Added a GUI theme selector in preferences and a new class for handling GUI changes.

Added a new feature for editing style sheets and variable colors and see immediately the result.
Made Qwt plots (and items) stylable.
Added icons, improved styling possibilities of QMinimizePanel, fixed minor bugs in RicThemeColorEditorFeature.

ApplicationCode/Application/RiaGuiApplication.cpp

@@ -417,6 +417,8 @@ void RiaGuiApplication::initialize()
 {
     RiaApplication::initialize();
 
+    RiuGuiTheme::updateGuiTheme( m_preferences->guiTheme() );
+
     applyGuiPreferences( nullptr );
 
     // Create main windows

ApplicationCode/Application/RiaPreferences.cpp

@@ -384,6 +384,8 @@ RiaPreferences::RiaPreferences( void )
                        "",
                        "Defines preferred minimum distance between surface points in XY-plane",
                        "" );
+
+    CAF_PDM_InitFieldNoDefault( &m_guiTheme, "guiTheme", "GUI theme", "", "", "" );
 }
 
 //--------------------------------------------------------------------------------------------------
@@ -595,6 +597,7 @@ void RiaPreferences::defineUiOrdering( QString uiConfigName, caf::PdmUiOrdering&
         uiOrdering.add( &m_showTestToolbar );
         uiOrdering.add( &m_includeFractureDebugInfoFile );
         uiOrdering.add( &m_holoLensExportFolder );
+        uiOrdering.add( &m_guiTheme );
     }
 
     uiOrdering.skipRemainingFields( true );
@@ -681,6 +684,11 @@ void RiaPreferences::fieldChangedByUi( const caf::PdmFieldHandle* changedField,
         m_pageTopMargin    = defaultMarginSize( m_pageSize() );
         m_pageBottomMargin = defaultMarginSize( m_pageSize() );
     }
+
+    if ( changedField == &m_guiTheme )
+    {
+        RiuGuiTheme::updateGuiTheme( m_guiTheme() );
+    }
 }
 //--------------------------------------------------------------------------------------------------
 ///
@@ -991,6 +999,14 @@ bool RiaPreferences::openExportedPdfInViewer() const
     return m_openExportedPdfInViewer;
 }
 
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+RiuGuiTheme::ThemeEnum RiaPreferences::guiTheme() const
+{
+    return m_guiTheme();
+}
+
 //--------------------------------------------------------------------------------------------------
 ///
 //--------------------------------------------------------------------------------------------------

ApplicationCode/Application/RiaPreferences.h

@@ -25,6 +25,7 @@
 #include "RiaFontCache.h"
 #include "RiaGuiApplication.h"
 #include "RiaQDateTimeTools.h"
+#include "RiuGuiTheme.h"
 
 #include "cafAppEnum.h"
 #include "cafPdmChildField.h"
@@ -112,6 +113,8 @@ public:
     bool        showProgressBar() const;
     bool        openExportedPdfInViewer() const;
 
+    RiuGuiTheme::ThemeEnum guiTheme() const;
+
     std::map<RiaDefines::FontSettingType, RiaFontCache::FontSize> defaultFontSizes() const;
 
     void        writePreferencesToApplicationStore();
@@ -212,6 +215,8 @@ private:
     caf::PdmField<bool>    m_showProgressBar;
     caf::PdmField<QString> m_gtestFilter;
 
+    caf::PdmField<caf::AppEnum<RiuGuiTheme::ThemeEnum>> m_guiTheme;
+
     caf::PdmField<PageSizeEnum>        m_pageSize;
     caf::PdmField<PageOrientationEnum> m_pageOrientation;
     caf::PdmField<double>              m_pageLeftMargin;

ApplicationCode/Application/Tools/RiaColorTools.cpp

@@ -25,6 +25,8 @@
 #include <algorithm>
 #include <cmath>
 
+#include <QPalette>
+
 //--------------------------------------------------------------------------------------------------
 /// Uses W3.org relative luminance calculation taking into account the different luminance of the different colors
 /// https://www.w3.org/TR/WCAG20-TECHS/G18.html
@@ -141,6 +143,24 @@ cvf::Color3f RiaColorTools::fromQColorTo3f( QColor color )
     return cvf::Color3f( color.redF(), color.greenF(), color.blueF() );
 }
 
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+QColor RiaColorTools::systemPaletteTextColor()
+{
+    QPalette systemPalette;
+
+    return systemPalette.color( QPalette::Text );
+}
+
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+cvf::Color3f RiaColorTools::systemPaletteTextColor3f()
+{
+    return fromQColorTo3f( systemPaletteTextColor() );
+}
+
 //--------------------------------------------------------------------------------------------------
 ///
 //--------------------------------------------------------------------------------------------------

ApplicationCode/Application/Tools/RiaColorTools.h

@@ -42,6 +42,9 @@ public:
     static QColor       toQColor( cvf::Color4f color );
     static cvf::Color3f fromQColorTo3f( QColor );
 
+    static QColor       systemPaletteTextColor();
+    static cvf::Color3f systemPaletteTextColor3f();
+
     static cvf::Color3f
                   blendCvfColors( const cvf::Color3f& color1, const cvf::Color3f& color2, int weight1 = 1, int weight2 = 1 );
     static QColor blendQColors( const QColor& color1, const QColor& color2, int weight1 = 1, int weight2 = 1 );