Add windows support for modifiers

native/libwinbridge/bridge.cpp

@@ -17,11 +17,11 @@ HWND window;
 
 const wchar_t* const winclass = L"Espanso";
 
-keypress_callback keypressCallback;
+KeypressCallback keypress_callback;
 void * interceptor_instance;
 
-void register_keypress_callback(void * self, keypress_callback callback) {
-    keypressCallback = callback;
+void register_keypress_callback(void * self, KeypressCallback callback) {
+    keypress_callback = callback;
     interceptor_instance = self;
 }
 
@@ -92,10 +92,14 @@ LRESULT CALLBACK window_worker_procedure(HWND window, unsigned int msg, WPARAM w
                     std::array<WCHAR, 4> buffer;
                     int result = ToUnicodeEx(raw->data.keyboard.VKey, raw->data.keyboard.MakeCode, lpKeyState.data(), buffer.data(), buffer.size(), 0, currentKeyboardLayout);
 
-                    // If a result is available, invoke the callback
-                    if (result >= 1) {
-                        //std::cout << buffer[0] << " " << buffer[1] << " res=" << result <<  " vk=" << raw->data.keyboard.VKey << " rsc=" << raw->data.keyboard.MakeCode << std::endl;
-                        keypressCallback(interceptor_instance, reinterpret_cast<int32_t*>(buffer.data()), buffer.size());
+                    //std::cout << result << " " << buffer[0] << " " << raw->data.keyboard.VKey << std::endl;
+
+                    // We need to call the callback in two different ways based on the type of key
+                    // The only modifier we use that has a result > 0 is the BACKSPACE, so we have to consider it.
+                    if (result >= 1 && raw->data.keyboard.VKey != VK_BACK) {
+                        keypress_callback(interceptor_instance, reinterpret_cast<int32_t*>(buffer.data()), buffer.size(), 0, raw->data.keyboard.VKey);
+                    }else{
+                        keypress_callback(interceptor_instance, nullptr, 0, 1, raw->data.keyboard.VKey);
                     }
                 }
             }

native/libwinbridge/bridge.h

@@ -8,15 +8,15 @@
  * Called when a new keypress is made, the first argument is an int array,
  * while the second is the size of the array.
  */
-typedef void (*keypress_callback)(void * self, int32_t *buffer, int32_t len);
+typedef void (*KeypressCallback)(void * self, int32_t *buffer, int32_t len, int32_t is_modifier, int32_t key_code);
 
-extern keypress_callback keypressCallback;
+extern KeypressCallback keypress_callback;
 extern void * interceptor_instance;
 
 /*
  * Register the callback that will be called when a keypress was made
  */
-extern "C" void register_keypress_callback(void *self, keypress_callback callback);
+extern "C" void register_keypress_callback(void *self, KeypressCallback callback);
 
 /*
  * Initialize the Windows worker's parameters

src/keyboard/windows.rs

@@ -1,7 +1,8 @@
 use std::thread;
 use std::sync::mpsc;
 use widestring::{U16CString};
-use crate::keyboard::KeyEvent;
+use crate::keyboard::{KeyEvent, KeyModifier};
+use crate::keyboard::KeyModifier::*;
 
 #[repr(C)]
 pub struct WindowsKeyboardInterceptor {
@@ -12,16 +13,14 @@ impl super::KeyboardInterceptor for WindowsKeyboardInterceptor {
     fn initialize(&self) {
         unsafe {
             register_keypress_callback(self,keypress_callback);
+            initialize_window();
         }
     }
 
     fn start(&self) {
-        thread::spawn(|| {
         unsafe {
-                initialize_window();
             eventloop();
         }
-        });
     }
 }
 
@@ -51,21 +50,41 @@ impl super::KeyboardSender for WindowsKeyboardSender {
 
 // Native bridge code
 
-extern fn keypress_callback(_self: *mut WindowsKeyboardInterceptor, raw_buffer: *const i32, len: i32) {
+extern fn keypress_callback(_self: *mut WindowsKeyboardInterceptor, raw_buffer: *const i32, len: i32,
+                            is_modifier: i32, key_code: i32) {
     unsafe {
+        if is_modifier == 0 {  // Char event
             // Convert the received buffer to a character
             let buffer = std::slice::from_raw_parts(raw_buffer, len as usize);
-        let r = std::char::from_u32(buffer[0] as u32).unwrap();
+            let r = std::char::from_u32(buffer[0] as u32);
 
             // Send the char through the channel
-        (*_self).sender.send(r).unwrap();
+            if let Some(c) = r {
+                (*_self).sender.send(KeyEvent::Char(c)).unwrap();
+            }
+        }else{  // Modifier event
+            let modifier: Option<KeyModifier> = match key_code {
+                0x5B | 0x5C => Some(META),
+                0x10 => Some(SHIFT),
+                0x12 => Some(ALT),
+                0x11 => Some(CTRL),
+                0x08  => Some(BACKSPACE),
+                _ => None,
+            };
+
+            if let Some(modifier) = modifier {
+                (*_self).sender.send(KeyEvent::Modifier(modifier)).unwrap();
+            }
+        }
     }
 }
 
 #[allow(improper_ctypes)]
 #[link(name="winbridge", kind="static")]
 extern {
-    fn register_keypress_callback(s: *const WindowsKeyboardInterceptor, cb: extern fn(_self: *mut WindowsKeyboardInterceptor, *const i32, i32));
+    fn register_keypress_callback(s: *const WindowsKeyboardInterceptor,
+                                  cb: extern fn(_self: *mut WindowsKeyboardInterceptor, *const i32,
+                                                i32, i32, i32));
     fn initialize_window();
     fn eventloop();
     fn send_string(string: *const u16);