examples/button_click.rs

@@ -4,9 +4,12 @@ use embedded_graphics::prelude::*;
 use embedded_graphics_simulator::{
     OutputSettingsBuilder, SimulatorDisplay, SimulatorEvent, Window,
 };
+use lvgl::input_device::{InputData, Pointer};
 use lvgl::style::Style;
 use lvgl::widgets::{Btn, Label};
-use lvgl::{self, Align, Color, Event, LvError, Part, State, Widget, UI};
+use lvgl::{self, Align, Color, LvError, Part, State, Widget, UI};
+use std::cell::RefCell;
+use std::rc::Rc;
 use std::time::Instant;
 
 fn main() -> Result<(), LvError> {
@@ -21,6 +24,22 @@ fn main() -> Result<(), LvError> {
     // Implement and register your display:
     ui.disp_drv_register(display)?;
 
+    // Register the input mode
+    let latest_touch_point: Rc<RefCell<Option<Point>>> = Rc::new(RefCell::new(None));
+    let internal = Rc::clone(&latest_touch_point);
+    let mut touch_screen = Pointer::new(move || {
+        let info = internal.borrow().clone();
+        if info.is_some() {
+            let point = info.unwrap();
+            println!("Changed to {:?}", point);
+            Some(InputData::Touch(point).pressed().once())
+        } else {
+            None
+        }
+    });
+
+    ui.indev_drv_register(&mut touch_screen)?;
+
     // Create screen and widgets
     let mut screen = ui.scr_act()?;
 
@@ -64,7 +83,7 @@ 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.borrow_mut().replace(point);
                 }
                 SimulatorEvent::Quit => break 'running,
                 _ => {}

lvgl/src/input_device.rs

@@ -0,0 +1,185 @@
+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::Empty(self)
+    }
+
+    pub fn and_continued(self) -> BufferStatus {
+        BufferStatus::Buffered(self)
+    }
+}
+
+#[derive(Debug, Copy, Clone, Ord, PartialOrd, Eq, PartialEq)]
+pub enum BufferStatus {
+    Empty(InputState),
+    Buffered(InputState),
+}
+
+pub struct Pointer<F>
+where
+    F: Fn() -> Option<BufferStatus>,
+{
+    pub(crate) driver: lvgl_sys::lv_indev_drv_t,
+    pub(crate) descriptor: Option<lvgl_sys::lv_indev_t>,
+    handler: F,
+}
+
+impl<F> Pointer<F>
+where
+    F: Fn() -> Option<BufferStatus>,
+{
+    pub fn new(mut handler: F) -> Self {
+        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 = &mut handler as *mut _ as lvgl_sys::lv_indev_drv_user_data_t;
+            indev_drv
+        };
+        Self {
+            handler,
+            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() -> Option<BufferStatus>,
+{
+    let mut data = *data;
+    // convert user data to function
+    let user_closure = &mut *((*indev_drv).user_data as *mut F);
+    // call user data
+    let result: Option<BufferStatus> = user_closure();
+    return if let Some(info) = result {
+        match info {
+            BufferStatus::Empty(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::Empty(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::Empty(InputState::Released(InputData::Key(_))) => false,
+            BufferStatus::Empty(InputState::Pressed(InputData::Key(_))) => false,
+            BufferStatus::Buffered(InputState::Released(InputData::Key(_))) => true,
+            BufferStatus::Buffered(InputState::Pressed(InputData::Key(_))) => true,
+        }
+    } else {
+        false
+    };
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::{Color, 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 + From<Color>,
+    {
+        p: PhantomData<C>,
+    }
+
+    impl<C> DrawTarget<C> for FakeDisplay<C>
+    where
+        C: PixelColor + From<Color>,
+    {
+        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() -> Point {
+            Point::new(120, 23)
+        }
+
+        let mut touch_screen =
+            Pointer::new(|| InputData::Touch(read_touchpad_device()).pressed().once());
+
+        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;

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 {
-            unsafe {
+            lvgl_sys::lv_init();
-                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/ui.rs

@@ -1,3 +1,4 @@
+use crate::input_device::{BufferStatus, Pointer};
 use crate::mem::Box;
 use crate::{Color, Event, LvError, LvResult, Obj, Widget};
 use core::marker::PhantomData;
@@ -56,6 +57,17 @@ where
         }
     }
 
+    pub fn indev_drv_register<F>(&mut self, input_device: &mut Pointer<F>) -> LvResult<()>
+    where
+        F: Fn() -> Option<BufferStatus>,
+    {
+        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,