Gui: fix transparency saving in PrefColorButton

src/Gui/PrefWidgets.cpp

@@ -552,18 +552,23 @@ void PrefColorButton::restorePreferences()
     return;
   }
 
-  QColor col = color();
+  if (!m_Restored)
+    m_Default = color();
 
-  unsigned int icol = (col.red() << 24) | (col.green() << 16) | (col.blue() << 8);
+  const QColor &col = m_Default;
 
-  auto lcol = static_cast<unsigned long>(icol);
+  unsigned int icol = (col.red() << 24) | (col.green() << 16) | (col.blue() << 8) | col.alpha();
+
+  unsigned long lcol = static_cast<unsigned long>(icol);
   lcol = getWindowParameter()->GetUnsigned( entryName(), lcol );
   icol = static_cast<unsigned int>(lcol);
   int r = (icol >> 24)&0xff;
   int g = (icol >> 16)&0xff;
   int b = (icol >>  8)&0xff;
-
-  setColor(QColor(r,g,b));
+  int a = (icol      )&0xff;
+  if (!this->allowTransparency())
+      a = 0xff;
+  setColor(QColor(r,g,b,a));
 }
 
 void PrefColorButton::savePreferences()
@@ -576,8 +581,8 @@ void PrefColorButton::savePreferences()
 
   QColor col = color();
   // (r,g,b,a) with a = 255 (opaque)
-  unsigned int icol = (col.red() << 24) | (col.green() << 16) | (col.blue() << 8) | 255;
-  auto lcol = static_cast<unsigned long>(icol);
+  unsigned int icol = (col.red() << 24) | (col.green() << 16) | (col.blue() << 8) | col.alpha();
+  unsigned long lcol = static_cast<unsigned long>(icol);
   getWindowParameter()->SetUnsigned( entryName(), lcol );
 }
 

src/Gui/PrefWidgets.h

@@ -329,6 +329,9 @@ protected:
   // restore from/save to parameters
   void restorePreferences() override;
   void savePreferences() override;
+
+private:
+  QColor m_Default;
 };
 
 /** The PrefUnitSpinBox class.

src/Gui/Widgets.cpp

@@ -44,6 +44,7 @@
 #include <Base/Exception.h>
 #include <Base/Interpreter.h>
 #include <App/ExpressionParser.h>
+#include <App/Material.h>
 
 #include "Widgets.h"
 #include "Action.h"
@@ -685,6 +686,30 @@ QColor ColorButton::color() const
     return d->col;
 }
 
+/**
+ * Sets the packed color \a c to the button.
+ */
+void ColorButton::setPackedColor(uint32_t c)
+{
+    App::Color color;
+    color.setPackedValue(c);
+    d->col.setRedF(color.r);
+    d->col.setGreenF(color.g);
+    d->col.setBlueF(color.b);
+    d->col.setAlphaF(color.a);
+    d->dirty = true;
+    update();
+}
+
+/**
+ * Returns the current packed color of the button.
+ */
+uint32_t ColorButton::packedColor() const
+{
+    App::Color color(d->col.redF(), d->col.greenF(), d->col.blueF(), d->col.alphaF());
+    return color.getPackedValue();
+}
+
 void ColorButton::setAllowChangeColor(bool ok)
 {
     d->allowChange = ok;

src/Gui/Widgets.h

@@ -238,6 +238,9 @@ public:
     void setColor(const QColor&);
     QColor color() const;
 
+    void setPackedColor(uint32_t);
+    uint32_t packedColor() const;
+
     void setAllowChangeColor(bool);
     bool allowChangeColor() const;