[calamares] Support noexpand

- When in noexpand mode, just don't grow the window, and assume
   widgets elsewhere will get scrollbars automatically.

src/branding/default/branding.desc

@@ -17,7 +17,7 @@ welcomeExpandingLogo:   true
 # Size and expansion policy for Calamares.
 #  - "normal" or unset, expand as needed, use *windowSize*
 #  - "fullscreen", start as large as possible, ignore *windowSize*
-#  - "noexpand", never expand, use *windowSize*
+#  - "noexpand", don't expand automatically, use *windowSize*
 windowExpanding:    normal
 
 # Size of Calamares window, expressed as w,h. Both w and h

src/calamares/CalamaresWindow.cpp

@@ -147,7 +147,8 @@ CalamaresWindow::CalamaresWindow( QWidget* parent )
     CalamaresUtils::unmarginLayout( mainLayout );
 
     m_viewManager = Calamares::ViewManager::instance( this );
-    connect( m_viewManager, &Calamares::ViewManager::enlarge, this, &CalamaresWindow::enlarge );
+    if ( branding->windowExpands() )
+        connect( m_viewManager, &Calamares::ViewManager::enlarge, this, &CalamaresWindow::enlarge );
 
     mainLayout->addWidget( m_viewManager->centralWidget() );
 }

src/libcalamaresui/Branding.h

@@ -112,6 +112,7 @@ public:
     bool welcomeStyleCalamares() const { return m_welcomeStyleCalamares; }
     bool welcomeExpandingLogo() const { return m_welcomeExpandingLogo; }
     bool windowMaximize() const { return m_windowExpansion == WindowExpansion::Fullscreen; }
+    bool windowExpands() const { return m_windowExpansion != WindowExpansion::Fixed; }
     QPair< WindowDimension, WindowDimension > windowSize() const
     {
         return QPair< WindowDimension, WindowDimension >( m_windowWidth, m_windowHeight );