kbruch/src/rationalwidget.cpp

   1 /***************************************************************************
   2                           rationalwidget.h  -  paint a rational number
   3                              -------------------
   4     begin                : 2004/06/04
   5     copyright            : (C) 2004 by Sebastian Stein
   6     email                : seb.kde@hpfsc.de
   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 "rationalwidget.h"
  19 #include "rationalwidget.moc"
  20
  21 /* these includes are needed for Qt support */
  22 #include <qpainter.h>
  23 #include <qstring.h>
  24
  25 RationalWidget::RationalWidget(QWidget * parent, const char * name, const QString pnumber, const uint pperiodStart, const uint pperiodLength):
  26                         FractionBaseWidget(parent, name), m_number(pnumber),
  27                                 m_periodStart(pperiodStart), m_periodLength(pperiodLength)
  28 {
  29 #ifdef DEBUG
  30         kdDebug() << "constructor RationalWidget" << endl;
  31 #endif
  32 }
  33
  34 RationalWidget::~RationalWidget()
  35 {
  36 #ifdef DEBUG
  37         kdDebug() << "destructor RationalWidget" << endl;
  38 #endif
  39 }
  40
  41 void RationalWidget::setRational(const QString pnumber, const uint pperiodStart, const uint pperiodLength)
  42 {
  43         m_number = pnumber;
  44         m_periodStart = pperiodStart;
  45         m_periodLength = pperiodLength;
  46
  47         update();
  48
  49         return;
  50 }
  51
  52 void RationalWidget::paintEvent(QPaintEvent* /* p_paintEvent */)
  53 {
  54         // our x position, we paint from left to right;
  55         // we don't want to start directly on the border, so add the margin
  56         int x_pos = _MARGIN_X;
  57         int x_startPos = _MARGIN_X;
  58         bool tmp_painting = false;
  59
  60         // start the painter
  61         QPainter paint(this);
  62
  63         // ratios and operation signs are painted with the same font
  64         paint.setFont(m_font);
  65
  66         // set the pen for painting
  67         QPen pen(Qt::SolidLine);
  68         pen.setWidth(0);
  69         paint.setPen(pen);
  70
  71         // get the font height; the font height doesn't change while painting
  72         QFontMetrics & fm = * new QFontMetrics(paint.fontMetrics());
  73         int fontHeight = fm.lineSpacing(); // get the font height
  74
  75         // now we can correctly set the height of the widget
  76         setMinimumHeight(2 * fontHeight + 10);
  77         setMaximumHeight(2 * fontHeight + 10);
  78
  79         // paint each char one by one
  80         for (uint stringPos = 0; stringPos < m_number.length(); stringPos++)
  81         {
  82                 // check if the period line starts over the current number
  83                 if (m_periodLength > 0 && stringPos == m_periodStart && tmp_painting == false)
  84                 {
  85                         x_startPos = x_pos;
  86                         tmp_painting = true;
  87                 }
  88
  89                 // paint the current number (or comma)
  90                 paintMiddle(paint, QString(m_number[stringPos]), x_pos, fm, m_colorNumber, false);
  91
  92                 // check if the period line ends over the current number; in this case
  93                 // draw the period line
  94                 if (tmp_painting == true && m_periodStart + m_periodLength - 1 == stringPos)
  95                 {
  96                         tmp_painting = false;
  97
  98                         // paint the period line above the numbers
  99                         paint.fillRect(x_startPos, fontHeight - 3, x_pos - x_startPos, 1, m_colorNumber);
 100                 }
 101         }
 102
 103         // paint a = at the end
 104         x_pos += _MARGIN_X;
 105         paintMiddle(paint, "=", x_pos, fm, m_colorOperation);
 106
 107         // stop the painter
 108         paint.end();
 109
 110         // the space we needed for painting is the minimum width of the widget
 111         setMinimumWidth(x_pos);
 112
 113         return;
 114 }