lvgl/src/api.rs

@@ -0,0 +1,207 @@
+use core::marker::PhantomData;
+use core::time::Duration;
+use core::sync::atomic::{AtomicBool, Ordering};
+
+// There can only be a single reference to LittlevGL library.
+static LVGL_IN_USE: AtomicBool = AtomicBool::new(false);
+
+#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Debug)]
+pub enum LvError {
+    AlreadyInUse,
+}
+
+pub struct UI {
+    // LittlevGL is not thread-safe by default.
+    _not_send: PhantomData<*const ()>
+}
+
+impl UI {
+    pub fn init() -> Result<Self, LvError> {
+        if LVGL_IN_USE.compare_and_swap(false, true, Ordering::SeqCst) == false {
+            // lvgl_sys::lv_init();
+            Ok(Self {
+                _not_send: PhantomData,
+            })
+        } else {
+            Err(LvError::AlreadyInUse)
+        }
+    }
+
+    pub fn disp_drv_register(&mut self, _display: &mut DisplayDriver) {
+        // register it
+        // lvgl_sys::lv_disp_drv_register(&mut disp_drv);
+    }
+
+    pub fn tick_inc(&mut self, _tick_period: Duration) {
+        // lvgl_sys::lv_tick_inc(tick_period);
+    }
+
+    pub fn task_handler(&mut self) {
+        // lvgl_sys::lv_task_handler();
+    }
+}
+
+pub struct DisplayDriver {
+    refresh_lines: u32,
+    current_screen: Screen,
+}
+
+impl DisplayDriver {
+    pub fn new(refresh_lines: u32) -> Self {
+        Self{ refresh_lines, current_screen: Screen::new() }
+    }
+
+    // Ensure cannot delete the current loaded screen
+    pub fn load_scr(&mut self, screen: Screen) {
+        self.current_screen = screen;
+    }
+
+    pub fn scr_act(&mut self) -> &mut Screen {
+        &mut self.current_screen
+    }
+}
+
+pub trait LvObject {
+    fn label_create(&self) -> Label where Self: Sized {
+        Label{ parent: self }
+    }
+
+    fn btn_create<F>(&self) -> Button<F> where Self: Sized, F: FnMut() {
+        Button{ parent: self, event_callback: None }
+    }
+}
+
+pub struct Screen {
+    _not_send: PhantomData<*const ()>
+}
+
+impl Screen {
+    pub fn new() -> Self {
+        Self { _not_send: PhantomData }
+    }
+}
+
+impl LvObject for Screen {}
+
+pub struct Label<'a> {
+    parent: &'a dyn LvObject,
+}
+
+impl<'a> Label<'a> {
+    pub fn set_text(&mut self, _text: &str) {
+        // set text call to unsafe...
+    }
+}
+
+impl<'a> LvObject for Label<'a> {}
+
+pub struct Button<'a, F> where F: FnMut() {
+    parent: &'a dyn LvObject,
+    event_callback: Option<F>,
+}
+
+impl<'a, F> Button<'a, F> where F: FnMut() {
+    pub fn on_event(&mut self, callback: F) {
+        // add callback
+        self.event_callback = Some(callback);
+    }
+}
+
+impl<'a, F> LvObject for Button<'a, F> where F: FnMut() {}
+
+
+#[cfg(test)]
+mod test {
+    use crate::api::{UI, DisplayDriver, LvObject};
+    use core::time::Duration;
+    use std::sync::{Mutex, Arc};
+
+    #[test]
+    fn basic_usage() {
+        let mut ui = UI::init().unwrap();
+
+        let refresh_lines = 10;
+        let mut display = DisplayDriver::new(refresh_lines);
+        ui.disp_drv_register(&mut display);
+        let display = Arc::new(Mutex::new(display));
+
+        {
+            let mut disp = display.clone();
+            let mut d = disp.lock().unwrap();
+            let screen = d.scr_act();
+
+            let mut button = screen.btn_create();
+
+            let mut inner_disp = display.clone();
+            button.on_event(|| {
+                // something
+                let mut disp = inner_disp.lock().unwrap();
+                let screen = disp.scr_act();
+                let mut label = screen.label_create();
+                label.set_text("Clicked");
+            });
+
+            let mut label = button.label_create();
+            label.set_text("Click me!");
+        };
+
+        {
+            let mut disp = display.clone();
+            let mut d = disp.lock().unwrap();
+            let screen = d.scr_act();
+            let mut button2 = screen.btn_create();
+            button2.on_event(|| {
+                // else
+            });
+            let mut label2 = button2.label_create();
+            label2.set_text("Else");
+        };
+
+        ui.tick_inc(Duration::from_millis(5));
+        ui.task_handler();
+    }
+
+    #[test]
+    fn test_usage() {
+        // // can use Arc<Mutex<lvgl::App>> to share between threads
+        // let mut app = lvgl::App::init().unwrap();
+        //
+        // let disp = DisplayDriver::new();
+        // app.register_display_driver(&disp); // takes (&mut self, ...)
+        //
+        // let screen: &mut lvgl::Screen = disp.new_screen(); // takes (&mut self)
+        // disp.load_screen(&screen); // takes (&self) because it just need the ref to
+        // // the screen to load, as all the screens are already internal.
+        //
+        // let button = screen.new_button(); // takes (&self)
+        // button.on_event(|&mut app, &mut btn, ev| {
+        //     let mut label: &mut Label = app.cur_screen().new_label();
+        //     if let lvgl::Event::Clicked = ev {
+        //         btn.set_text("clicked!");
+        //     }
+        //     app.load_screen(&screen);
+        // });
+        //
+        // let mut lbl_click = button.new_label();
+        // lbl_click.set_text("Click me!");
+        //
+        //
+        // // lvgl::Timer returns reference to same internal object
+        // app.tick(Duration::from_millis(1)); // takes (&mut self)
+        //
+        // app.task_handler(); // takes (&mut self)
+        //
+        // // Multiple Displays can be instantiated
+        // // Multiple Screen's in each Display
+        // // Screen can be instantiated independently
+        // // Any specific object impl Screenable(trait) (can be used anywhere Screen is used)
+        // // To get active screen from a Display use `lv_disp_get_scr_act(disp)`
+        // let screen = disp.get_active_screen();
+        // // To set an active screen in a Display use `lv_disp_load_scr(disp, scr)`
+        // disp.load_screen(screen);
+        //
+        // let mut screen = Screen::new();
+        // let mut button = screen.add_button();
+        // let mut btn_lbl = button.create_label();
+    }
+}

lvgl/src/lib.rs

@@ -1,7 +1,11 @@
-#![no_std]
+// #![no_std]
 
 pub mod display;
 mod objx;
 
+mod api;
+
 pub use display::DisplayDriver;
 pub use objx::*;
+
+