QuantitySpinBox: Moved getIcon() and some data members to ExpressionBinding class.

Conflicts:
	src/Gui/QuantitySpinBox.cpp

src/Gui/ExpressionBinding.cpp

@@ -22,6 +22,8 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
+# include <QPixmapCache>
+# include <BitmapFactory.h>
 #endif
 #include "ExpressionBinding.h"
 #include "Command.h"
@@ -35,6 +37,8 @@ using namespace Gui;
 using namespace App;
 
 ExpressionBinding::ExpressionBinding()
+    : iconLabel(0)
+    , iconHeight(-1)
 {
 }
 
@@ -104,6 +108,22 @@ std::string ExpressionBinding::getEscapedExpressionString() const
     return Base::Tools::escapedUnicodeFromUtf8(getExpressionString().c_str());
 }
 
+QPixmap ExpressionBinding::getIcon(const char* name, const QSize& size) const
+{
+    QString key = QString::fromAscii("%1_%2x%3")
+        .arg(QString::fromAscii(name))
+        .arg(size.width())
+        .arg(size.height());
+    QPixmap icon;
+    if (QPixmapCache::find(key, icon))
+        return icon;
+
+    icon = BitmapFactory().pixmapFromSvg(name, size);
+    if (!icon.isNull())
+        QPixmapCache::insert(key, icon);
+    return icon;
+}
+
 bool ExpressionBinding::apply(const std::string & propName)
 {
     if (hasExpression()) {