Remap Cocoa/macOS menu item key modifiers

As part of adding ADB keyboard support (#56), we're now running into
conflicts between the guest and host OS keyboard shortcuts when running
on macOS hosts.

SDL2 unconditionally adds some menu items to the "Window" menu, and
there are built-in ones too. As a workaround, we now iterate over all
menu items are swap out command for control, since the the latter is
generally unused in classic Mac OS.

CMakeLists.txt

@@ -116,6 +116,11 @@ platform_glob(SOURCES "${PROJECT_SOURCE_DIR}/*.cpp"
                       "${PROJECT_SOURCE_DIR}/*.hpp"
                       "${PROJECT_SOURCE_DIR}/*.h")
 
+if (APPLE)
+    platform_glob(APPLE_SOURCES "${PROJECT_SOURCE_DIR}/*.m")
+    list(APPEND SOURCES ${APPLE_SOURCES})
+endif()
+
 file(GLOB TEST_SOURCES "${PROJECT_SOURCE_DIR}/cpu/ppc/test/*.cpp")
 
 add_executable(dingusppc ${SOURCES} $<TARGET_OBJECTS:core>
@@ -143,6 +148,12 @@ else()
                                     ${CMAKE_DL_LIBS} ${CMAKE_THREAD_LIBS_INIT})
 endif()
 
+if (APPLE)
+    find_library(COCOA_LIBRARY Cocoa)
+    target_link_libraries(dingusppc PRIVATE ${COCOA_LIBRARY})
+endif()
+
+
 if (DPPC_68K_DEBUGGER)
     target_link_libraries(dingusppc PRIVATE capstone)
 endif()

main_sdl.cpp

@@ -25,11 +25,20 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 #include <loguru.hpp>
 #include <SDL.h>
 
+#ifdef __APPLE__
+extern "C" void remap_appkit_menu_shortcuts();
+#endif
+
 bool init() {
     if (SDL_Init(SDL_INIT_VIDEO)) {
         LOG_F(ERROR, "SDL_Init error: %s", SDL_GetError());
         return false;
     }
+
+#ifdef __APPLE__
+    remap_appkit_menu_shortcuts();
+#endif
+
     return true;
 }
 

main_sdl.m

@@ -0,0 +1,40 @@
+/*
+DingusPPC - The Experimental PowerPC Macintosh emulator
+Copyright (C) 2018-23 divingkatae and maximum
+                      (theweirdo)     spatium
+
+(Contact divingkatae#1017 or powermax#2286 on Discord for more info)
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <Cocoa/Cocoa.h>
+
+/** @file SDL-specific main function additions for macOS hosts. */
+
+// Replace Command shortcuts with Control shortcuts in the menu bar, so that
+// they're not going to conflict with ones in the guest OS (but we still allow
+// some of them to be used in the host OS, e.g. Control+Q to quit).
+void remap_appkit_menu_shortcuts(void) {
+    for (NSMenuItem *menuItem in [NSApp mainMenu].itemArray) {
+        if (menuItem.hasSubmenu) {
+            for (NSMenuItem *item in menuItem.submenu.itemArray) {
+                if (item.keyEquivalentModifierMask & NSEventModifierFlagCommand) {
+                    item.keyEquivalentModifierMask &= ~NSEventModifierFlagCommand;
+                    item.keyEquivalentModifierMask |= NSEventModifierFlagControl;
+                }
+            }
+        }
+    }
+}