kbruch/src/exerciseconvert.cpp

   1 /***************************************************************************
   2                               exerciseconvert.h
   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 "exerciseconvert.h"
  19 #include "exerciseconvert.moc"
  20
  21 /* these includes are needed for KDE support */
  22 #include <kapplication.h>
  23 #include <klocale.h>
  24 #include <kmessagebox.h>
  25 #include <knumvalidator.h>
  26
  27 /* these includes are needed for Qt support */
  28 #include <qlabel.h>
  29 #include <qlayout.h>
  30 #include <qlineedit.h>
  31 #include <qpushbutton.h>
  32 #include <qtooltip.h>
  33 #include <qwhatsthis.h>
  34
  35 /* standard C++ library includes */
  36 #include <stdlib.h>
  37
  38 #include "rationalwidget.h"
  39 #include "resultwidget.h"
  40
  41 /* ----- public member functions ----- */
  42
  43 /* constructor */
  44 ExerciseConvert::ExerciseConvert(QWidget * parent, const char * name):
  45                 ExerciseBase(parent, name)
  46 {
  47 #ifdef DEBUG
  48         kdDebug() << "constructor ExerciseConvert()" << endl;
  49 #endif
  50
  51         /* create a new task */
  52         QApplication::setOverrideCursor(waitCursor); /* show the sand clock */
  53         createTask();
  54         QApplication::restoreOverrideCursor(); /* show the normal cursor */
  55
  56         // the next thing to do on a button click would be to check the entered
  57         // result
  58         m_currentState = _CHECK_TASK;
  59
  60         baseWidget = new QWidget(this, "baseWidget");
  61         baseGrid = new QGridLayout(this, 1, 1, 0, -1, "baseGrid");
  62         baseGrid->addWidget(baseWidget, 0, 0);
  63
  64         // this is a VBox
  65         realLayout = new QVBoxLayout(baseWidget, 5, 5, "realLayout");
  66
  67         // add a spacer at the top of the VBox
  68         QSpacerItem * v_spacer = new QSpacerItem(1, 1);
  69         realLayout->addItem(v_spacer);
  70
  71         // now a line holding the task, input fields and result
  72         QHBoxLayout * taskLineHBoxLayout = new QHBoxLayout(5, "taskLineHBoxLayout");
  73         realLayout->addLayout(taskLineHBoxLayout);
  74
  75         // first left is the rational widget
  76         m_rationalWidget = new RationalWidget(baseWidget, "m_rationalWidget", m_number, m_periodStart, m_periodLength);
  77         taskLineHBoxLayout->addWidget(m_rationalWidget);
  78
  79         // now we have the input fields aligned in a VBox
  80         QVBoxLayout * inputLayout = new QVBoxLayout(5, "inputLayout");
  81         taskLineHBoxLayout->addLayout(inputLayout);
  82
  83         // to validate, that the input is an int
  84         KIntValidator *valnum = new KIntValidator( this );
  85
  86         /* add input box so the user can enter numerator */
  87         numer_edit = new QLineEdit(baseWidget, "numer_edit");
  88         numer_edit->setValidator( valnum ); // use the int validator
  89         QToolTip::add(numer_edit, i18n("Enter the numerator of your result"));
  90         inputLayout->addWidget(numer_edit);
  91
  92         /* add a line between the edit boxes */
  93         edit_line = new QFrame(baseWidget, "edit_line");
  94         edit_line->setGeometry(QRect(100, 100, 20, 20));
  95         edit_line->setFrameStyle(QFrame::HLine | QFrame::Sunken);
  96         inputLayout->addWidget(edit_line);
  97
  98         /* add input box so the user can enter denominator */
  99         deno_edit = new QLineEdit(baseWidget, "deno_edit");
 100         deno_edit->setValidator( valnum ); // use the int validator
 101         QToolTip::add(deno_edit, i18n("Enter the denominator of your result"));
 102         inputLayout->addWidget(deno_edit);
 103
 104         // next is the result widget
 105         m_resultWidget = new ResultWidget(baseWidget, "m_resultWidget", m_result);
 106         taskLineHBoxLayout->addWidget(m_resultWidget);
 107         m_resultWidget->hide();
 108
 109         // at the right end we have a label just showing CORRECT or WRONG
 110         result_label = new QLabel(baseWidget, "result_lable");
 111         result_label->setText(i18n("WRONG"));
 112         taskLineHBoxLayout->addWidget(result_label);
 113         result_label->hide();
 114
 115         // add another spacer in the middle of the VBox
 116         v_spacer = new QSpacerItem(1, 1, QSizePolicy::Expanding, QSizePolicy::Minimum);
 117         taskLineHBoxLayout->addItem(v_spacer);
 118
 119         // --- that is the end of the horizontal line ---
 120
 121         // add another spacer in the middle of the VBox
 122         v_spacer = new QSpacerItem(1, 1);
 123         realLayout->addItem(v_spacer);
 124
 125         // the lower part of the VBox holds just a right aligned button
 126         QHBoxLayout * lowerHBox = new QHBoxLayout(1, "lowerHBox");
 127         realLayout->addLayout(lowerHBox);
 128         lowerHBox->addStretch(100);
 129
 130         // the right aligned button
 131         m_checkButton = new QPushButton( baseWidget, "m_checkButton" );
 132         m_checkButton->setText(i18n("&Check Task"));
 133         m_checkButton->setDefault(true); // is the default button of the dialog
 134         QToolTip::add(m_checkButton, i18n("Click on this button to check your result. The button will not work if you have not entered a result yet."));
 135         lowerHBox->addWidget(m_checkButton, 1, Qt::AlignRight);
 136         QObject::connect(m_checkButton, SIGNAL(clicked()), this, SLOT(slotCheckButtonClicked()));
 137
 138         // that the user can start typing without moving the focus
 139         numer_edit->setFocus();
 140
 141         // show the whole layout
 142         baseWidget->show();
 143
 144         // add tooltip and qwhatsthis help to the widget
 145         QToolTip::add(this, i18n("In this exercise you have to convert a number into a fraction."));
 146         QWhatsThis::add(this, i18n("In this exercise you have to convert a given number into a fraction by entering numerator and denominator. Do not forget to reduce the result!"));
 147 }
 148
 149 /* destructor */
 150 ExerciseConvert::~ExerciseConvert()
 151 {
 152 #ifdef DEBUG
 153         kdDebug() << "destructor ExerciseConvert()" << endl;
 154 #endif
 155
 156         /* no need to delete any child widgets, Qt does it by itself */
 157 }
 158
 159 /** resets the current state, creates a new task and count the last task as
 160  * wrong, if it wasn't solved (in _NEXT_TASK state) yet
 161  * mainly used after changing the task parameters */
 162 void ExerciseConvert::forceNewTask()
 163 {
 164 #ifdef DEBUG
 165         kdDebug() << "forceNewTask ExerciseConvert()" << endl;
 166 #endif
 167
 168         if (m_currentState == _CHECK_TASK)
 169         {
 170                 // emit the signal for wrong
 171                 signalExerciseSolvedWrong();
 172         }
 173         m_currentState = _CHECK_TASK;
 174         m_checkButton->setText(i18n("&Check Task"));
 175
 176         // generate next task
 177         (void) nextTask();
 178 }
 179
 180
 181 /* ------ public slots ------ */
 182
 183 void ExerciseConvert::update()
 184 {
 185         // call update of components
 186         m_rationalWidget->updateAndRepaint();
 187         m_resultWidget->updateAndRepaint();
 188
 189         // update for itself
 190         ((QWidget *) this)->update();
 191 }
 192
 193
 194 /* ------ private member functions ------ */
 195
 196 void ExerciseConvert::createTask()
 197 {
 198         // the tasks are hardcoded here; there are some algorithms to convert
 199         // rational numbers to fractions, but it is not worth the effort here
 200         switch(int((double(rand()) / RAND_MAX) * 18 + 1))
 201         {
 202                 case  0 :   m_number = KGlobal::locale()->formatNumber(0.5, 1);
 203                                                 m_periodStart = 2;
 204                                                 m_periodLength = 0;
 205                                                 m_result = ratio(1, 2);
 206                                                 break;
 207                 case  1 :   m_number = KGlobal::locale()->formatNumber(0.3, 1);
 208                                                 m_periodStart = 2;
 209                                                 m_periodLength = 1;
 210                                                 m_result = ratio(1, 3);
 211                                                 break;
 212                 case  2 :   m_number = KGlobal::locale()->formatNumber(0.6, 1);
 213                                                 m_periodStart = 2;
 214                                                 m_periodLength = 1;
 215                                                 m_result = ratio(2, 3);
 216                                                 break;
 217                 case  3 :   m_number = KGlobal::locale()->formatNumber(0.25, 2);
 218                                                 m_periodStart = 2;
 219                                                 m_periodLength = 0;
 220                                                 m_result = ratio(1, 4);
 221                                                 break;
 222                 case  4 :   m_number = KGlobal::locale()->formatNumber(0.75, 2);
 223                                                 m_periodStart = 2;
 224                                                 m_periodLength = 0;
 225                                                 m_result = ratio(3, 4);
 226                                                 break;
 227                 case  5 :   m_number = KGlobal::locale()->formatNumber(0.2, 1);
 228                                                 m_periodStart = 2;
 229                                                 m_periodLength = 0;
 230                                                 m_result = ratio(1, 5);
 231                                                 break;
 232                 case  6 :   m_number = KGlobal::locale()->formatNumber(0.4, 1);
 233                                                 m_periodStart = 2;
 234                                                 m_periodLength = 0;
 235                                                 m_result = ratio(2, 5);
 236                                                 break;
 237                 case  7 :   m_number = KGlobal::locale()->formatNumber(0.6, 1);
 238                                                 m_periodStart = 2;
 239                                                 m_periodLength = 0;
 240                                                 m_result = ratio(3, 5);
 241                                                 break;
 242                 case  8 :   m_number = KGlobal::locale()->formatNumber(0.8, 1);
 243                                                 m_periodStart = 2;
 244                                                 m_periodLength = 0;
 245                                                 m_result = ratio(4, 5);
 246                                                 break;
 247                 case  9 :   m_number = KGlobal::locale()->formatNumber(0.16, 2);
 248                                                 m_periodStart = 3;
 249                                                 m_periodLength = 1;
 250                                                 m_result = ratio(1, 6);
 251                                                 break;
 252                 case 10 :   m_number = KGlobal::locale()->formatNumber(0.142857, 6);
 253                                                 m_periodStart = 2;
 254                                                 m_periodLength = 6;
 255                                                 m_result = ratio(1, 7);
 256                                                 break;
 257                 case 11 :   m_number = KGlobal::locale()->formatNumber(0.125, 3);
 258                                                 m_periodStart = 2;
 259                                                 m_periodLength = 0;
 260                                                 m_result = ratio(1, 8);
 261                                                 break;
 262                 case 12 :   m_number = KGlobal::locale()->formatNumber(0.375, 3);
 263                                                 m_periodStart = 2;
 264                                                 m_periodLength = 0;
 265                                                 m_result = ratio(3, 8);
 266                                                 break;
 267                 case 13 :   m_number = KGlobal::locale()->formatNumber(0.1, 1);
 268                                                 m_periodStart = 2;
 269                                                 m_periodLength = 1;
 270                                                 m_result = ratio(1, 9);
 271                                                 break;
 272                 case 14 :   m_number = KGlobal::locale()->formatNumber(0.1, 1);
 273                                                 m_periodStart = 2;
 274                                                 m_periodLength = 0;
 275                                                 m_result = ratio(1, 10);
 276                                                 break;
 277                 case 15 :   m_number = KGlobal::locale()->formatNumber(0.05, 2);
 278                                                 m_periodStart = 2;
 279                                                 m_periodLength = 0;
 280                                                 m_result = ratio(1, 20);
 281                                                 break;
 282                 case 16 :   m_number = KGlobal::locale()->formatNumber(0.01, 2);
 283                                                 m_periodStart = 2;
 284                                                 m_periodLength = 0;
 285                                                 m_result = ratio(1, 100);
 286                                                 break;
 287                 case 17 :   m_number = KGlobal::locale()->formatNumber(0.83, 2);
 288                                                 m_periodStart = 3;
 289                                                 m_periodLength = 1;
 290                                                 m_result = ratio(5, 6);
 291                                                 break;
 292                 default :
 293                 case 18 :   m_number = KGlobal::locale()->formatNumber(0.001, 3);
 294                                                 m_periodStart = 2;
 295                                                 m_periodLength = 0;
 296                                                 m_result = ratio(1, 1000);
 297                                                 break;
 298         }
 299
 300         return;
 301 }
 302
 303 /**     - checks, if the user solved the task correctly
 304                 - emits signals if task was solved correctly or wrong */
 305 void ExerciseConvert::showResult()
 306 {
 307         QString tmp_str; /* to build a string for a label */
 308         QPalette pal;
 309         QColorGroup cg;
 310         ratio entered_result;
 311
 312         // change the tooltip of the check button
 313         QToolTip::add(m_checkButton, i18n("Click on this button to get to the next task."));
 314
 315         numer_edit->setEnabled(false);
 316         deno_edit->setEnabled(false);
 317
 318         m_resultWidget->setResult(m_result);
 319         m_resultWidget->show();
 320
 321         // an empty numerator field will be interpreted as 0
 322         if (numer_edit->text().isEmpty() == true)
 323                 numer_edit->setText("0");
 324
 325         // an empty denominator field will be interpreted as 1
 326         if (deno_edit->text().isEmpty() == true)
 327                 deno_edit->setText("1");
 328
 329         /* store the entered result to check it, but without reducing */
 330         entered_result.setNumerator(numer_edit->text().toInt(), false);
 331         entered_result.setDenominator(deno_edit->text().toInt(), false);
 332
 333         // check the entered result; 0/1 == 0/5 -> true,
 334         // but 0/1 == 0/0 -> false
 335         // a 0 for denominator is never allowed (always counted as wrong)
 336         //
 337         // we have to get the 0 directly from the input field, because
 338         // Ratio::setDenominator(0, false) will set the denominator to 1 to ensure
 339         // the Ratio is valid
 340         if ( (deno_edit->text().toInt() != 0) && ((entered_result == m_result) ||
 341                   (m_result.numerator() == 0 && entered_result.numerator() == 0)) )
 342         {
 343                 // emit the signal for correct
 344                 signalExerciseSolvedCorrect();
 345
 346                 /* yes, the user entered the correct result */
 347                 result_label->setText(i18n("CORRECT"));
 348                 pal = result_label->palette(); /* set green font color */
 349                 cg = pal.active();
 350                 cg.setColor(QColorGroup::Foreground, QColor(6, 179, 0));
 351                 pal.setActive(cg);
 352                 cg = pal.inactive();
 353                 cg.setColor(QColorGroup::Foreground, QColor(6, 179, 0));
 354                 pal.setInactive(cg);
 355                 result_label->setPalette(pal);
 356                 result_label->show(); /* show the result at the end of the task */
 357         } else {
 358                 // emit the signal for wrong
 359                 signalExerciseSolvedWrong();
 360
 361                 /* no, the user entered the wrong result */
 362                 result_label->setText(i18n("WRONG"));
 363                 pal = result_label->palette(); /* set red font color */
 364                 cg = pal.active();
 365                 cg.setColor(QColorGroup::Foreground, QColor(red));
 366                 pal.setActive(cg);
 367                 cg = pal.inactive();
 368                 cg.setColor(QColorGroup::Foreground, QColor(red));
 369                 pal.setInactive(cg);
 370                 result_label->setPalette(pal);
 371
 372                 result_label->show(); /* show the result at the end of the task */
 373
 374                 // if the user entered a 0 for the denominator (division by 0) we have to
 375                 // get the 0 directly from the input field, because
 376                 // Ratio::setDenominator(0, true) will set the denominator to 1 to ensure
 377                 // the Ratio is valid
 378                 if (deno_edit->text().toInt() == 0)
 379                 {
 380                         KMessageBox::information(this,
 381                                                  i18n("You entered a 0 as the denominator. This means division by zero, which is not allowed. This task will be counted as not correctly solved."));
 382                 } else {
 383                         /* maybe the entered ratio was not reduced */
 384                         entered_result.reduce();
 385                         if (entered_result == m_result)
 386                                 KMessageBox::information(this,
 387                                                          i18n("You entered the correct result, but not reduced.\nAlways enter your results as reduced. This task will be counted as not correctly solved."));
 388                 }
 389         } /* if (entered_result == result) */
 390
 391         return;
 392 }
 393
 394 /** generate the next task and show it to the user */
 395 void ExerciseConvert::nextTask()
 396 {
 397         // change the tooltip of the check button
 398         QToolTip::add(m_checkButton, i18n("Click on this button to check your result. The button will not work if you have not entered a result yet."));
 399
 400         numer_edit->setEnabled(true);
 401         deno_edit->setEnabled(true);
 402
 403         result_label->hide(); /* do not show the result at the end of the task */
 404         m_resultWidget->hide();
 405
 406         /* clear user input */
 407         deno_edit->setText("");
 408         numer_edit->setText("");
 409         numer_edit->setFocus();
 410
 411         /* create a new task */
 412         QApplication::setOverrideCursor(waitCursor); /* show the sand clock */
 413         createTask();
 414         QApplication::restoreOverrideCursor(); /* show the normal cursor */
 415
 416         // update the task widget
 417         m_rationalWidget->setRational(m_number, m_periodStart, m_periodLength);
 418
 419         return;
 420 }
 421
 422 /* ------ private slots ------ */
 423
 424 void ExerciseConvert::slotCheckButtonClicked()
 425 {
 426         if (m_currentState == _CHECK_TASK)
 427         {
 428                 // if nothing has been entered by the user, we don't check the result yet
 429                 if (numer_edit->text().isEmpty() == true && deno_edit->text().isEmpty() ==
 430 true)
 431                         return;
 432                 m_currentState = _NEXT_TASK;
 433                 m_checkButton->setText(i18n("N&ext Task"));
 434                 (void) showResult();
 435         } else {
 436                 m_currentState = _CHECK_TASK;
 437                 m_checkButton->setText(i18n("&Check Task"));
 438                 (void) nextTask();
 439         }
 440
 441         return;
 442 }