Simplify example

examples/button_click.rs

@@ -1,3 +1,4 @@
+use core::cell::Cell;
 use cstr_core::CString;
 use embedded_graphics::pixelcolor::Rgb565;
 use embedded_graphics::prelude::*;
@@ -8,8 +9,6 @@ use lvgl::input_device::{BufferStatus, InputData, Pointer};
 use lvgl::style::Style;
 use lvgl::widgets::{Btn, Label};
 use lvgl::{self, Align, Color, LvError, Part, State, Widget, UI};
-use std::cell::RefCell;
-use std::rc::Rc;
 use std::thread::sleep;
 use std::time::{Duration, Instant};
 
@@ -26,13 +25,11 @@ fn main() -> Result<(), LvError> {
     ui.disp_drv_register(display)?;
 
     // Initial state of input
-    let latest_touch_status: Rc<RefCell<BufferStatus>> = Rc::new(RefCell::new(
-        InputData::Touch(Point::new(0, 0)).released().once(),
-    ));
+    let latest_touch_status: Cell<BufferStatus> =
+        Cell::new(InputData::Touch(Point::new(0, 0)).released().once());
 
     // Register the input mode
-    let internal = Rc::clone(&latest_touch_status);
-    let mut touch_screen = Pointer::new(move || internal.borrow().clone());
+    let mut touch_screen = Pointer::new(|| latest_touch_status.get());
 
     ui.indev_drv_register(&mut touch_screen)?;
 
@@ -52,7 +49,7 @@ fn main() -> Result<(), LvError> {
 
     let mut btn_state = false;
     button.on_event(|mut btn, event| {
-        println!("Some event! {:?}", event);
+        println!("Button received event: {:?}", event);
         if let lvgl::Event::Clicked = event {
             if btn_state {
                 let nt = CString::new("Click me!").unwrap();
@@ -62,7 +59,6 @@ fn main() -> Result<(), LvError> {
                 btn_lbl.set_text(nt.as_c_str()).unwrap();
             }
             btn_state = !btn_state;
-            println!("Clicked! Inner..");
             btn.toggle().unwrap();
         }
     })?;

lvgl/src/input_device.rs

@@ -47,7 +47,7 @@ pub struct Pointer {
 }
 
 impl Pointer {
-    pub fn new<F>(mut handler: F) -> Self
+    pub fn new<F>(handler: F) -> Self
     where
         F: Fn() -> BufferStatus,
     {

lvgl/src/ui.rs

@@ -1,4 +1,4 @@
-use crate::input_device::{BufferStatus, Pointer};
+use crate::input_device::Pointer;
 use crate::mem::Box;
 use crate::{Color, Event, LvError, LvResult, Obj, Widget};
 use core::marker::PhantomData;