macOS: register with window server via TransformProcessType for subprocess window display

Author: pepc84

mode/CppMode.jar

@@ -3364,6 +3364,20 @@ void PApplet::run(){
     initPerlin(0); // initialize noise table with default seed
 
 #if defined(__APPLE__)
+    // Register with macOS window server -- required when launched as a subprocess
+    // (e.g. from Processing IDE). Without this, GLFW cannot create windows.
+    {
+        void* handle = dlopen("/System/Library/Frameworks/ApplicationServices.framework/ApplicationServices", RTLD_LAZY);
+        if (handle) {
+            typedef int (*TFunc)(void*);
+            TFunc f = (TFunc)dlsym(handle, "TransformProcessType");
+            if (f) {
+                // kProcessTransformToForegroundApplication = 1
+                unsigned int psn[2] = {0, 1}; // kCurrentProcess
+                f(psn);
+            }
+        }
+    }
     glfwInitHint(GLFW_COCOA_CHDIR_RESOURCES, GLFW_FALSE);
 #endif
     if(!glfwInit()){

src/Processing.cpp

@@ -35,27 +35,10 @@ public void launch() {
         }
         ProcessBuilder pb;
         if (System.getProperty("os.name","").toLowerCase().contains("mac")) {
-          // macOS: wrap in minimal .app bundle so the process gets window server access
-          java.io.File appBundle = new java.io.File(sketchFolder, exeToRun.getName() + ".app");
-          java.io.File macosDir = new java.io.File(appBundle, "Contents/MacOS");
-          macosDir.mkdirs();
-          java.io.File bundledBin = new java.io.File(macosDir, exeToRun.getName());
-          java.nio.file.Files.copy(exeToRun.toPath(), bundledBin.toPath(),
-              java.nio.file.StandardCopyOption.REPLACE_EXISTING);
-          bundledBin.setExecutable(true);
-          // Write minimal Info.plist
-          java.io.File plist = new java.io.File(appBundle, "Contents/Info.plist");
-          java.nio.file.Files.writeString(plist.toPath(),
-              "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
-              + "<!DOCTYPE plist PUBLIC \"-//Apple//DTD PLIST 1.0//EN\" \"http://www.apple.com/DTDs/PropertyList-1.0.dtd\">\n"
-              + "<plist version=\"1.0\"><dict>\n"
-              + "<key>CFBundleExecutable</key><string>" + exeToRun.getName() + "</string>\n"
-              + "<key>CFBundleIdentifier</key><string>processing.cpp." + exeToRun.getName() + "</string>\n"
-              + "<key>CFBundleName</key><string>" + exeToRun.getName() + "</string>\n"
-              + "<key>NSHighResolutionCapable</key><true/>\n"
-              + "<key>NSPrincipalClass</key><string>NSApplication</string>\n"
-              + "</dict></plist>\n");
-          pb = new ProcessBuilder("open", "-W", "-n", appBundle.getAbsolutePath());
+          // macOS: launch directly -- the .app bundle approach breaks stdio piping
+          // Just run the binary directly; modern macOS allows subprocess windows
+          // as long as the parent process has screen access (Processing does).
+          pb = new ProcessBuilder(exeToRun.getAbsolutePath());
         } else {
           pb = new ProcessBuilder(exeToRun.getAbsolutePath());
         }