GHOST/Wayland: primary clipboard support

Match X11's primary clipboard support
(typically used for MMB to paste the previous selection).

3 files changed, 341 insertions, 7 deletions

diff --git a/intern/ghost/CMakeLists.txt b/intern/ghost/CMakeLists.txt
index 72621648608..c05f2a327b1 100644
--- a/intern/ghost/CMakeLists.txt
+++ b/intern/ghost/CMakeLists.txt
@@ -376,6 +376,10 @@ elseif(WITH_GHOST_X11 OR WITH_GHOST_WAYLAND)
     generate_protocol_bindings(
       "${WAYLAND_PROTOCOLS_DIR}/unstable/tablet/tablet-unstable-v2.xml"
     )
+    # Primary-selection.
+    generate_protocol_bindings(
+      "${WAYLAND_PROTOCOLS_DIR}/unstable/primary-selection/primary-selection-unstable-v1.xml"
+    )
 
     add_definitions(-DWITH_GHOST_WAYLAND)
 
diff --git a/intern/ghost/intern/GHOST_SystemWayland.cpp b/intern/ghost/intern/GHOST_SystemWayland.cpp
index b8b9fda8f74..6db8b9d33f8 100644
--- a/intern/ghost/intern/GHOST_SystemWayland.cpp
+++ b/intern/ghost/intern/GHOST_SystemWayland.cpp
@@ -51,6 +51,7 @@
 
 /* Generated by `wayland-scanner`. */
 #include <pointer-constraints-unstable-v1-client-protocol.h>
+#include <primary-selection-unstable-v1-client-protocol.h>
 #include <relative-pointer-unstable-v1-client-protocol.h>
 #include <tablet-unstable-v2-client-protocol.h>
 #include <xdg-output-unstable-v1-client-protocol.h>
@@ -426,6 +427,53 @@ static void gwl_xdg_decor_system_destroy(GWL_XDG_Decor_System *decor)
   delete decor;
 }
 
+struct GWL_PrimarySelection_DataOffer {
+  struct zwp_primary_selection_offer_v1 *id = nullptr;
+  std::atomic<bool> in_use = false;
+
+  std::unordered_set<std::string> types;
+};
+
+struct GWL_PrimarySelection_DataSource {
+  struct zwp_primary_selection_source_v1 *wl_source = nullptr;
+  char *buffer_out = nullptr;
+  size_t buffer_out_len = 0;
+};
+
+/** Primary selection support. */
+struct GWL_PrimarySelection {
+
+  GWL_PrimarySelection_DataSource *data_source = nullptr;
+  std::mutex data_source_mutex;
+
+  GWL_PrimarySelection_DataOffer *data_offer = nullptr;
+  std::mutex data_offer_mutex;
+};
+
+static void gwl_primary_selection_discard_offer(GWL_PrimarySelection *primary)
+{
+  if (primary->data_offer == nullptr) {
+    return;
+  }
+  zwp_primary_selection_offer_v1_destroy(primary->data_offer->id);
+  delete primary->data_offer;
+  primary->data_offer = nullptr;
+}
+
+static void gwl_primary_selection_discard_source(GWL_PrimarySelection *primary)
+{
+  GWL_PrimarySelection_DataSource *data_source = primary->data_source;
+  if (data_source == nullptr) {
+    return;
+  }
+  free(data_source->buffer_out);
+  if (data_source->wl_source) {
+    zwp_primary_selection_source_v1_destroy(data_source->wl_source);
+  }
+  delete primary->data_source;
+  primary->data_source = nullptr;
+}
+
 struct GWL_Seat {
   GHOST_SystemWayland *system = nullptr;
 
@@ -515,6 +563,9 @@ struct GWL_Seat {
   struct GWL_DataSource *data_source = nullptr;
   std::mutex data_source_mutex;
 
+  struct zwp_primary_selection_device_v1 *primary_selection_device = nullptr;
+  struct GWL_PrimarySelection primary_selection;
+
   /** Last device that was active. */
   uint32_t data_source_serial = 0;
 };
@@ -540,6 +591,8 @@ struct GWL_Display {
   struct zwp_tablet_manager_v2 *tablet_manager = nullptr;
   struct zwp_relative_pointer_manager_v1 *relative_pointer_manager = nullptr;
   struct zwp_pointer_constraints_v1 *pointer_constraints = nullptr;
+
+  struct zwp_primary_selection_device_manager_v1 *primary_selection_device_manager = nullptr;
 };
 
 #undef LOG
@@ -642,6 +695,22 @@ static void display_destroy(GWL_Display *display)
       }
     }
 
+    {
+      GWL_PrimarySelection *primary = &seat->primary_selection;
+      std::lock_guard lock{primary->data_offer_mutex};
+      gwl_primary_selection_discard_offer(primary);
+    }
+
+    {
+      GWL_PrimarySelection *primary = &seat->primary_selection;
+      std::lock_guard lock{primary->data_source_mutex};
+      gwl_primary_selection_discard_source(primary);
+    }
+
+    if (seat->primary_selection_device) {
+      zwp_primary_selection_device_v1_destroy(seat->primary_selection_device);
+    }
+
     if (seat->data_device) {
       wl_data_device_release(seat->data_device);
     }
@@ -696,6 +765,10 @@ static void display_destroy(GWL_Display *display)
     zwp_pointer_constraints_v1_destroy(display->pointer_constraints);
   }
 
+  if (display->primary_selection_device_manager) {
+    zwp_primary_selection_device_manager_v1_destroy(display->primary_selection_device_manager);
+  }
+
   if (display->wl_compositor) {
     wl_compositor_destroy(display->wl_compositor);
   }
@@ -1250,6 +1323,35 @@ static std::string read_pipe(GWL_DataOffer *data_offer,
   return data;
 }
 
+static std::string read_pipe_primary(GWL_PrimarySelection_DataOffer *data_offer,
+                                     const std::string mime_receive,
+                                     std::mutex *mutex)
+{
+  int pipefd[2];
+  if (UNLIKELY(pipe(pipefd) != 0)) {
+    return {};
+  }
+  zwp_primary_selection_offer_v1_receive(data_offer->id, mime_receive.c_str(), pipefd[1]);
+  close(pipefd[1]);
+
+  data_offer->in_use.store(false);
+
+  if (mutex) {
+    mutex->unlock();
+  }
+  /* WARNING: `data_offer_base` may be freed from now on. */
+
+  std::string data;
+  ssize_t len;
+  char buffer[4096];
+  while ((len = read(pipefd[0], buffer, sizeof(buffer))) > 0) {
+    data.insert(data.end(), buffer, buffer + len);
+  }
+  close(pipefd[0]);
+
+  return data;
+}
+
 /**
  * A target accepts an offered mime type.
  *
@@ -2881,6 +2983,158 @@ static const struct wl_keyboard_listener keyboard_listener = {
 /** \} */
 
 /* -------------------------------------------------------------------- */
+/** \name Listener (Primary Selection Offer), #zwp_primary_selection_offer_v1_listener
+ * \{ */
+
+static CLG_LogRef LOG_WL_PRIMARY_SELECTION_OFFER = {"ghost.wl.handle.primary_selection_offer"};
+#define LOG (&LOG_WL_PRIMARY_SELECTION_OFFER)
+
+static void primary_selection_offer_offer(void *data,
+                                          struct zwp_primary_selection_offer_v1 *id,
+                                          const char *type)
+{
+  GWL_PrimarySelection_DataOffer *data_offer = static_cast<GWL_PrimarySelection_DataOffer *>(data);
+  if (data_offer->id != id) {
+    CLOG_INFO(LOG, 2, "offer: %p: offer for unknown selection %p of %s (skipped)", data, id, type);
+    return;
+  }
+
+  data_offer->types.insert(std::string(type));
+}
+
+static const struct zwp_primary_selection_offer_v1_listener primary_selection_offer_listener = {
+    primary_selection_offer_offer,
+};
+
+#undef LOG
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Listener (Primary Selection Device), #zwp_primary_selection_device_v1_listener
+ * \{ */
+
+static CLG_LogRef LOG_WL_PRIMARY_SELECTION_DEVICE = {"ghost.wl.handle.primary_selection_device"};
+#define LOG (&LOG_WL_PRIMARY_SELECTION_DEVICE)
+
+static void primary_selection_device_handle_data_offer(
+    void * /*data*/,
+    struct zwp_primary_selection_device_v1 * /*zwp_primary_selection_device_v1*/,
+    struct zwp_primary_selection_offer_v1 *id)
+{
+  CLOG_INFO(LOG, 2, "data_offer");
+
+  GWL_PrimarySelection_DataOffer *data_offer = new GWL_PrimarySelection_DataOffer;
+  data_offer->id = id;
+  zwp_primary_selection_offer_v1_add_listener(id, &primary_selection_offer_listener, data_offer);
+}
+
+static void primary_selection_device_handle_selection(
+    void *data,
+    struct zwp_primary_selection_device_v1 * /*zwp_primary_selection_device_v1*/,
+    struct zwp_primary_selection_offer_v1 *id)
+{
+  GWL_PrimarySelection *primary = static_cast<GWL_PrimarySelection *>(data);
+
+  std::lock_guard lock{primary->data_offer_mutex};
+
+  /* Delete old data offer. */
+  if (primary->data_offer != nullptr) {
+    gwl_primary_selection_discard_offer(primary);
+  }
+
+  if (id == nullptr) {
+    CLOG_INFO(LOG, 2, "selection: (skipped)");
+    return;
+  }
+  CLOG_INFO(LOG, 2, "selection");
+  /* Get new data offer. */
+  GWL_PrimarySelection_DataOffer *data_offer = static_cast<GWL_PrimarySelection_DataOffer *>(
+      zwp_primary_selection_offer_v1_get_user_data(id));
+  primary->data_offer = data_offer;
+
+  auto read_selection_fn = [](GWL_PrimarySelection *primary) {
+    GHOST_SystemWayland *system = static_cast<GHOST_SystemWayland *>(GHOST_ISystem::getSystem());
+    primary->data_offer_mutex.lock();
+
+    GWL_PrimarySelection_DataOffer *data_offer = primary->data_offer;
+    std::string mime_receive;
+    for (const std::string type : {mime_text_utf8, mime_text_plain}) {
+      if (data_offer->types.count(type)) {
+        mime_receive = type;
+        break;
+      }
+    }
+    const std::string data = read_pipe_primary(
+        data_offer, mime_receive, &primary->data_offer_mutex);
+
+    {
+      std::lock_guard lock{system_clipboard_mutex};
+      system->clipboard_primary_set(data);
+    }
+  };
+
+  std::thread read_thread(read_selection_fn, primary);
+  read_thread.detach();
+}
+
+static const struct zwp_primary_selection_device_v1_listener primary_selection_device_listener = {
+    primary_selection_device_handle_data_offer,
+    primary_selection_device_handle_selection,
+};
+
+#undef LOG
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Listener (Primary Selection Source), #zwp_primary_selection_source_v1_listener
+ * \{ */
+
+static CLG_LogRef LOG_WL_PRIMARY_SELECTION_SOURCE = {"ghost.wl.handle.primary_selection_source"};
+#define LOG (&LOG_WL_PRIMARY_SELECTION_SOURCE)
+
+static void primary_selection_source_send(void *data,
+                                          struct zwp_primary_selection_source_v1 * /*source*/,
+                                          const char * /*mime_type*/,
+                                          int32_t fd)
+{
+  CLOG_INFO(LOG, 2, "send");
+
+  GWL_PrimarySelection *primary = static_cast<GWL_PrimarySelection *>(data);
+
+  std::lock_guard lock{primary->data_source_mutex};
+  GWL_PrimarySelection_DataSource *data_source = primary->data_source;
+
+  const char *const buffer = data_source->buffer_out;
+  if (write(fd, buffer, data_source->buffer_out_len) < 0) {
+    GHOST_PRINT("error writing to primary clipboard: " << std::strerror(errno) << std::endl);
+  }
+  close(fd);
+}
+
+static void primary_selection_source_cancelled(void *data,
+                                               struct zwp_primary_selection_source_v1 *source)
+{
+  CLOG_INFO(LOG, 2, "cancelled");
+
+  GWL_PrimarySelection *primary = static_cast<GWL_PrimarySelection *>(data);
+
+  if (source == primary->data_source->wl_source) {
+    gwl_primary_selection_discard_source(primary);
+  }
+}
+
+static const struct zwp_primary_selection_source_v1_listener primary_selection_source_listener = {
+    primary_selection_source_send,
+    primary_selection_source_cancelled,
+};
+
+#undef LOG
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
 /** \name Listener (Seat), #wl_seat_listener
  * \{ */
 
@@ -2927,6 +3181,17 @@ static void seat_handle_capabilities(void *data,
     seat->wl_keyboard = wl_seat_get_keyboard(wl_seat);
     wl_keyboard_add_listener(seat->wl_keyboard, &keyboard_listener, data);
   }
+
+  if (seat->system) {
+    zwp_primary_selection_device_manager_v1 *primary_selection_device_manager =
+        seat->system->wl_primary_selection_manager();
+    seat->primary_selection_device = zwp_primary_selection_device_manager_v1_get_device(
+        primary_selection_device_manager, seat->wl_seat);
+
+    zwp_primary_selection_device_v1_add_listener(seat->primary_selection_device,
+                                                 &primary_selection_device_listener,
+                                                 &seat->primary_selection);
+  }
 }
 
 static void seat_handle_name(void *data, struct wl_seat * /*wl_seat*/, const char *name)
@@ -3297,6 +3562,12 @@ static void global_handle_add(void *data,
     display->pointer_constraints = static_cast<zwp_pointer_constraints_v1 *>(
         wl_registry_bind(wl_registry, name, &zwp_pointer_constraints_v1_interface, 1));
   }
+  else if (!strcmp(interface, zwp_primary_selection_device_manager_v1_interface.name)) {
+    display->primary_selection_device_manager =
+        static_cast<zwp_primary_selection_device_manager_v1 *>(wl_registry_bind(
+            wl_registry, name, &zwp_primary_selection_device_manager_v1_interface, 1));
+  }
+
   else {
     found = false;
 
@@ -3564,20 +3835,52 @@ GHOST_TSuccess GHOST_SystemWayland::getButtons(GHOST_Buttons &buttons) const
   return GHOST_kSuccess;
 }
 
-char *GHOST_SystemWayland::getClipboard(bool /*selection*/) const
+char *GHOST_SystemWayland::getClipboard(bool selection) const
 {
-  char *clipboard = static_cast<char *>(malloc(clipboard_.size() + 1));
-  memcpy(clipboard, clipboard_.data(), clipboard_.size() + 1);
+  const std::string &buf = selection ? clipboard_primary_ : clipboard_;
+  char *clipboard = static_cast<char *>(malloc(buf.size() + 1));
+  memcpy(clipboard, buf.data(), buf.size() + 1);
   return clipboard;
 }
 
-void GHOST_SystemWayland::putClipboard(const char *buffer, bool /*selection*/) const
+static void system_clipboard_put_primary_selection(GWL_Display *display, const char *buffer)
 {
-  if (UNLIKELY(!display_->data_device_manager || display_->seats.empty())) {
+  if (!display->primary_selection_device_manager) {
     return;
   }
+  GWL_Seat *seat = display->seats[0];
+  GWL_PrimarySelection *primary = &seat->primary_selection;
 
-  GWL_Seat *seat = display_->seats[0];
+  std::lock_guard lock{primary->data_source_mutex};
+
+  gwl_primary_selection_discard_source(primary);
+
+  GWL_PrimarySelection_DataSource *data_source = new GWL_PrimarySelection_DataSource;
+  primary->data_source = data_source;
+
+  data_source->buffer_out_len = strlen(buffer);
+  data_source->buffer_out = static_cast<char *>(malloc(data_source->buffer_out_len));
+  std::memcpy(data_source->buffer_out, buffer, data_source->buffer_out_len);
+
+  data_source->wl_source = zwp_primary_selection_device_manager_v1_create_source(
+      display->primary_selection_device_manager);
+
+  zwp_primary_selection_source_v1_add_listener(
+      data_source->wl_source, &primary_selection_source_listener, primary);
+
+  for (const std::string &type : mime_send) {
+    zwp_primary_selection_source_v1_offer(data_source->wl_source, type.c_str());
+  }
+
+  if (seat->primary_selection_device) {
+    zwp_primary_selection_device_v1_set_selection(
+        seat->primary_selection_device, data_source->wl_source, seat->data_source_serial);
+  }
+}
+
+static void system_clipboard_put(GWL_Display *display, const char *buffer)
+{
+  GWL_Seat *seat = display->seats[0];
 
   std::lock_guard lock{seat->data_source_mutex};
 
@@ -3590,7 +3893,7 @@ void GHOST_SystemWayland::putClipboard(const char *buffer, bool /*selection*/) c
   std::memcpy(data_source->buffer_out, buffer, data_source->buffer_out_len);
 
   data_source->wl_data_source = wl_data_device_manager_create_data_source(
-      display_->data_device_manager);
+      display->data_device_manager);
 
   wl_data_source_add_listener(data_source->wl_data_source, &data_source_listener, seat);
 
@@ -3604,6 +3907,20 @@ void GHOST_SystemWayland::putClipboard(const char *buffer, bool /*selection*/) c
   }
 }
 
+void GHOST_SystemWayland::putClipboard(const char *buffer, bool selection) const
+{
+  if (UNLIKELY(!display_->data_device_manager || display_->seats.empty())) {
+    return;
+  }
+
+  if (selection) {
+    system_clipboard_put_primary_selection(display_, buffer);
+  }
+  else {
+    system_clipboard_put(display_, buffer);
+  }
+}
+
 uint8_t GHOST_SystemWayland::getNumDisplays() const
 {
   return display_ ? uint8_t(display_->outputs.size()) : 0;
@@ -4345,6 +4662,11 @@ wl_compositor *GHOST_SystemWayland::wl_compositor()
   return display_->wl_compositor;
 }
 
+struct zwp_primary_selection_device_manager_v1 *GHOST_SystemWayland::wl_primary_selection_manager()
+{
+  return display_->primary_selection_device_manager;
+}
+
 #ifdef WITH_GHOST_WAYLAND_LIBDECOR
 
 libdecor *GHOST_SystemWayland::libdecor_context()
@@ -4412,6 +4734,11 @@ void GHOST_SystemWayland::clipboard_set(const std::string &clipboard)
   clipboard_ = clipboard;
 }
 
+void GHOST_SystemWayland::clipboard_primary_set(const std::string &clipboard)
+{
+  clipboard_primary_ = clipboard;
+}
+
 void GHOST_SystemWayland::window_surface_unref(const wl_surface *wl_surface)
 {
 #define SURFACE_CLEAR_PTR(surface_test) \
diff --git a/intern/ghost/intern/GHOST_SystemWayland.h b/intern/ghost/intern/GHOST_SystemWayland.h
index ca78ccb89ab..ddcd63610ef 100644
--- a/intern/ghost/intern/GHOST_SystemWayland.h
+++ b/intern/ghost/intern/GHOST_SystemWayland.h
@@ -158,6 +158,7 @@ class GHOST_SystemWayland : public GHOST_System {
 
   struct wl_display *wl_display();
   struct wl_compositor *wl_compositor();
+  struct zwp_primary_selection_device_manager_v1 *wl_primary_selection_manager();
 
 #ifdef WITH_GHOST_WAYLAND_LIBDECOR
   libdecor *libdecor_context();
@@ -173,6 +174,7 @@ class GHOST_SystemWayland : public GHOST_System {
   /* WAYLAND utility functions. */
 
   void clipboard_set(const std::string &clipboard);
+  void clipboard_primary_set(const std::string &clipboard);
 
   /** Clear all references to this surface to prevent accessing NULL pointers. */
   void window_surface_unref(const wl_surface *wl_surface);
@@ -192,4 +194,5 @@ class GHOST_SystemWayland : public GHOST_System {
  private:
   struct GWL_Display *display_;
   std::string clipboard_;
+  std::string clipboard_primary_;
 };