Add Caps Lock support (#30470)

Closes #21700

Release Notes:

- Added caps lock support and show a warning if the user is entering an
SSH password with Caps Lock enabled

---------

Co-authored-by: Mikayla Maki <mikayla@zed.dev>
Co-authored-by: Mikayla Maki <mikayla.c.maki@gmail.com>
Co-authored-by: 张小白 <364772080@qq.com>

crates/gpui/src/platform/windows/events.rs

@@ -1227,6 +1227,7 @@ where
 {
     let virtual_key = VIRTUAL_KEY(wparam.loword());
     let mut modifiers = current_modifiers();
+    let capslock = current_capslock();
 
     match virtual_key {
         VK_SHIFT | VK_CONTROL | VK_MENU | VK_LWIN | VK_RWIN => {
@@ -1239,6 +1240,7 @@ where
             state.last_reported_modifiers = Some(modifiers);
             Some(PlatformInput::ModifiersChanged(ModifiersChangedEvent {
                 modifiers,
+                capslock,
             }))
         }
         vkey => {
@@ -1371,6 +1373,12 @@ pub(crate) fn current_modifiers() -> Modifiers {
     }
 }
 
+#[inline]
+pub(crate) fn current_capslock() -> Capslock {
+    let on = unsafe { GetKeyState(VK_CAPITAL.0 as i32) & 1 } > 0;
+    Capslock { on: on }
+}
+
 fn get_client_area_insets(
     handle: HWND,
     is_maximized: bool,

crates/gpui/src/platform/windows/window.rs

@@ -559,6 +559,10 @@ impl PlatformWindow for WindowsWindow {
         current_modifiers()
     }
 
+    fn capslock(&self) -> Capslock {
+        current_capslock()
+    }
+
     fn set_input_handler(&mut self, input_handler: PlatformInputHandler) {
         self.0.state.borrow_mut().input_handler = Some(input_handler);
     }