fix some on properties and signal connection

app/gcompose/src/PropertyWidgets.h

@@ -14,11 +14,14 @@
 
 #include "Core/Property.h"
 #include "Core/Object.h"
+#include "Core/Signal.h"
 #include "Math/Dense.h"
 
 namespace uLib {
 namespace Qt {
 
+double parseWithUnits(const QString& text, double* factorOut = nullptr, QString* suffixOut = nullptr);
+
 class PropertyWidgetBase : public QWidget {
     Q_OBJECT
 public:
@@ -30,6 +33,9 @@ protected:
     PropertyBase* m_BaseProperty;
     QHBoxLayout* m_Layout;
     QLabel* m_Label;
+    // Stores the uLib signal connection so it can be disconnected on destruction,
+    // preventing use-after-free when PropertyEditor::clear() deletes widgets.
+    Connection m_Connection;
 };
 
 class UnitLineEdit : public QLineEdit {
@@ -37,6 +43,7 @@ class UnitLineEdit : public QLineEdit {
 public:
     UnitLineEdit(QWidget* parent = nullptr);
     void setValue(double val);
+    void setUnits(const QString& suffix, double factor = 1.0);
     double getValue() const { return m_Value; }
     void setIntegerOnly(bool b);
 
@@ -86,11 +93,19 @@ class VectorPropertyWidget : public PropertyWidgetBase {
 public:
     VectorPropertyWidget(Property<VecT>* prop, QWidget* parent = nullptr)
         : PropertyWidgetBase(prop, parent), m_Prop(prop) {
+        QString units = QString::fromStdString(prop->GetUnits());
+        double factor = 1.0;
+        if (!units.isEmpty()) {
+            parseWithUnits("1 " + units, &factor);
+        }
         for (int i = 0; i < Size; ++i) {
             m_Edits[i] = new UnitLineEdit(this);
             if (std::is_integral<typename VecT::Scalar>::value) {
                 m_Edits[i]->setIntegerOnly(true);
             }
+            if (!units.isEmpty()) {
+               m_Edits[i]->setUnits(units, factor);
+            }
             m_Layout->addWidget(m_Edits[i], 1);
             
             connect(m_Edits[i], &UnitLineEdit::valueManualChanged, [this, i](double val){
@@ -100,10 +115,11 @@ public:
             });
         }
         updateEdits();
-        uLib::Object::connect(m_Prop, &Property<VecT>::PropertyChanged, [this](){
+        m_Connection = uLib::Object::connect(m_Prop, &Property<VecT>::PropertyChanged, [this](){
             updateEdits();
         });
     }
+    ~VectorPropertyWidget() { m_Connection.disconnect(); }
 
 private:
     void updateEdits() {