ui: Handle main window refresh independently

- Cleanup various dead code and minor restructure for clarity
- Separate host and guest updates
- Fix freezes while moving or resizing the main window on Windows by
  registering event watch callback

include/ui/xemu-display.h

@@ -1,32 +0,0 @@
-#ifndef XEMU_DISPLAY_H
-#define XEMU_DISPLAY_H
-
-/* Avoid compiler warning because macro is redefined in SDL_syswm.h. */
-#undef WIN32_LEAN_AND_MEAN
-
-#include <SDL3/SDL.h>
-
-#include "ui/kbd-state.h"
-
-struct xemu_console {
-    DisplayChangeListener dcl;
-    DisplaySurface *surface;
-    DisplayOptions *opts;
-    SDL_Texture *texture;
-    SDL_Window *real_window;
-    SDL_Renderer *real_renderer;
-    int idx;
-    int last_vm_running; /* per console for caption reasons */
-    int x, y, w, h;
-    int hidden;
-    int opengl;
-    int updates;
-    int idle_counter;
-    int ignore_hotkeys;
-    SDL_GLContext winctx;
-    QKbdState *kbd;
-    bool y0_top;
-    bool scanout_mode;
-};
-
-#endif /* XEMU_DISPLAY_H */

ui/sdl2.c

@@ -285,7 +285,7 @@ static void absolute_mouse_grab(struct sdl2_console *scon)
     }
 }
 
-static void sdl_mouse_mode_change(Notifier *notify, void *data)
+static void mouse_mode_change(Notifier *notify, void *data)
 {
     if (qemu_input_is_absolute(sdl2_console[0].dcl.con)) {
         if (!absolute_enabled) {
@@ -939,7 +939,7 @@ static void sdl2_display_init(DisplayState *ds, DisplayOptions *o)
         SDL_SetWindowIcon(sdl2_console[0].real_window, icon);
     }
 
-    mouse_mode_notifier.notify = sdl_mouse_mode_change;
+    mouse_mode_notifier.notify = mouse_mode_change;
     qemu_add_mouse_mode_change_notifier(&mouse_mode_notifier);
 
     sdl_cursor_hidden = SDL_CreateCursor(&data, &data, 8, 1, 0, 0);
@@ -961,12 +961,12 @@ static QemuDisplay qemu_display_sdl2 = {
     .init       = sdl2_display_init,
 };
 
-static void register_sdl1(void)
+static void register_xemu_display(void)
 {
     qemu_display_register(&qemu_display_sdl2);
 }
 
-type_init(register_sdl1);
+type_init(register_xemu_display);
 
 #ifdef CONFIG_OPENGL
 module_dep("ui-opengl");

ui/xui/main.cc

@@ -189,7 +189,7 @@ void xemu_hud_set_framebuffer_texture(GLuint tex, bool flip)
     g_flip_req = flip;
 }
 
-void xemu_hud_render(void)
+void xemu_hud_update(void)
 {
     ImGuiIO& io = ImGui::GetIO();
     uint32_t now = SDL_GetTicks();
@@ -320,7 +320,10 @@ void xemu_hud_render(void)
 
     // static bool show_demo = true;
     // if (show_demo) ImGui::ShowDemoWindow(&show_demo);
+}
 
+void xemu_hud_render()
+{
     ImGui::Render();
     ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
 

ui/xui/misc.cc

@@ -30,7 +30,9 @@ static void RunOnMainThread(std::function<void()> &&func)
             [](void *userdata) {
                 std::unique_ptr<std::function<void()>> f(
                     static_cast<std::function<void()> *>(userdata));
+                xemu_main_loop_lock();
                 (*f)();
+                xemu_main_loop_unlock();
             },
             p, false)) {
         delete p;

ui/xui/xemu-hud.h

@@ -36,10 +36,13 @@ void xemu_toggle_fullscreen(void);
 SDL_Window *xemu_get_window(void);
 void xemu_eject_disc(Error **errp);
 void xemu_load_disc(const char *path, Error **errp);
+void xemu_main_loop_lock(void);
+void xemu_main_loop_unlock(void);
 
 // Implemented in xemu_hud.cc
 void xemu_hud_init(SDL_Window *window, void *sdl_gl_context);
 void xemu_hud_cleanup(void);
+void xemu_hud_update(void);
 void xemu_hud_render(void);
 void xemu_hud_process_sdl_events(SDL_Event *event);
 void xemu_hud_should_capture_kbd_mouse(int *kbd, int *mouse);