Improved logical and physical DPI APIs.

Made physicalSize() return QSizeF instead, to prevent rounding errors.
Added logicalSize() as the base to compute font pixel sizes instead, and
added convenience functions in QScreen to access the logical and
physical sizes and DPI metrics.

Task-number: QTBUG-21736
Task-number: QTBUG-21737
Change-Id: Ic705dc98eb3632617659e65a0c9a552673dc0c65
Reviewed-on: http://codereview.qt-project.org/5888
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>

2 files changed, 3 insertions, 3 deletions

diff --git a/src/plugins/platforms/xlib/qxlibscreen.cpp b/src/plugins/platforms/xlib/qxlibscreen.cpp
index e6263c0b33..314a3e4ecb 100644
--- a/src/plugins/platforms/xlib/qxlibscreen.cpp
+++ b/src/plugins/platforms/xlib/qxlibscreen.cpp
@@ -218,7 +218,7 @@ QXlibScreen::QXlibScreen()
 
     int physicalWidth = DisplayWidthMM(mDisplay->nativeDisplay(), mScreen);
     int physicalHeight = DisplayHeightMM(mDisplay->nativeDisplay(), mScreen);
-    mPhysicalSize = QSize(physicalWidth,physicalHeight);
+    mPhysicalSize = QSizeF(physicalWidth, physicalHeight);
 
     int xSocketNumber = XConnectionNumber(mDisplay->nativeDisplay());
 
diff --git a/src/plugins/platforms/xlib/qxlibscreen.h b/src/plugins/platforms/xlib/qxlibscreen.h
index 6e1a3e401d..13fc03ef0f 100644
--- a/src/plugins/platforms/xlib/qxlibscreen.h
+++ b/src/plugins/platforms/xlib/qxlibscreen.h
@@ -62,7 +62,7 @@ public:
     QRect geometry() const { return mGeometry; }
     int depth() const { return mDepth; }
     QImage::Format format() const { return mFormat; }
-    QSize physicalSize() const { return mPhysicalSize; }
+    QSizeF physicalSize() const { return mPhysicalSize; }
 
     Window rootWindow();
     unsigned long blackPixel();
@@ -94,7 +94,7 @@ private:
 
     void handleSelectionRequest(XEvent *event);
     QRect mGeometry;
-    QSize mPhysicalSize;
+    QSizeF mPhysicalSize;
     int mDepth;
     QImage::Format mFormat;
     QXlibCursor *mCursor;