feat: add keyboard layout support

programs/include/gui/desktop.hpp

@@ -13,6 +13,7 @@
 #include "gui/mtk/widgets.hpp"
 #include "gui/terminal.hpp"
 #include <Api/Syscall.hpp>
+#include <montauk/keyboard.h>
 
 namespace gui {
 
@@ -234,6 +235,12 @@ struct DesktopState {
     uint64_t thermal_last_poll;
     Rect temp_icon_rect;
 
+    // Keyboard layouts. The desktop translates hardware scan codes before
+    // dispatching events, so embedded and external apps see the same layout.
+    montauk::keyboard::State keyboard;
+    Rect keyboard_layout_rect;
+    uint64_t keyboard_last_poll;
+
     int screen_w, screen_h;
     uint32_t* background_cache;
     int background_cache_pitch;
@@ -269,5 +276,6 @@ void desktop_draw_panel(DesktopState* ds);
 void desktop_draw_window(DesktopState* ds, int idx);
 void desktop_handle_mouse(DesktopState* ds);
 void desktop_handle_keyboard(DesktopState* ds, const montauk::abi::KeyEvent& key);
+bool desktop_refresh_keyboard_layouts(DesktopState* ds, bool force);
 
 } // namespace gui

programs/include/gui/mtk/widgets.hpp

@@ -395,7 +395,7 @@ inline void text_input_delete_range(char* text, int* len, int start, int end) {
 inline bool text_input_char_allowed(char ch, TextInputCharFilter filter = nullptr,
                                     void* userdata = nullptr) {
     unsigned char u = (unsigned char)ch;
-    if (u < 0x20 || u >= 0x7F) return false;
+    if (u < 0x20 || u == 0x7F) return false;
     return filter == nullptr || filter(ch, userdata);
 }
 

programs/include/gui/widgets.hpp

@@ -240,7 +240,8 @@ struct TextBox {
                 cursor--;
                 text[text_len] = '\0';
             }
-        } else if (key.ascii >= 32 && key.ascii < 127) {
+        } else if ((unsigned char)key.ascii >= 32
+                   && (unsigned char)key.ascii != 127) {
             // Printable character
             if (text_len < 254) {
                 for (int i = text_len; i > cursor; i--) {