core: add an ANR dialog

for xdg-shell, we can ping the wm_base, and thus render an ANR dialog if an app dies

for XWayland, there probably is a similar method, but I don't know about it and don't care.

src/protocols/XDGShell.cpp

@@ -3,6 +3,7 @@
 #include <algorithm>
 #include "../Compositor.hpp"
 #include "../managers/SeatManager.hpp"
+#include "../managers/ANRManager.hpp"
 #include "../helpers/Monitor.hpp"
 #include "core/Seat.hpp"
 #include "core/Compositor.hpp"
@@ -740,6 +741,11 @@ CXDGWMBase::CXDGWMBase(SP<CXdgWmBase> resource_) : resource(resource_) {
 
         LOGM(LOG, "New xdg_surface at {:x}", (uintptr_t)RESOURCE.get());
     });
+
+    resource->setPong([this](CXdgWmBase* r, uint32_t serial) {
+        g_pANRManager->onResponse(self.lock());
+        events.pong.emit();
+    });
 }
 
 bool CXDGWMBase::good() {
@@ -750,6 +756,10 @@ wl_client* CXDGWMBase::client() {
     return pClient;
 }
 
+void CXDGWMBase::ping() {
+    resource->sendPing(1337);
+}
+
 CXDGShellProtocol::CXDGShellProtocol(const wl_interface* iface, const int& ver, const std::string& name) : IWaylandProtocol(iface, ver, name) {
     grab           = makeShared<CSeatGrab>();
     grab->keyboard = true;

src/protocols/XDGShell.hpp

@@ -241,12 +241,17 @@ class CXDGWMBase {
 
     bool                                    good();
     wl_client*                              client();
+    void                                    ping();
 
     std::vector<WP<CXDGPositionerResource>> positioners;
     std::vector<WP<CXDGSurfaceResource>>    surfaces;
 
     WP<CXDGWMBase>                          self;
 
+    struct {
+        CSignal pong;
+    } events;
+
   private:
     SP<CXdgWmBase> resource;
     wl_client*     pClient = nullptr;