Use DPI of current screen for PDF rendering

Includes some fixes from Albert:
 * kscreen cmake fixes
   Don't make libkscreen mandatory, give the proper version we need
 * Fix the @since
 * Kill Resolution and use a QSizeF
   I first thought QSizeF didn't make sense, but well what's a dpi if not a number of pixels in width and some others in height?
 * Remove unwanted const
 * Remove unneeded utils.h includes
 * Fix comments on realDPIXY()
 * Make it compile in non X11

REVIEW: 111829

CMakeLists.txt

@@ -10,12 +10,16 @@ set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_SOURCE_DIR}/cmake/modules)
 macro_optional_find_package(QImageBlitz)
 macro_log_feature(QIMAGEBLITZ_FOUND "QImageBlitz" "An image effects library" "http://sourceforge.net/projects/qimageblitz" TRUE "kdesupport" "Required to build Okular.")
 
+macro_optional_find_package(LibKScreen)
+macro_log_feature(LibKScreen_FOUND "LibKScreen" "KDE screen management library" "https://projects.kde.org/projects/kdereview/libkscreen" FALSE "1.0.2" "DPI detection support")
+
 add_definitions(${QT_DEFINITIONS} ${KDE4_DEFINITIONS})
 add_definitions(-DQT_USE_FAST_CONCATENATION -DQT_USE_FAST_OPERATOR_PLUS)
 include_directories(
    ${CMAKE_CURRENT_SOURCE_DIR}
    ${KDE4_INCLUDES}
    ${QIMAGEBLITZ_INCLUDES}
+   ${LibKScreen_INCLUDE_DIR}
 )
 
 add_subdirectory( active )
@@ -131,6 +135,10 @@ ENDIF(APPLE)
 
 target_link_libraries(okularcore  ${OKULAR_IOKIT} ${KDE4_KIO_LIBS} ${KDE4_PHONON_LIBRARY} ${KDE4_KJSAPI_LIBRARY} ${MATH_LIB} ${KDE4_THREADWEAVER_LIBRARY} )
 
+if(LibKScreen_FOUND)
+    target_link_libraries(okularcore ${LibKScreen_LIBRARY})
+endif(LibKScreen_FOUND)
+
 set_target_properties(okularcore PROPERTIES VERSION 3.0.0 SOVERSION 3 )
 
 install(TARGETS okularcore ${INSTALL_TARGETS_DEFAULT_ARGS} )

config-okular.h.cmake

@@ -1,2 +1,5 @@
 /* Defines if force the use DRM in okular */
 #define OKULAR_FORCE_DRM ${_OKULAR_FORCE_DRM}
+
+/* Defines if LibKScreen is present */
+#define HAVE_LIBKSCREEN ${LibKScreen_FOUND}

core/document.cpp

@@ -84,6 +84,7 @@
 #include "view.h"
 #include "view_p.h"
 #include "form.h"
+#include "utils.h"
 
 #include <memory>
 
@@ -267,6 +268,14 @@ QString DocumentPrivate::localizedSize(const QSizeF &size) const
             inchesHeight = size.height() / 72.0;
         break;
 
+        case Generator::Pixels:
+        {
+            const QSizeF dpi = m_generator->dpi();
+            inchesWidth = size.width() / dpi.width();
+            inchesHeight = size.height() / dpi.height();
+        }
+        break;
+
         case Generator::None:
         break;
     }
@@ -917,6 +926,9 @@ bool DocumentPrivate::openDocumentInternal( const KService::Ptr& offer, bool iss
     QObject::connect( m_generator, SIGNAL(notice(QString,int)), m_parent, SIGNAL(notice(QString,int)) );
 
     QApplication::setOverrideCursor( Qt::WaitCursor );
+
+    m_generator->setDPI(Utils::realDpi(m_widget));
+
     bool openOk = false;
     if ( !isstdin )
     {

core/generator.cpp

@@ -31,7 +31,8 @@ GeneratorPrivate::GeneratorPrivate()
     : m_document( 0 ),
       mPixmapGenerationThread( 0 ), mTextPageGenerationThread( 0 ),
       m_mutex( 0 ), m_threadsMutex( 0 ), mPixmapReady( true ), mTextPageReady( true ),
-      m_closing( false ), m_closingLoop( 0 )
+      m_closing( false ), m_closingLoop( 0 ),
+      m_dpi(72.0, 72.0)
 {
 }
 
@@ -422,6 +423,18 @@ const SourceReference * Generator::dynamicSourceReference( int /*pageNr*/, doubl
   return 0;
 }
 
+void Generator::setDPI(const QSizeF & dpi)
+{
+     Q_D( Generator );
+     d->m_dpi = dpi;
+}
+
+QSizeF Generator::dpi() const
+{
+     Q_D( const Generator );
+     return d->m_dpi;
+}
+
 PixmapRequest::PixmapRequest( DocumentObserver *observer, int pageNumber, int width, int height, int priority, PixmapRequestFeatures features )
   : d( new PixmapRequestPrivate )
 {

core/generator.h

@@ -20,6 +20,7 @@
 #include <QtCore/QList>
 #include <QtCore/QObject>
 #include <QtCore/QSharedDataPointer>
+#include <QtCore/QSizeF>
 #include <QtCore/QString>
 #include <QtCore/QVariant>
 #include <QtCore/QVector>
@@ -308,7 +309,8 @@ class OKULAR_EXPORT Generator : public QObject
         enum PageSizeMetric
         {
           None,   ///< The page size is not defined in a physical metric.
-          Points  ///< The page size is given in 1/72 inches.
+          Points, ///< The page size is given in 1/72 inches.
+          Pixels  ///< The page size is given in screen pixels @since 0.19 (KDE 4.13)
         };
 
         /**
@@ -384,6 +386,13 @@ class OKULAR_EXPORT Generator : public QObject
          */
         bool hasFeature( GeneratorFeature feature ) const;
 
+        /**
+         * Update DPI of the generator
+         *
+         * @since 0.19 (KDE 4.13)
+         */
+        void setDPI(const QSizeF &dpi);
+
     Q_SIGNALS:
         /**
          * This signal should be emitted whenever an error occurred in the generator.
@@ -476,6 +485,12 @@ class OKULAR_EXPORT Generator : public QObject
          */
         void updatePageBoundingBox( int page, const NormalizedRect & boundingBox );
 
+        /**
+         * Returns DPI, previously set via setDPI()
+         * @since 0.19 (KDE 4.13)
+         */
+        QSizeF dpi() const;
+
     protected Q_SLOTS:
         /**
          * Gets the font data for the given font

core/generator_p.h

@@ -64,6 +64,7 @@ class GeneratorPrivate
         bool mTextPageReady : 1;
         bool m_closing : 1;
         QEventLoop *m_closingLoop;
+        QSizeF m_dpi;
 };
 
 

core/utils.cpp

@@ -18,7 +18,11 @@
 #include <QIODevice>
 
 #ifdef Q_WS_X11
-#include <QX11Info>
+  #include "config-okular.h"
+  #if HAVE_LIBKSCREEN
+   #include <kscreen/config.h>
+  #endif
+  #include <QX11Info>
 #endif
 
 #ifdef Q_WS_MAC
@@ -81,6 +85,48 @@ double Utils::realDpiY()
     return (double(w->height()) * 25.4) / double(w->heightMM());
 }
 
+QSizeF Utils::realDpi(QWidget* widgetOnScreen)
+{
+    // Firstly try to retrieve DPI via LibKScreen
+#if HAVE_LIBKSCREEN
+    KScreen::Config* config = KScreen::Config::current();
+    KScreen::OutputList outputs = config->outputs();
+    QPoint globalPos = widgetOnScreen->parentWidget() ?
+                   widgetOnScreen->mapToGlobal(widgetOnScreen->pos()):
+                   widgetOnScreen->pos();
+    QRect widgetRect(globalPos, widgetOnScreen->size());
+
+    KScreen::Output* selectedOutput = 0;
+    int maxArea = 0;
+    Q_FOREACH(KScreen::Output *output, outputs) {
+        if (output->currentMode()) {
+            QRect outputRect(output->pos(),output->currentMode()->size());
+            QRect intersection = outputRect.intersected(widgetRect);
+            int area = intersection.width()*intersection.height();
+            if (area > maxArea) {
+                maxArea = area;
+                selectedOutput = output;
+            }
+        }
+    }
+
+    if (selectedOutput) {
+        kDebug() << "Found widget at output #" << selectedOutput->id();
+        QRect outputRect(selectedOutput->pos(),selectedOutput->currentMode()->size());
+        QSize szMM = selectedOutput->sizeMm();
+        QSizeF res(static_cast<qreal>(outputRect.width())*25.4/szMM.width(),
+                   static_cast<qreal>(outputRect.height())*25.4/szMM.height());
+        kDebug() << "Output DPI is " << res;
+        return res;
+    }
+#endif
+    // this is also fallback for LibKScreen branch if KScreen::Output
+    // for particular widget was not found
+    const QDesktopWidget* desktop = QApplication::desktop();
+    return QSizeF((desktop->width() * 25.4) / desktop->widthMM(),
+            (desktop->height() * 25.4) / desktop->heightMM());
+}
+
 #elif defined(Q_WS_MAC)
     /*
      * Code copied from http://developer.apple.com/qa/qa2001/qa1217.html
@@ -164,6 +210,11 @@ double Utils::realDpiY()
 {
     return dpiY();
 }
+
+QSizeF Utils::realDpi(QWidget*)
+{
+    return QSizeF(realDpiX(), realDpiY());
+}
 #else
 
 double Utils::dpiX()
@@ -185,6 +236,11 @@ double Utils::realDpiY()
 {
     return dpiY();
 }
+
+QSizeF Utils::realDpi(QWidget*)
+{
+    return QSizeF(realDpiX(), realDpiY());
+}
 #endif
 
 inline static bool isWhite( QRgb argb ) {

core/utils.h

@@ -15,6 +15,7 @@
 
 class QRect;
 class QImage;
+class QWidget;
 
 namespace Okular
 {
@@ -50,6 +51,7 @@ class OKULAR_EXPORT Utils
      * setting. Otherwise, returns the same as dpiX(),
      *
      * @since 0.9 (KDE 4.3)
+     * @deprecated Can not work with multi-monitor configurations
      */
     static double realDpiX();
 
@@ -60,9 +62,20 @@ class OKULAR_EXPORT Utils
      * setting. Otherwise, returns the same as dpiX(),
      *
      * @since 0.9 (KDE 4.3)
+     * @deprecated Can not work with multi-monitor configurations
      */
     static double realDpiY();
 
+    /**
+     * Return the real DPI of the display containing given widget
+     *
+     * On X11, it can indicate the real horizontal DPI value without any Xrdb
+     * setting. Otherwise, returns the same as realDpiX/Y(),
+     *
+     * @since 0.19 (KDE 4.13)
+     */
+    static QSizeF realDpi(QWidget* widgetOnScreen);
+
     /**
      * Compute the smallest rectangle that contains all non-white pixels in image),
      * in normalized [0,1] coordinates.
@@ -75,3 +88,5 @@ class OKULAR_EXPORT Utils
 }
 
 #endif
+
+/* kate: replace-tabs on; indent-width 4; */

generators/poppler/generator_pdf.cpp

@@ -425,7 +425,6 @@ PDFGenerator::PDFGenerator( QObject *parent, const QVariantList &args )
     : Generator( parent, args ), pdfdoc( 0 ),
     docInfoDirty( true ), docSynopsisDirty( true ),
     docEmbeddedFilesDirty( true ), nextFontPage( 0 ),
-    dpiX( 72.0 /*Okular::Utils::dpiX()*/ ), dpiY( 72.0 /*Okular::Utils::dpiY()*/ ),
     annotProxy( 0 ), synctex_scanner( 0 )
 {
     setFeature( Threaded );
@@ -627,8 +626,8 @@ void PDFGenerator::loadPages(QVector<Okular::Page*> &pagesVector, int rotation,
         if (p)
         {
             const QSizeF pSize = p->pageSizeF();
-            w = pSize.width() / 72.0 * dpiX;
+            w = pSize.width() / 72.0 * dpi().width();
-            h = pSize.height() / 72.0 * dpiY;
+            h = pSize.height() / 72.0 * dpi().height();
             Okular::Rotation orientation = Okular::Rotation0;
             switch (p->orientation())
             {
@@ -908,8 +907,8 @@ QImage PDFGenerator::image( Okular::PixmapRequest * request )
     if ( page->rotation() % 2 )
         qSwap( pageWidth, pageHeight );
 
-    double fakeDpiX = request->width() * dpiX / pageWidth,
+    qreal fakeDpiX = request->width() / pageWidth * dpi().width();
-           fakeDpiY = request->height() * dpiY / pageHeight;
+    qreal fakeDpiY = request->height() / pageHeight * dpi().height();
 
     // generate links rects only the first time
     bool genObjectRects = !rectsGenerated.at( page->number() );
@@ -1759,8 +1758,8 @@ void PDFGenerator::loadPdfSync( const QString & filePath, QVector<Okular::Page*>
 
         // magic numbers for TeX's RSU's (Ridiculously Small Units) conversion to pixels
         Okular::NormalizedPoint p(
-            ( pt.x * dpiX ) / ( 72.27 * 65536.0 * pagesVector[pt.page]->width() ),
+            ( pt.x * dpi().width() ) / ( 72.27 * 65536.0 * pagesVector[pt.page]->width() ),
-            ( pt.y * dpiY ) / ( 72.27 * 65536.0 * pagesVector[pt.page]->height() )
+            ( pt.y * dpi().height() ) / ( 72.27 * 65536.0 * pagesVector[pt.page]->height() )
             );
         QString file = pt.file;
         Okular::SourceReference * sourceRef = new Okular::SourceReference( file, pt.row, pt.column );
@@ -1781,7 +1780,7 @@ const Okular::SourceReference * PDFGenerator::dynamicSourceReference( int pageNr
     if  ( !synctex_scanner )
         return 0;
 
-    if (synctex_edit_query(synctex_scanner, pageNr + 1, absX * 72. / dpiX, absY * 72. / dpiY) > 0)
+    if (synctex_edit_query(synctex_scanner, pageNr + 1, absX * 72. / dpi().width(), absY * 72. / dpi().height()) > 0)
     {
         synctex_node_t node;
         // TODO what should we do if there is really more than one node?
@@ -1852,8 +1851,8 @@ void PDFGenerator::fillViewportFromSourceReference( Okular::DocumentViewport & v
             if ( !viewport.isValid() ) return;
 
             // TeX small points ...
-            double px = (synctex_node_visible_h( node ) * dpiX) / 72.27;
+            double px = (synctex_node_visible_h( node ) * dpi().width()) / 72.27;
-            double py = (synctex_node_visible_v( node ) * dpiY) / 72.27;
+            double py = (synctex_node_visible_v( node ) * dpi().height()) / 72.27;
             viewport.rePos.normalizedX = px / document()->page(viewport.pageNumber)->width();
             viewport.rePos.normalizedY = ( py + 0.5 ) / document()->page(viewport.pageNumber)->height();
             viewport.rePos.enabled = true;

generators/poppler/generator_pdf.h

@@ -68,7 +68,7 @@ class PDFGenerator : public Okular::Generator, public Okular::ConfigInterface, p
         const Okular::DocumentSynopsis * generateDocumentSynopsis();
         Okular::FontInfo::List fontsForPage( int page );
         const QList<Okular::EmbeddedFile*> * embeddedFiles() const;
-        PageSizeMetric pagesSizeMetric() const { return Points; }
+        PageSizeMetric pagesSizeMetric() const { return Pixels; }
 
         // [INHERITED] document information
         bool isAllowed( Okular::Permission permission ) const;
@@ -144,8 +144,6 @@ class PDFGenerator : public Okular::Generator, public Okular::ConfigInterface, p
         mutable bool docEmbeddedFilesDirty;
         mutable QList<Okular::EmbeddedFile*> docEmbeddedFiles;
         int nextFontPage;
-        double dpiX;
-        double dpiY;
         PopplerAnnotationProxy *annotProxy;
         QHash<Okular::Annotation*, Poppler::Annotation*> annotationsHash;