Defer files opened by fopenFiles on macOS

inc/app.h

@@ -11,14 +11,20 @@ typedef struct app_ {
     struct theme_* theme;
     int draw_mode; // shaded or wireframe
     int draw_proj; // orthographic or perspective
+
+    unsigned deferred_count;
+    char** deferred_files;
 } app_t;
 
 /*  Calls instance_run on every instance */
 bool app_run(app_t* app);
 
-/*  Triggered from the UI */
+/*  Synchronously loads a file (triggered from UI menu items) */
 struct instance_* app_open(app_t* app, const char* filename);
 
+/*  Loads a file when control returns to the event loop */
+void app_defer_open(app_t* app, const char* filename);
+
 /*  Changes the view mode for the whole application */
 void app_view_shaded(app_t* app);
 void app_view_wireframe(app_t* app);

platform/darwin.mm

@@ -103,8 +103,12 @@ -(void)onAboutMenu {
 
 void fopenFiles(id self, SEL _cmd, NSApplication* application,
                 NSArray<NSString *>* openFiles) {
+    //  We defer loading files until control hits the main event loop.  This
+    //  prevents an issue when someone starts the app by dragging a file onto
+    //  its icon, which would otherwise call fopenFiles within the first call
+    //  to glfwCreateWindow, hanging until the app is re-focused.
     for (NSString* t in openFiles) {
-        app_open(GLUE->app, [t UTF8String]);
+        app_defer_open(GLUE->app, [t UTF8String]);
     }
 }
 
@@ -148,7 +152,7 @@ void fopenFiles(id self, SEL _cmd, NSApplication* application,
         window_new("", 1.0f, 1.0f);
 
         //  If no file was opened, then load the default
-        if (app->instance_count == 0) {
+        if (app->instance_count == 0 && !app->deferred_files) {
             app_open(app, ":/sphere");
         }
     }

src/app.c

@@ -34,6 +34,15 @@ instance_t* app_open(app_t* app, const char* filename) {
     return instance;
 }
 
+void app_defer_open(app_t* app, const char* filename) {
+    const size_t len = strlen(filename);
+    char* f = calloc(1, len + 1);
+    strcpy(f, filename);
+    app->deferred_files = realloc(app->deferred_files,
+                                  sizeof(char*) * app->deferred_count + 1);
+    app->deferred_files[app->deferred_count++] = f;
+}
+
 void app_view_shaded(app_t* app) {
     app->draw_mode = DRAW_SHADED;
     for (unsigned i=0; i < app->instance_count; ++i) {
@@ -82,8 +91,20 @@ instance_t* app_get_front(app_t* app) {
 }
 
 bool app_run(app_t* app) {
-    unsigned i=0;
+    /*  On some platforms, we defer loading of files until the event loop
+     *  begins running, so handle them all here. */
+    if (app->deferred_files) {
+        for (unsigned i=0; i < app->deferred_count; ++i) {
+            app_open(app, app->deferred_files[i]);
+            free(app->deferred_files[i]);
+        }
+        free(app->deferred_files);
+        app->deferred_files = NULL;
+        app->deferred_count = 0;
+    }
+
     bool needs_redraw = false;
+    unsigned i = 0;
     while (i < app->instance_count) {
         needs_redraw |= instance_draw(app->instances[i], app->theme);
         if (glfwWindowShouldClose(app->instances[i]->window)) {

src/main.c

@@ -14,6 +14,8 @@ int main(int argc, char** argv) {
         .instances_size=0,
         .theme=NULL,
         .draw_mode=DRAW_SHADED,
+        .deferred_count=0,
+        .deferred_files=NULL,
     };
     app.theme = theme_new_solarized();