From 2c2a977e04525fa64c8905e6455eaf42e7d6af10 Mon Sep 17 00:00:00 2001
From: Paddle <PaddleStroke@users.noreply.github.com>
Date: Mon, 18 Sep 2023 18:54:34 +0200
Subject: [PATCH] Add setter/getter for constraint expression.

---
 src/Mod/Sketcher/App/SketchObject.cpp | 39 +++++++++++++++++++++++++++
 src/Mod/Sketcher/App/SketchObject.h   |  7 +++++
 2 files changed, 46 insertions(+)

diff --git a/src/Mod/Sketcher/App/SketchObject.cpp b/src/Mod/Sketcher/App/SketchObject.cpp
index 32918af027..59bdb450d6 100644
--- a/src/Mod/Sketcher/App/SketchObject.cpp
+++ b/src/Mod/Sketcher/App/SketchObject.cpp
@@ -660,6 +660,45 @@ int SketchObject::moveDatumsToEnd()
     return 0;
 }
 
+bool SketchObject::constraintHasExpression(int constNum)
+{
+    App::ObjectIdentifier path = Constraints.createPath(constNum);
+    auto info = getExpression(path);
+    if (info.expression) {
+        return true;
+    }
+    return false;
+}
+
+std::string SketchObject::getConstraintExpression(int constNum)
+{
+    App::ObjectIdentifier path = Constraints.createPath(constNum);
+    auto info = getExpression(path);
+    if (info.expression) {
+        std::string expression = info.expression->toString();
+        return expression;
+    }
+
+    return "";
+}
+
+void SketchObject::setConstraintExpression(int constNum, std::string& newExpression)
+{
+    App::ObjectIdentifier path = Constraints.createPath(constNum);
+    auto info = getExpression(path);
+    if (info.expression) {
+        try {
+            std::shared_ptr<App::Expression> expr(App::Expression::parse(this, newExpression));
+            // there is a bug in the SketchObject API because setExpression() is protected but public in DocumentObject
+            App::DocumentObject* base = this;
+            base->setExpression(path, expr);
+        }
+        catch (const Base::Exception&) {
+            Base::Console().Error("Failed to set constraint expression.");
+        }
+    }
+}
+
 int SketchObject::setVirtualSpace(int ConstrId, bool isinvirtualspace)
 {
     // no need to check input data validity as this is an sketchobject managed operation.
diff --git a/src/Mod/Sketcher/App/SketchObject.h b/src/Mod/Sketcher/App/SketchObject.h
index 4274a27c57..b33a1b21e0 100644
--- a/src/Mod/Sketcher/App/SketchObject.h
+++ b/src/Mod/Sketcher/App/SketchObject.h
@@ -269,6 +269,13 @@ public:
     /// Move Dimensional constraints at the end of the properties array
     int moveDatumsToEnd();
 
+    // Check if a constraint has an expression associated.
+    bool constraintHasExpression(int constNum);
+    // Get a constraint associated expression
+    std::string getConstraintExpression(int constNum);
+    // Set a constraint associated expression
+    void setConstraintExpression(int constNum, std::string& newExpression);
+
     /// set the driving status of this constraint and solve
     int setVirtualSpace(int ConstrId, bool isinvirtualspace);
     /// set the driving status of a group of constraints at once