Substract virtual keycode not sent in WindowEvent

[chrisduerr]

This issue was originally reported by @NickeZ in alacritty/alacritty#1010.

I've tested this with a slightly modified version of the window.rs example:
https://gist.github.com/chrisduerr/5dead96a0279592d2e320e088b611a87

The general issue is that when the Shift key and the Substract key are pressed at the same time, the WindowEvent's KeyboardInput will have None as virtual_keycode.

However reading the DeviceEvent's KeyboardInput, it will report Some(Substract) as the virtual_keycode.

To compare the two outputs directly, here's the WindowEvent output:

KeyboardInput { device_id: DeviceId(X(DeviceId(3))), input: KeyboardInput { scancode: 12, state: Released, virtual_keycode: None, modifiers: ModifiersState { shift: true, ctrl: false, alt: false, logo: false } } }

And here's the DeviceEvent output:

Key(KeyboardInput { scancode: 12, state: Released, virtual_keycode: Some(Subtract), modifiers: ModifiersState { shift: false, ctrl: false, alt: false, logo: false } })

To be it seems like the WindowEvent should also report Some(Substract) as the virtual_keycode, or report Some(Underline) at least. However not reporting any virtual_keycode seems a bit strange to me.

Simililar problems have been reported for the Key0 virtual_keycode.

[NickeZ]

It is actually a change in winit that broke this. If I revert the following changeset it works again: rust-windowing/winit@52a78d6#diff-c3f6b02da9e467b737e84b8236fa5ba2

[NickeZ]

The following changes to winit and alacritty fixes my issues. I don't know what the proper solution is though. Seems like a lot of fields will have to be added to these structs to support all keys.

diff --git a/src/events.rs b/src/events.rs
index 2947db1..3ed5b02 100644
--- a/src/events.rs
+++ b/src/events.rs
@@ -379,6 +379,7 @@ pub enum VirtualKeyCode {
     LBracket,
     LControl,
     LMenu,
+    LParen,
     LShift,
     LWin,
     Mail,
@@ -404,6 +405,7 @@ pub enum VirtualKeyCode {
     RBracket,
     RControl,
     RMenu,
+    RParen,
     RShift,
     RWin,
     Semicolon,
@@ -414,6 +416,7 @@ pub enum VirtualKeyCode {
     Sysrq,
     Tab,
     Underline,
+    Underscore,
     Unlabeled,
     VolumeDown,
     VolumeUp,
diff --git a/src/platform/linux/x11/events.rs b/src/platform/linux/x11/events.rs
index c17cfe7..76e3209 100644
--- a/src/platform/linux/x11/events.rs
+++ b/src/platform/linux/x11/events.rs
@@ -181,8 +181,8 @@ pub fn keysym_to_element(keysym: libc::c_uint) -> Option<VirtualKeyCode> {
         //ffi::XK_ampersand => events::VirtualKeyCode::Ampersand,
         ffi::XK_apostrophe => events::VirtualKeyCode::Apostrophe,
         //ffi::XK_quoteright => events::VirtualKeyCode::Quoteright,
-        //ffi::XK_parenleft => events::VirtualKeyCode::Parenleft,
-        //ffi::XK_parenright => events::VirtualKeyCode::Parenright,
+        ffi::XK_parenleft => events::VirtualKeyCode::LParen,
+        ffi::XK_parenright => events::VirtualKeyCode::RParen,
         //ffi::XK_asterisk => events::VirtualKeyCode::Asterisk,
         ffi::XK_plus => events::VirtualKeyCode::Add,
         ffi::XK_comma => events::VirtualKeyCode::Comma,
@@ -236,7 +236,7 @@ pub fn keysym_to_element(keysym: libc::c_uint) -> Option<VirtualKeyCode> {
         ffi::XK_backslash => events::VirtualKeyCode::Backslash,
         ffi::XK_bracketright => events::VirtualKeyCode::RBracket,
         //ffi::XK_asciicircum => events::VirtualKeyCode::Asciicircum,
-        //ffi::XK_underscore => events::VirtualKeyCode::Underscore,
+        ffi::XK_underscore => events::VirtualKeyCode::Underscore,
         ffi::XK_grave => events::VirtualKeyCode::Grave,
         //ffi::XK_quoteleft => events::VirtualKeyCode::Quoteleft,
         ffi::XK_a => events::VirtualKeyCode::A,

diff --git a/src/config.rs b/src/config.rs
index be96715..56c4a30 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -1841,6 +1841,7 @@ enum Key {
     LBracket,
     LControl,
     LMenu,
+    LParen,
     LShift,
     LWin,
     Mail,
@@ -1866,6 +1867,7 @@ enum Key {
     RBracket,
     RControl,
     RMenu,
+    RParen,
     RShift,
     RWin,
     Semicolon,
@@ -1876,6 +1878,7 @@ enum Key {
     Sysrq,
     Tab,
     Underline,
+    Underscore,
     Unlabeled,
     VolumeDown,
     VolumeUp,
@@ -1998,6 +2001,7 @@ impl Key {
             Key::LBracket => LBracket,
             Key::LControl => LControl,
             Key::LMenu => LMenu,
+            Key::LParen => LParen,
             Key::LShift => LShift,
             Key::LWin => LWin,
             Key::Mail => Mail,
@@ -2023,6 +2027,7 @@ impl Key {
             Key::RBracket => RBracket,
             Key::RControl => RControl,
             Key::RMenu => RMenu,
+            Key::RParen => RParen,
             Key::RShift => RShift,
             Key::RWin => RWin,
             Key::Semicolon => Semicolon,
@@ -2033,6 +2038,7 @@ impl Key {
             Key::Sysrq => Sysrq,
             Key::Tab => Tab,
             Key::Underline => Underline,
+            Key::Underscore => Underscore,
             Key::Unlabeled => Unlabeled,
             Key::VolumeDown => VolumeDown,
             Key::VolumeUp => VolumeUp,

[francesca64]

Was this ever fixed? (This also belongs on winit, obviously.)

[NickeZ]

No, I never submitted a PR because my patch doesn't solve the general problem that there are a lot of commented out keys in src/platform/linux/x11/events.rs.

[francesca64]

That problem will honestly never be fixed unless someone decides to push for more rigorous keyboard API design (rust-windowing/winit#71) which I don't see as likely to happen in the foreseeable future.

[traviscross]

This issue has been filed with winit as rust-windowing/winit#600.