Add better single instance detection (use rpc fifo file existence with unlink to detect process instead of pidof gsr-ui)

TODO

@@ -195,3 +195,13 @@ Add a window that shows a warning for wayland users, that wayland doesn't suppor
 Add a window that shows a warning if gpu video encoding isn't supported.
 
 Disable system notifications when recording. Does the notification dbus interface support pausing notifications?
+
+Automatically mark window region in window capture for screenshot on x11.
+
+Disable hotkeys if virtual keyboard is found (either at startup or after running), if grab type if not virtual. Show a notification if that happens that hotkeys have been disabled.
+    Detect if keyboard is locked by listening to gsr-ui virtual keyboard events and if no event is received after pressing a key (when writing to it after receiving input from another keyboard)
+    then remove the keyboard grab and show a message or something.
+        This can happen if the gsr-ui virtual keyboard is grabbed by some other software.
+        Maybe this can be fixed automatically by grabbing gsr-ui virtual keyboard and releasing it just before we write to it and then release it again.
+        But wont keyboard remapping software grab the keyboard first if they detect it quickly?
+            If we fail to grab it because some other software did then dont grab any keyboards nor gsr-ui virtual keyboards, just listen to them.

src/Rpc.cpp

@@ -32,7 +32,7 @@ namespace gsr {
             fclose(file);
 
         if(!fifo_filepath.empty())
-            remove(fifo_filepath.c_str());
+            unlink(fifo_filepath.c_str());
     }
 
     bool Rpc::create(const char *name) {
@@ -44,15 +44,16 @@ namespace gsr {
         char fifo_filepath_tmp[PATH_MAX];
         get_runtime_filepath(fifo_filepath_tmp, sizeof(fifo_filepath_tmp), name);
         fifo_filepath = fifo_filepath_tmp;
-        remove(fifo_filepath.c_str());
+        unlink(fifo_filepath.c_str());
 
         if(mkfifo(fifo_filepath.c_str(), 0600) != 0) {
             fprintf(stderr, "Error: mkfifo failed, error: %s, %s\n", strerror(errno), fifo_filepath.c_str());
+            fifo_filepath.clear();
             return false;
         }
 
         if(!open_filepath(fifo_filepath.c_str())) {
-            remove(fifo_filepath.c_str());
+            unlink(fifo_filepath.c_str());
             fifo_filepath.clear();
             return false;
         }

src/main.cpp

@@ -14,7 +14,6 @@
 #include <mglpp/system/Clock.hpp>
 
 // TODO: Make keyboard/controller controllable for steam deck (and other controllers).
-// TODO: Keep track of gpu screen recorder run by other programs to not allow recording at the same time, or something.
 // TODO: Add systray by using org.kde.StatusNotifierWatcher/etc dbus directly.
 // TODO: Make sure the overlay always stays on top. Test with starting the overlay and then opening youtube in fullscreen.
 //       This is done in Overlay::force_window_on_top, but it's not called right now. It cant be used because the overlay will be on top of
@@ -220,17 +219,17 @@ int main(int argc, char **argv) {
 
     set_display_server_environment_variables();
 
-    // TODO: This is a shitty method to detect if multiple instances of gsr-ui is running but this will work properly even in flatpak
+    auto rpc = std::make_unique<gsr::Rpc>();
-    // that uses pid sandboxing. Replace this with a better method once we no longer rely on linux global hotkeys on some platform.
+    const bool rpc_created = rpc->create("gsr-ui");
-    // TODO: This method doesn't work when disabling hotkeys and the method below with pidof gsr-ui doesn't work in flatpak.
+    if(!rpc_created)
-    // What do? creating a pid file doesn't work in flatpak either.
+        fprintf(stderr, "Error: Failed to create rpc\n");
-    // TODO: This doesn't work in flatpak when disabling hotkeys.
+
-    if(is_gsr_ui_virtual_keyboard_running() || gsr::pidof("gsr-ui", getpid()) != -1) {
+    if(is_gsr_ui_virtual_keyboard_running() || !rpc_created) {
         if(launch_action == LaunchAction::LAUNCH_DAEMON)
             return 1;
 
-        gsr::Rpc rpc;
+        rpc = std::make_unique<gsr::Rpc>();
-        if(rpc.open("gsr-ui") && rpc.write("show_ui\n", 8)) {
+        if(rpc->open("gsr-ui") && rpc->write("show_ui\n", 8)) {
             fprintf(stderr, "Error: another instance of gsr-ui is already running, opening that one instead\n");
         } else {
             fprintf(stderr, "Error: failed to send command to running gsr-ui instance, user will have to open the UI manually with Alt+Z\n");
@@ -243,6 +242,12 @@ int main(int argc, char **argv) {
     if(gsr::pidof("gpu-screen-recorder", getpid()) != -1) {
         const char *args[] = { "gsr-notify", "--text", "GPU Screen Recorder is already running in another process.\nPlease close it before using GPU Screen Recorder UI.", "--timeout", "5.0", "--icon-color", "ff0000", "--bg-color", "ff0000", nullptr };
         gsr::exec_program_daemonized(args);
+        return 1;
+    }
+
+    if(mgl_init(MGL_WINDOW_SYSTEM_X11) != 0) {
+        fprintf(stderr, "Error: failed to initialize mgl. Failed to either connect to the X11 server or setup opengl\n");
+        return 1;
     }
 
     if(is_flatpak())
@@ -288,11 +293,6 @@ int main(int argc, char **argv) {
         disable_prime_run();
     }
 
-    if(mgl_init(MGL_WINDOW_SYSTEM_X11) != 0) {
-        fprintf(stderr, "Error: failed to initialize mgl. Failed to either connect to the X11 server or setup opengl\n");
-        exit(1);
-    }
-
     gsr::SupportedCaptureOptions capture_options = gsr::get_supported_capture_options(gsr_info);
 
     std::string resources_path;
@@ -325,10 +325,6 @@ int main(int argc, char **argv) {
     if(launch_action == LaunchAction::LAUNCH_SHOW)
         overlay->show();
 
-    auto rpc = std::make_unique<gsr::Rpc>();
-    if(!rpc->create("gsr-ui"))
-        fprintf(stderr, "Error: Failed to create rpc, commands won't be received\n");
-
     rpc_add_commands(rpc.get(), overlay.get());
 
     // TODO: Add hotkeys in Overlay when using x11 global hotkeys. The hotkeys in Overlay should duplicate each key that is used for x11 global hotkeys.