UI: Add command line option for starting up always on top

Closes jp9000/obs-studio#853

UI/obs-app.cpp

@@ -70,6 +70,7 @@ bool opt_studio_mode = false;
 bool opt_start_replaybuffer = false;
 bool opt_minimize_tray = false;
 bool opt_allow_opengl = false;
+bool opt_always_on_top = false;
 string opt_starting_collection;
 string opt_starting_profile;
 string opt_starting_scene;
@@ -1757,6 +1758,9 @@ int main(int argc, char *argv[])
 		} else if (arg_is(argv[i], "--verbose", nullptr)) {
 			log_verbose = true;
 
+		} else if (arg_is(argv[i], "--always-on-top", nullptr)) {
+			opt_always_on_top = true;
+
 		} else if (arg_is(argv[i], "--unfiltered_log", nullptr)) {
 			unfiltered_log = true;
 
@@ -1801,6 +1805,7 @@ int main(int argc, char *argv[])
 			"--minimize-to-tray: Minimize to system tray.\n" <<
 			"--portable, -p: Use portable mode.\n\n" <<
 			"--verbose: Make log more verbose.\n" <<
+			"--always-on-top: Start in 'always on top' mode.\n\n" <<
 			"--unfiltered_log: Make log unfiltered.\n\n" <<
 			"--allow-opengl: Allow OpenGL on Windows.\n\n" <<
 			"--version, -V: Get current version.\n";

UI/obs-app.hpp

@@ -182,4 +182,5 @@ extern bool opt_start_replaybuffer;
 extern bool opt_minimize_tray;
 extern bool opt_studio_mode;
 extern bool opt_allow_opengl;
+extern bool opt_always_on_top;
 extern std::string opt_starting_scene;

UI/window-basic-main.cpp

@@ -1371,7 +1371,7 @@ void OBSBasic::OBSInit()
 
 	bool alwaysOnTop = config_get_bool(App()->GlobalConfig(), "BasicWindow",
 			"AlwaysOnTop");
-	if (alwaysOnTop) {
+	if (alwaysOnTop || opt_always_on_top) {
 		SetAlwaysOnTop(this, true);
 		ui->actionAlwaysOnTop->setChecked(true);
 	}