Support token editing within GraphEditor UI

source/MaterialXGraphEditor/Graph.cpp

@@ -1009,6 +1009,8 @@ void Graph::showPropertyEditorValue(UiNodePtr node, mx::InputPtr input, const mx
                 nodeInput->setValueString(temp);
                 nodeInput->setValue(temp, nodeInput->getType());
                 updateMaterials();
+
+                _currUiNode->buildUiTokenMap(); // Re-build token map
             }
         }
     }
@@ -1062,16 +1064,16 @@ void Graph::setUiNodeInfo(UiNodePtr node, const std::string& type, const std::st
     }
     else
     {
-        if (node->getNode())
+        if (mx::ConstNodePtr mxNode = node->getNode())
         {
-            mx::NodeDefPtr nodeDef = node->getNode()->getNodeDef(node->getNode()->getName());
+            mx::NodeDefPtr nodeDef = mxNode->getNodeDef(mxNode->getName());
             if (nodeDef)
             {
                 for (mx::InputPtr input : nodeDef->getActiveInputs())
                 {
-                    if (node->getNode()->getInput(input->getName()))
+                    if (mxNode->getInput(input->getName()))
                     {
-                        input = node->getNode()->getInput(input->getName());
+                        input = mxNode->getInput(input->getName());
                     }
                     UiPinPtr inPin = std::make_shared<UiPin>(_state.nextUiId, node, ax::NodeEditor::PinKind::Input, input);
                     node->getInputPins().push_back(inPin);
@@ -1081,16 +1083,18 @@ void Graph::setUiNodeInfo(UiNodePtr node, const std::string& type, const std::st
 
                 for (mx::OutputPtr output : nodeDef->getActiveOutputs())
                 {
-                    if (node->getNode()->getOutput(output->getName()))
+                    if (mxNode->getOutput(output->getName()))
                     {
-                        output = node->getNode()->getOutput(output->getName());
+                        output = mxNode->getOutput(output->getName());
                     }
                     UiPinPtr outPin = std::make_shared<UiPin>(_state.nextUiId, node, ax::NodeEditor::PinKind::Output, output);
                     node->getOutputPins().push_back(outPin);
                     _state.pins.push_back(outPin);
                     ++_state.nextUiId;
                 }
             }
+
+            node->buildUiTokenMap(); // Build initial token map
         }
         else if (node->getInput())
         {
@@ -3662,41 +3666,63 @@ void Graph::propertyEditor()
 
             showPropertyEditorOutputConnections(_currUiNode);;
         }
-
-        // Find tokens within currUiNode
-        mx::ConstNodePtr node = _currUiNode->getNode();
-        if (node != nullptr)
+
+        // Draw token table
+        if (const auto& currTokenMap = _currUiNode->getUiTokenMap(); !currTokenMap.empty())
         {
-            mx::StringResolverPtr resolver = node->createStringResolver();
-            const mx::StringMap& tokens = resolver->getFilenameSubstitutions();
+            ImGui::Text("Tokens");
+            ImGui::SameLine();
+            drawHelpMarker("All tokens that are within scope of the selected node. Token values will be string-substituted into listed 'Affected Inputs'.");
+
+            int tokenCount = static_cast<int>(currTokenMap.size() + 1u); // Add 1 to account for header row
+            ImVec2 tableHeight(0.0f, TEXT_BASE_HEIGHT * std::min(SCROLL_LINE_COUNT, tokenCount));
 
-            if (!tokens.empty())
+            // Use `ImGuiTableFlags_SizingFixedFit` to set default column width to fit content
+            if (ImGui::BeginTable("tokens_node_table", 4, tableFlags | ImGuiTableFlags_SizingFixedFit, tableHeight))
             {
-                ImGui::Text("Tokens");
-
-                ImVec2 tableSize(0.0f, TEXT_BASE_HEIGHT * std::min(SCROLL_LINE_COUNT, static_cast<int>(tokens.size())));
-                bool haveTable = ImGui::BeginTable("tokens_node_table", 2, tableFlags, tableSize);
-                if (haveTable)
+                ImGui::SetWindowFontScale(_fontScale);
+
+                ImGui::TableSetupColumn("Name");
+                ImGui::TableSetupColumn("Value");
+                ImGui::TableSetupColumn("Source Element");
+                ImGui::TableSetupColumn("Affected Inputs");
+
+                // Set tooltips for each of table's columns
+                constexpr std::array tableHeadersTooltips = { "", "Press <enter> to set token value.", "The graph element where the token is declared.", "Node inputs which reference the token." };
+                drawTableHeadersRowWithTooltips(tableHeadersTooltips);
+
+                for (const auto& [tokenName, tokenPtr] : currTokenMap)
                 {
-                    ImGui::SetWindowFontScale(_fontScale);
+                    ImGui::TableNextRow(); // Start new row
+                    ImGui::PushID(&tokenName);
 
-                    for (const auto& [token, value] : tokens)
-                    {
-
-                        ImGui::TableNextRow();
-                        ImGui::TableNextColumn();
-                        ImGui::PushID(&token);
+                    // Name
+                    ImGui::TableNextColumn();
+                    ImGui::Text("%s", tokenName.c_str());
 
-                        ImGui::Text("%s", token.c_str());
-                        ImGui::TableNextColumn();
-                        ImGui::Text("%s", value.c_str());
+                    // Value
+                    ImGui::TableNextColumn();
+                    std::string tokenValue = tokenPtr->getValue();
 
-                        ImGui::PopID();
+                    if (ImGui::InputText("##token_value", &tokenValue, ImGuiInputTextFlags_EnterReturnsTrue))
+                    {
+                        tokenPtr->setValue(tokenValue);  // Write out new token value
+                        updateMaterials();               // Trigger update of material
                     }
-
-                    ImGui::EndTable();
-                    ImGui::SetWindowFontScale(1.0f);
+
+                    // Source Element
+                    ImGui::TableNextColumn();
+                    ImGui::Text("%s", tokenPtr->getSourceElementString().c_str());
+
+                    // Affected Inputs
+                    ImGui::TableNextColumn();
+                    ImGui::Text("%s", tokenPtr->getAffectedInputsString().c_str());
+
+                    ImGui::PopID();
                 }
+
+                ImGui::EndTable();
+                ImGui::SetWindowFontScale(1.0f); // Restore font scale
             }
         }
 
@@ -3760,6 +3786,20 @@ void Graph::showHelp() const
         ImGui::BulletText("\"Node Info\" Will toggle showing node information.");
     }
 }
+void Graph::drawHelpMarker(const char* content)
+{
+    constexpr float WRAP_POSITION = 32.f; // Compile-time definition of text-wrap position
+
+    ImGui::TextDisabled(HELP_MARKER_TEXT); // Draw help marker
+    if (!ImGui::IsItemHovered())
+        return; // If help marker isn't hovered return early
+
+    ImGui::BeginTooltip();
+    ImGui::PushTextWrapPos(ImGui::GetFontSize() * WRAP_POSITION);
+    ImGui::TextUnformatted(content);
+    ImGui::PopTextWrapPos();
+    ImGui::EndTooltip();
+}
 
 void Graph::addNodePopup(bool cursor)
 {

source/MaterialXGraphEditor/Graph.h

@@ -272,6 +272,35 @@ class Graph
 
     void showHelp() const;
 
+    // A compile-time constant member variable that corresponds to the function below. Defined in header as visibility is desirable here.
+    static constexpr char HELP_MARKER_TEXT[] = "(?)";
+    // Static helper function to draw a marker via ImGui which shows a tooltip when hovered
+    static void drawHelpMarker(const char* content);
+
+    // Static helper function to display tooltips for headers in an ImGui table
+    template <std::size_t N> static void drawTableHeadersRowWithTooltips(const std::array<const char*, N>& tooltips)
+    {
+        const int columnCount = ImGui::TableGetColumnCount();
+        if (columnCount == 0 || columnCount != N)
+            return; // Given array size should match number of columns in table
+
+        ImGui::TableNextRow(ImGuiTableRowFlags_Headers);
+        for (int col = 0; col < columnCount; ++col)
+        {
+            if (!ImGui::TableSetColumnIndex(col))
+                continue;                                       // Do not draw if column is not visible
+            ImGui::TableHeader(ImGui::TableGetColumnName(col)); // Header name
+
+            std::string colTooltip = tooltips[col];
+            if (!colTooltip.empty() && ImGui::IsItemHovered())
+            {
+                ImGui::BeginTooltip();
+                ImGui::TextUnformatted(tooltips[col]);
+                ImGui::EndTooltip();
+            }
+        }
+    }
+
   private:
     mx::StringVec _geomFilter;
     mx::StringVec _mtlxFilter;
@@ -357,5 +386,4 @@ class Graph
     // Options
     bool _saveNodePositions;
 };
-
 #endif

source/MaterialXGraphEditor/UiNode.cpp

@@ -95,6 +95,72 @@ mx::NodeGraphPtr UiNode::getNodeGraph() const
     return _element ? _element->asA<mx::NodeGraph>() : nullptr;
 }
 
+void UiNode::buildUiTokenMap()
+{
+    // Helper inline lambda function to avoid repeating code for mapping of tokens declared on element itself vs on element's corresponding nodedef
+    auto handleTokenMapping = [&](const mx::ConstInterfaceElementPtr& interfaceElem, mx::ElementPtr sourceElem)
+    {
+        std::vector<mx::TokenPtr> tokens = interfaceElem->getActiveTokens();
+        for (auto token : tokens)
+        {
+            std::string key = token->getName();
+
+            // Insert into map, but do not allow parent values to override child values
+            _uiTokenMap.try_emplace(key, std::make_shared<UiToken>(token, sourceElem));
+        }
+    };
+
+    _uiTokenMap.clear(); // Assume we want clean slate
+
+    mx::ElementPtr currElem = getNode();
+    while (currElem)
+    {
+        if (mx::ConstInterfaceElementPtr interfaceElem = currElem->asA<mx::InterfaceElement>())
+        {
+            handleTokenMapping(interfaceElem, currElem);
+
+            // If the node is a nodegraph, also check for tokens on corresponding nodedef
+            if (mx::ConstNodeGraphPtr nodegraph = currElem->asA<mx::NodeGraph>())
+            {
+                if (mx::NodeDefPtr nodedef = nodegraph->getNodeDef())
+                {
+                    handleTokenMapping(nodedef, nodedef);
+                }
+            }
+        }
+        currElem = currElem->getParent();
+    }
+
+    // Traverse through inputs and determine which tokens their value depends on
+    for (const auto& input : getNode()->getActiveInputs())
+    {
+        if (input->getType() != "filename")
+            continue;
+
+        mx::StringResolverPtr inputResolver = input->createStringResolver();
+        const mx::StringMap& inputTokens = inputResolver->getFilenameSubstitutions();
+
+        mx::StringMap inputTokensRenormalized;
+        for (const auto& entry : inputTokens)
+        {
+            // Store tokens without excess delimiters
+            inputTokensRenormalized[entry.first] = entry.first.substr(1, entry.first.size() - 2);
+        }
+
+        std::string inputValue = input->getValueString();
+        if (inputValue.empty() && input->hasInterfaceName())
+            inputValue = input->getInterfaceInput()->getValueString(); // Get value from referenced interface
+
+        for (const auto& entry : inputTokens)
+        {
+            if (inputValue.find(entry.first) != std::string::npos)
+            {
+                // Append to affected inputs of corresponding entry in token map
+                _uiTokenMap[inputTokensRenormalized[entry.first]]->addAffectedInput(input);
+            }
+        }
+    }
+}
 // return the uiNode connected with input name
 UiNodePtr UiNode::getConnectedNode(const std::string& name)
 {

source/MaterialXGraphEditor/UiNode.h

@@ -10,6 +10,9 @@
 
 #include <imgui_node_editor.h>
 
+#include <atomic>
+#include <sstream>
+
 namespace mx = MaterialX;
 namespace ed = ax::NodeEditor;
 
@@ -160,6 +163,65 @@ class UiPin
     bool _connected;
 };
 
+class UiToken
+{
+  public:
+    UiToken(const mx::TokenPtr& token, const mx::ElementPtr& elem) : _tokenPtr(token), _sourceElement(elem) { }
+
+    std::string getValue() const { return _tokenPtr->getValueString(); }
+    void setValue(const std::string& val) const
+    {
+        _tokenPtr->setValueString(val);
+    }
+
+    std::string getSourceElementString() const
+    {
+        std::string _sourceElementName = _sourceElement->getName();
+        return _sourceElementName.empty() ? "<DOCUMENT>" : _sourceElementName;
+    }
+
+    void addAffectedInput(const mx::InputPtr& input)
+    {
+        _affectedInputs.push_back(input);
+        _isAffectedInputsDirty.store(true);
+    }
+
+    std::string getAffectedInputsString()
+    {
+        if (_isAffectedInputsDirty.load())
+            buildAffectedInputsStream();
+        return _affectedInputsStream.str();
+    }
+
+    const std::vector<mx::InputPtr>& getAffectedInputs() const { return _affectedInputs; };
+
+  private:
+    const mx::TokenPtr _tokenPtr;
+    const mx::ElementPtr _sourceElement;
+
+    std::vector<mx::InputPtr> _affectedInputs{};
+    std::ostringstream _affectedInputsStream{};
+
+    // Track whether changes were made to inputs in order to re-build stream accordingly
+    std::atomic<bool> _isAffectedInputsDirty{ true };
+
+    void buildAffectedInputsStream()
+    {
+        if (!_isAffectedInputsDirty.load())
+            return;
+        _affectedInputsStream.clear();
+        for (size_t i = 0; i < _affectedInputs.size(); ++i)
+        {
+            _affectedInputsStream << _affectedInputs[i]->getName();
+            if (i < _affectedInputs.size() - 1)
+                _affectedInputsStream << ", ";
+        }
+        _isAffectedInputsDirty.store(false);
+    }
+};
+
+using UiTokenPtr = std::shared_ptr<UiToken>;
+
 // The visual representation of a node in a graph.
 class UiNode
 {
@@ -248,6 +310,11 @@ class UiNode
     std::vector<UiPinPtr>& getOutputPins() { return _outputPins; }
     const std::vector<UiPinPtr>& getOutputPins() const { return _outputPins; }
 
+    const std::unordered_map<std::string, UiTokenPtr>& getUiTokenMap() const { return _uiTokenMap; }
+
+    // Build a map of relevant UI info for tokens in scope of this node. Should be called lazily (i.e. only when needed)
+    void buildUiTokenMap();
+
     // Edge collection accessors
     std::vector<UiEdge>& getEdges() { return _edges; }
     const std::vector<UiEdge>& getEdges() const { return _edges; }
@@ -277,6 +344,8 @@ class UiNode
     std::vector<UiPinPtr> _outputPins;
     std::vector<UiEdge> _edges;
 
+    std::unordered_map<std::string, UiTokenPtr> _uiTokenMap;
+
     bool _showAllInputs;
     bool _showOutputsInEditor;
 };