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# guitartunerui.cpp Example File

demos/mobile/guitartuner/src/guitartunerui.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2015 The Qt Company Ltd.
     ** Contact: http://www.qt.io/licensing/
     **
     ** This file is part of the QtDeclarative module of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:BSD$
     ** You may use this file under the terms of the BSD license as follows:
     **
     ** "Redistribution and use in source and binary forms, with or without
     ** modification, are permitted provided that the following conditions are
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     **   * Redistributions of source code must retain the above copyright
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     **     the documentation and/or other materials provided with the
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     **     from this software without specific prior written permission.
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     #include <QTimer>

     #include "guitartunerui.h"
     #include "ui_guitartunerui.h"

     GuitarTunerUI::GuitarTunerUI(QWidget *parent) :
         QWidget(parent),
         ui(new Ui::GuitarTunerUI),
         m_maximumPrecision(0)
     {
         ui->setupUi(this);

         // Set up the class attributes to proper values.
         m_outputActive = false;
         m_muted = false;
         m_outputVolumeLevel = getVolumeFromSoundSlider();
         m_inputVolumeLevel = 1.0 - m_outputVolumeLevel;

         // Set up the current tone, the frequency, and the name for it.
         m_currentToneIndex = 5;
         updateFrequencyByToneIndex(m_currentToneIndex);

         // Connect the signals from UI into proper slots.
         connect(ui->soundSlider, SIGNAL(valueChanged(int)),
                 SLOT(changeVolume()));
         connect(ui->soundButton, SIGNAL(toggled(bool)),
                 SLOT(toggleSound(bool)));
         connect(ui->modeButton, SIGNAL(clicked()),
                 SLOT(toggleInputOrOutput()));
         connect(ui->buttonNext, SIGNAL(clicked()), SLOT(next()));
         connect(ui->buttonPrev, SIGNAL(clicked()), SLOT(prev()));

         // Initialise up the UI by calling toggleInputOrOutput
         // for the first time.
         toggleInputOrOutput();
     }

     GuitarTunerUI::~GuitarTunerUI()
     {
         delete ui;
     }

     void GuitarTunerUI::changeEvent(QEvent *e)
     {
         QWidget::changeEvent(e);
         switch (e->type()) {
         case QEvent::LanguageChange:
             ui->retranslateUi(this);
             break;
         default:
             break;
         }
     }

     /**
       * Returns a value from 0 to 1, representing the volume.
       */
     qreal GuitarTunerUI::getVolumeFromSoundSlider() const
     {
         qreal value = ui->soundSlider->value();
         return value/ui->soundSlider->maximum();
     }

     /**
       * Updates the m_currentToneFrequency and m_currentToneString,
       * according to the given index. Also updates the UI.
       */
     void GuitarTunerUI::updateFrequencyByToneIndex(int index)
     {

         switch (index) {
         case 0: {
                 m_currentToneFrequency = FrequencyE;
                 m_currentToneString = "E";
                 break;
             }
         case 1: {
                 m_currentToneFrequency = FrequencyA;
                 m_currentToneString = "A";
                 break;
             }
         case 2: {
                 m_currentToneFrequency = FrequencyD;
                 m_currentToneString = "D";
                 break;
             }
         case 3: {
                 m_currentToneFrequency = FrequencyG;
                 m_currentToneString = "G";
                 break;
             }
         case 4: {
                 m_currentToneFrequency = FrequencyB;
                 m_currentToneString = "B";
                 break;
             }
         case 5: {
                 m_currentToneFrequency = FrequencyE2;
                 m_currentToneString = "e";
                 break;
             }
         default: {
                 qDebug() << "invalid index!" << index;
             }
         }
         // Set the noteLabel text according to the current tone.
         ui->noteLabel->setText(m_currentToneString);
     }

     /**
       * Returns the volume.
       */
     qreal GuitarTunerUI::getVolume() const
     {
         return m_outputVolumeLevel;
     }

     /**
       * Returns true if the sound is muted.
       */
     bool GuitarTunerUI::getMuteState() const
     {
         return m_muted;
     }

     /**
       * Returns the microphone sensitivity.
       */
     qreal GuitarTunerUI::getMicrophoneSensitivity() const
     {
         return m_inputVolumeLevel;
     }

     /**
       * Returns whether the input mode is active.
       */
     bool GuitarTunerUI::isInputModeActive() const
     {
         return !m_outputActive;
     }

     /**
       * Returns the current target frequency.
       */
     qreal GuitarTunerUI::getFrequency() const
     {
         return m_currentToneFrequency;
     }

     /**
       * Toggles the sound according to the parameter.
       * Has no effect if output is not active.
       */
     void GuitarTunerUI::toggleSound(bool noSound)
     {
         if (!m_outputActive) {
             return;
         }
         m_muted = noSound;
         emit muteChanged(m_muted);
     }

     /**
       * Changes the volume or microphone sensitivity.
       */
     void GuitarTunerUI::changeVolume()
     {
         qreal resultingAmplitude = getVolumeFromSoundSlider();
         qDebug() << "resultingAmplitude" << resultingAmplitude;
         if (m_outputActive) {
             m_outputVolumeLevel = resultingAmplitude;
             emit volumeChanged(resultingAmplitude);
         }
         else {
             m_inputVolumeLevel = resultingAmplitude;
             emit microphoneSensitivityChanged(1.0-resultingAmplitude);
         }
     }

     /**
       * Toggles input or output, depending of the current state.
       */
     void GuitarTunerUI::toggleInputOrOutput()
     {
         // If output mode is active:
         if (m_outputActive) {
             // Change UI to correspond to the input mode.
             m_outputActive = false;
             ui->soundSlider->setValue(m_inputVolumeLevel*100);
             ui->soundButton->setDisabled(true);
             ui->soundButton->hide();
             ui->micSensitivityLabel->show();
             emit modeChanged(true);
             ui->modeButton->setText("To tone mode");
         }
         // Else:
         else {
             // Change UI to correspond to the output mode.
             m_outputActive = true;
             ui->soundSlider->setValue(m_outputVolumeLevel*100);
             ui->soundButton->setDisabled(false);
             ui->micSensitivityLabel->hide();
             ui->soundButton->show();
             emit modeChanged(false);
             ui->modeButton->setText("To listen mode");
         }
     }

     /**
       * Receives the low voice signal.
       */
     void GuitarTunerUI::lowVoice()
     {
         if (ui->noteLabel->font().bold()) {
             QFont font;
             font.setBold(false);
             font.setUnderline(false);
             ui->noteLabel->setFont(font);
         }
     }

     /**
       * Receives the voice difference signal.
       * The difference is qreal, where increase of 1 corresponds
       * to increase of 1 tone to the target frequency.
       */
     void GuitarTunerUI::voiceDifference(qreal difference)
     {
         if (ui->noteLabel->font().bold()) {
             QFont font;
             font.setBold(false);
             font.setUnderline(false);
             ui->noteLabel->setFont(font);
         }
         ui->correctSoundSlider->setValue(difference*m_maximumPrecision);
     }

     /**
       * Receives the correct frequency signal.
       * Makes the UI to visualize correct frequency event.
       */
     void GuitarTunerUI::correctFrequencyObtained()
     {
         qDebug() << "CORRECT FREQUENCY";
         QFont font;
         font.setBold(true);
         font.setUnderline(true);
         ui->noteLabel->setFont(font);
     }

     /**
       * Sets up the maximum voice difference.
       */
     void GuitarTunerUI::setMaximumVoiceDifference(int max)
     {
         // Assert that the maximum precision is known.
         Q_ASSERT(m_maximumPrecision != 0);
         // Set the maximum and minimum values of the correctSoundSlider
         // to the +- max*m_maximumPrecision, and set the tick interval
         // to be m_maximumPrecision.
         ui->correctSoundSlider->setMaximum(max*m_maximumPrecision);
         ui->correctSoundSlider->setMinimum(-max*m_maximumPrecision);
         ui->correctSoundSlider->setTickInterval(max*m_maximumPrecision);
     }

     /**
       * Stores the maximum precision per note. Used to setup the
       * correct sound slider.
       */
     void GuitarTunerUI::setMaximumPrecisionPerNote(int max)
     {
         m_maximumPrecision = max;
     }

     /**
       * Changes the tone to the next value.
       */
     void GuitarTunerUI::next()
     {
         changeTone((m_currentToneIndex + 1) % 6);
     }

     /**
       * Changes the tone to the previous value.
       */
     void GuitarTunerUI::prev()
     {
         changeTone((m_currentToneIndex + 5) % 6);
     }

     /**
       * Changes the tone according to the new index.
       */
     void GuitarTunerUI::changeTone(int newIndex)
     {
         m_currentToneIndex = newIndex;
         updateFrequencyByToneIndex(m_currentToneIndex);
         qDebug() << "targetFrequencyChanged" << m_currentToneFrequency;
         emit targetFrequencyChanged(m_currentToneFrequency);
     }