Icon toolbar and resizable browser lists in material editor; mute debug logs

Toolbar: every action is now an icon button (tooltip carries the label,
text fallback with no icon set) via a local iconBtn helper matching the
StageEditor/Timeline convention — Create Material, Presets, Create + Bind,
Bind Current. Icons fill the standard button height (GetFrameHeight, zero
frame padding) so the row stays uniform.

Browser: the materials list and the create-node list are now split by a
draggable HorizontalSplitter (sibling to the column VerticalSplitter)
instead of a fixed 45% / separator; m_browserListRatio holds the list's
share (clamped 0.15-0.85). Create-node entries get a per-category glyph
(Material/Texture/Geometry/Light/Utility) sized to the text line height.

Silence the temporary node-editor drag-regression tracing: the
[NodeGraph] event-trace block is #if 0'd, its PersistNodePosition logs
commented, and the [ed] g_AxNodeEditorDebugLog hook install is commented
out (the vendored editor's dumps are guarded on that hook).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/ui/MaterialEditorPanel.cpp

@@ -182,6 +182,37 @@ void VerticalSplitter(const char* id, float* width, float minWidth, float maxWid
     ImGui::SameLine(0.0f, 0.0f);
 }
 
+// Horizontal drag-splitter stacked between two vertically-arranged panels.
+// Adjusts *ratio (fraction of totalHeight given to the panel above) by the
+// mouse drag; colours match VerticalSplitter.
+void HorizontalSplitter(const char* id, float* ratio, float totalHeight,
+                        float minRatio, float maxRatio) {
+    const float width = std::max(1.0f, ImGui::GetContentRegionAvail().x);
+    ImGui::InvisibleButton(id, ImVec2(width, 6.0f));
+    const bool hovered = ImGui::IsItemHovered();
+    const bool active  = ImGui::IsItemActive();
+    if (hovered || active)
+        ImGui::SetMouseCursor(ImGuiMouseCursor_ResizeNS);
+    if (active && totalHeight > 1.0f)
+        *ratio = std::clamp(*ratio + ImGui::GetIO().MouseDelta.y / totalHeight, minRatio, maxRatio);
+    ImVec2 rectMin = ImGui::GetItemRectMin();
+    ImVec2 rectMax = ImGui::GetItemRectMax();
+    ImGui::GetWindowDrawList()->AddRectFilled(
+        ImVec2(rectMin.x, rectMin.y + 2.0f), ImVec2(rectMax.x, rectMax.y - 2.0f),
+        (hovered || active) ? IM_COL32(250, 150, 66, 200) : IM_COL32(80, 80, 80, 180));
+}
+
+// Small glyph for a create-node list entry, keyed by the derived category
+// (see MaterialManager::DeriveCategory: Material/Texture/Geometry/Light/Utility).
+Icon IconForNodeCategory(const std::string& category) {
+    if (category == "Material") return Icon::Swatchbook;
+    if (category == "Texture")  return Icon::Grid;
+    if (category == "Geometry") return Icon::Cube;
+    if (category == "Light")    return Icon::Lightbulb;
+    if (category == "Utility")  return Icon::Code;
+    return Icon::CircleDot;
+}
+
 // Networks referenced from .mtlx (or authored elsewhere) carry no uiPosition
 // custom data, so every node would seed at (0,0) in a pile. Give those nodes
 // layered left-to-right positions instead: each node sits one column left of
@@ -227,8 +258,9 @@ void ApplyFallbackLayout(ShaderGraphSnapshot& graph) {
 
 MaterialEditorPanel::MaterialEditorPanel() {
     // Route the vendored editor's click-time hit-test dump into our log so
-    // it interleaves with the [NodeGraph] event trace.
+    // it interleaves with the [NodeGraph] event trace. Disabled: uncomment to
-    g_AxNodeEditorDebugLog = [](const char* msg) { LOG_INFO(std::string(msg)); };
+    // re-enable the [ed] trace while diagnosing the drag regression.
+    // g_AxNodeEditorDebugLog = [](const char* msg) { LOG_INFO(std::string(msg)); };
 
     NE::Config config;
     config.SettingsFile = nullptr; // layout persists as USD uiPosition custom data, not an on-disk .json
@@ -612,25 +644,34 @@ void MaterialEditorPanel::CommitInputEdit(const ShaderGraphNode& node, const Sha
 }
 
 void MaterialEditorPanel::RenderToolbar() {
-    // Create Material icon button
+    // Every toolbar action is an icon button; the tooltip carries the label.
-    bool createClicked;
+    // The icon fills the full button height (standard frame height, zero frame
+    // padding) so the buttons stay a uniform, standard-row-height square. Falls
+    // back to a text button only when no icon set is loaded.
+    const float btnH = ImGui::GetFrameHeight();
+    auto iconBtn = [&](const char* id, Icon icon, const char* fallback, const char* tip) -> bool {
+        bool clicked;
         if (m_iconManager) {
-        createClicked = ImGui::ImageButton("##createMaterial",
+            ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(0.f, 0.f));
-                                           ImTextureRef(m_iconManager->Get(Icon::FilePlus)),
+            clicked = ImGui::ImageButton(id, ImTextureRef(m_iconManager->Get(icon)),
-                                           ImVec2(18.f, 18.f));
+                                         ImVec2(btnH, btnH));
+            ImGui::PopStyleVar();
         } else {
-        createClicked = ImGui::Button("Create Material");
+            clicked = ImGui::Button(fallback);
         }
         if (ImGui::IsItemHovered())
-        ImGui::SetTooltip("Create Material");
+            ImGui::SetTooltip("%s", tip);
-    if (createClicked)
+        return clicked;
+    };
+
+    if (iconBtn("##createMaterial", Icon::FilePlus, "Create Material", "Create Material"))
         CreateNewMaterial();
 
     // Presets menu: entries appear per node source when the required shader
     // definitions are registered, and need an open material to apply to.
     ImGui::SameLine();
     ImGui::BeginDisabled(m_materialPath.IsEmpty());
-    if (ImGui::Button("Presets"))
+    if (iconBtn("##presets", Icon::Swatchbook, "Presets", "Presets"))
         ImGui::OpenPopup("MaterialPresets");
     ImGui::EndDisabled();
     if (ImGui::BeginPopup("MaterialPresets")) {
@@ -657,11 +698,13 @@ void MaterialEditorPanel::RenderToolbar() {
         ImGui::SameLine();
         ImGui::Text("Selected: %s", m_targetPrimPath.GetText());
         ImGui::SameLine();
-        if (ImGui::Button("Create + Bind Material"))
+        if (iconBtn("##createBind", Icon::ObjectGroup, "Create + Bind",
+                    "Create + Bind Material to Selected"))
             CreateAndBindMaterialForTarget();
         ImGui::SameLine();
         ImGui::BeginDisabled(m_materialPath.IsEmpty());
-        if (ImGui::Button("Bind Current Material to Selected"))
+        if (iconBtn("##bindCurrent", Icon::Link, "Bind Current",
+                    "Bind Current Material to Selected"))
             BindMaterialToTarget(m_materialPath, m_targetPrimPath);
         ImGui::EndDisabled();
     }
@@ -698,9 +741,12 @@ void MaterialEditorPanel::RenderMaterialBrowser() {
         std::find(materials.begin(), materials.end(), m_browserSelection) == materials.end())
         m_browserSelection = pxr::SdfPath();
 
-    // Top ~45%: materials list. Below: persistent searchable create-node
+    // Materials list (top) and the persistent searchable create-node list
-    // list (Hypershade's create bar, with Nuke-style filtering).
+    // (bottom, Hypershade's create bar with Nuke-style filtering), split by a
-    ImGui::BeginChild("MaterialBrowserList", ImVec2(0.0f, ImGui::GetContentRegionAvail().y * 0.45f), false);
+    // draggable horizontal splitter; m_browserListRatio is the list's share.
+    const float browserAvail = ImGui::GetContentRegionAvail().y;
+    const float listHeight = std::max(1.0f, browserAvail * m_browserListRatio);
+    ImGui::BeginChild("MaterialBrowserList", ImVec2(0.0f, listHeight), false);
     for (const pxr::SdfPath& path : materials) {
         const bool isSelected = (path == m_browserSelection);
         const bool isOpen     = (path == m_materialPath);
@@ -721,7 +767,8 @@ void MaterialEditorPanel::RenderMaterialBrowser() {
     }
     ImGui::EndChild();
 
-    ImGui::Separator();
+    HorizontalSplitter("##BrowserListSplitter", &m_browserListRatio, browserAvail, 0.15f, 0.85f);
+
     ImGui::TextUnformatted("Create Node");
     ImGui::SetNextItemWidth(-FLT_MIN);
     ImGui::InputTextWithHint("##BrowserNodeSearch", "search...",
@@ -773,6 +820,12 @@ void MaterialEditorPanel::RenderMaterialBrowser() {
             }
             if (!categoryOpen)
                 continue;
+            if (m_iconManager) {
+                const float h = ImGui::GetTextLineHeight();
+                ImGui::Image(ImTextureRef(m_iconManager->Get(IconForNodeCategory(info->category))),
+                             ImVec2(h, h));
+                ImGui::SameLine(0.0f, ImGui::GetStyle().ItemInnerSpacing.x);
+            }
             std::string itemLabel = info->label + "##" + std::to_string(i);
             if (ImGui::Selectable(itemLabel.c_str(), false))
                 m_pendingCreateShaderId = info->identifier; // created at view center next canvas pass
@@ -1225,6 +1278,9 @@ void MaterialEditorPanel::RenderNodeGraphCanvas() {
     // event logs once, not per frame. Event order in the editor is:
     // LMB press -> node becomes active (and is brought to front) -> drag
     // moves it -> release -> "click" -> selection updates -> position save.
+    // Disabled: flip to #if 1 to re-enable the [NodeGraph] trace while
+    // diagnosing the node-editor drag regression.
+#if 0
     {
         // Logs the mouse position and every node's editor rect with a hit
         // verdict, and returns the hit paths. Topmost is unknown to us, but
@@ -1378,6 +1434,7 @@ void MaterialEditorPanel::RenderNodeGraphCanvas() {
             LOG_INFO(msg);
         }
     }
+#endif
 
     // Mirror the editor's node selection (first selected node) for the
     // properties section under the preview.
@@ -1611,8 +1668,8 @@ void MaterialEditorPanel::PersistNodePosition(NE::NodeId nodeId) {
     for (const auto& node : m_graph.nodes) {
         if (node.path == path) {
             if (node.uiPosition == newValue) {
-                LOG_INFO("[NodeGraph] position save for " + path.GetString() +
+                // LOG_INFO("[NodeGraph] position save for " + path.GetString() +
-                         " ignored (echo of snapshot seed)");
+                //          " ignored (echo of snapshot seed)");
                 return;
             }
             break;
@@ -1625,16 +1682,16 @@ void MaterialEditorPanel::PersistNodePosition(NE::NodeId nodeId) {
         : pxr::GfVec2f(0.0f, 0.0f);
 
     if (oldValue == newValue) {
-        LOG_INFO("[NodeGraph] position save for " + path.GetString() +
+        // LOG_INFO("[NodeGraph] position save for " + path.GetString() +
-                 " ignored (customData already matches)");
+        //          " ignored (customData already matches)");
         return;
     }
 
-    char moveMsg[256];
+    // char moveMsg[256];
-    std::snprintf(moveMsg, sizeof(moveMsg),
+    // std::snprintf(moveMsg, sizeof(moveMsg),
-                  "[NodeGraph] move committed: %s (%.1f, %.1f) -> (%.1f, %.1f)",
+    //               "[NodeGraph] move committed: %s (%.1f, %.1f) -> (%.1f, %.1f)",
-                  path.GetText(), oldValue[0], oldValue[1], newValue[0], newValue[1]);
+    //               path.GetText(), oldValue[0], oldValue[1], newValue[0], newValue[1]);
-    LOG_INFO(std::string(moveMsg));
+    // LOG_INFO(std::string(moveMsg));
 
     pxr::UsdStageRefPtr stage = m_stage;
     m_commandHistory->Push(std::make_unique<AttributeSetCommand>(

src/ui/MaterialEditorPanel.h

@@ -157,6 +157,11 @@ private:
     float m_browserWidth = 220.0f;
     float m_previewWidth = 320.0f;
 
+    /// Fraction of the browser column's height given to the materials list;
+    /// the create-node list takes the rest. User-adjustable via the horizontal
+    /// splitter between them.
+    float m_browserListRatio = 0.45f;
+
     /// Search text of the browser's persistent create-node list.
     char m_browserNodeSearchBuf[128] = "";
     /// Shader id clicked in the browser's create-node list; created at the