win32: make context menu items accessible from the window menu

This makes the context menu items accessible from the window menu,
which can be opened by either right-clicking on the title bar or
left-clicking on the mpv icon on the title bar.

video/out/w32_common.c

@@ -1532,7 +1532,7 @@ static LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam,
         }
         break;
     }
-    case WM_SYSCOMMAND:
+    case WM_SYSCOMMAND: {
         switch (wParam & 0xFFF0) {
         case SC_SCREENSAVE:
         case SC_MONITORPOWER:
@@ -1550,7 +1550,18 @@ static LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam,
             }
             break;
         }
+        // All custom items must use ids of less than 0xF000. The context menu items are
+        // also larger than WM_USER, which excludes SCF_ISSECURE.
+        if (wParam > WM_USER && wParam < 0xF000) {
+            const char *cmd = mp_win32_menu_get_cmd(w32->menu_ctx, LOWORD(wParam));
+            if (cmd) {
+                mp_cmd_t *cmdt = mp_input_parse_cmd(w32->input_ctx, bstr0(cmd), "");
+                mp_input_queue_cmd(w32->input_ctx, cmdt);
+                return 0;
+            }
+        }
         break;
+    }
     case WM_NCACTIVATE:
         // Cosmetic to remove blinking window border when initializing window
         if (!w32->opts->border)
@@ -2031,7 +2042,7 @@ static MP_THREAD_VOID gui_thread(void *ptr)
         goto done;
     }
 
-    w32->menu_ctx = mp_win32_menu_init();
+    w32->menu_ctx = mp_win32_menu_init(w32->window);
     update_dark_mode(w32);
     update_corners_pref(w32);
     if (w32->opts->window_affinity)

video/out/win32/menu.c

@@ -25,6 +25,8 @@
 #include "menu.h"
 
 struct menu_ctx {
+    HWND  hwnd;
+    bool  updated;
     HMENU menu;
     void *ta_data; // talloc context for MENUITEMINFOW.dwItemData
 };
@@ -178,9 +180,11 @@ static void build_menu(void *talloc_ctx, HMENU hmenu, struct mpv_node *node)
     }
 }
 
-struct menu_ctx *mp_win32_menu_init(void)
+struct menu_ctx *mp_win32_menu_init(HWND hwnd)
 {
     struct menu_ctx *ctx = talloc_ptrtype(NULL, ctx);
+    ctx->hwnd = hwnd;
+    ctx->updated = false;
     ctx->menu = CreatePopupMenu();
     ctx->ta_data = talloc_new(ctx);
     return ctx;
@@ -218,6 +222,17 @@ void mp_win32_menu_update(struct menu_ctx *ctx, struct mpv_node *data)
     talloc_free_children(ctx->ta_data);
 
     build_menu(ctx->ta_data, ctx->menu, data);
+    if (!ctx->updated) {
+        append_menu(GetSystemMenu(ctx->hwnd, FALSE), MIIM_FTYPE, MFT_SEPARATOR, 0, NULL, NULL, NULL);
+        append_menu(GetSystemMenu(ctx->hwnd, FALSE), MIIM_STRING | MIIM_SUBMENU, 0, 0,
+                    build_title(ctx->ta_data, "mpv", NULL), ctx->menu, NULL);
+        ctx->updated = true;
+    } else if (data->format != MPV_FORMAT_NODE_ARRAY) {
+        // recreate ctx->menu because it is destroyed here
+        GetSystemMenu(ctx->hwnd, TRUE);
+        ctx->menu = CreatePopupMenu();
+        ctx->updated = false;
+    }
 }
 
 const char* mp_win32_menu_get_cmd(struct menu_ctx *ctx, UINT id)

video/out/win32/menu.h

@@ -23,7 +23,7 @@
 struct mpv_node;
 struct menu_ctx;
 
-struct menu_ctx *mp_win32_menu_init(void);
+struct menu_ctx *mp_win32_menu_init(HWND hwnd);
 void mp_win32_menu_uninit(struct menu_ctx *ctx);
 void mp_win32_menu_show(struct menu_ctx *ctx, HWND hwnd);
 void mp_win32_menu_update(struct menu_ctx *ctx, struct mpv_node *data);