Cargo.toml

@@ -1,7 +1,6 @@
 [workspace]
 members = [
     "lvgl",
-    "lvgl-sys",
     "lvgl-codegen",
-    "examples"
+    "lvgl-sys",
 ]

README.md

@@ -1,18 +1,19 @@
-<h1 align="center"> LittlevGL - Open-source Embedded GUI Library in Rust</h1>
+<h1 align="center"> LVGL - Open-source Embedded GUI Library in Rust</h1>
 
-![Original LittlevGL demo image](lv_demo.png)
+![Original LVGL demo image](lv_demo.png)
 
 <p align="center">
-LittlevGL provides everything you need to create a Graphical User Interface (GUI) on embedded systems with easy-to-use graphical elements, beautiful visual effects and low memory footprint. 
+LVGL provides everything you need to create a Graphical User Interface (GUI) on embedded systems with easy-to-use graphical elements, beautiful visual effects and low memory footprint. 
 </p>
 <p align="center">
-LittlevGL is compatible with <samp>#![no_std]</samp> environments by default.
+LVGL is compatible with <samp>#![no_std]</samp> environments by default.
 </p>
 
 <h4 align="center">
-<a href="https://lvgl.io/">Official LittlevGL Website </a> &middot; 
+<a href="https://github.com/rafaelcaricio/lvgl-rs-wasm">Rust to WASM demo</a> &middot;
+<a href="https://lvgl.io/">Official LVGL Website </a> &middot;
 <a href="https://github.com/littlevgl/lvgl">C library repository</a> &middot;
-<a href="https://lvgl.io/demos">Live demo</a>
+<a href="https://lvgl.io/demos">Official live demos</a>
 </h4>
 
 ---
@@ -42,7 +43,7 @@ $ cargo add lvgl
 
 The build requires the environment variable bellow to be set:
 
-- `DEP_LV_CONFIG_PATH`: Path to the directory containing the `lv_conf.h` header file used for configuration of LittlevGL library.
+- `DEP_LV_CONFIG_PATH`: Path to the directory containing the `lv_conf.h` header file used for configuration of LVGL library.
 
 We recommend the `lv_conf.h` file to be in your project's root directory. If so, the command to build your project would be:
 ```shell script
@@ -58,10 +59,17 @@ for `no_std`, so we need to use a workaround to build "lvgl-rs". The mainstrem i
 ```shell
 $ DEP_LV_CONFIG_PATH=`pwd` cargo build -Zfeatures=build_dep
 ```
+### LVGL Global Allocator
+
+A [global allocator](https://doc.rust-lang.org/std/alloc/trait.GlobalAlloc.html) for Rust leveraging the
+[LVGL memory allocator](https://github.com/lvgl/lvgl/blob/master/src/misc/lv_mem.h) is provided, but not enabled 
+by default. Can be enabled by the feature `lvgl_alloc`. This will make all dynamic memory to be allocated by LVGL 
+internal memory manager.
 
 ## Running the demo
 
-**Hint for macOS users**: Before you run the demos you need to make sure you have [libsdl](https://www.libsdl.org) installed on your machine. To install it, use HomeBrew:
+**Hint for macOS users**: Before you run the demos you need to make sure you have [libsdl](https://www.libsdl.org)
+installed on your machine. To install it, use HomeBrew:
 
 ```shell
 $ brew install sdl2

examples/Cargo.toml

@@ -1,34 +0,0 @@
-[package]
-name = "demo"
-version = "0.1.0"
-authors = ["Rafael Caricio <crates@caric.io>"]
-edition = "2018"
-publish = false
-
-[dev-dependencies]
-lvgl = { path = "../lvgl" }
-lvgl-sys = { path = "../lvgl-sys" }
-embedded-graphics = "0.6.2"
-embedded-graphics-simulator = "0.2.1"
-heapless = "0.5.5"
-cstr_core = { version = "0.2.0", features = ["alloc"] }
-
-[[example]]
-name = "demo"
-path = "demo.rs"
-
-[[example]]
-name = "bar"
-path = "bar.rs"
-
-[[example]]
-name = "button_click"
-path = "button_click.rs"
-
-[[example]]
-name = "gauge"
-path = "gauge.rs"
-
-[[example]]
-name = "arc"
-path = "arc.rs"

examples/arc.rs

@@ -11,7 +11,31 @@ use lvgl::{LvError, Widget};
 use lvgl_sys;
 use std::time::Instant;
 
+fn mem_info() -> lvgl_sys::lv_mem_monitor_t {
+    let mut info = lvgl_sys::lv_mem_monitor_t {
+        total_size: 0,
+        free_cnt: 0,
+        free_size: 0,
+        free_biggest_size: 0,
+        used_cnt: 0,
+        max_used: 0,
+        used_pct: 0,
+        frag_pct: 0,
+    };
+    unsafe {
+        lvgl_sys::lv_mem_monitor(&mut info as *mut _);
+    }
+    info
+}
+
 fn main() -> Result<(), LvError> {
+    println!("meminfo init: {:?}", mem_info());
+    run_arc_demo()?;
+    println!("meminfo end: {:?}", mem_info());
+    Ok(())
+}
+
+fn run_arc_demo() -> Result<(), LvError> {
     let display: SimulatorDisplay<Rgb565> = SimulatorDisplay::new(Size::new(
         lvgl_sys::LV_HOR_RES_MAX,
         lvgl_sys::LV_VER_RES_MAX,
@@ -58,6 +82,7 @@ fn main() -> Result<(), LvError> {
         if i > 270 {
             forward = if forward { false } else { true };
             i = 1;
+            println!("meminfo running: {:?}", mem_info());
         }
         angle = if forward { angle + 1 } else { angle - 1 };
         arc.set_end_angle(angle + 135)?;

examples/demo.rs

@@ -88,7 +88,7 @@ fn main() -> Result<(), LvError> {
     Ok(())
 }
 
-// Reference to native font for LittlevGL, defined in the file: "fonts_noto_sans_numeric_80.c"
+// Reference to native font for LVGL, defined in the file: "fonts_noto_sans_numeric_80.c"
 // TODO: Create a macro for defining a safe wrapper for fonts.
 // Maybe sometihng like:
 //

examples/include/lv_conf.h

@@ -80,7 +80,7 @@ typedef int16_t lv_coord_t;
 #define LV_MEM_CUSTOM      0
 #if LV_MEM_CUSTOM == 0
 /* Size of the memory used by `lv_mem_alloc` in bytes (>= 2kB)*/
-#  define LV_MEM_SIZE    (32U * 1024U)
+#  define LV_MEM_SIZE    (1048576U) // 1Mb
 
 /* Complier prefix for a big array declaration */
 #  define LV_MEM_ATTR

lvgl-sys/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "lvgl-sys"
-description = "Raw bindings to the LittlevGL C library."
+description = "Raw bindings to the LVGL C library."
 version = "0.5.2"
 authors = ["Rafael Caricio <crates.lvgl-sys@caric.io>"]
 edition = "2018"

lvgl-sys/README.md

@@ -5,7 +5,7 @@ Rust raw bindings for LittlevGL library.
 
 Build requires environment variables to be set:
 
-- `DEP_LV_CONFIG_PATH`: Path to the directory containing the `lv_conf.h` header file used for configuration of LittlevGL library.
+- `DEP_LV_CONFIG_PATH`: Path to the directory containing the `lv_conf.h` header file used for configuration of LVGL library.
 
 We recommend the `lv_conf.h` file to be in your project's root directory. If so, the command to build your project would be:
 ```shell script

lvgl/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "lvgl"
-description = "LittlevGL bindings for Rust. A powerful and easy-to-use embedded GUI with many widgets, advanced visual effects (opacity, antialiasing, animations) and low memory requirements (16K RAM, 64K Flash)."
+description = "LVGL bindings for Rust. A powerful and easy-to-use embedded GUI with many widgets, advanced visual effects (opacity, antialiasing, animations) and low memory requirements (16K RAM, 64K Flash)."
 version = "0.5.2"
 authors = ["Rafael Caricio <crates.lvgl@caric.io>"]
 edition = "2018"
@@ -18,9 +18,40 @@ embedded-graphics = "0.6.2"
 cstr_core = "0.2.3"
 bitflags = "1.2.1"
 
+[features]
+alloc = ["cstr_core/alloc"]
+lvgl_alloc = ["alloc"]
+
 [build-dependencies]
 quote = "1.0.9"
 proc-macro2 = "1.0.24"
 lvgl-codegen = { version = "0.5.2", path = "../lvgl-codegen" }
 lvgl-sys = { version = "0.5.2", path = "../lvgl-sys" }
 
+[dev-dependencies]
+embedded-graphics-simulator = "0.2.1"
+heapless = "0.5.5"
+
+[[example]]
+name = "demo"
+path = "../examples/demo.rs"
+required-features = ["alloc"]
+
+[[example]]
+name = "bar"
+path = "../examples/bar.rs"
+required-features = ["alloc"]
+
+[[example]]
+name = "button_click"
+path = "../examples/button_click.rs"
+required-features = ["alloc"]
+
+[[example]]
+name = "gauge"
+path = "../examples/gauge.rs"
+
+[[example]]
+name = "arc"
+path = "../examples/arc.rs"
+required-features = ["lvgl_alloc"]

lvgl/src/allocator.rs

@@ -0,0 +1,20 @@
+use core::alloc::{GlobalAlloc, Layout};
+
+// Register the global allocator
+#[global_allocator]
+static ALLOCATOR: LvglAlloc = LvglAlloc;
+
+pub struct LvglAlloc;
+
+unsafe impl GlobalAlloc for LvglAlloc {
+    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+        // Make sure LVGL is initialized!
+        crate::lvgl_init();
+        lvgl_sys::lv_mem_alloc(layout.size() as lvgl_sys::size_t) as *mut u8
+    }
+
+    unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
+        crate::lvgl_init();
+        lvgl_sys::lv_mem_free(ptr as *const cty::c_void)
+    }
+}

lvgl/src/lib.rs

@@ -17,13 +17,52 @@
 #[macro_use]
 extern crate bitflags;
 
-pub(crate) mod mem;
+#[cfg(feature = "lvgl_alloc")]
+extern crate alloc;
+
+// We can ONLY use `alloc::boxed::Box` if `lvgl_alloc` is enabled.
+// That is because we use `Box` to send memory references to LVGL. Since the global allocator, when
+// `lvgl_alloc` feature is enabled, is the LVGL memory manager then everything is in LVGL
+// managed memory anyways. In that case we can use the Rust's provided Box definition.
+//
+#[cfg(feature = "lvgl_alloc")]
+use ::alloc::boxed::Box;
+
+#[cfg(feature = "lvgl_alloc")]
+mod allocator;
+
 mod support;
 mod ui;
 #[macro_use]
 mod lv_core;
 pub mod widgets;
 
+#[cfg(not(feature = "lvgl_alloc"))]
+pub(crate) mod mem;
+
+// When LVGL allocator is not used on the Rust code, we need a way to add objects to the LVGL
+// managed memory. We implement a very simple `Box` that has the minimal features to copy memory
+// safely to the LVGL managed memory.
+//
+#[cfg(not(feature = "lvgl_alloc"))]
+use crate::mem::Box;
+
 pub use lv_core::*;
 pub use support::*;
 pub use ui::*;
+
+use core::sync::atomic::{AtomicBool, Ordering};
+
+// Initialize LVGL only once.
+static LVGL_INITIALIZED: AtomicBool = AtomicBool::new(false);
+
+pub(crate) fn lvgl_init() {
+    if LVGL_INITIALIZED
+        .compare_exchange(false, true, Ordering::Relaxed, Ordering::Relaxed)
+        .is_ok()
+    {
+        unsafe {
+            lvgl_sys::lv_init();
+        }
+    }
+}

lvgl/src/lv_core/obj.rs

@@ -1,9 +1,9 @@
 use crate::lv_core::style::Style;
-use crate::mem::Box;
+use crate::Box;
 use crate::{Align, LvError, LvResult};
 use core::ptr;
 
-/// Represents a native LittlevGL object
+/// Represents a native LVGL object
 pub trait NativeObject {
     /// Provide common way to access to the underlying native object pointer.
     fn raw(&self) -> LvResult<ptr::NonNull<lvgl_sys::lv_obj_t>>;
@@ -28,7 +28,7 @@ impl NativeObject for Obj {
     }
 }
 
-/// A wrapper for all LittlevGL common operations on generic objects.
+/// A wrapper for all LVGL common operations on generic objects.
 pub trait Widget: NativeObject {
     type SpecialEvent;
     type Part: Into<u8>;
@@ -146,8 +146,8 @@ macro_rules! define_object {
                 unsafe {
                     let mut raw = self.raw()?;
                     let obj = raw.as_mut();
-                    let user_closure = $crate::mem::Box::new(f)?;
-                    obj.user_data = $crate::mem::Box::into_raw(user_closure) as *mut cty::c_void;
+                    let user_closure = $crate::Box::new(f);
+                    obj.user_data = $crate::Box::into_raw(user_closure) as *mut cty::c_void;
                     lvgl_sys::lv_obj_set_event_cb(
                         obj,
                         lvgl_sys::lv_event_cb_t::Some($crate::support::event_callback::<Self, F>),

lvgl/src/lv_core/style.rs

@@ -1,4 +1,4 @@
-use crate::mem::Box;
+use crate::Box;
 use crate::{Color, LvResult, State};
 use core::mem;
 use cstr_core::CStr;
@@ -31,7 +31,7 @@ impl Default for Style {
         let raw = unsafe {
             let mut style = mem::MaybeUninit::<lvgl_sys::lv_style_t>::uninit();
             lvgl_sys::lv_style_init(style.as_mut_ptr());
-            Box::new(style.assume_init()).unwrap()
+            Box::new(style.assume_init())
         };
         Self { raw }
     }

lvgl/src/mem.rs

@@ -1,4 +1,3 @@
-use crate::{LvError, LvResult};
 use core::mem;
 use core::ops::{Deref, DerefMut};
 use core::ptr::NonNull;
@@ -12,7 +11,7 @@ pub(crate) struct Box<T>(NonNull<T>);
 
 impl<T> Box<T> {
     /// Allocate memory using LVGL memory API and place `T` in the LVGL tracked memory.
-    pub fn new(value: T) -> LvResult<Box<T>> {
+    pub fn new(value: T) -> Box<T> {
         let size = mem::size_of::<T>();
         let inner = unsafe {
             let ptr = lvgl_sys::lv_mem_alloc(size as lvgl_sys::size_t) as *mut T;
@@ -29,9 +28,11 @@ impl<T> Box<T> {
                     p.as_ptr().write(value);
                     p
                 })
-                .ok_or(LvError::LvOOMemory)?
+                .unwrap_or_else(|| {
+                    panic!("Could not allocate memory {} bytes", size);
+                })
         };
-        Ok(Box(inner))
+        Box(inner)
     }
 
     pub fn into_raw(self) -> *mut T {
@@ -71,32 +72,21 @@ impl<T> AsMut<T> for Box<T> {
 #[cfg(test)]
 mod test {
     use super::*;
-    use std::sync::Once;
     use std::vec::Vec;
 
-    static INIT_LVGL: Once = Once::new();
-
-    fn init() {
-        INIT_LVGL.call_once(|| {
-            unsafe {
-                lvgl_sys::lv_init();
-            };
-        });
-    }
-
     #[test]
     fn place_value_in_lv_mem() {
-        init();
+        crate::lvgl_init();
 
-        let v = Box::new(5).unwrap();
+        let v = Box::new(5);
         drop(v);
-        let v = Box::new(10).unwrap();
+        let v = Box::new(10);
         drop(v);
     }
 
     #[test]
     fn place_complex_value_in_lv_mem() {
-        init();
+        crate::lvgl_init();
 
         #[repr(C)]
         #[derive(Debug)]
@@ -119,11 +109,7 @@ mod test {
             };
 
             println!("{:?}", p);
-            let mut b = Box::new(p).unwrap_or_else(|_| {
-                let info = mem_info();
-                println!("mem info: {:?}", &info);
-                panic!("OOM");
-            });
+            let mut b = Box::new(p);
 
             println!("memory address is {:p}", b.as_mut());
 
@@ -159,7 +145,7 @@ mod test {
             used_cnt: 0,
             max_used: 0,
             used_pct: 0,
-            frag_pct: 0
+            frag_pct: 0,
         };
         unsafe {
             lvgl_sys::lv_mem_monitor(&mut info as *mut _);

lvgl/src/support.rs

@@ -65,7 +65,7 @@ impl From<Color> for Rgb565 {
     }
 }
 
-/// Events are triggered in LittlevGL when something happens which might be interesting to
+/// Events are triggered in LVGL when something happens which might be interesting to
 /// the user, e.g. if an object:
 ///  - is clicked
 ///  - is dragged

lvgl/src/ui.rs

@@ -1,4 +1,4 @@
-use crate::mem::Box;
+use crate::Box;
 use crate::{Color, Event, LvError, LvResult, Obj, Widget};
 use core::marker::PhantomData;
 use core::mem::MaybeUninit;
@@ -10,7 +10,7 @@ use embedded_graphics::pixelcolor::PixelColor;
 use embedded_graphics::prelude::*;
 use embedded_graphics::{drawable, DrawTarget};
 
-// There can only be a single reference to LittlevGL library.
+// There can only be a single reference to LVGL library.
 static LVGL_IN_USE: AtomicBool = AtomicBool::new(false);
 
 // TODO: Make this an external configuration
@@ -23,13 +23,13 @@ where
     T: DrawTarget<C>,
     C: PixelColor + From<Color>,
 {
-    // LittlevGL is not thread-safe by default.
+    // LVGL is not thread-safe by default.
     _not_sync: PhantomData<*mut ()>,
     // Later we can add possibility to have multiple displays by using `heapless::Vec`
     display_data: Option<DisplayUserData<T, C>>,
 }
 
-// LittlevGL does not use thread locals.
+// LVGL does not use thread locals.
 unsafe impl<T, C> Send for UI<T, C>
 where
     T: DrawTarget<C>,
@@ -47,9 +47,7 @@ where
             .compare_exchange(false, true, Ordering::Relaxed, Ordering::Relaxed)
             .is_ok()
         {
-            unsafe {
-                lvgl_sys::lv_init();
-            }
+            crate::lvgl_init();
             Ok(Self {
                 _not_sync: PhantomData,
                 display_data: None,
@@ -75,15 +73,15 @@ where
             // Initialize the display buffer
             lvgl_sys::lv_disp_buf_init(
                 disp_buf.as_mut_ptr(),
-                Box::into_raw(Box::new(refresh_buffer1)?) as *mut cty::c_void,
-                Box::into_raw(Box::new(refresh_buffer2)?) as *mut cty::c_void,
+                Box::into_raw(Box::new(refresh_buffer1)) as *mut cty::c_void,
+                Box::into_raw(Box::new(refresh_buffer2)) as *mut cty::c_void,
                 lvgl_sys::LV_HOR_RES_MAX * REFRESH_BUFFER_LEN as u32,
             );
             // Basic initialization of the display driver
             lvgl_sys::lv_disp_drv_init(disp_drv.as_mut_ptr());
-            let mut disp_drv = Box::new(disp_drv.assume_init())?;
+            let mut disp_drv = Box::new(disp_drv.assume_init());
             // Assign the buffer to the display
-            disp_drv.buffer = Box::into_raw(Box::new(disp_buf.assume_init())?);
+            disp_drv.buffer = Box::into_raw(Box::new(disp_buf.assume_init()));
             // Set your driver function
             disp_drv.flush_cb = Some(display_callback_wrapper::<T, C>);
             disp_drv.user_data = &mut self.display_data as *mut _ as *mut cty::c_void;
@@ -166,12 +164,12 @@ unsafe extern "C" fn display_callback_wrapper<T, C>(
         // TODO: Can we do anything when there is a error while flushing?
         let _ = display_flush(&mut user_data.display, (x1, x2), (y1, y2), color_p);
     }
-    // Indicate to LittlevGL that we are ready with the flushing
+    // Indicate to LVGL that we are ready with the flushing
     lvgl_sys::lv_disp_flush_ready(disp_drv);
 }
 
 // We separate this display flush function to reduce the amount of unsafe code we need to write.
-// This also provides a good separation of concerns, what is necessary from LittlevGL to work and
+// This also provides a good separation of concerns, what is necessary from LVGL to work and
 // what is the lvgl-rs wrapper responsibility.
 fn display_flush<T, C>(
     display: &mut T,