oKular: Add method(s) to get the DPI of the primary screen

some generators use QX11Info to get the DPI of the display.
    Obviously this is not portable, add a getDpi? method to utils
    which can be used by generators.
    Currently only the DVI converter is converted.
    The CMakeLists.txt change assumes that non existing variables
    gets expanded to empty strings.

svn path=/trunk/playground/graphics/okular/; revision=600099

CMakeLists.txt

@@ -62,7 +62,12 @@ kde4_automoc(${okularcore_SRCS})
 
 kde4_add_library(okularcore SHARED ${okularcore_SRCS})
 
-target_link_libraries(okularcore  ${KDE4_KPARTS_LIBS} ${QT_QTCORE_LIBRARY} ${KDE4_KDEUI_LIBS} ${QT_QTGUI_LIBRARY} m )
+# Special handling for linking okularcore on OSX/Apple
+IF(APPLE)
+    SET(OKULAR_IOKIT "-framework IOKit" CACHE STRING "Apple IOKit framework")
+ENDIF(APPLE)
+
+target_link_libraries(okularcore  ${OKULAR_IOKIT} ${KDE4_KPARTS_LIBS} ${QT_QTCORE_LIBRARY} ${KDE4_KDEUI_LIBS} ${QT_QTGUI_LIBRARY} m )
 
 install(TARGETS okularcore DESTINATION ${LIB_INSTALL_DIR} )
 

core/utils.cpp

@@ -9,6 +9,17 @@
 
 #include "utils.h"
 
+#ifdef Q_WS_X11
+#include <QX11Info>
+#endif
+
+#ifdef Q_WS_MAC
+#include <ApplicationServices/ApplicationServices.h>
+#include <IOKit/graphics/IOGraphicsLib.h>
+#endif
+
+
+
 using namespace Okular;
 
 QRect Utils::rotateRect( const QRect & source, int width, int height, int orientation )
@@ -37,3 +48,90 @@ QRect Utils::rotateRect( const QRect & source, int width, int height, int orient
 
     return ret;
 }
+
+#if defined(Q_WS_X11)
+double Utils::getDpiX() {
+    return QX11Info::appDpiX();
+}
+
+double Utils::getDpiY() {
+    return QX11Info::appDpiY();
+}
+#elif defined(Q_WS_MAC)
+    /*
+     * Code copied from http://developer.apple.com/qa/qa2001/qa1217.html
+     */
+    //    Handy utility function for retrieving an int from a CFDictionaryRef
+    static int GetIntFromDictionaryForKey( CFDictionaryRef desc, CFStringRef key )
+    {
+        CFNumberRef value;
+        int num = 0;
+        if ( (value = (CFNumberRef)CFDictionaryGetValue(desc, key)) == NULL || CFGetTypeID(value) != CFNumberGetTypeID())
+            return 0;
+        CFNumberGetValue(value, kCFNumberIntType, &num);
+        return num;
+    }
+
+    CGDisplayErr GetDisplayDPI(
+        CFDictionaryRef displayModeDict,
+        CGDirectDisplayID displayID,
+        double *horizontalDPI, double *verticalDPI )
+    {
+        CGDisplayErr err = kCGErrorFailure;
+        io_connect_t displayPort;
+        CFDictionaryRef displayDict;
+
+        //    Grab a connection to IOKit for the requested display
+        displayPort = CGDisplayIOServicePort( displayID );
+        if ( displayPort != MACH_PORT_NULL )
+        {
+            //    Find out what IOKit knows about this display
+            displayDict = IODisplayCreateInfoDictionary(displayPort, 0);
+            if ( displayDict != NULL )
+            {
+                const double mmPerInch = 25.4;
+                double horizontalSizeInInches =
+                    (double)GetIntFromDictionaryForKey(displayDict,
+                                                       CFSTR(kDisplayHorizontalImageSize)) / mmPerInch;
+                double verticalSizeInInches =
+                    (double)GetIntFromDictionaryForKey(displayDict,
+                                                       CFSTR(kDisplayVerticalImageSize)) / mmPerInch;
+
+                //    Make sure to release the dictionary we got from IOKit
+                CFRelease(displayDict);
+
+                // Now we can calculate the actual DPI
+                // with information from the displayModeDict
+                *horizontalDPI =
+                    (double)GetIntFromDictionaryForKey( displayModeDict, kCGDisplayWidth )
+                    / horizontalSizeInInches;
+                *verticalDPI = (double)GetIntFromDictionaryForKey( displayModeDict,
+                        kCGDisplayHeight ) / verticalSizeInInches;
+                err = CGDisplayNoErr;
+            }
+        }
+        return err;
+    }
+
+double Utils::getDpiX() {
+    double x,y;
+    CGDisplayErr err = GetDisplayDPI( CGDisplayCurrentMode(kCGDirectMainDisplay),
+                                      kCGDirectMainDisplay,
+                                      &x, &y );
+
+    return err == CGDisplayNoErr ? x : 72.0;
+}
+
+double Utils::getDpiY() {
+    double x,y;
+    CGDisplayErr err = GetDisplayDPI( CGDisplayCurrentMode(kCGDirectMainDisplay),
+                                      kCGDirectMainDisplay,
+                                      &x, &y );
+
+    return err == CGDisplayNoErr ? y : 72.0;
+}
+#else
+#error "Not yet contributed"
+#endif
+
+

core/utils.h

@@ -28,6 +28,16 @@ class OKULAR_EXPORT Utils
      * specified \p orientation .
      */
     static QRect rotateRect( const QRect & source, int width, int height, int orientation );
+
+    /**
+     * Return the horizontal DPI of the main display
+     */
+    static double getDpiX();
+
+    /**
+     * Return the vertical DPI of the main display
+     */
+    static double getDpiY();
 };
 
 }

generators/dvi/generator_dvi.cpp

@@ -17,7 +17,6 @@
 #include "pageSize.h"
 
 #include <qapplication.h>
-#include <QX11Info>
 #include <qstring.h>
 #include <qurl.h>
 #include <qvector.h>
@@ -45,7 +44,7 @@ bool DviGenerator::loadDocument( const QString & fileName, QVector< Okular::Page
 
     kDebug() << "# of pages: " << m_dviRenderer->dviFile->total_pages << endl;
 
-    m_resolution = QX11Info::appDpiY();
+    m_resolution = Okular::Utils::getDpiY();
     loadPages( pagesVector, 0 );
 
     ready = true;