[client] clipboard: add transport provider interface

Route clipboard exchange through a provider interface. Connected
transports take priority while SPICE remains the fallback.

Track asynchronous X11 and Wayland transfers by request, preserving
clipboard ownership across provider changes.

Use PureSpice clipboard status notifications for capability and
lifecycle updates.

client/src/main.c

@@ -63,6 +63,7 @@
 #endif
 #include "keybind.h"
 #include "clipboard.h"
+#include "clipboard_spice.h"
 #include "kb.h"
 #include "egl_dynprocs.h"
 #include "gl_dynprocs.h"
@@ -108,11 +109,7 @@ l_cursorRepaint;
 
 _Atomic(enum RunState) p_appState = APP_STATE_RUNNING;
 
-struct AppState g_state =
-{
-  .cbRemoteType = SPICE_DATA_NONE,
-  .cbWriteType  = SPICE_DATA_NONE,
-};
+struct AppState g_state = { 0 };
 struct CursorState g_cursor;
 
 // this structure is initialized in config.c
@@ -1031,11 +1028,13 @@ static int renderThread(void * unused)
   {
     lgInput_setTransport(NULL, NULL);
     lgAudio_setTransport(NULL, NULL);
+    lgClipboard_setTransport(NULL, NULL);
   }
   else
   {
     lgInput_dropTransport();
     lgAudio_dropTransport();
+    lgClipboard_dropTransport();
   }
 
   core_stopCursorThread();
@@ -1087,6 +1086,7 @@ int main_cursorThread(void * unused)
       {
         lgInput_dropTransport();
         lgAudio_dropTransport();
+        lgClipboard_dropTransport();
       }
       app_setState(status == LG_TRANSPORT_DISCONNECTED ?
         APP_STATE_RESTART : APP_STATE_SHUTDOWN);
@@ -1229,6 +1229,7 @@ int main_frameThread(void * unused)
       {
         lgInput_dropTransport();
         lgAudio_dropTransport();
+        lgClipboard_dropTransport();
         app_setState(APP_STATE_RESTART);
       }
       else if (status == LG_TRANSPORT_END)
@@ -1507,6 +1508,8 @@ static void checkUUID(void)
 
   g_params.useSpiceInput = false;
   lgInput_setFallback(NULL, NULL);
+  lgcSpice_setAvailable(false);
+  lgClipboard_setFallback(NULL, NULL);
   atomic_store_explicit(&g_state.spiceClose, true, memory_order_release);
   purespice_disconnect();
 }
@@ -1554,6 +1557,10 @@ void spiceReady(void)
   else
     DEBUG_WARN("Failed to obtain SPICE server information");
 
+  if (g_params.useSpiceClipboard &&
+      !atomic_load_explicit(&g_state.spiceClose, memory_order_acquire))
+    lgClipboard_setFallback(&LGC_Spice, NULL);
+
   if (g_params.useSpiceInput)
     keybind_inputRegister();
 
@@ -1721,10 +1728,11 @@ int spiceThread(void * arg)
     .clipboard =
     {
       .enable  = g_params.useSpiceClipboard,
-      .notice  = cb_spiceNotice,
-      .data    = cb_spiceData,
-      .release = cb_spiceRelease,
-      .request = cb_spiceRequest
+      .notice  = lgcSpice_notice,
+      .data    = lgcSpice_data,
+      .release = lgcSpice_release,
+      .request = lgcSpice_request,
+      .status  = lgcSpice_setAvailable,
     },
     .display  =
     {
@@ -1784,10 +1792,13 @@ int spiceThread(void * arg)
         DEBUG_ERROR("failed to process spice messages");
       goto end;
     }
+
   }
 
   lgInput_setFallback(NULL, NULL);
   lgAudio_setFallback(NULL, NULL);
+  lgcSpice_setAvailable(false);
+  lgClipboard_setFallback(NULL, NULL);
 #if ENABLE_AUDIO
   lgaSpice_setAvailable(false);
 #endif
@@ -1795,8 +1806,10 @@ int spiceThread(void * arg)
 
 end:
 
+  lgcSpice_setAvailable(false);
   lgInput_setFallback(NULL, NULL);
   lgAudio_setFallback(NULL, NULL);
+  lgClipboard_setFallback(NULL, NULL);
 #if ENABLE_AUDIO
   lgaSpice_setAvailable(false);
 #endif
@@ -1911,6 +1924,7 @@ static int lg_run(void)
   frameTimingInit();
   lgInput_init();
   lgAudio_init();
+  lgClipboard_init();
 
 #ifdef ENABLE_TESTS
   memset(&l_testCapture, 0, sizeof(l_testCapture));
@@ -2214,9 +2228,9 @@ static int lg_run(void)
   }
 
   g_state.ds->startup();
-  g_state.cbAvailable = g_state.ds->cbInit && g_state.ds->cbInit();
-  if (g_state.cbAvailable)
-    g_state.cbRequestList = ll_new();
+  const bool clipboardAvailable =
+    g_state.ds->cbInit && g_state.ds->cbInit();
+  lgClipboard_setLocalAvailable(clipboardAvailable);
 
   if (g_params.captureOnStart)
     core_setGrab(true);
@@ -2386,6 +2400,13 @@ restart:
     g_state.transportOps->getAudioOps(g_state.transport, &audioOpaque) : NULL;
   lgAudio_setTransport(audioOps, audioOpaque);
 
+  void * clipboardOpaque = NULL;
+  const LG_ClipboardOps * clipboardOps =
+    g_state.transportOps->getClipboardOps ?
+      g_state.transportOps->getClipboardOps(
+          g_state.transport, &clipboardOpaque) : NULL;
+  lgClipboard_setTransport(clipboardOps, clipboardOpaque);
+
   if (inputOps || lgInput_available())
     keybind_inputRegister();
   checkUUID();
@@ -2404,6 +2425,7 @@ restart:
     {
       lgInput_dropTransport();
       lgAudio_dropTransport();
+      lgClipboard_dropTransport();
       atomic_store_explicit(
           &g_state.lgHostConnected, false, memory_order_release);
       DEBUG_INFO("Waiting for the host to restart...");
@@ -2426,6 +2448,7 @@ restart:
     core_stopCursorThread();
     lgInput_dropTransport();
     lgAudio_dropTransport();
+    lgClipboard_dropTransport();
     g_state.transportOps->disconnect(g_state.transport);
 
     app_setState(APP_STATE_RUNNING);
@@ -2474,14 +2497,21 @@ static void lg_shutdown(void)
     lgInput_dropTransport();
     if (g_state.transport &&
         g_state.transportOps->sessionValid(g_state.transport))
+    {
       lgAudio_setTransport(NULL, NULL);
+      lgClipboard_setTransport(NULL, NULL);
+    }
     else
+    {
       lgAudio_dropTransport();
+      lgClipboard_dropTransport();
+    }
     g_state.transportOps->destroy(&g_state.transport);
   }
 
   lgInput_free();
   lgAudio_free();
+  lgClipboard_setLocalAvailable(false);
 
   if (g_state.frameEvent)
   {
@@ -2503,12 +2533,7 @@ static void lg_shutdown(void)
 
   if (g_state.ds)
     g_state.ds->shutdown();
-
-  if (g_state.cbRequestList)
-  {
-    ll_free(g_state.cbRequestList);
-    g_state.cbRequestList = NULL;
-  }
+  lgClipboard_free();
 
   app_releaseAllKeybinds();
   ll_free(g_state.bindings);