okular/core/utils.cpp

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