Add button change event handler

Cargo.toml

@@ -38,10 +38,6 @@ lto = true
 strip = "debuginfo"
 opt-level = "z"
 
-[[example]]
-name = "screen"
-required-features = ["screen"]
-
 [package.metadata.docs.rs]
 features = ["ev3", "screen"]
 rustdoc-args = ["--cfg", "docsrs"]
@@ -50,6 +46,10 @@ rustdoc-args = ["--cfg", "docsrs"]
 name = "buttons"
 required-features = ["ev3"]
 
+[[example]]
+name = "screen"
+required-features = ["screen"]
+
 [[test]]
 name = "ev3"
 required-features = ["ev3"]

docker/Dockerfile

@@ -3,7 +3,6 @@ FROM debian:trixie-slim
 RUN dpkg --add-architecture armel
 
 RUN apt-get update
-# RUN sed -i "s#deb http://security.debian.org/debian-security stretch/updates main#deb http://deb.debian.org/debian-security stretch/updates main#g" /etc/apt/sources.list
 
 RUN apt-get --yes install curl cmake pkg-config clang g++ g++-arm-linux-gnueabi crossbuild-essential-armel libssl-dev libssl-dev:armel libclang-dev \
     && rm -rf /var/lib/apt/lists/*

examples/button_handlers.rs

@@ -0,0 +1,26 @@
+extern crate ev3dev_lang_rust;
+
+use ev3dev_lang_rust::{Button, Ev3Result};
+
+fn main() -> Ev3Result<()> {
+    let mut button = Button::new()?;
+
+    button.set_change_handler(|pressed_buttons| println!("Pressed buttons: {:?}", pressed_buttons));
+
+    button.set_up_handler(|is_pressed| println!("Button 'up' is pressed: {}", is_pressed));
+    button.set_down_handler(|is_pressed| println!("Button 'down' is pressed: {}", is_pressed));
+    button.set_left_handler(|is_pressed| println!("Button 'left' is pressed: {}", is_pressed));
+    button.set_right_handler(|is_pressed| println!("Button 'right' is pressed: {}", is_pressed));
+    button.set_enter_handler(|is_pressed| println!("Button 'enter' is pressed: {}", is_pressed));
+    button.set_backspace_handler(|is_pressed| {
+        println!("Button 'backspace' is pressed: {}", is_pressed)
+    });
+    button.set_backspace_handler(|is_pressed| {
+        println!("Button 'backspace' is pressed: {}", is_pressed)
+    });
+
+    loop {
+        button.process();
+        std::thread::sleep(std::time::Duration::from_millis(100));
+    }
+}

src/ev3.rs

@@ -203,6 +203,7 @@ struct ButtonMapEntry {
     pub key_code: u32,
 }
 
+type ButtonChangeHandler = Box<dyn Fn(HashSet<String>)>;
 type ButtonHandler = Box<dyn Fn(bool)>;
 
 /// This implementation depends on the availability of the EVIOCGKEY ioctl
@@ -211,6 +212,7 @@ type ButtonHandler = Box<dyn Fn(bool)>;
 struct ButtonFileHandler {
     file_map: HashMap<String, FileMapEntry>,
     button_map: HashMap<String, ButtonMapEntry>,
+    button_change_handler: Option<ButtonChangeHandler>,
     button_handlers: HashMap<String, ButtonHandler>,
     pressed_buttons: HashSet<String>,
 }
@@ -220,6 +222,10 @@ impl std::fmt::Debug for ButtonFileHandler {
         f.debug_struct("ButtonFileHandler")
             .field("file_map", &self.file_map)
             .field("button_map", &self.button_map)
+            .field(
+                "button_change_handler",
+                &self.button_change_handler.is_some(),
+            )
             .field("button_handlers", &self.button_map.keys())
             .field("pressed_buttons", &self.pressed_buttons)
             .finish()
@@ -232,6 +238,7 @@ impl ButtonFileHandler {
         ButtonFileHandler {
             file_map: HashMap::new(),
             button_map: HashMap::new(),
+            button_change_handler: None,
             button_handlers: HashMap::new(),
             pressed_buttons: HashSet::new(),
         }
@@ -258,15 +265,20 @@ impl ButtonFileHandler {
         Ok(())
     }
 
-    /// Sets an event listener for the given button.
-    fn set_button_listener(&mut self, name: &str, listener: Option<ButtonHandler>) {
-        if let Some(listener) = listener {
+    /// Sets an event handler for the given button.
+    fn set_button_handler(&mut self, name: &str, handler: Option<ButtonHandler>) {
+        if let Some(listener) = handler {
             self.button_handlers.insert(name.to_owned(), listener);
         } else {
             self.button_handlers.remove(name);
         }
     }
 
+    /// Sets an event handler for any button state change.
+    fn set_button_change_handler(&mut self, handler: Option<ButtonChangeHandler>) {
+        self.button_change_handler = handler;
+    }
+
     /// Gets a copy of the currently pressed buttons.
     fn get_pressed_buttons(&self) -> HashSet<String> {
         self.pressed_buttons.clone()
@@ -309,11 +321,20 @@ impl ButtonFileHandler {
         }
 
         let difference = old_pressed_buttons.symmetric_difference(&self.pressed_buttons);
+
+        let mut difference_count = 0;
         for button in difference {
+            difference_count += 1;
             if self.button_handlers.contains_key(button) {
                 self.button_handlers[button](self.get_button_state(button));
             }
         }
+
+        if difference_count > 0 {
+            if let Some(ref handler) = self.button_change_handler {
+                handler(self.get_pressed_buttons());
+            }
+        }
     }
 }
 
@@ -329,10 +350,10 @@ impl ButtonFileHandler {
 /// use std::time::Duration;
 ///
 /// # fn main() -> ev3dev_lang_rust::Ev3Result<()> {
-/// let button = Button::new()?;
+/// let mut button = Button::new()?;
 ///
 /// button.set_down_handler(|is_pressed| {
-///     println("Is 'down' pressed: {is_pressed}");
+///     println!("Is 'down' pressed: {is_pressed}");
 /// });
 ///
 /// loop {
@@ -379,10 +400,10 @@ impl Button {
     /// use std::time::Duration;
     ///
     /// # fn main() -> ev3dev_lang_rust::Ev3Result<()> {
-    /// let button = Button::new()?;
+    /// let mut button = Button::new()?;
     ///
     /// button.set_down_handler(|is_pressed| {
-    ///     println("Is 'down' pressed: {is_pressed}");
+    ///     println!("Is 'down' pressed: {is_pressed}");
     /// });
     ///
     /// loop {
@@ -420,6 +441,40 @@ impl Button {
         self.button_handler.borrow().get_pressed_buttons()
     }
 
+    /// Set an event handler, that is called by `process()` if any button state changes.
+    /// Has a set of all pressed buttons as parameter.
+    ///
+    /// ```no_run
+    /// use ev3dev_lang_rust::Button;
+    /// use std::thread;
+    /// use std::time::Duration;
+    ///
+    /// # fn main() -> ev3dev_lang_rust::Ev3Result<()> {
+    /// let mut button = Button::new()?;
+    ///
+    /// button.set_change_handler(|pressed_buttons| {
+    ///     println!("pressed buttons: {:?}", pressed_buttons);
+    /// });
+    ///
+    /// loop {
+    ///     button.process();
+    ///     thread::sleep(Duration::from_millis(100));
+    /// }
+    /// # }
+    /// ```
+    pub fn set_change_handler(&mut self, handler: impl Fn(HashSet<String>) + 'static) {
+        self.button_handler
+            .borrow_mut()
+            .set_button_change_handler(Some(Box::new(handler)))
+    }
+
+    /// Removes the change event handler.
+    pub fn remove_change_handler(&mut self) {
+        self.button_handler
+            .borrow_mut()
+            .set_button_change_handler(None)
+    }
+
     ev3_button_functions!(up);
     ev3_button_functions!(down);
     ev3_button_functions!(left);

src/ev3_button_functions.rs

@@ -14,26 +14,26 @@ macro_rules! ev3_button_functions {
             #[doc = ""]
             #[doc = "loop {"]
             #[doc = "    button.process();"]
-            #[doc = "    println(\"Is '" $button_name "' pressed: {}\", button.is_" $button_name "());"]
+            #[doc = "    println!(\"Is '" $button_name "' pressed: {}\", button.is_" $button_name "());"]
             #[doc = "    thread::sleep(Duration::from_millis(100));"]
             #[doc = "}"]
             #[doc = "# }"]
             #[doc = "```"]
             pub fn [<is_ $button_name>] (&self) -> bool {
-                self.button_handler.borrow().get_button_state("$button_name")
+                self.button_handler.borrow().get_button_state(stringify!($button_name))
             }
 
-            #[doc = "Set an event handler for changes in the pressed state of the `" $button_name "` button."]
+            #[doc = "Set an event handler, that is called by `process()` if the pressed state of the `" $button_name "` button changes."]
             #[doc = "```no_run"]
             #[doc = "use ev3dev_lang_rust::Button;"]
             #[doc = "use std::thread;"]
             #[doc = "use std::time::Duration;"]
             #[doc = ""]
             #[doc = "# fn main() -> ev3dev_lang_rust::Ev3Result<()> {"]
-            #[doc = "let button = Button::new()?;"]
+            #[doc = "let mut button = Button::new()?;"]
             #[doc = ""]
             #[doc = "button.set_" $button_name "_handler(|is_pressed| {"]
-            #[doc = "    println(\"Is '" $button_name "' pressed: {is_pressed}\");"]
+            #[doc = "    println!(\"Is '" $button_name "' pressed: {}\", is_pressed);"]
             #[doc = "});"]
             #[doc = ""]
             #[doc = "loop {"]
@@ -45,14 +45,14 @@ macro_rules! ev3_button_functions {
             pub fn [<set_ $button_name _handler>](&mut self, handler: impl Fn(bool) + 'static) {
                 self.button_handler
                     .borrow_mut()
-                    .set_button_listener("$button_name", Some(Box::new(handler)));
+                    .set_button_handler(stringify!($button_name), Some(Box::new(handler)));
             }
 
             #[doc = "Removes the event handler of the `" $button_name "` button."]
             pub fn [<remove_ $button_name _handler>](&mut self) {
                 self.button_handler
                     .borrow_mut()
-                    .set_button_listener("$button_name", None);
+                    .set_button_handler(stringify!($button_name), None);
             }
         }
     };