Merge pull request #4321 from Autodesk/kheloua/dev/EMSUSD-2789_port_expr_var_support_LE

EMSUSD-2789: Add Variable Expression Support to Layer editor

Author: seando-adsk

lib/usd/ui/layerEditor/layerTreeItem.cpp

@@ -21,6 +21,10 @@
 #include <maya/MGlobal.h>
 #include <maya/MQtUtil.h>
 
+#if PXR_VERSION >= 2308
+#include <pxr/usd/sdf/variableExpression.h>
+#endif
+
 #include <algorithm>
 
 PXR_NAMESPACE_USING_DIRECTIVE
@@ -81,13 +85,15 @@ const LayerActionDefinitions& LayerTreeItem::actionButtonsDefinition()
 
 LayerTreeItem::LayerTreeItem(
     SdfLayerRefPtr         in_usdLayer,
+    UsdStageRefPtr         in_stage,
     LayerType              in_layerType,
     std::string            in_subLayerPath,
     std::set<std::string>* in_incomingLayers,
     bool                   in_sharedStage,
     std::set<std::string>* in_sharedLayers,
     RecursionDetector*     in_recursionDetector)
     : _layer(std::move(in_usdLayer))
+    , _stage(std::move(in_stage))
     , _isTargetLayer(false)
     , _layerType(in_layerType)
     , _subLayerPath(in_subLayerPath)
@@ -138,11 +144,44 @@ void LayerTreeItem::populateChildren(RecursionDetector* recursionDetector)
     recursionDetector->push(_layer->GetRealPath());
 
     for (auto const path : subPaths) {
+#if PXR_VERSION >= 2308
+        // Resolve any variable expressions in the path using the stage's expression variables
+        std::string resolvedPath = path;
+        if (_stage && SdfVariableExpression::IsExpression(path)) {
+            auto resolveExprVarsFromLayer =
+                [](SdfVariableExpression& varExpr, SdfLayerRefPtr fromLayer, std::string& outPath) {
+                    if (fromLayer && fromLayer->HasExpressionVariables()) {
+                        auto expressionVars = fromLayer->GetExpressionVariables();
+                        auto result = varExpr.Evaluate(expressionVars);
+                        if (result.errors.empty() && !result.value.IsEmpty()) {
+                            outPath = result.value.UncheckedGet<std::string>();
+                        }
+                    }
+                };
+
+            SdfVariableExpression varExpr(path);
+            // Get the root layer's expression variables for resolution context
+            auto rootLayer = _stage->GetRootLayer();
+            resolveExprVarsFromLayer(varExpr, rootLayer, resolvedPath);
+
+            // Expression variables are composed across session layer and root
+            // layer of a stage. So we do another pass with the session layer
+            // to override/set the resolvedPath in case it is present in the
+            // session layer
+            auto sessionLayer = _stage->GetSessionLayer();
+            resolveExprVarsFromLayer(varExpr, sessionLayer, resolvedPath);
+        }
+
+        std::string actualPath = SdfComputeAssetPathRelativeToLayer(_layer, resolvedPath);
+        auto        subLayer = SdfLayer::FindOrOpen(actualPath);
+#else
         std::string actualPath = SdfComputeAssetPathRelativeToLayer(_layer, path);
         auto        subLayer = SdfLayer::FindOrOpen(actualPath);
+#endif
         if (!subLayer || !recursionDetector->contains(subLayer->GetRealPath())) {
             auto item = new LayerTreeItem(
                 subLayer,
+                _stage,
                 LayerType::SubLayer,
                 path,
                 &_incomingLayers,
@@ -230,14 +269,9 @@ AbstractCommandHook* LayerTreeItem::commandHook() const
     return parentModel()->sessionState()->commandHook();
 }
 
-PXR_NS::UsdStageRefPtr const& LayerTreeItem::stage() const
-{
-    return parentModel()->sessionState()->stage();
-}
-
 bool LayerTreeItem::isMuted() const
 {
-    return isInvalidLayer() || !stage() ? false : stage()->IsLayerMuted(_layer->GetIdentifier());
+    return isInvalidLayer() || !_stage ? false : _stage->IsLayerMuted(_layer->GetIdentifier());
 }
 
 bool LayerTreeItem::appearsMuted() const

lib/usd/ui/layerEditor/layerTreeItem.h

@@ -98,6 +98,7 @@ class LayerTreeItem : public QStandardItem
 public:
     LayerTreeItem(
         PXR_NS::SdfLayerRefPtr in_usdLayer,
+        PXR_NS::UsdStageRefPtr in_stage,
         LayerType              in_layerType = LayerType::SubLayer,
         std::string            in_subLayerPath = "",
         std::set<std::string>* in_incomingLayers = nullptr,
@@ -127,8 +128,6 @@ class LayerTreeItem : public QStandardItem
     const std::string& displayName() const { return _displayName; }
     // if a sublayer, get the path we were saved with in the parent
     const std::string& subLayerPath() const { return _subLayerPath; }
-    // shortcut to get stage from model
-    PXR_NS::UsdStageRefPtr const& stage() const;
 
     // is the layer muted at the stage level?
     bool isMuted() const;
@@ -202,6 +201,7 @@ class LayerTreeItem : public QStandardItem
 
 protected:
     PXR_NS::SdfLayerRefPtr _layer;
+    PXR_NS::UsdStageRefPtr _stage;
     std::string            _displayName;
     bool                   _isTargetLayer = false;
     LayerType              _layerType = LayerType::SubLayer;

lib/usd/ui/layerEditor/layerTreeModel.cpp

@@ -343,6 +343,7 @@ void LayerTreeModel::rebuildModel(bool refreshLockState /*= false*/)
         if (showSessionLayer) {
             appendRow(new LayerTreeItem(
                 sessionLayer,
+                _sessionState->stage(),
                 LayerType::SessionLayer,
                 "",
                 &incomingLayers,
@@ -351,7 +352,13 @@ void LayerTreeModel::rebuildModel(bool refreshLockState /*= false*/)
         }
 
         appendRow(new LayerTreeItem(
-            rootLayer, LayerType::RootLayer, "", &incomingLayers, sharedStage, &sharedLayers));
+            rootLayer,
+            _sessionState->stage(),
+            LayerType::RootLayer,
+            "",
+            &incomingLayers,
+            sharedStage,
+            &sharedLayers));
 
         updateTargetLayer(InRebuildModel::Yes);
 

lib/usd/ui/layerEditor/warningDialogs.cpp

@@ -72,18 +72,17 @@ bool confirmDialog_internal(
 
     if (okCancel) {
         msgBox.setStandardButtons(QMessageBox::Ok | QMessageBox::Cancel);
-        msgBox.setDefaultButton(QMessageBox::Cancel);
+        msgBox.setDefaultButton(QMessageBox::Ok);
+        msgBox.button(QMessageBox::Ok)->setFocus();
     } else {
         msgBox.setStandardButtons(QMessageBox::Ok);
     }
 
     if (!showIcon)
         msgBox.setStyleSheet(QString("QLabel{min-width: %1px;}").arg(DPIScale(400)));
 
-    if (okButtonText != nullptr) {
+    if (okButtonText != nullptr)
         msgBox.button(QMessageBox::Ok)->setText(*okButtonText);
-        msgBox.button(QMessageBox::Ok)->setFocus();
-    }
 
     return msgBox.exec() == QMessageBox::Ok;
 }