Set minimum height of workbench switcher to show all items when possible

src/Gui/Action.cpp

@@ -28,6 +28,7 @@
 # include <boost/bind.hpp>
 # include <QActionEvent>
 # include <QApplication>
+# include <QDesktopWidget>
 # include <QEvent>
 # include <QMessageBox>
 # include <QToolBar>
@@ -345,6 +346,18 @@ WorkbenchComboBox::~WorkbenchComboBox()
 {
 }
 
+void WorkbenchComboBox::showPopup()
+{
+    int rows = count();
+    if (rows > 0) {
+        int height = view()->sizeHintForRow(0);
+        int maxHeight = QApplication::desktop()->height();
+        view()->setMinimumHeight(qMin(height * rows, maxHeight/2));
+    }
+
+    QComboBox::showPopup();
+}
+
 void WorkbenchComboBox::actionEvent ( QActionEvent* e )
 {
     QAction *action = e->action();

src/Gui/Action.h

@@ -124,6 +124,7 @@ class GuiExport WorkbenchComboBox : public QComboBox
 public:
     WorkbenchComboBox(WorkbenchGroup* wb, QWidget* parent=0);
     virtual ~WorkbenchComboBox();
+    void showPopup();
 
 public Q_SLOTS:
     void onActivated(int);