Qt5 disable native draw via SAL_VCL_QT5_NO_NATIVE

Primary as a debugging measure to compare output for Qt5Graphics.
Checks mpToolkitName, so we just disable it for qt5 not kde5.

Change-Id: Ib7a67c4bec16d81dd87b6351ba106f655d37948b
Reviewed-on: https://gerrit.libreoffice.org/58790
Tested-by: Jenkins
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>

vcl/inc/qt5/Qt5Data.hxx

@@ -40,6 +40,8 @@ public:
     virtual bool ErrorTrapPop(bool bIgnoreError = true) override;
 
     QCursor& getCursor(PointerStyle ePointerStyle);
+
+    static bool noNativeControls();
 };
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

vcl/inc/qt5/Qt5Graphics.hxx

@@ -27,6 +27,7 @@
 #include <QtGui/QPainterPath>
 #include <QtGui/QRegion>
 
+#include "Qt5Data.hxx"
 #include "Qt5Graphics_Controls.hxx"
 
 class PhysicalFontCollection;
@@ -216,6 +217,8 @@ public:
 
 inline bool Qt5Graphics::IsNativeControlSupported(ControlType nType, ControlPart nPart)
 {
+    if (Qt5Data::noNativeControls())
+        return false;
     return m_aControl.IsNativeControlSupported(nType, nPart);
 }
 

vcl/qt5/Qt5Data.cxx

@@ -309,4 +309,13 @@ void Qt5Data::ErrorTrapPush() {}
 
 bool Qt5Data::ErrorTrapPop(bool /*bIgnoreError*/) { return false; }
 
+bool Qt5Data::noNativeControls()
+{
+    static const bool bNoNative
+        = ((nullptr != getenv("SAL_VCL_QT5_NO_NATIVE")) && (nullptr != ImplGetSVData())
+           && (nullptr != ImplGetSVData()->maAppData.mpToolkitName)
+           && ImplGetSVData()->maAppData.mpToolkitName->match("qt5"));
+    return bNoNative;
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

vcl/qt5/Qt5Frame.cxx

@@ -483,6 +483,9 @@ static Color toColor(const QColor& rColor)
 
 void Qt5Frame::UpdateSettings(AllSettings& rSettings)
 {
+    if (Qt5Data::noNativeControls())
+        return;
+
     StyleSettings style(rSettings.GetStyleSettings());
 
     // General settings