Bar widget (#12)

* Implement simple bar widget

* Make it easier to create new examples

* Add bar example

* Add README to examples

* Remove unnecessary imports

Cargo.toml

@@ -2,5 +2,5 @@
 members = [
     "lvgl",
     "lvgl-sys",
-    "examples/demo",
+    "examples"
 ]

README.md

@@ -54,4 +54,10 @@ That is required, so we can safely provide Rust pointers through FFI. For that r
 
 ## Running the demo
 
-[This project contains an example that can run in a desktop simulator.](./examples/demo)
+[This project contains examples that can run in a desktop simulator.](./examples)
+
+To run the `demo` example:
+
+```shell
+$ DEP_LV_CONFIG_PATH=`pwd`/examples/include cargo run --example demo
+```

examples/Cargo.toml

@@ -0,0 +1,20 @@
+[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"
+embedded-graphics-simulator = "0.2.0"
+
+[[example]]
+name = "demo"
+path = "demo.rs"
+
+[[example]]
+name = "bar"
+path = "bar.rs"

examples/README.md

@@ -0,0 +1,8 @@
+## Examples of how to use various  `lvgl-rs` widgets/components
+
+All examples can be executed using:
+```shell
+cargo run --example <name>
+```
+
+The `DEP_LV_CONFIG_PATH` environment variable is necessary, as explained in the [README](../README.md).

examples/bar.rs

@@ -0,0 +1,82 @@
+use embedded_graphics::pixelcolor::Rgb565;
+use embedded_graphics::prelude::*;
+use embedded_graphics_simulator::{
+    OutputSettingsBuilder, SimulatorDisplay, SimulatorEvent, Window,
+};
+use lvgl::{self, widgets::Bar, Align, Color, DisplayDriver, Object, Style, UI};
+use lvgl_sys;
+use std::sync::{mpsc, Arc, Mutex};
+use std::thread::sleep;
+use std::time::Duration;
+
+fn main() -> Result<(), String> {
+    let mut display: SimulatorDisplay<Rgb565> = SimulatorDisplay::new(Size::new(
+        lvgl_sys::LV_HOR_RES_MAX,
+        lvgl_sys::LV_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().unwrap();
+
+    // Implement and register your display:
+    let display_driver = DisplayDriver::new(&mut display);
+    ui.disp_drv_register(display_driver);
+
+    // Create screen and widgets
+    let mut screen = ui.scr_act();
+
+    let mut screen_style = Style::new();
+    screen_style.set_body_main_color(Color::from_rgb((0, 0, 0)));
+    screen_style.set_body_grad_color(Color::from_rgb((0, 0, 0)));
+    screen.set_style(screen_style);
+
+    // Create the bar object
+    let mut bar = Bar::new(&mut screen);
+    bar.set_size(50, 175);
+    bar.set_align(&mut screen, Align::Center, 0, 0);
+    bar.set_range(0, 100);
+    bar.set_value(0);
+
+    let threaded_ui = Arc::new(Mutex::new(ui));
+
+    let (stop_ch, read_ch) = mpsc::channel();
+    let closure_ui = threaded_ui.clone();
+    let tick_thr = std::thread::spawn(move || loop {
+        let period = Duration::from_millis(5);
+        closure_ui.lock().unwrap().tick_inc(period);
+
+        sleep(period);
+        if read_ch.try_recv().is_ok() {
+            break;
+        }
+    });
+
+    let mut i = 0;
+    'running: loop {
+        if i > 100 {
+            i = 0;
+        }
+        bar.set_value(i);
+        i += 1;
+
+        sleep(Duration::from_millis(25));
+
+        threaded_ui.lock().unwrap().task_handler();
+
+        window.update(&display);
+
+        for event in window.events() {
+            match event {
+                SimulatorEvent::Quit => break 'running,
+                _ => {}
+            }
+        }
+    }
+
+    stop_ch.send(true).unwrap();
+    tick_thr.join().unwrap();
+
+    Ok(())
+}

examples/demo/README.md

@@ -1,12 +0,0 @@
-From base of the repository, install LVGL git submodule.
-
-```
-git submodule update --init
-```
-
-Run this demo:
-
-```
-cd examples/demo/
-DEP_LV_CONFIG_PATH=./include cargo run
-```

lvgl/src/lib.rs

@@ -2,11 +2,12 @@
 
 extern crate alloc;
 
-mod global;
 mod display;
+mod global;
+#[macro_use]
 mod support;
-mod widgets;
+pub mod widgets;
 
-pub use global::{UI, LvError};
 pub use display::DisplayDriver;
+pub use global::{LvError, UI};
 pub use support::*;

lvgl/src/support.rs

@@ -111,20 +111,23 @@ impl Object for ObjectX {
 macro_rules! define_object {
     ($item:ident) => {
         pub struct $item {
-            core: ObjectX,
+            core: $crate::support::ObjectX,
         }
 
-        impl NativeObject for $item {
-            fn raw(&self) -> ptr::NonNull<lvgl_sys::lv_obj_t> {
+        impl $crate::support::NativeObject for $item {
+            fn raw(&self) -> core::ptr::NonNull<lvgl_sys::lv_obj_t> {
                 self.core.raw()
             }
         }
 
-        impl Object for $item {
-            fn set_style(&mut self, style: Style) {
+        impl $crate::support::Object for $item {
+            fn set_style(&mut self, style: $crate::support::Style) {
                 unsafe {
-                    let boxed = Box::new(style.raw);
-                    lvgl_sys::lv_obj_set_style(self.raw().as_mut(), Box::into_raw(boxed));
+                    let boxed = alloc::boxed::Box::new(style.raw);
+                    lvgl_sys::lv_obj_set_style(
+                        self.raw().as_mut(),
+                        alloc::boxed::Box::into_raw(boxed),
+                    );
                 };
             }
         }
@@ -200,7 +203,7 @@ pub enum Themes {
 }
 
 pub struct Style {
-    raw: lvgl_sys::lv_style_t,
+    pub(crate) raw: lvgl_sys::lv_style_t,
 }
 
 impl Style {

lvgl/src/widgets/bar.rs

@@ -0,0 +1,33 @@
+use crate::support::{NativeObject, ObjectX};
+use core::ptr;
+use lvgl_sys;
+
+define_object!(Bar);
+
+impl Bar {
+    pub fn new<C>(parent: &mut C) -> Self
+    where
+        C: NativeObject,
+    {
+        let raw = unsafe {
+            let ptr = lvgl_sys::lv_bar_create(parent.raw().as_mut(), ptr::null_mut());
+            ptr::NonNull::new_unchecked(ptr)
+        };
+        let core = ObjectX::from_raw(raw);
+        Self { core }
+    }
+
+    /// Set minimum and the maximum values of the bar
+    pub fn set_range(&mut self, min: i16, max: i16) {
+        unsafe {
+            lvgl_sys::lv_bar_set_range(self.core.raw().as_mut(), min, max);
+        }
+    }
+
+    /// Set the value of the bar
+    pub fn set_value(&mut self, value: i16) {
+        unsafe {
+            lvgl_sys::lv_bar_set_value(self.core.raw().as_mut(), value, 0);
+        }
+    }
+}

lvgl/src/widgets/mod.rs

@@ -0,0 +1,3 @@
+mod bar;
+
+pub use self::bar::Bar;