Merge pull request #262 from rtbo/is_from_send_event

add API BaseEvent::is_from_send_event and xkb_keyboard_mouse_event example

Cargo.toml

@@ -137,3 +137,7 @@ name = "screenshot"
 [[example]]
 name = "xkb_init"
 required-features = ["xkb"]
+
+[[example]]
+name = "xkb_keyboard_mouse_event"
+required-features = ["xkb"]

examples/xkb_keyboard_mouse_event.rs

@@ -0,0 +1,231 @@
+use xcb::{x, xkb, BaseEvent, Xid};
+
+fn setup_xcb() -> xcb::Result<xcb::Connection> {
+    let (conn, screen_num) =
+        xcb::Connection::connect_with_extensions(None, &[xcb::Extension::Xkb], &[])?;
+
+    // we need at least xkb-1.0 to be available on client machine
+    {
+        let xkb_ver = conn.wait_for_reply(conn.send_request(&xkb::UseExtension {
+            wanted_major: 1,
+            wanted_minor: 0,
+        }))?;
+
+        assert!(xkb_ver.supported(), "xkb-1.0 support is required");
+    }
+
+    // we now select what events we want to receive
+    // such as map change, keyboard hotplug ...
+    // note that key strokes are given directly by
+    // the x::Event::KeyPress, not by xkb
+    {
+        let events = xkb::EventType::NEW_KEYBOARD_NOTIFY
+            | xkb::EventType::MAP_NOTIFY
+            | xkb::EventType::STATE_NOTIFY;
+
+        let map_parts = xkb::MapPart::KEY_TYPES
+            | xkb::MapPart::KEY_SYMS
+            | xkb::MapPart::MODIFIER_MAP
+            | xkb::MapPart::EXPLICIT_COMPONENTS
+            | xkb::MapPart::KEY_ACTIONS
+            | xkb::MapPart::KEY_BEHAVIORS
+            | xkb::MapPart::VIRTUAL_MODS
+            | xkb::MapPart::VIRTUAL_MOD_MAP;
+
+        let cookie = conn.send_request_checked(&xkb::SelectEvents {
+            device_spec: xkb::Id::UseCoreKbd as xkb::DeviceSpec,
+            affect_which: events,
+            clear: xkb::EventType::empty(),
+            select_all: events,
+            affect_map: map_parts,
+            map: map_parts,
+            details: &[],
+        });
+
+        conn.check_request(cookie)?;
+    }
+
+    // proceed with window creation
+    {
+        let setup = conn.get_setup();
+        let screen = setup.roots().nth(screen_num as usize).unwrap();
+        let window: x::Window = conn.generate_id();
+
+        conn.send_request(&x::CreateWindow {
+            depth: x::COPY_FROM_PARENT as u8,
+            wid: window,
+            parent: screen.root(),
+            x: 0,
+            y: 0,
+            width: 500,
+            height: 500,
+            border_width: 10,
+            class: x::WindowClass::InputOutput,
+            visual: screen.root_visual(),
+            value_list: &[
+                x::Cw::BackPixel(screen.white_pixel()),
+                // Register to receive keyboard-related events for this window
+                x::Cw::EventMask(
+                    x::EventMask::FOCUS_CHANGE
+                        | x::EventMask::KEY_PRESS
+                        | x::EventMask::KEY_RELEASE
+                        | x::EventMask::BUTTON_PRESS
+                        | x::EventMask::BUTTON_RELEASE
+                        | x::EventMask::BUTTON_MOTION,
+                ),
+            ],
+        });
+        // Make the window visible
+        conn.send_request(&x::MapWindow { window });
+
+        // Set window title
+        let title = "XCB Keyboard Event Tester";
+        conn.send_request(&x::ChangeProperty {
+            mode: x::PropMode::Replace,
+            window,
+            property: x::ATOM_WM_NAME,
+            r#type: x::ATOM_STRING,
+            data: title.as_bytes(),
+        });
+
+        conn.flush()?;
+    }
+    Ok(conn)
+}
+
+fn print_key_event(
+    key_event: &x::KeyPressEvent,
+    is_pressed: bool,
+    last_xkb_state_event: Option<&xkb::StateNotifyEvent>,
+) {
+    let winid = key_event.event().resource_id();
+    let keycode = key_event.detail();
+    let event_mods = key_event.state();
+    let down_up = if is_pressed { "DOWN" } else { "UP" };
+    println!("Window {winid:#x} received key {down_up}");
+    if key_event.is_from_send_event() {
+        println!("  (event is synthetic, simulated)");
+    }
+    println!("  Keycode: {keycode}");
+    println!("  Event modifiers: {event_mods:#?}");
+
+    if let Some(xkb_state) = last_xkb_state_event {
+        print_xkb_state(&xkb_state);
+    }
+}
+
+fn print_button_event(
+    button_event: &x::ButtonPressEvent,
+    is_pressed: bool,
+    last_xkb_state_event: Option<&xkb::StateNotifyEvent>,
+) {
+    let winid = button_event.event().resource_id();
+    let button = button_event.detail();
+    let event_mods = button_event.state();
+    let down_up = if is_pressed { "DOWN" } else { "UP" };
+    println!("Window {winid:#x} received mouse button {down_up}");
+    if button_event.is_from_send_event() {
+        println!("  (event is synthetic, simulated)");
+    }
+    println!("  Button: {button:#?}");
+    println!("  Event modifiers: {event_mods:#?}");
+
+    if let Some(xkb_state) = last_xkb_state_event {
+        print_xkb_state(&xkb_state);
+    }
+}
+
+fn print_xkb_state(xkb_state: &xkb::StateNotifyEvent) {
+    let has_mods = !xkb_state.mods().is_empty();
+    let has_btns = !xkb_state.ptr_btn_state().is_empty();
+    if has_mods || has_btns {
+        println!("  XKB last state:");
+        println!("    Change: {changed:#?}", changed = xkb_state.changed());
+        if has_mods {
+            println!("    Modifiers: {mods:#?}", mods = xkb_state.mods());
+        }
+        if has_btns {
+            println!("    Buttons: {btns:#?}", btns = xkb_state.ptr_btn_state());
+        }
+    }
+}
+
+fn main() -> xcb::Result<()> {
+    let conn = setup_xcb()?;
+
+    println!();
+    println!(">>> XCB & XKB initialized, watching events now");
+    println!(">>> Press `Escape` to quit");
+
+    // proceed with the event loop
+    let mut last_xkb_state_event = None;
+    let mut last_event_is_packed = false;
+    while let Ok(event) = conn.wait_for_event() {
+        // dbg!(&event); // debug event details
+
+        // decide when to add a blank line before the event
+        // used to pack motion events together (without blank line) as they can generate a lot of events
+        match (last_event_is_packed, &event) {
+            (false, xcb::Event::X(x::Event::MotionNotify(_))) => {
+                println!();
+                last_event_is_packed = false;
+            }
+            (true, xcb::Event::X(x::Event::MotionNotify(_))) => {}
+            (_, xcb::Event::Xkb(xkb::Event::StateNotify(_))) => {}
+            _ => {
+                println!();
+                last_event_is_packed = false;
+            }
+        }
+
+        match event {
+            xcb::Event::X(x::Event::FocusIn(focus_event)) => {
+                let winid = focus_event.event().resource_id();
+                println!("Window {winid:#x} got input focus");
+            }
+            xcb::Event::X(x::Event::FocusOut(focus_event)) => {
+                let winid = focus_event.event().resource_id();
+                println!("Window {winid:#x} lost input focus");
+            }
+            xcb::Event::X(x::Event::KeyPress(key_event)) => {
+                print_key_event(&key_event, true, last_xkb_state_event.as_ref());
+                if key_event.detail() == 9 {
+                    println!();
+                    println!("`Escape` was pressed, exiting..");
+                    break;
+                }
+            }
+            xcb::Event::X(x::Event::KeyRelease(key_event)) => {
+                print_key_event(&key_event, false, last_xkb_state_event.as_ref());
+            }
+            xcb::Event::X(x::Event::ButtonPress(button_event)) => {
+                print_button_event(&button_event, true, last_xkb_state_event.as_ref());
+            }
+            xcb::Event::X(x::Event::ButtonRelease(button_event)) => {
+                print_button_event(&button_event, false, last_xkb_state_event.as_ref());
+            }
+            xcb::Event::X(x::Event::MotionNotify(motion_event)) => {
+                let winid = motion_event.event().resource_id();
+                let button = motion_event.state();
+                // Single line info to use less space, as motions generates a lot of events
+                print!("Window {winid:#x} received mouse button ({button:#?}) movement: ");
+                println!(
+                    "(root x={root_x} y={root_y}) | (win x={win_x} y={win_y})",
+                    root_x = motion_event.root_x(),
+                    root_y = motion_event.root_y(),
+                    win_x = motion_event.event_x(),
+                    win_y = motion_event.event_y(),
+                );
+                last_event_is_packed = true;
+            }
+            xcb::Event::Xkb(xkb::Event::StateNotify(state_event)) => {
+                last_xkb_state_event = Some(state_event);
+            }
+            _ => {
+                dbg!(event); // debug unhandled event details
+            }
+        }
+    }
+
+    Ok(())
+}

src/base.rs

@@ -81,6 +81,14 @@ pub trait BaseEvent: Raw<xcb_generic_event_t> {
 
     /// The number associated to this event
     const NUMBER: u32;
+
+    /// Check whether this event was emitted by the SendEvent request
+    /// See `[crate::x::SendEvent]`.
+    fn is_from_send_event(&self) -> bool {
+        let ev = self.as_raw();
+        let response_type = unsafe { (*ev).response_type };
+        (response_type & 0x80) != 0
+    }
 }
 
 /// A trait for GE_GENERIC events