libkdeedu/kdeeduplot/kplotwidget.cpp

   1 /***************************************************************************
   2                           kplotwidget.cpp - A widget for plotting in KStars
   3                              -------------------
   4     begin                : Sun 18 May 2003
   5     copyright            : (C) 2003 by Jason Harris
   6     email                : kstars@30doradus.org
   7  ***************************************************************************/
   8
   9 /***************************************************************************
  10  *                                                                         *
  11  *   This program is free software; you can redistribute it and/or modify  *
  12  *   it under the terms of the GNU General Public License as published by  *
  13  *   the Free Software Foundation; either version 2 of the License, or     *
  14  *   (at your option) any later version.                                   *
  15  *                                                                         *
  16  ***************************************************************************/
  17
  18 #include <math.h> //for log10(), pow(), modf()
  19 #include <kdebug.h>
  20 #include <qpainter.h>
  21 #include <qpixmap.h>
  22
  23 #include "kplotwidget.h"
  24
  25 KPlotWidget::KPlotWidget( double x1, double x2, double y1, double y2, QWidget *parent, const char* name )
  26  : QWidget( parent, name, WNoAutoErase ),
  27    dXtick(0.0), dYtick(0.0),
  28    nmajX(0), nminX(0), nmajY(0), nminY(0),
  29    ShowAxes( true ), ShowTickMarks( true ), ShowTickLabels( true ), ShowGrid( false ),
  30    XAxisLabel(), YAxisLabel() {
  31
  32         setBackgroundMode( QWidget::NoBackground );
  33
  34         //set DataRect
  35         setLimits( x1, x2, y1, y2 );
  36         setDefaultPadding();
  37
  38         //Set PixRect (starts at (0,0) because we will translate by leftPadding(), topPadding() )
  39         PixRect = QRect( 0, 0, width() - leftPadding() - rightPadding(),
  40                                height() - topPadding() - bottomPadding() );
  41
  42         buffer = new QPixmap();
  43
  44         //default colors:
  45         setBGColor( QColor( "black" ) );
  46         setFGColor( QColor( "white" ) );
  47         setGridColor( QColor( "grey" ) );
  48
  49         ObjectList.setAutoDelete( TRUE );
  50 }
  51
  52 KPlotWidget::~KPlotWidget()
  53 {
  54         delete (buffer);
  55 }
  56
  57 void KPlotWidget::setLimits( double x1, double x2, double y1, double y2 ) {
  58         double XA1, XA2, YA1, YA2;
  59         if (x2<x1) { XA1=x2; XA2=x1; }
  60         else { XA1=x1; XA2=x2; }
  61         if ( y2<y1) { YA1=y2; YA2=y1; }
  62         else { YA1=y1; YA2=y2; }
  63
  64         DataRect = DRect( XA1, YA1, XA2-XA1, YA2-YA1 );
  65         updateTickmarks();
  66 }
  67
  68 void KPlotWidget::updateTickmarks() {
  69         // Determine the number and spacing of tickmarks for the current plot limits.
  70         if ( dataWidth() == 0.0 ) {
  71                 kdWarning() << "X range invalid! " << x() << " to " << x2() << endl;
  72                 DataRect.setWidth( 1.0 );
  73                 return;
  74         }
  75         if ( dataHeight() == 0.0 ) {
  76                 kdWarning() << "Y range invalid! " << y() << " to " << y2() << endl;
  77                 DataRect.setHeight( 1.0 );
  78                 return;
  79         }
  80
  81         int nmajor(0), nminor(0);
  82         double z(0.0), z2(0.0);
  83         double Range(0.0), s(0.0), t(0.0), pwr(0.0), dTick(0.0);
  84
  85         //loop over X and Y axes...the z variables substitute for either X or Y
  86         for ( unsigned int iaxis=0; iaxis<2; ++iaxis ) {
  87                 if ( iaxis == 1 ) {
  88                         z = x(); z2 = x2();
  89                 } else {
  90                         z = y(); z2 = y2();
  91                 }
  92
  93                 //determine size of region to be drawn, in draw units
  94                 Range = z2 - z;
  95
  96                 //s is the power-of-ten factor of Range:
  97                 //Range = t * s; s = 10^(pwr).  e.g., Range=350.0 then t=3.5, s = 100.0; pwr = 2.0
  98                 modf( log10(Range), &pwr );
  99                 s = pow( 10.0, pwr );
 100                 t = Range/s;
 101
 102                 //adjust s and t such that t is between 3 and 5:
 103                 if ( t < 3.0 ) { t *= 10.0; s /= 10.0; } //t now btwn 3 and 30
 104                 if ( t < 6.0 ) { //accept current values
 105                         dTick = s;
 106                         nmajor = int(t);
 107                         nminor = 5;
 108                 } else if ( t < 10.0 ) { //factor of 2
 109                         dTick = s*2.0;
 110                         nmajor = int(t/2.0);
 111                         nminor = 4;
 112                 } else if ( t < 20.0 ) { //factor of 4
 113                         dTick = s*4.0;
 114                         nmajor = int(t/4.0);
 115                         nminor = 4;
 116                 } else { //factor of 5
 117                         dTick = s*5.0;
 118                         nmajor = int(t/5.0);
 119                         nminor = 5;
 120                 }
 121
 122                 if ( iaxis==1 ) { //X axis
 123                         nmajX = nmajor;
 124                         nminX = nminor;
 125                         dXtick = dTick;
 126                 } else { //Y axis
 127                         nmajY = nmajor;
 128                         nminY = nminor;
 129                         dYtick = dTick;
 130                 }
 131         } //end for iaxis
 132 }
 133
 134 void KPlotWidget::resizeEvent( QResizeEvent* /* e */ ) {
 135         int newWidth = width() - leftPadding() - rightPadding();
 136         int newHeight = height() - topPadding() - bottomPadding();
 137         PixRect = QRect( 0, 0, newWidth, newHeight );
 138
 139         buffer->resize( width(), height() );
 140 }
 141
 142 void KPlotWidget::paintEvent( QPaintEvent* /* e */ ) {
 143         QPainter p;
 144
 145         p.begin( buffer );
 146         p.fillRect( 0, 0, width(), height(), bgColor() );
 147         p.translate( leftPadding(), topPadding() );
 148
 149         drawObjects( &p );
 150         drawBox( &p );
 151
 152         p.end();
 153         bitBlt( this, 0, 0, buffer );
 154 }
 155
 156 void KPlotWidget::drawObjects( QPainter *p ) {
 157         for ( KPlotObject *po = ObjectList.first(); po; po = ObjectList.next() ) {
 158
 159                 if ( po->points()->count() ) {
 160                         //draw the plot object
 161                         p->setPen( QColor( po->color() ) );
 162
 163                         switch ( po->type() ) {
 164                                 case KPlotObject::POINTS :
 165                                 {
 166                                         p->setBrush( QColor( po->color() ) );
 167
 168                                         for ( DPoint *dp = po->points()->first(); dp; dp = po->points()->next() ) {
 169                                                 QPoint q = dp->qpoint( PixRect, DataRect );
 170                                                 int x1 = q.x() - po->size()/2;
 171                                                 int y1 = q.y() - po->size()/2;
 172
 173                                                 switch( po->param() ) {
 174                                                         case KPlotObject::CIRCLE : p->drawEllipse( x1, y1, po->size(), po->size() ); break;
 175                                                         case KPlotObject::SQUARE : p->drawRect( x1, y1, po->size(), po->size() ); break;
 176                                                         case KPlotObject::LETTER : p->drawText( q, po->name().left(1) ); break;
 177                                                         default: p->drawPoint( q );
 178                                                 }
 179                                         }
 180
 181                                         p->setBrush( Qt::NoBrush );
 182                                         break;
 183                                 }
 184
 185                                 case KPlotObject::CURVE :
 186                                 {
 187                                         p->setPen( QPen( QColor( po->color() ), po->size(), (QPen::PenStyle)po->param() ) );
 188                                         DPoint *dp = po->points()->first();
 189                                         p->moveTo( dp->qpoint( PixRect, DataRect ) );
 190                                         for ( dp = po->points()->next(); dp; dp = po->points()->next() )
 191                                                 p->lineTo( dp->qpoint( PixRect, DataRect ) );
 192                                         break;
 193                                 }
 194
 195                                 case KPlotObject::LABEL : //draw label centered at point in x, and slightly below point in y.
 196                                 {
 197                                         QPoint q = po->points()->first()->qpoint( PixRect, DataRect );
 198                                         p->drawText( q.x()-20, q.y()+6, 40, 10, Qt::AlignCenter | Qt::DontClip, po->name() );
 199                                         break;
 200                                 }
 201
 202                                 case KPlotObject::POLYGON :
 203                                 {
 204                                         p->setPen( QPen( QColor( po->color() ), po->size(), (QPen::PenStyle)po->param() ) );
 205                                         p->setBrush( po->color() );
 206
 207                                         QPointArray a( po->count() );
 208
 209                                         unsigned int i=0;
 210                                         for ( DPoint *dp = po->points()->first(); dp; dp = po->points()->next() )
 211                                                 a.setPoint( i++, dp->qpoint( PixRect, DataRect ) );
 212
 213                                         p->drawPolygon( a );
 214                                         break;
 215                                 }
 216
 217                                 case KPlotObject::UNKNOWN_TYPE : break;
 218                         }
 219                 }
 220         }
 221 }
 222
 223 double KPlotWidget::dmod( double a, double b ) { return ( b * ( ( a / b ) - int( a / b ) ) ); }
 224
 225 void KPlotWidget::drawBox( QPainter *p ) {
 226         //First, fill in padding region with bgColor() to mask out-of-bounds plot data
 227         p->setPen( bgColor() );
 228         p->setBrush( bgColor() );
 229
 230         //left padding ( don't forget: we have translated by XPADDING, YPADDING )
 231         p->drawRect( -leftPadding(), -topPadding(), leftPadding(), height() );
 232
 233         //right padding
 234         p->drawRect( PixRect.width(), -topPadding(), rightPadding(), height() );
 235
 236         //top padding
 237         p->drawRect( 0, -topPadding(), PixRect.width(), topPadding() );
 238
 239         //bottom padding
 240         p->drawRect( 0, PixRect.height(), PixRect.width(), bottomPadding() );
 241
 242         if ( ShowGrid ) {
 243                 //Grid lines are placed at locations of primary axes' major tickmarks
 244                 p->setPen( gridColor() );
 245
 246                 //vertical grid lines
 247                 double x0 = x() - dmod( x(), dXtick ); //zeropoint; x(i) is this plus i*dXtick1
 248                 for ( int ix = 0; ix <= nmajX+1; ix++ ) {
 249                         int px = int( PixRect.width() * ( (x0 + ix*dXtick - x())/dataWidth() ) );
 250                         p->drawLine( px, 0, px, PixRect.height() );
 251                 }
 252
 253                 //horizontal grid lines
 254                 double y0 = y() - dmod( y(), dYtick ); //zeropoint; y(i) is this plus i*mX
 255                 for ( int iy = 0; iy <= nmajY+1; iy++ ) {
 256                         int py = int( PixRect.height() * ( (y0 + iy*dYtick - y())/dataHeight() ) );
 257                         p->drawLine( 0, py, PixRect.width(), py );
 258                 }
 259         }
 260
 261         p->setPen( fgColor() );
 262         p->setBrush( Qt::NoBrush );
 263
 264         if ( ShowAxes ) p->drawRect( PixRect ); //box outline
 265
 266         if ( ShowTickMarks ) {
 267                 //spacing between minor tickmarks (in data units)
 268                 double dminX = dXtick/nminX;
 269                 double dminY = dYtick/nminY;
 270
 271                 //set small font for tick labels
 272                 QFont f = p->font();
 273                 int s = f.pointSize();
 274                 f.setPointSize( s - 2 );
 275                 p->setFont( f );
 276
 277                 //--- Draw X tickmarks---//
 278                 double x0 = x() - dmod( x(), dXtick ); //zeropoint; tickmark i is this plus i*dXtick (in data units)
 279                 if ( x() < 0.0 ) x0 -= dXtick;
 280
 281                 for ( int ix = 0; ix <= nmajX+1; ix++ ) {
 282                         //position of tickmark i (in screen units)
 283                         int px = int( PixRect.width() * ( (x0 + ix*dXtick - x() )/dataWidth() ) );
 284
 285                         if ( px > 0 && px < PixRect.width() ) {
 286                                 p->drawLine( px, PixRect.height() - 2, px, PixRect.height() - BIGTICKSIZE - 2 );
 287                                 p->drawLine( px, 0, px, BIGTICKSIZE );
 288                         }
 289
 290                         //tick label
 291                         if ( ShowTickLabels ) {
 292                                 double lab = x0 + ix*dXtick;
 293                                 if ( fabs(lab)/dXtick < 0.00001 ) lab = 0.0; //fix occassional roundoff error with "0.0" label
 294
 295                                 QString str = QString( "%1" ).arg( lab, 0, 'g', 2 );
 296                                 if ( px > 0 && px < PixRect.width() ) {
 297                                         QRect r( px - BIGTICKSIZE, PixRect.height()+BIGTICKSIZE, 2*BIGTICKSIZE, BIGTICKSIZE );
 298                                         p->drawText( r, Qt::AlignCenter | Qt::DontClip, str );
 299                                 }
 300                         }
 301
 302                         //draw minor ticks
 303                         for ( int j=0; j < nminX; j++ ) {
 304                                 //position of minor tickmark j (in screen units)
 305                                 int pmin = int( px + PixRect.width()*j*dminX/dataWidth() );
 306
 307                                 if ( pmin > 0 && pmin < PixRect.width() ) {
 308                                         p->drawLine( pmin, PixRect.height() - 2, pmin, PixRect.height() - SMALLTICKSIZE - 2 );
 309                                         p->drawLine( pmin, 0, pmin, SMALLTICKSIZE );
 310                                 }
 311                         }
 312                 }
 313
 314                 //--- Draw Y tickmarks---//
 315                 double y0 = y() - dmod( y(), dYtick ); //zeropoint; tickmark i is this plus i*dYtick1 (in data units)
 316                 if ( y() < 0.0 ) y0 -= dYtick;
 317
 318                 for ( int iy = 0; iy <= nmajY+1; iy++ ) {
 319                         //position of tickmark i (in screen units)
 320                         int py = PixRect.height() - int( PixRect.height() * ( (y0 + iy*dYtick - y())/dataHeight() ) );
 321                         if ( py > 0 && py < PixRect.height() ) {
 322                                 p->drawLine( 0, py, BIGTICKSIZE, py );
 323                                 p->drawLine( PixRect.width()-2, py, PixRect.width()-BIGTICKSIZE-2, py );
 324                         }
 325
 326                         //tick label
 327                         if ( ShowTickLabels ) {
 328                                 double lab = y0 + iy*dYtick;
 329                                 if ( fabs(lab)/dYtick < 0.00001 ) lab = 0.0; //fix occassional roundoff error with "0.0" label
 330
 331                                 QString str = QString( "%1" ).arg( lab, 0, 'g', 2 );
 332                                 if ( py > 0 && py < PixRect.height() ) {
 333                                         QRect r( -2*BIGTICKSIZE, py-SMALLTICKSIZE, 2*BIGTICKSIZE, 2*SMALLTICKSIZE );
 334                                         p->drawText( r, Qt::AlignCenter | Qt::DontClip, str );
 335                                 }
 336                         }
 337
 338                         //minor ticks
 339                         for ( int j=0; j < nminY; j++ ) {
 340                                 //position of minor tickmark j (in screen units)
 341                                 int pmin = int( py - PixRect.height()*j*dminY/dataHeight() );
 342                                 if ( pmin > 0 && pmin < PixRect.height() ) {
 343                                         p->drawLine( 0, pmin, SMALLTICKSIZE, pmin );
 344                                         p->drawLine( PixRect.width()-2, pmin, PixRect.width()-SMALLTICKSIZE-2, pmin );
 345                                 }
 346                         }
 347                 } //end draw Y tickmarks
 348         } //end if ( ShowTickMarks )
 349
 350         //Draw X Axis Label
 351         if ( ! XAxisLabel.isEmpty() ) {
 352                 QRect r( 0, PixRect.height() + 2*YPADDING, PixRect.width(), YPADDING );
 353                 p->drawText( r, Qt::AlignCenter, XAxisLabel );
 354         }
 355
 356         //Draw Y Axis Label.  We need to draw the text sideways.
 357         if ( ! YAxisLabel.isEmpty() ) {
 358                 //store current painter translation/rotation state
 359                 p->save();
 360
 361                 //translate coord sys to left corner of axis label rectangle, then rotate 90 degrees.
 362                 p->translate( -3*XPADDING, PixRect.height() );
 363                 p->rotate( -90.0 );
 364
 365                 QRect r( 0, 0, PixRect.height(), XPADDING );
 366                 p->drawText( r, Qt::AlignCenter, YAxisLabel ); //draw the label, now that we are sideways
 367
 368                 p->restore();  //restore translation/rotation state
 369         }
 370 }
 371
 372 int KPlotWidget::leftPadding() const {
 373         if ( LeftPadding >= 0 ) return LeftPadding;
 374         if ( ! YAxisLabel.isEmpty() && ShowTickLabels ) return 3*XPADDING;
 375         if ( ! YAxisLabel.isEmpty() || ShowTickLabels ) return 2*XPADDING;
 376         return XPADDING;
 377 }
 378
 379 int KPlotWidget::rightPadding() const {
 380         if ( RightPadding >= 0 ) return RightPadding;
 381         return XPADDING;
 382 }
 383
 384 int KPlotWidget::topPadding() const {
 385         if ( TopPadding >= 0 ) return TopPadding;
 386         return YPADDING;
 387 }
 388
 389 int KPlotWidget::bottomPadding() const {
 390         if ( BottomPadding >= 0 ) return BottomPadding;
 391         if ( ! XAxisLabel.isEmpty() && ShowTickLabels ) return 3*YPADDING;
 392         if ( ! XAxisLabel.isEmpty() || ShowTickLabels ) return 2*YPADDING;
 393         return YPADDING;
 394 }
 395
 396 #include "kplotwidget.moc"