okular/core/utils.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2006 by Luigi Toscano <luigi.toscano@tiscali.it>        *
   3  *   Copyright (C) 2008 by Pino Toscano <pino@kde.org>                     *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  ***************************************************************************/
  10
  11 #include "utils.h"
  12 #include "utils_p.h"
  13
  14 #include <QtCore/QRect>
  15 #include <QImage>
  16 #include <QIODevice>
  17
  18 #ifdef Q_WS_X11
  19 #include <QX11Info>
  20 #endif
  21
  22 #ifdef Q_WS_MAC
  23 #include <ApplicationServices/ApplicationServices.h>
  24 #include <IOKit/graphics/IOGraphicsLib.h>
  25 #endif
  26
  27
  28
  29 using namespace Okular;
  30
  31 QRect Utils::rotateRect( const QRect & source, int width, int height, int orientation )
  32 {
  33     QRect ret;
  34
  35     // adapt the coordinates of the boxes to the rotation
  36     switch ( orientation )
  37     {
  38         case 1:
  39             ret = QRect( width - source.y() - source.height(), source.x(),
  40                          source.height(), source.width() );
  41             break;
  42         case 2:
  43             ret = QRect( width - source.x() - source.width(), height - source.y() - source.height(),
  44                          source.width(), source.height() );
  45             break;
  46         case 3:
  47             ret = QRect( source.y(), height - source.x() - source.width(),
  48                          source.height(), source.width() );
  49             break;
  50         case 0:  // no modifications
  51         default: // other cases
  52             ret = source;
  53     }
  54
  55     return ret;
  56 }
  57
  58 #if defined(Q_WS_X11)
  59
  60 double Utils::dpiX()
  61 {
  62     return QX11Info::appDpiX();
  63 }
  64
  65 double Utils::dpiY()
  66 {
  67     return QX11Info::appDpiY();
  68 }
  69
  70 #elif defined(Q_WS_MAC)
  71     /*
  72      * Code copied from http://developer.apple.com/qa/qa2001/qa1217.html
  73      */
  74     //    Handy utility function for retrieving an int from a CFDictionaryRef
  75     static int GetIntFromDictionaryForKey( CFDictionaryRef desc, CFStringRef key )
  76     {
  77         CFNumberRef value;
  78         int num = 0;
  79         if ( (value = (CFNumberRef)CFDictionaryGetValue(desc, key)) == NULL || CFGetTypeID(value) != CFNumberGetTypeID())
  80             return 0;
  81         CFNumberGetValue(value, kCFNumberIntType, &num);
  82         return num;
  83     }
  84
  85     static CGDisplayErr GetDisplayDPI( CFDictionaryRef displayModeDict, CGDirectDisplayID displayID,
  86                                        double *horizontalDPI, double *verticalDPI )
  87     {
  88         CGDisplayErr err = kCGErrorFailure;
  89         io_connect_t displayPort;
  90         CFDictionaryRef displayDict;
  91
  92         //    Grab a connection to IOKit for the requested display
  93         displayPort = CGDisplayIOServicePort( displayID );
  94         if ( displayPort != MACH_PORT_NULL )
  95         {
  96             //    Find out what IOKit knows about this display
  97             displayDict = IODisplayCreateInfoDictionary(displayPort, 0);
  98             if ( displayDict != NULL )
  99             {
 100                 const double mmPerInch = 25.4;
 101                 double horizontalSizeInInches =
 102                     (double)GetIntFromDictionaryForKey(displayDict,
 103                                                        CFSTR(kDisplayHorizontalImageSize)) / mmPerInch;
 104                 double verticalSizeInInches =
 105                     (double)GetIntFromDictionaryForKey(displayDict,
 106                                                        CFSTR(kDisplayVerticalImageSize)) / mmPerInch;
 107
 108                 //    Make sure to release the dictionary we got from IOKit
 109                 CFRelease(displayDict);
 110
 111                 // Now we can calculate the actual DPI
 112                 // with information from the displayModeDict
 113                 *horizontalDPI =
 114                     (double)GetIntFromDictionaryForKey( displayModeDict, kCGDisplayWidth )
 115                     / horizontalSizeInInches;
 116                 *verticalDPI = (double)GetIntFromDictionaryForKey( displayModeDict,
 117                         kCGDisplayHeight ) / verticalSizeInInches;
 118                 err = CGDisplayNoErr;
 119             }
 120         }
 121         return err;
 122     }
 123
 124 double Utils::dpiX()
 125 {
 126     double x,y;
 127     CGDisplayErr err = GetDisplayDPI( CGDisplayCurrentMode(kCGDirectMainDisplay),
 128                                       kCGDirectMainDisplay,
 129                                       &x, &y );
 130
 131     return err == CGDisplayNoErr ? x : 72.0;
 132 }
 133
 134 double Utils::dpiY()
 135 {
 136     double x,y;
 137     CGDisplayErr err = GetDisplayDPI( CGDisplayCurrentMode(kCGDirectMainDisplay),
 138                                       kCGDirectMainDisplay,
 139                                       &x, &y );
 140
 141     return err == CGDisplayNoErr ? y : 72.0;
 142 }
 143 #else
 144 #include <QDesktopWidget>
 145
 146 double Utils::dpiX()
 147 {
 148     return QDesktopWidget().physicalDpiX();
 149 }
 150
 151 double Utils::dpiY()
 152 {
 153     return QDesktopWidget().physicalDpiY();
 154 }
 155 #endif
 156
 157 inline static bool isWhite( QRgb argb ) {
 158     return ( argb & 0xFFFFFF ) == 0xFFFFFF; // ignore alpha
 159 }
 160
 161 NormalizedRect Utils::imageBoundingBox( const QImage * image )
 162 {
 163     if ( !image )
 164         return NormalizedRect();
 165
 166     int width = image->width();
 167     int height = image->height();
 168     int left, top, bottom, right, x, y;
 169
 170 #ifdef BBOX_DEBUG
 171     QTime time;
 172     time.start();
 173 #endif
 174
 175     // Scan pixels for top non-white
 176     for ( top = 0; top < height; ++top )
 177         for ( x = 0; x < width; ++x )
 178             if ( !isWhite( image->pixel( x, top ) ) )
 179                 goto got_top;
 180     return NormalizedRect( 0, 0, 0, 0 ); // the image is blank
 181 got_top:
 182     left = right = x;
 183
 184     // Scan pixels for bottom non-white
 185     for ( bottom = height-1; bottom >= top; --bottom )
 186         for ( x = width-1; x >= 0; --x )
 187             if ( !isWhite( image->pixel( x, bottom ) ) )
 188                 goto got_bottom;
 189     Q_ASSERT( 0 ); // image changed?!
 190 got_bottom:
 191     if ( x < left )
 192         left = x;
 193     if ( x > right )
 194         right = x;
 195
 196     // Scan for leftmost and rightmost (we already found some bounds on these):
 197     for ( y = top; y <= bottom && ( left > 0 || right < width-1 ); ++y )
 198     {
 199         for ( x = 0; x < left; ++x )
 200             if ( !isWhite( image->pixel( x, y ) ) )
 201                 left = x;
 202         for ( x = width-1; x > right+1; --x )
 203             if ( !isWhite( image->pixel( x, y ) ) )
 204                 right = x;
 205     }
 206
 207     NormalizedRect bbox( QRect( left, top, ( right - left + 1), ( bottom - top + 1 ) ),
 208                          image->width(), image->height() );
 209
 210 #ifdef BBOX_DEBUG
 211     kDebug() << "Computed bounding box" << bbox << "in" << time.elapsed() << "ms";
 212 #endif
 213
 214     return bbox;
 215 }
 216
 217 void Okular::copyQIODevice( QIODevice *from, QIODevice *to )
 218 {
 219     QByteArray buffer( 65536, '\0' );
 220     qint64 read = 0;
 221     qint64 written = 0;
 222     while ( ( read = from->read( buffer.data(), buffer.size() ) ) > 0 )
 223     {
 224         written = to->write( buffer.constData(), read );
 225         if ( read != written )
 226             break;
 227     }
 228 }