) -> $crate::LvResult<()>
             where
                 F: FnMut(Self, $crate::support::Event<<Self as $crate::Widget>::SpecialEvent>),

lvgl/src/widgets/arc.rs

@@ -1,59 +1,56 @@
-use crate::{LvResult, NativeObject};
-
-define_object!(Arc, lv_arc_create, part = ArcPart);
+use crate::widgets::Arc;
 
 impl Arc {
-    /// Set the start angle, for the given arc part.
-    /// 0 degrees for the right, 90 degrees for the bottom, etc.
-    pub fn set_start_angle(&mut self, angle: u16, part: ArcPart) -> LvResult<()> {
-        match part {
-            ArcPart::Background => unsafe {
-                lvgl_sys::lv_arc_set_bg_start_angle(self.core.raw()?.as_mut(), angle)
-            },
-            ArcPart::Indicator => unsafe {
-                lvgl_sys::lv_arc_set_start_angle(self.core.raw()?.as_mut(), angle)
-            },
-        }
-        Ok(())
-    }
-
-    /// Set the end angle, for the given arc part.
-    /// 0 degrees for the right, 90 degrees for the bottom, etc.
-    pub fn set_end_angle(&mut self, angle: u16, part: ArcPart) -> LvResult<()> {
-        match part {
-            ArcPart::Background => unsafe {
-                lvgl_sys::lv_arc_set_bg_start_angle(self.core.raw()?.as_mut(), angle)
-            },
-            ArcPart::Indicator => unsafe {
-                lvgl_sys::lv_arc_set_end_angle(self.core.raw()?.as_mut(), angle)
-            },
-        }
-        Ok(())
-    }
-
-    /// Rotate the arc, `angle` degrees clockwise.
-    pub fn set_rotation(&mut self, angle: u16) -> LvResult<()> {
-        unsafe {
-            lvgl_sys::lv_arc_set_rotation(self.core.raw()?.as_mut(), angle);
-        }
-        Ok(())
-    }
+    // /// Set the start angle, for the given arc part.
+    // /// 0 degrees for the right, 90 degrees for the bottom, etc.
+    // pub fn set_start_angle(&mut self, angle: u16, part: ArcPart) -> LvResult<()> {
+    //     match part {
+    //         ArcPart::Background => unsafe {
+    //             lvgl_sys::lv_arc_set_bg_start_angle(self.core.raw()?.as_mut(), angle)
+    //         },
+    //         ArcPart::Indicator => unsafe {
+    //             lvgl_sys::lv_arc_set_start_angle(self.core.raw()?.as_mut(), angle)
+    //         },
+    //     }
+    //     Ok(())
+    // }
+    //
+    // /// Set the end angle, for the given arc part.
+    // /// 0 degrees for the right, 90 degrees for the bottom, etc.
+    // pub fn set_end_angle(&self, angle: u16, part: ArcPart) -> LvResult<()> {
+    //     match part {
+    //         ArcPart::Background => unsafe {
+    //             lvgl_sys::lv_arc_set_bg_end_angle(self.core.raw()?.as_mut(), angle)
+    //         },
+    //         ArcPart::Indicator => unsafe {
+    //             lvgl_sys::lv_arc_set_end_angle(self.core.raw()?.as_mut(), angle)
+    //         },
+    //     }
+    //     Ok(())
+    // }
+    //
+    // /// Rotate the arc, `angle` degrees clockwise.
+    // pub fn set_rotation(&mut self, angle: u16) -> LvResult<()> {
+    //     unsafe {
+    //         lvgl_sys::lv_arc_set_rotation(self.core.raw()?.as_mut(), angle);
+    //     }
+    //     Ok(())
+    // }
 }
 
 /// The different parts, of an arc object.
+#[derive(Debug, Copy, Clone, PartialEq)]
+#[repr(u8)]
 pub enum ArcPart {
     /// The background of the arc.
-    Background,
+    Background = lvgl_sys::LV_ARC_PART_BG as u8,
     /// The indicator of the arc.
     /// This is what moves/changes, depending on the arc's value.
-    Indicator,
+    Indicator = lvgl_sys::LV_ARC_PART_INDIC as u8,
 }
 
 impl From<ArcPart> for u8 {
-    fn from(component: ArcPart) -> Self {
-        match component {
-            ArcPart::Background => lvgl_sys::LV_ARC_PART_BG as u8,
-            ArcPart::Indicator => lvgl_sys::LV_ARC_PART_INDIC as u8,
-        }
+    fn from(part: ArcPart) -> Self {
+        part as u8
     }
 }

lvgl/src/widgets/bar.rs

@@ -1,8 +1,7 @@
 use crate::support::Animation;
+use crate::widgets::Bar;
 use crate::{LvResult, NativeObject};
 
-define_object!(Bar, lv_bar_create, part = BarPart);
-
 impl Bar {
     /// Set minimum and the maximum values of the bar
     pub fn set_range(&mut self, min: i16, max: i16) -> LvResult<()> {

lvgl/src/widgets/btn.rs

@@ -1 +0,0 @@
-define_object!(Btn, lv_btn_create);

lvgl/src/widgets/gauge.rs

@@ -1,17 +1,3 @@
-use crate::{LvResult, NativeObject};
-
-define_object!(Gauge, lv_gauge_create, part = GaugePart);
-
-impl Gauge {
-    /// Set a new value on the gauge
-    pub fn set_value(&mut self, needle_id: u8, value: i32) -> LvResult<()> {
-        unsafe {
-            lvgl_sys::lv_gauge_set_value(self.core.raw()?.as_mut(), needle_id, value);
-        }
-        Ok(())
-    }
-}
-
 pub enum GaugePart {
     Main,
     Major,

lvgl/src/widgets/label.rs

@@ -1,41 +1,20 @@
+use crate::widgets::Label;
 use crate::{LvResult, NativeObject};
-use cstr_core::CString;
-
-define_object!(Label, lv_label_create);
 
 impl Label {
-    pub fn set_text(&mut self, text: &str) -> LvResult<()> {
-        let text = CString::new(text).unwrap();
-        unsafe {
-            lvgl_sys::lv_label_set_text(self.core.raw()?.as_mut(), text.as_ptr());
-        }
-        Ok(())
-    }
-
     pub fn set_label_align(&mut self, align: LabelAlign) -> LvResult<()> {
-        let align = match align {
-            LabelAlign::Left => lvgl_sys::LV_LABEL_ALIGN_LEFT,
-            LabelAlign::Center => lvgl_sys::LV_LABEL_ALIGN_CENTER,
-            LabelAlign::Right => lvgl_sys::LV_LABEL_ALIGN_RIGHT,
-            LabelAlign::Auto => lvgl_sys::LV_LABEL_ALIGN_AUTO,
-        } as lvgl_sys::lv_label_align_t;
         unsafe {
-            lvgl_sys::lv_label_set_align(self.core.raw()?.as_mut(), align);
-        }
-        Ok(())
-    }
-
-    pub fn set_recolor(&mut self, recolor: bool) -> LvResult<()> {
-        unsafe {
-            lvgl_sys::lv_label_set_recolor(self.core.raw()?.as_mut(), recolor);
+            lvgl_sys::lv_label_set_align(self.core.raw()?.as_mut(), align as u8);
         }
         Ok(())
     }
 }
 
+#[derive(Debug, Copy, Clone, PartialEq)]
+#[repr(u8)]
 pub enum LabelAlign {
-    Left,
-    Center,
-    Right,
-    Auto,
+    Left = lvgl_sys::LV_LABEL_ALIGN_LEFT as u8,
+    Center = lvgl_sys::LV_LABEL_ALIGN_CENTER as u8,
+    Right = lvgl_sys::LV_LABEL_ALIGN_RIGHT as u8,
+    Auto = lvgl_sys::LV_LABEL_ALIGN_AUTO as u8,
 }

lvgl/src/widgets/mod.rs

@@ -1,11 +1,12 @@
 mod arc;
 mod bar;
-mod btn;
 mod gauge;
 mod label;
 
+include!("generated.rs");
+
+use crate::{NativeObject, Widget};
 pub use arc::*;
 pub use bar::*;
-pub use btn::*;
 pub use gauge::*;
 pub use label::*;