Qt5/KDE5 use logicalDotsPerInch to report DPI

It looks like all other backend don't use the physical, but the
logical DPI to report the resolution.
So use the QScreens logical resolution when reporting the DPI
values. Also use QScreen for KDE5, as the Svp defaults to 96.

This might fix tdf#122131, but since I can't reproduce...

Change-Id: Iefc75acf26f8664f2a9ad995edbdc749be2228cf
Reviewed-on: https://gerrit.libreoffice.org/66525
Tested-by: Jenkins
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>

3 files changed, 31 insertions, 3 deletions

diff --git a/vcl/unx/kde5/KDE5SalFrame.cxx b/vcl/unx/kde5/KDE5SalFrame.cxx
index 9c82f6ca53b1..ec4a7ff8f45c 100644
--- a/vcl/unx/kde5/KDE5SalFrame.cxx
+++ b/vcl/unx/kde5/KDE5SalFrame.cxx
@@ -208,7 +208,7 @@ SalGraphics* KDE5SalFrame::AcquireGraphics()
 
     if (!m_pKDE5Graphics.get())
     {
-        m_pKDE5Graphics.reset(new KDE5SalGraphics());
+        m_pKDE5Graphics.reset(new KDE5SalGraphics(this));
         Qt5Frame::InitSvpSalGraphics(m_pKDE5Graphics.get());
     }
 
diff --git a/vcl/unx/kde5/KDE5SalGraphics.cxx b/vcl/unx/kde5/KDE5SalGraphics.cxx
index 583edf6e8e6c..290127d0526e 100644
--- a/vcl/unx/kde5/KDE5SalGraphics.cxx
+++ b/vcl/unx/kde5/KDE5SalGraphics.cxx
@@ -21,7 +21,11 @@
 
 #include <salbmp.hxx>
 
+#include <QtGui/QScreen>
+#include <QtGui/QWindow>
+
 #include <Qt5Tools.hxx>
+#include <Qt5Frame.hxx>
 
 static void QImage2BitmapBuffer(QImage* pImg, BitmapBuffer* pBuf)
 {
@@ -35,8 +39,9 @@ static void QImage2BitmapBuffer(QImage* pImg, BitmapBuffer* pBuf)
     }
 }
 
-KDE5SalGraphics::KDE5SalGraphics()
+KDE5SalGraphics::KDE5SalGraphics(Qt5Frame* pFrame)
     : SvpSalGraphics()
+    , m_pFrame(pFrame)
 {
 }
 
@@ -59,4 +64,22 @@ bool KDE5SalGraphics::drawNativeControl(ControlType nType, ControlPart nPart,
     return bHandled;
 }
 
+void KDE5SalGraphics::GetResolution(sal_Int32& rDPIX, sal_Int32& rDPIY)
+{
+    char* pForceDpi;
+    if ((pForceDpi = getenv("SAL_FORCEDPI")))
+    {
+        OString sForceDPI(pForceDpi);
+        rDPIX = rDPIY = sForceDPI.toInt32();
+        return;
+    }
+
+    if (!m_pFrame || !m_pFrame->GetQWidget()->window()->windowHandle())
+        return;
+
+    QScreen* pScreen = m_pFrame->GetQWidget()->window()->windowHandle()->screen();
+    rDPIX = pScreen->logicalDotsPerInchX();
+    rDPIY = pScreen->logicalDotsPerInchY();
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/unx/kde5/KDE5SalGraphics.hxx b/vcl/unx/kde5/KDE5SalGraphics.hxx
index d5b01542e877..109a0fa8ac29 100644
--- a/vcl/unx/kde5/KDE5SalGraphics.hxx
+++ b/vcl/unx/kde5/KDE5SalGraphics.hxx
@@ -29,13 +29,15 @@
 #include <QtGui/QImage>
 #include <QtWidgets/QPushButton>
 
+class Qt5Frame;
+
 /**
  * Handles native graphics requests and performs the needed drawing operations.
  */
 class KDE5SalGraphics : public SvpSalGraphics
 {
 public:
-    KDE5SalGraphics();
+    KDE5SalGraphics(Qt5Frame* pFrame);
     virtual bool IsNativeControlSupported(ControlType, ControlPart) override;
 
     virtual bool hitTestNativeControl(ControlType, ControlPart, const tools::Rectangle&,
@@ -48,8 +50,11 @@ public:
                                         ControlState, const ImplControlValue&, const OUString&,
                                         tools::Rectangle&, tools::Rectangle&) override;
 
+    virtual void GetResolution(sal_Int32& rDPIX, sal_Int32& rDPIY) override;
+
 private:
     Qt5Graphics_Controls m_aControl;
+    Qt5Frame* m_pFrame;
 };
 
 inline bool KDE5SalGraphics::IsNativeControlSupported(ControlType nType, ControlPart nPart)