README.md

@@ -47,6 +47,12 @@ $ DEP_LV_CONFIG_PATH=`pwd` cargo build -Zfeatures=build_dep
 
 ## 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:
+
+```shell
+$ brew install sdl2
+```
+
 [This project contains examples that can run in a desktop simulator.](./examples)
 
 First, make sure to pull `lvgl-rs` submodules:

examples/Cargo.toml

@@ -13,6 +13,10 @@ embedded-graphics-simulator = "0.2.0"
 heapless = "0.5.5"
 cstr_core = { version = "0.2.0", features = ["alloc"] }
 
+[[example]]
+name = "simple"
+path = "simple.rs"
+
 [[example]]
 name = "demo"
 path = "demo.rs"

examples/arc.rs

@@ -8,14 +8,11 @@ use lvgl::style::Style;
 use lvgl::widgets::{Arc, Label, LabelAlign};
 use lvgl::{self, Align, Color, Part, State, UI};
 use lvgl::{LvError, Widget};
-use lvgl_sys;
 use std::time::Instant;
 
 fn main() -> Result<(), LvError> {
-    let display: SimulatorDisplay<Rgb565> = SimulatorDisplay::new(Size::new(
-        lvgl_sys::LV_HOR_RES_MAX,
-        lvgl_sys::LV_VER_RES_MAX,
-    ));
+    let display: SimulatorDisplay<Rgb565> =
+        SimulatorDisplay::new(Size::new(lvgl::HOR_RES_MAX, lvgl::VER_RES_MAX));
 
     let output_settings = OutputSettingsBuilder::new().scale(2).build();
     let mut window = Window::new("Arc Example", &output_settings);

examples/bar.rs

@@ -7,14 +7,11 @@ use embedded_graphics_simulator::{
 use lvgl::style::Style;
 use lvgl::widgets::{Bar, Label, LabelAlign};
 use lvgl::{self, Align, Animation, Color, Event, LvError, Part, State, Widget, UI};
-use lvgl_sys;
 use std::time::Instant;
 
 fn main() -> Result<(), LvError> {
-    let display: SimulatorDisplay<Rgb565> = SimulatorDisplay::new(Size::new(
-        lvgl_sys::LV_HOR_RES_MAX,
-        lvgl_sys::LV_VER_RES_MAX,
-    ));
+    let display: SimulatorDisplay<Rgb565> =
+        SimulatorDisplay::new(Size::new(lvgl::HOR_RES_MAX, lvgl::VER_RES_MAX));
 
     let output_settings = OutputSettingsBuilder::new().scale(2).build();
     let mut window = Window::new("Bar Example", &output_settings);

examples/button_click.rs

@@ -4,26 +4,34 @@ use embedded_graphics::prelude::*;
 use embedded_graphics_simulator::{
     OutputSettingsBuilder, SimulatorDisplay, SimulatorEvent, Window,
 };
+
+use lvgl::input_device::{BufferStatus, InputData, Pointer};
 use lvgl::style::Style;
 use lvgl::widgets::{Btn, Label};
-use lvgl::{self, Align, Color, Event, LvError, Part, State, Widget, UI};
-use lvgl_sys;
-use std::time::Instant;
+use lvgl::{self, Align, Color, LvError, Part, State, Widget, UI};
+
+use std::thread::sleep;
+use std::time::{Duration, Instant};
 
 fn main() -> Result<(), LvError> {
-    let display: SimulatorDisplay<Rgb565> = SimulatorDisplay::new(Size::new(
-        lvgl_sys::LV_HOR_RES_MAX,
-        lvgl_sys::LV_VER_RES_MAX,
-    ));
+    let display: SimulatorDisplay<Rgb565> =
+        SimulatorDisplay::new(Size::new(lvgl::HOR_RES_MAX, lvgl::VER_RES_MAX));
 
     let output_settings = OutputSettingsBuilder::new().scale(2).build();
     let mut window = Window::new("Bar Example", &output_settings);
 
     let mut ui = UI::init()?;
 
-    // Implement and register your display:
+    // Register your display:
     ui.disp_drv_register(display)?;
 
+    // Define the initial state of your input
+    let mut latest_touch_status = InputData::Touch(Point::new(0, 0)).released().once();
+
+    // Register a new input device that's capable of reading the current state of the input
+    let mut touch_screen = Pointer::new(|| latest_touch_status);
+    ui.indev_drv_register(&mut touch_screen)?;
+
     // Create screen and widgets
     let mut screen = ui.scr_act()?;
 
@@ -40,6 +48,7 @@ fn main() -> Result<(), LvError> {
 
     let mut btn_state = false;
     button.on_event(|mut btn, event| {
+        println!("Button received event: {:?}", event);
         if let lvgl::Event::Clicked = event {
             if btn_state {
                 let nt = CString::new("Click me!").unwrap();
@@ -49,17 +58,25 @@ fn main() -> Result<(), LvError> {
                 btn_lbl.set_text(nt.as_c_str()).unwrap();
             }
             btn_state = !btn_state;
-            println!("Clicked! Inner..");
             btn.toggle().unwrap();
         }
     })?;
 
     let mut loop_started = Instant::now();
+    let mut latest_touch_point = Point::new(0, 0);
     'running: loop {
         ui.task_handler();
         window.update(ui.get_display_ref().unwrap());
 
-        for event in window.events() {
+        let mut events = window.events().peekable();
+
+        if events.peek().is_none() {
+            latest_touch_status = InputData::Touch(latest_touch_point.clone())
+                .released()
+                .once();
+        }
+
+        for event in events {
             match event {
                 SimulatorEvent::MouseButtonUp {
                     mouse_btn: _,
@@ -67,13 +84,16 @@ fn main() -> Result<(), LvError> {
                 } => {
                     println!("Clicked on: {:?}", point);
                     // Send a event to the button directly
-                    ui.event_send(&mut button, Event::Clicked)?;
+                    latest_touch_point = point.clone();
+                    latest_touch_status = InputData::Touch(point).pressed().once();
                 }
                 SimulatorEvent::Quit => break 'running,
                 _ => {}
             }
         }
 
+        sleep(Duration::from_millis(15));
+
         ui.tick_inc(loop_started.elapsed());
         loop_started = Instant::now();
     }

examples/demo.rs

@@ -13,10 +13,8 @@ use std::thread::sleep;
 use std::time::{Duration, Instant};
 
 fn main() -> Result<(), LvError> {
-    let display: SimulatorDisplay<Rgb565> = SimulatorDisplay::new(Size::new(
-        lvgl_sys::LV_HOR_RES_MAX,
-        lvgl_sys::LV_VER_RES_MAX,
-    ));
+    let display: SimulatorDisplay<Rgb565> =
+        SimulatorDisplay::new(Size::new(lvgl::HOR_RES_MAX, lvgl::VER_RES_MAX));
 
     let output_settings = OutputSettingsBuilder::new().scale(2).build();
     let mut window = Window::new("PineTime", &output_settings);

examples/gauge.rs

@@ -6,14 +6,11 @@ use embedded_graphics_simulator::{
 use lvgl::style::{Opacity, Style};
 use lvgl::widgets::Gauge;
 use lvgl::{self, Align, Color, LvError, Part, State, Widget, UI};
-use lvgl_sys;
 use std::time::Instant;
 
 fn main() -> Result<(), LvError> {
-    let display: SimulatorDisplay<Rgb565> = SimulatorDisplay::new(Size::new(
-        lvgl_sys::LV_HOR_RES_MAX,
-        lvgl_sys::LV_VER_RES_MAX,
-    ));
+    let display: SimulatorDisplay<Rgb565> =
+        SimulatorDisplay::new(Size::new(lvgl::HOR_RES_MAX, lvgl::VER_RES_MAX));
 
     let output_settings = OutputSettingsBuilder::new().scale(2).build();
     let mut window = Window::new("Gauge Example", &output_settings);
@@ -36,7 +33,7 @@ fn main() -> Result<(), LvError> {
     gauge_style.set_radius(State::DEFAULT, 5);
     gauge_style.set_bg_opa(State::DEFAULT, Opacity::OPA_COVER);
     gauge_style.set_bg_color(State::DEFAULT, Color::from_rgb((192, 192, 192)));
-    // Set some paddings
+    // Set some padding's
     gauge_style.set_pad_inner(State::DEFAULT, 20);
     gauge_style.set_pad_top(State::DEFAULT, 20);
     gauge_style.set_pad_left(State::DEFAULT, 5);

examples/simple.rs

@@ -0,0 +1,52 @@
+use embedded_graphics::pixelcolor::Rgb565;
+use embedded_graphics::prelude::*;
+use embedded_graphics_simulator::{
+    OutputSettingsBuilder, SimulatorDisplay, SimulatorEvent, Window,
+};
+use lvgl::widgets::Keyboard;
+use lvgl::LvError;
+use lvgl::UI;
+use std::time::Instant;
+
+fn main() -> Result<(), LvError> {
+    let display: SimulatorDisplay<Rgb565> =
+        SimulatorDisplay::new(Size::new(lvgl::HOR_RES_MAX, lvgl::VER_RES_MAX));
+
+    let output_settings = OutputSettingsBuilder::new().scale(2).build();
+    let mut window = Window::new("Simple Example", &output_settings);
+
+    // Initialize LVGL
+    let mut ui = UI::init()?;
+
+    // Register your display
+    ui.disp_drv_register(display)?;
+
+    // Get the active screen
+    let mut screen = ui.scr_act()?;
+
+    // Create a Keyboard widget on the screen
+    let _ = Keyboard::new(&mut screen)?;
+
+    let mut loop_started = Instant::now();
+    'running: loop {
+        // Tell LVGL to process UI related tasks
+        ui.task_handler();
+
+        // Update your window with the latest display image
+        window.update(ui.get_display_ref().unwrap());
+
+        for event in window.events() {
+            match event {
+                SimulatorEvent::Quit => break 'running,
+                _ => {}
+            }
+        }
+
+        // Tell LVGL how much time has past since last loop
+        ui.tick_inc(loop_started.elapsed());
+
+        loop_started = Instant::now();
+    }
+
+    Ok(())
+}

lvgl-codegen/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "lvgl-codegen"
-version = "0.4.0"
+version = "0.5.0"
 description = "Code generation based on LVGL source code"
 authors = ["Rafael Caricio <crates.lvgl@caric.io>"]
 readme = "README.md"
@@ -15,4 +15,3 @@ lazy_static = "1.4.0"
 proc-macro2 = "1.0.18"
 Inflector = "0.11.4"
 syn = { version = "1.0.31", features = ["full"]}
-

lvgl-codegen/src/lib.rs

@@ -1,12 +1,11 @@
 use inflector::cases::pascalcase::to_pascal_case;
 use lazy_static::lazy_static;
 use proc_macro2::{Ident, TokenStream};
-use quote::format_ident;
+use quote::{format_ident, ToTokens};
 use quote::quote;
 use regex::Regex;
 use std::collections::HashMap;
 use std::error::Error;
-use syn::export::ToTokens;
 use syn::{FnArg, ForeignItem, ForeignItemFn, Item, ReturnType};
 
 type CGResult<T> = Result<T, Box<dyn Error>>;

lvgl-sys/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "lvgl-sys"
 description = "Raw bindings to the LittlevGL C library."
-version = "0.4.0"
+version = "0.5.0"
 authors = ["Rafael Caricio <crates.lvgl-sys@caric.io>"]
 edition = "2018"
 license = "MIT"

lvgl-sys/build.rs

@@ -62,25 +62,48 @@ fn main() {
         .include(&lv_config_dir)
         .compile("lvgl");
 
-    let cc_args = [
+    let mut cc_args = vec![
         "-DLV_CONF_INCLUDE_SIMPLE=1",
         "-I",
         lv_config_dir.to_str().unwrap(),
         "-I",
         vendor.to_str().unwrap(),
+        "-fvisibility=default",
     ];
 
+    // Set correct target triple for bindgen when cross-compiling
+    let target = env::var("TARGET").expect("Cargo build scripts always have TARGET");
+    let host = env::var("HOST").expect("Cargo build scripts always have HOST");
+    if target != host {
+        cc_args.push("-target");
+        cc_args.push(target.as_str());
+    }
+
+    let mut additional_args = Vec::new();
+    if target.ends_with("emscripten") {
+        if let Ok(em_path) = env::var("EMSDK") {
+            additional_args.push("-I".to_string());
+            additional_args.push(format!("{}/upstream/emscripten/system/include/libc", em_path));
+            additional_args.push("-I".to_string());
+            additional_args.push(format!("{}/upstream/emscripten/system/lib/libc/musl/arch/emscripten", em_path));
+            additional_args.push("-I".to_string());
+            additional_args.push(format!("{}/upstream/emscripten/system/include/SDL", em_path));
+        }
+    }
+
     let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
-    bindgen::Builder::default()
+    let bindings = bindgen::Builder::default()
         .header(shims_dir.join("lvgl_sys.h").to_str().unwrap())
         .layout_tests(false)
         .use_core()
         .rustfmt_bindings(true)
         .ctypes_prefix("cty")
         .clang_args(&cc_args)
+        .clang_args(&additional_args)
         .generate()
-        .expect("Unable to generate bindings")
-        .write_to_file(out_path.join("bindings.rs"))
+        .expect("Unable to generate bindings");
+
+    bindings.write_to_file(out_path.join("bindings.rs"))
         .expect("Can't write bindings!");
 }
 

lvgl/Cargo.toml

@@ -12,7 +12,7 @@ keywords = ["littlevgl", "lvgl", "graphical_interfaces"]
 build = "build.rs"
 
 [dependencies]
-lvgl-sys = { version = "0.4.0", path = "../lvgl-sys" }
+lvgl-sys = { version = "0.5.0", path = "../lvgl-sys" }
 cty = "0.2.1"
 embedded-graphics = "0.6.2"
 cstr_core = { version = "0.2.0" }
@@ -21,6 +21,5 @@ bitflags = "1.2.1"
 [build-dependencies]
 quote = "1.0.7"
 proc-macro2 = "1.0.18"
-lvgl-codegen = { version = "0.4.0", path = "../lvgl-codegen" }
-lvgl-sys = { version = "0.4.0", path = "../lvgl-sys" }
-
+lvgl-codegen = { version = "0.5.0", path = "../lvgl-codegen" }
+lvgl-sys = { version = "0.5.0", path = "../lvgl-sys" }

lvgl/src/input_device.rs

@@ -0,0 +1,176 @@
+use crate::mem::Box;
+use crate::LvResult;
+use core::mem::MaybeUninit;
+use embedded_graphics::geometry::Point;
+
+#[derive(Debug, Copy, Clone, Ord, PartialOrd, Eq, PartialEq)]
+pub enum InputData {
+    Touch(Point),
+    Key(u32),
+}
+
+impl InputData {
+    pub fn released(self) -> InputState {
+        InputState::Released(self)
+    }
+
+    pub fn pressed(self) -> InputState {
+        InputState::Pressed(self)
+    }
+}
+
+#[derive(Debug, Copy, Clone, Ord, PartialOrd, Eq, PartialEq)]
+pub enum InputState {
+    Released(InputData),
+    Pressed(InputData),
+}
+
+impl InputState {
+    pub fn once(self) -> BufferStatus {
+        BufferStatus::Once(self)
+    }
+
+    pub fn and_continued(self) -> BufferStatus {
+        BufferStatus::Buffered(self)
+    }
+}
+
+#[derive(Debug, Copy, Clone, Ord, PartialOrd, Eq, PartialEq)]
+pub enum BufferStatus {
+    Once(InputState),
+    Buffered(InputState),
+}
+
+pub struct Pointer {
+    pub(crate) driver: lvgl_sys::lv_indev_drv_t,
+    pub(crate) descriptor: Option<lvgl_sys::lv_indev_t>,
+}
+
+impl Pointer {
+    pub fn new<F>(handler: F) -> Self
+    where
+        F: Fn() -> BufferStatus,
+    {
+        let driver = unsafe {
+            let mut indev_drv = MaybeUninit::uninit();
+            lvgl_sys::lv_indev_drv_init(indev_drv.as_mut_ptr());
+            let mut indev_drv = indev_drv.assume_init();
+            indev_drv.type_ = lvgl_sys::LV_INDEV_TYPE_POINTER as lvgl_sys::lv_indev_type_t;
+            indev_drv.read_cb = Some(read_input::<F>);
+            indev_drv.user_data = Box::into_raw(Box::new(handler).unwrap()) as *mut _
+                as lvgl_sys::lv_indev_drv_user_data_t;
+            indev_drv
+        };
+        Self {
+            driver,
+            descriptor: None,
+        }
+    }
+
+    pub(crate) unsafe fn set_descriptor(
+        &mut self,
+        descriptor: *mut lvgl_sys::lv_indev_t,
+    ) -> LvResult<()> {
+        // TODO: check if not null && check if `self.descriptor` is not already set!
+        self.descriptor = Some(*descriptor);
+        Ok(())
+    }
+}
+
+unsafe extern "C" fn read_input<F>(
+    indev_drv: *mut lvgl_sys::lv_indev_drv_t,
+    data: *mut lvgl_sys::lv_indev_data_t,
+) -> bool
+where
+    F: Fn() -> BufferStatus,
+{
+    // convert user data to function
+    let user_closure = &mut *((*indev_drv).user_data as *mut F);
+    // call user data
+    let info: BufferStatus = user_closure();
+    match info {
+        BufferStatus::Once(InputState::Pressed(InputData::Touch(point))) => {
+            (*data).point.x = point.x as lvgl_sys::lv_coord_t;
+            (*data).point.y = point.y as lvgl_sys::lv_coord_t;
+            (*data).state = lvgl_sys::LV_INDEV_STATE_PR as lvgl_sys::lv_indev_state_t;
+            false
+        }
+        BufferStatus::Once(InputState::Released(InputData::Touch(point))) => {
+            (*data).point.x = point.x as lvgl_sys::lv_coord_t;
+            (*data).point.y = point.y as lvgl_sys::lv_coord_t;
+            (*data).state = lvgl_sys::LV_INDEV_STATE_REL as lvgl_sys::lv_indev_state_t;
+            false
+        }
+        BufferStatus::Buffered(InputState::Pressed(InputData::Touch(point))) => {
+            (*data).point.x = point.x as lvgl_sys::lv_coord_t;
+            (*data).point.y = point.y as lvgl_sys::lv_coord_t;
+            (*data).state = lvgl_sys::LV_INDEV_STATE_PR as lvgl_sys::lv_indev_state_t;
+            true
+        }
+        BufferStatus::Buffered(InputState::Released(InputData::Touch(point))) => {
+            (*data).point.x = point.x as lvgl_sys::lv_coord_t;
+            (*data).point.y = point.y as lvgl_sys::lv_coord_t;
+            (*data).state = lvgl_sys::LV_INDEV_STATE_REL as lvgl_sys::lv_indev_state_t;
+            true
+        }
+        BufferStatus::Once(InputState::Released(InputData::Key(_))) => false,
+        BufferStatus::Once(InputState::Pressed(InputData::Key(_))) => false,
+        BufferStatus::Buffered(InputState::Released(InputData::Key(_))) => true,
+        BufferStatus::Buffered(InputState::Pressed(InputData::Key(_))) => true,
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::UI;
+    use core::marker::PhantomData;
+    use embedded_graphics::drawable::Pixel;
+    use embedded_graphics::geometry::Size;
+    use embedded_graphics::pixelcolor::PixelColor;
+    use embedded_graphics::pixelcolor::Rgb565;
+    use embedded_graphics::DrawTarget;
+
+    struct FakeDisplay<C>
+    where
+        C: PixelColor,
+    {
+        p: PhantomData<C>,
+    }
+
+    impl<C> DrawTarget<C> for FakeDisplay<C>
+    where
+        C: PixelColor,
+    {
+        type Error = ();
+
+        fn draw_pixel(&mut self, item: Pixel<C>) -> Result<(), Self::Error> {
+            Ok(())
+        }
+
+        fn size(&self) -> Size {
+            Size::new(crate::VER_RES_MAX, crate::HOR_RES_MAX)
+        }
+    }
+
+    //#[test]
+    // We cannot test right now by having instances of UI global state... :(
+    // I need to find a way to test while having global state...
+    fn pointer_input_device() -> LvResult<()> {
+        let mut ui = UI::init()?;
+
+        let disp: FakeDisplay<Rgb565> = FakeDisplay { p: PhantomData };
+
+        ui.disp_drv_register(disp)?;
+
+        fn read_touchpad_device() -> BufferStatus {
+            InputData::Touch(Point::new(120, 23)).pressed().once()
+        }
+
+        let mut touch_screen = Pointer::new(|| read_touchpad_device());
+
+        ui.indev_drv_register(&mut touch_screen)?;
+
+        Ok(())
+    }
+}

lvgl/src/lib.rs

@@ -3,6 +3,7 @@
 #[macro_use]
 extern crate bitflags;
 
+pub mod input_device;
 pub(crate) mod mem;
 mod support;
 mod ui;
@@ -13,3 +14,6 @@ pub mod widgets;
 pub use lv_core::*;
 pub use support::*;
 pub use ui::*;
+
+pub const HOR_RES_MAX: u32 = lvgl_sys::LV_HOR_RES_MAX;
+pub const VER_RES_MAX: u32 = lvgl_sys::LV_VER_RES_MAX;

lvgl/src/mem.rs

@@ -70,16 +70,17 @@ impl<T> AsMut<T> for Box<T> {
 mod test {
     use super::*;
     use core::mem::MaybeUninit;
-    use std::sync::Once;
-
-    static INIT_LVGL: Once = Once::new();
 
     fn init() {
-        INIT_LVGL.call_once(|| {
         unsafe {
             lvgl_sys::lv_init();
         };
-        });
+    }
+
+    fn teardown() {
+        unsafe {
+            lvgl_sys::lv_deinit();
+        }
     }
 
     #[test]
@@ -90,6 +91,8 @@ mod test {
         drop(v);
         let v = Box::new(10).unwrap();
         drop(v);
+
+        teardown();
     }
 
     #[test]
@@ -129,6 +132,8 @@ mod test {
             }
             assert_eq!(point.x, i);
         }
+
+        teardown();
     }
 
     fn print_mem_info() {

lvgl/src/support.rs

@@ -27,6 +27,24 @@ impl Color {
     pub fn from_raw(raw: lvgl_sys::lv_color_t) -> Self {
         Self { raw }
     }
+
+    pub fn r(&self) -> u8 {
+        unsafe {
+            lvgl_sys::_LV_COLOR_GET_R(self.raw) as u8
+        }
+    }
+
+    pub fn g(&self) -> u8 {
+        unsafe {
+            lvgl_sys::_LV_COLOR_GET_G(self.raw) as u8
+        }
+    }
+
+    pub fn b(&self) -> u8 {
+        unsafe {
+            lvgl_sys::_LV_COLOR_GET_B(self.raw) as u8
+        }
+    }
 }
 
 impl From<Color> for Rgb888 {
@@ -61,6 +79,7 @@ impl From<Color> for Rgb565 {
 ///
 /// All objects (such as Buttons/Labels/Sliders etc.) receive these generic events
 /// regardless of their type.
+#[derive(Debug, Copy, Clone, Ord, PartialOrd, Eq, PartialEq)]
 pub enum Event<T> {
     /// The object has been pressed
     Pressed,
@@ -140,6 +159,7 @@ impl<S> From<Event<S>> for lvgl_sys::lv_event_t {
 }
 
 /// These events are sent only by pointer-like input devices (E.g. mouse or touchpad)
+#[derive(Debug, Copy, Clone, Ord, PartialOrd, Eq, PartialEq)]
 pub enum PointerEvent {
     DragBegin,
     DragEnd,
@@ -231,3 +251,25 @@ impl From<Animation> for lvgl_sys::lv_anim_enable_t {
         }
     }
 }
+
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use lvgl_sys;
+
+    #[test]
+    fn color_properties_accessible() {
+        let color = Color::from_rgb((206, 51, 255));
+
+        if lvgl_sys::LV_COLOR_DEPTH == 32 {
+            assert_eq!(color.r(), 206);
+            assert_eq!(color.g(), 51);
+            assert_eq!(color.b(), 255);
+        } else if lvgl_sys::LV_COLOR_DEPTH == 16 {
+            assert_eq!(color.r(), 25);
+            assert_eq!(color.g(), 12);
+            assert_eq!(color.b(), 31);
+        }
+    }
+}

lvgl/src/ui.rs

@@ -1,3 +1,4 @@
+use crate::input_device::Pointer;
 use crate::mem::Box;
 use crate::{Color, Event, LvError, LvResult, Obj, Widget};
 use core::marker::PhantomData;
@@ -56,6 +57,26 @@ where
         }
     }
 
+    pub fn indev_drv_register(&mut self, input_device: &mut Pointer) -> LvResult<()> {
+        if self.display_data.is_none() {
+            // TODO: Better yet would be to create a display struct that one register the
+            // input device in that instance. Represents better the LVGL correct usage. Also it's
+            // inline with unrepresentable invalid states using Rust type system.
+            // ```rust
+            // let disp = ui.disp_drv_register(embed_graph_disp)?;
+            // disp.indev_drv_register(disp);
+            // ...
+            // window.update(&disp)
+            // ```
+            return Err(LvError::Uninitialized);
+        }
+        unsafe {
+            let descr = lvgl_sys::lv_indev_drv_register(&mut input_device.driver as *mut _);
+            input_device.set_descriptor(descr)?;
+        }
+        Ok(())
+    }
+
     pub fn disp_drv_register(&mut self, display: T) -> LvResult<()> {
         self.display_data = Some(DisplayUserData {
             display,