Node Editor: Link Drag Search Menu

This commit adds a search menu when links are dragged above empty
space. When releasing the drag, a menu displays all compatible
sockets with the source link. The "main" sockets (usually the first)
are weighted above other sockets in the search, so they appear first
when you type the name of the node.

A few special operators for creating a reroute or a group input node
are also added to the search.

Translation is started after choosing a node so it can be placed
quickly, since users would likely adjust the position after anyway.

A small "+" is displayed next to the cursor to give a hint about this.

Further improvements are possible after this first iteration:
 - Support custom node trees.
 - Better drawing of items in the search menu.
 - Potential tweaks to filtering of items, depending on user feedback.

Thanks to Juanfran Matheu for developing an initial patch.

Differential Revision: https://developer.blender.org/D8286

4 files changed, 344 insertions, 29 deletions

diff --git a/source/blender/nodes/intern/node_declaration.cc b/source/blender/nodes/intern/node_declaration.cc
index 7a19acd2510..75d47cfd386 100644
--- a/source/blender/nodes/intern/node_declaration.cc
+++ b/source/blender/nodes/intern/node_declaration.cc
@@ -51,7 +51,9 @@ bNodeSocket &SocketDeclaration::update_or_build(bNodeTree &ntree,
                                                 bNodeSocket &socket) const
 {
   /* By default just rebuild. */
-  return this->build(ntree, node, (eNodeSocketInOut)socket.in_out);
+  BLI_assert(socket.in_out == in_out_);
+  UNUSED_VARS_NDEBUG(socket);
+  return this->build(ntree, node);
 }
 
 void SocketDeclaration::set_common_flags(bNodeSocket &socket) const
diff --git a/source/blender/nodes/intern/node_socket.cc b/source/blender/nodes/intern/node_socket.cc
index dbc4f489a88..d83c05b38a1 100644
--- a/source/blender/nodes/intern/node_socket.cc
+++ b/source/blender/nodes/intern/node_socket.cc
@@ -191,7 +191,6 @@ static void refresh_socket_list(bNodeTree &ntree,
                                 bNode &node,
                                 ListBase &sockets,
                                 Span<SocketDeclarationPtr> socket_decls,
-                                const eNodeSocketInOut in_out,
                                 const bool do_id_user)
 {
   Vector<bNodeSocket *> old_sockets = sockets;
@@ -210,7 +209,7 @@ static void refresh_socket_list(bNodeTree &ntree,
     bNodeSocket *new_socket = nullptr;
     if (old_socket_with_same_identifier == nullptr) {
       /* Create a completely new socket. */
-      new_socket = &socket_decl->build(ntree, node, in_out);
+      new_socket = &socket_decl->build(ntree, node);
     }
     else {
       STRNCPY(old_socket_with_same_identifier->name, socket_decl->name().c_str());
@@ -258,8 +257,8 @@ static void refresh_node(bNodeTree &ntree,
                          blender::nodes::NodeDeclaration &node_decl,
                          bool do_id_user)
 {
-  refresh_socket_list(ntree, node, node.inputs, node_decl.inputs(), SOCK_IN, do_id_user);
-  refresh_socket_list(ntree, node, node.outputs, node_decl.outputs(), SOCK_OUT, do_id_user);
+  refresh_socket_list(ntree, node, node.inputs, node_decl.inputs(), do_id_user);
+  refresh_socket_list(ntree, node, node.outputs, node_decl.outputs(), do_id_user);
 }
 
 void node_verify_sockets(bNodeTree *ntree, bNode *node, bool do_id_user)
diff --git a/source/blender/nodes/intern/node_socket_declarations.cc b/source/blender/nodes/intern/node_socket_declarations.cc
index 1795cc339e7..4fef5b96e9f 100644
--- a/source/blender/nodes/intern/node_socket_declarations.cc
+++ b/source/blender/nodes/intern/node_socket_declarations.cc
@@ -23,6 +23,52 @@
 
 namespace blender::nodes::decl {
 
+/**
+ * \note This function only deals with declarations, not the field status of existing nodes. If the
+ * field status of existing nodes was stored on the sockets, an improvement would be to check the
+ * existing socket's current status instead of the declaration.
+ */
+static bool field_types_are_compatible(const SocketDeclaration &input,
+                                       const SocketDeclaration &output)
+{
+  if (output.output_field_dependency().field_type() == OutputSocketFieldType::FieldSource) {
+    if (input.input_field_type() == InputSocketFieldType::None) {
+      return false;
+    }
+  }
+  return true;
+}
+
+static bool sockets_can_connect(const SocketDeclaration &socket_decl,
+                                const bNodeSocket &other_socket)
+{
+  /* Input sockets cannot connect to input sockets, outputs cannot connect to outputs. */
+  if (socket_decl.in_out() == other_socket.in_out) {
+    return false;
+  }
+
+  if (other_socket.declaration) {
+    if (socket_decl.in_out() == SOCK_IN) {
+      if (!field_types_are_compatible(socket_decl, *other_socket.declaration)) {
+        return false;
+      }
+    }
+    else {
+      if (!field_types_are_compatible(*other_socket.declaration, socket_decl)) {
+        return false;
+      }
+    }
+  }
+
+  return true;
+}
+
+static bool basic_types_can_connect(const SocketDeclaration &UNUSED(socket_decl),
+                                    const bNodeSocket &other_socket)
+{
+  return ELEM(other_socket.type, SOCK_FLOAT, SOCK_INT, SOCK_BOOLEAN, SOCK_VECTOR, SOCK_RGBA);
+}
+
 static void modify_subtype_except_for_storage(bNodeSocket &socket, int new_subtype)
 {
   const char *idname = nodeStaticSocketType(socket.type, new_subtype);
@@ -35,10 +81,10 @@ static void modify_subtype_except_for_storage(bNodeSocket &socket, int new_subty
 /** \name #Float
  * \{ */
 
-bNodeSocket &Float::build(bNodeTree &ntree, bNode &node, eNodeSocketInOut in_out) const
+bNodeSocket &Float::build(bNodeTree &ntree, bNode &node) const
 {
   bNodeSocket &socket = *nodeAddStaticSocket(
-      &ntree, &node, in_out, SOCK_FLOAT, subtype_, identifier_.c_str(), name_.c_str());
+      &ntree, &node, in_out_, SOCK_FLOAT, subtype_, identifier_.c_str(), name_.c_str());
   this->set_common_flags(socket);
   bNodeSocketValueFloat &value = *(bNodeSocketValueFloat *)socket.default_value;
   value.min = soft_min_value_;
@@ -68,10 +114,19 @@ bool Float::matches(const bNodeSocket &socket) const
   return true;
 }
 
+bool Float::can_connect(const bNodeSocket &socket) const
+{
+  if (!sockets_can_connect(*this, socket)) {
+    return false;
+  }
+  return basic_types_can_connect(*this, socket);
+}
+
 bNodeSocket &Float::update_or_build(bNodeTree &ntree, bNode &node, bNodeSocket &socket) const
 {
   if (socket.type != SOCK_FLOAT) {
-    return this->build(ntree, node, (eNodeSocketInOut)socket.in_out);
+    BLI_assert(socket.in_out == in_out_);
+    return this->build(ntree, node);
   }
   if (socket.typeinfo->subtype != subtype_) {
     modify_subtype_except_for_storage(socket, subtype_);
@@ -90,10 +145,10 @@ bNodeSocket &Float::update_or_build(bNodeTree &ntree, bNode &node, bNodeSocket &
 /** \name #Int
  * \{ */
 
-bNodeSocket &Int::build(bNodeTree &ntree, bNode &node, eNodeSocketInOut in_out) const
+bNodeSocket &Int::build(bNodeTree &ntree, bNode &node) const
 {
   bNodeSocket &socket = *nodeAddStaticSocket(
-      &ntree, &node, in_out, SOCK_INT, subtype_, identifier_.c_str(), name_.c_str());
+      &ntree, &node, in_out_, SOCK_INT, subtype_, identifier_.c_str(), name_.c_str());
   this->set_common_flags(socket);
   bNodeSocketValueInt &value = *(bNodeSocketValueInt *)socket.default_value;
   value.min = soft_min_value_;
@@ -123,10 +178,19 @@ bool Int::matches(const bNodeSocket &socket) const
   return true;
 }
 
+bool Int::can_connect(const bNodeSocket &socket) const
+{
+  if (!sockets_can_connect(*this, socket)) {
+    return false;
+  }
+  return basic_types_can_connect(*this, socket);
+}
+
 bNodeSocket &Int::update_or_build(bNodeTree &ntree, bNode &node, bNodeSocket &socket) const
 {
   if (socket.type != SOCK_INT) {
-    return this->build(ntree, node, (eNodeSocketInOut)socket.in_out);
+    BLI_assert(socket.in_out == in_out_);
+    return this->build(ntree, node);
   }
   if (socket.typeinfo->subtype != subtype_) {
     modify_subtype_except_for_storage(socket, subtype_);
@@ -145,10 +209,10 @@ bNodeSocket &Int::update_or_build(bNodeTree &ntree, bNode &node, bNodeSocket &so
 /** \name #Vector
  * \{ */
 
-bNodeSocket &Vector::build(bNodeTree &ntree, bNode &node, eNodeSocketInOut in_out) const
+bNodeSocket &Vector::build(bNodeTree &ntree, bNode &node) const
 {
   bNodeSocket &socket = *nodeAddStaticSocket(
-      &ntree, &node, in_out, SOCK_VECTOR, subtype_, identifier_.c_str(), name_.c_str());
+      &ntree, &node, in_out_, SOCK_VECTOR, subtype_, identifier_.c_str(), name_.c_str());
   this->set_common_flags(socket);
   bNodeSocketValueVector &value = *(bNodeSocketValueVector *)socket.default_value;
   copy_v3_v3(value.value, default_value_);
@@ -171,10 +235,19 @@ bool Vector::matches(const bNodeSocket &socket) const
   return true;
 }
 
+bool Vector::can_connect(const bNodeSocket &socket) const
+{
+  if (!sockets_can_connect(*this, socket)) {
+    return false;
+  }
+  return basic_types_can_connect(*this, socket);
+}
+
 bNodeSocket &Vector::update_or_build(bNodeTree &ntree, bNode &node, bNodeSocket &socket) const
 {
   if (socket.type != SOCK_VECTOR) {
-    return this->build(ntree, node, (eNodeSocketInOut)socket.in_out);
+    BLI_assert(socket.in_out == in_out_);
+    return this->build(ntree, node);
   }
   if (socket.typeinfo->subtype != subtype_) {
     modify_subtype_except_for_storage(socket, subtype_);
@@ -192,10 +265,10 @@ bNodeSocket &Vector::update_or_build(bNodeTree &ntree, bNode &node, bNodeSocket
 /** \name #Bool
  * \{ */
 
-bNodeSocket &Bool::build(bNodeTree &ntree, bNode &node, eNodeSocketInOut in_out) const
+bNodeSocket &Bool::build(bNodeTree &ntree, bNode &node) const
 {
   bNodeSocket &socket = *nodeAddStaticSocket(
-      &ntree, &node, in_out, SOCK_BOOLEAN, PROP_NONE, identifier_.c_str(), name_.c_str());
+      &ntree, &node, in_out_, SOCK_BOOLEAN, PROP_NONE, identifier_.c_str(), name_.c_str());
   this->set_common_flags(socket);
   bNodeSocketValueBoolean &value = *(bNodeSocketValueBoolean *)socket.default_value;
   value.value = default_value_;
@@ -213,16 +286,24 @@ bool Bool::matches(const bNodeSocket &socket) const
   return true;
 }
 
+bool Bool::can_connect(const bNodeSocket &socket) const
+{
+  if (!sockets_can_connect(*this, socket)) {
+    return false;
+  }
+  return basic_types_can_connect(*this, socket);
+}
+
 /** \} */
 
 /* -------------------------------------------------------------------- */
 /** \name #Color
  * \{ */
 
-bNodeSocket &Color::build(bNodeTree &ntree, bNode &node, eNodeSocketInOut in_out) const
+bNodeSocket &Color::build(bNodeTree &ntree, bNode &node) const
 {
   bNodeSocket &socket = *nodeAddStaticSocket(
-      &ntree, &node, in_out, SOCK_RGBA, PROP_NONE, identifier_.c_str(), name_.c_str());
+      &ntree, &node, in_out_, SOCK_RGBA, PROP_NONE, identifier_.c_str(), name_.c_str());
   this->set_common_flags(socket);
   bNodeSocketValueRGBA &value = *(bNodeSocketValueRGBA *)socket.default_value;
   copy_v4_v4(value.value, default_value_);
@@ -245,16 +326,24 @@ bool Color::matches(const bNodeSocket &socket) const
   return true;
 }
 
+bool Color::can_connect(const bNodeSocket &socket) const
+{
+  if (!sockets_can_connect(*this, socket)) {
+    return false;
+  }
+  return basic_types_can_connect(*this, socket);
+}
+
 /** \} */
 
 /* -------------------------------------------------------------------- */
 /** \name #String
  * \{ */
 
-bNodeSocket &String::build(bNodeTree &ntree, bNode &node, eNodeSocketInOut in_out) const
+bNodeSocket &String::build(bNodeTree &ntree, bNode &node) const
 {
   bNodeSocket &socket = *nodeAddStaticSocket(
-      &ntree, &node, in_out, SOCK_STRING, PROP_NONE, identifier_.c_str(), name_.c_str());
+      &ntree, &node, in_out_, SOCK_STRING, PROP_NONE, identifier_.c_str(), name_.c_str());
   STRNCPY(((bNodeSocketValueString *)socket.default_value)->value, default_value_.c_str());
   this->set_common_flags(socket);
   return socket;
@@ -271,18 +360,21 @@ bool String::matches(const bNodeSocket &socket) const
   return true;
 }
 
+bool String::can_connect(const bNodeSocket &socket) const
+{
+  return sockets_can_connect(*this, socket) && socket.type == SOCK_STRING;
+}
+
 /** \} */
 
 /* -------------------------------------------------------------------- */
 /** \name #IDSocketDeclaration
  * \{ */
 
-bNodeSocket &IDSocketDeclaration::build(bNodeTree &ntree,
-                                        bNode &node,
-                                        eNodeSocketInOut in_out) const
+bNodeSocket &IDSocketDeclaration::build(bNodeTree &ntree, bNode &node) const
 {
   bNodeSocket &socket = *nodeAddSocket(
-      &ntree, &node, in_out, idname_, identifier_.c_str(), name_.c_str());
+      &ntree, &node, in_out_, idname_, identifier_.c_str(), name_.c_str());
   this->set_common_flags(socket);
   return socket;
 }
@@ -298,12 +390,18 @@ bool IDSocketDeclaration::matches(const bNodeSocket &socket) const
   return true;
 }
 
+bool IDSocketDeclaration::can_connect(const bNodeSocket &socket) const
+{
+  return sockets_can_connect(*this, socket) && STREQ(socket.idname, idname_);
+}
+
 bNodeSocket &IDSocketDeclaration::update_or_build(bNodeTree &ntree,
                                                   bNode &node,
                                                   bNodeSocket &socket) const
 {
   if (StringRef(socket.idname) != idname_) {
-    return this->build(ntree, node, (eNodeSocketInOut)socket.in_out);
+    BLI_assert(socket.in_out == in_out_);
+    return this->build(ntree, node);
   }
   this->set_common_flags(socket);
   return socket;
@@ -315,10 +413,10 @@ bNodeSocket &IDSocketDeclaration::update_or_build(bNodeTree &ntree,
 /** \name #Geometry
  * \{ */
 
-bNodeSocket &Geometry::build(bNodeTree &ntree, bNode &node, eNodeSocketInOut in_out) const
+bNodeSocket &Geometry::build(bNodeTree &ntree, bNode &node) const
 {
   bNodeSocket &socket = *nodeAddSocket(
-      &ntree, &node, in_out, "NodeSocketGeometry", identifier_.c_str(), name_.c_str());
+      &ntree, &node, in_out_, "NodeSocketGeometry", identifier_.c_str(), name_.c_str());
   this->set_common_flags(socket);
   return socket;
 }
@@ -334,6 +432,11 @@ bool Geometry::matches(const bNodeSocket &socket) const
   return true;
 }
 
+bool Geometry::can_connect(const bNodeSocket &socket) const
+{
+  return sockets_can_connect(*this, socket) && socket.type == SOCK_GEOMETRY;
+}
+
 Span<GeometryComponentType> Geometry::supported_types() const
 {
   return supported_types_;
@@ -380,10 +483,10 @@ GeometryBuilder &GeometryBuilder::only_instances(bool value)
 /** \name #Shader
  * \{ */
 
-bNodeSocket &Shader::build(bNodeTree &ntree, bNode &node, eNodeSocketInOut in_out) const
+bNodeSocket &Shader::build(bNodeTree &ntree, bNode &node) const
 {
   bNodeSocket &socket = *nodeAddSocket(
-      &ntree, &node, in_out, "NodeSocketShader", identifier_.c_str(), name_.c_str());
+      &ntree, &node, in_out_, "NodeSocketShader", identifier_.c_str(), name_.c_str());
   this->set_common_flags(socket);
   return socket;
 }
@@ -399,6 +502,18 @@ bool Shader::matches(const bNodeSocket &socket) const
   return true;
 }
 
+bool Shader::can_connect(const bNodeSocket &socket) const
+{
+  if (!sockets_can_connect(*this, socket)) {
+    return false;
+  }
+  /* Basic types can convert to shaders, but not the other way around. */
+  if (in_out_ == SOCK_IN) {
+    return ELEM(socket.type, SOCK_VECTOR, SOCK_RGBA, SOCK_FLOAT, SOCK_INT, SOCK_BOOLEAN);
+  }
+  return socket.type == SOCK_SHADER;
+}
+
 /** \} */
 
 }  // namespace blender::nodes::decl
diff --git a/source/blender/nodes/intern/socket_search_link.cc b/source/blender/nodes/intern/socket_search_link.cc
new file mode 100644
index 00000000000..48f8106e58b
--- /dev/null
+++ b/source/blender/nodes/intern/socket_search_link.cc
@@ -0,0 +1,199 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include "BLI_set.hh"
+
+#include "BKE_node.h"
+
+#include "UI_interface.h"
+
+#include "NOD_node_declaration.hh"
+#include "NOD_socket_search_link.hh"
+
+namespace blender::nodes {
+
+void GatherLinkSearchOpParams::add_item(std::string socket_name,
+                                        SocketLinkOperation::LinkSocketFn fn,
+                                        const int weight)
+{
+
+  std::string name = std::string(node_type_.ui_name) + " " + UI_MENU_ARROW_SEP + socket_name;
+
+  items_.append({std::move(name), std::move(fn), weight});
+}
+
+const bNodeSocket &GatherLinkSearchOpParams::other_socket() const
+{
+  return other_socket_;
+}
+
+const bNodeTree &GatherLinkSearchOpParams::node_tree() const
+{
+  return node_tree_;
+}
+
+const bNodeType &GatherLinkSearchOpParams::node_type() const
+{
+  return node_type_;
+}
+
+eNodeSocketInOut GatherLinkSearchOpParams::in_out() const
+{
+  return other_socket_.in_out == SOCK_IN ? SOCK_OUT : SOCK_IN;
+}
+
+void LinkSearchOpParams::connect_available_socket(bNode &new_node, StringRef socket_name)
+{
+  const eNodeSocketInOut in_out = socket.in_out == SOCK_IN ? SOCK_OUT : SOCK_IN;
+  bNodeSocket *new_node_socket = bke::node_find_enabled_socket(new_node, in_out, socket_name);
+  if (new_node_socket == nullptr) {
+    /* If the socket isn't found, some node's search gather functions probably aren't configured
+     * properly. It's likely enough that it's worth avoiding a crash in a release build though. */
+    BLI_assert_unreachable();
+    return;
+  }
+  nodeAddLink(&node_tree, &new_node, new_node_socket, &node, &socket);
+}
+
+bNode &LinkSearchOpParams::add_node(StringRef idname)
+{
+  std::string idname_str = idname;
+  bNode *node = nodeAddNode(&C, &node_tree, idname_str.c_str());
+  BLI_assert(node != nullptr);
+  added_nodes_.append(node);
+  return *node;
+}
+
+bNode &LinkSearchOpParams::add_node(const bNodeType &node_type)
+{
+  return this->add_node(node_type.idname);
+}
+
+void LinkSearchOpParams::update_and_connect_available_socket(bNode &new_node,
+                                                             StringRef socket_name)
+{
+  if (new_node.typeinfo->updatefunc) {
+    new_node.typeinfo->updatefunc(&node_tree, &new_node);
+  }
+  this->connect_available_socket(new_node, socket_name);
+}
+
+void search_link_ops_for_declarations(GatherLinkSearchOpParams &params,
+                                      Span<SocketDeclarationPtr> declarations)
+{
+  const bNodeType &node_type = params.node_type();
+
+  const SocketDeclaration *main_socket = nullptr;
+  Vector<const SocketDeclaration *> connectable_sockets;
+
+  Set<StringRef> socket_names;
+  for (const int i : declarations.index_range()) {
+    const SocketDeclaration &socket = *declarations[i];
+    if (!socket_names.add(socket.name())) {
+      /* Don't add sockets with the same name to the search. Needed to support being called from
+       * #search_link_ops_for_basic_node, which should have "okay" behavior for nodes with
+       * duplicate socket names. */
+      continue;
+    }
+    if (!socket.can_connect(params.other_socket())) {
+      continue;
+    }
+    if (socket.is_default_link_socket() || main_socket == nullptr) {
+      /* Either the first connectable or explicitly tagged socket is the main socket. */
+      main_socket = &socket;
+    }
+    connectable_sockets.append(&socket);
+  }
+  for (const int i : connectable_sockets.index_range()) {
+    const SocketDeclaration &socket = *connectable_sockets[i];
+    /* Give non-main sockets a lower weight so that they don't show up at the top of the search
+     * when they are not explicitly searched for. The -1 is used to make sure that the first socket
+     * has a smaller weight than zero so that it does not have the same weight as the main socket.
+     * Negative weights are used to avoid making the heighest weight dependent on the number of
+     * sockets. */
+    const int weight = (&socket == main_socket) ? 0 : -1 - i;
+    params.add_item(
+        socket.name(),
+        [&node_type, &socket](LinkSearchOpParams &params) {
+          bNode &node = params.add_node(node_type);
+          socket.make_available(node);
+          params.update_and_connect_available_socket(node, socket.name());
+        },
+        weight);
+  }
+}
+
+static void search_link_ops_for_socket_templates(GatherLinkSearchOpParams &params,
+                                                 const bNodeSocketTemplate *templates,
+                                                 const eNodeSocketInOut in_out)
+{
+  const bNodeType &node_type = params.node_type();
+  const bNodeTreeType &node_tree_type = *params.node_tree().typeinfo;
+
+  Set<StringRef> socket_names;
+  for (const bNodeSocketTemplate *socket_template = templates; socket_template->type != -1;
+       socket_template++) {
+    eNodeSocketDatatype from = (eNodeSocketDatatype)socket_template->type;
+    eNodeSocketDatatype to = (eNodeSocketDatatype)params.other_socket().type;
+    if (in_out == SOCK_IN) {
+      std::swap(from, to);
+    }
+    if (node_tree_type.validate_link && !node_tree_type.validate_link(from, to)) {
+      continue;
+    }
+    if (!socket_names.add(socket_template->name)) {
+      /* See comment in #search_link_ops_for_declarations. */
+      continue;
+    }
+
+    params.add_item(
+        socket_template->name, [socket_template, node_type, in_out](LinkSearchOpParams &params) {
+          bNode &node = params.add_node(node_type);
+          bNodeSocket *new_node_socket = bke::node_find_enabled_socket(
+              node, in_out, socket_template->name);
+          if (new_node_socket != nullptr) {
+            /* Rely on the way #nodeAddLink switches in/out if necessary. */
+            nodeAddLink(&params.node_tree, &params.node, &params.socket, &node, new_node_socket);
+          }
+        });
+  }
+}
+
+void search_link_ops_for_basic_node(GatherLinkSearchOpParams &params)
+{
+  const bNodeType &node_type = params.node_type();
+
+  if (node_type.declare) {
+    if (node_type.declaration_is_dynamic) {
+      /* Dynamic declarations (whatever they end up being) aren't supported
+       * by this function, but still avoid a crash in release builds. */
+      BLI_assert_unreachable();
+      return;
+    }
+
+    const NodeDeclaration &declaration = *node_type.fixed_declaration;
+
+    search_link_ops_for_declarations(params, declaration.sockets(params.in_out()));
+  }
+  else if (node_type.inputs && params.in_out() == SOCK_IN) {
+    search_link_ops_for_socket_templates(params, node_type.inputs, SOCK_IN);
+  }
+  else if (node_type.outputs && params.in_out() == SOCK_OUT) {
+    search_link_ops_for_socket_templates(params, node_type.outputs, SOCK_OUT);
+  }
+}
+
+}  // namespace blender::nodes