Use new volume conversion API in examples.

Volumes sliders are now scaled cubically so that loudness changes
are perceived linearly.

Change-Id: Ibf00d6a97d872063d92457493417be5eb42f79ac
Reviewed-by: Christian Stromme <christian.stromme@qt.io>

2 files changed, 18 insertions, 4 deletions

diff --git a/examples/multimediawidgets/player/playercontrols.cpp b/examples/multimediawidgets/player/playercontrols.cpp
index 07aa2e731..80abf59b6 100644
--- a/examples/multimediawidgets/player/playercontrols.cpp
+++ b/examples/multimediawidgets/player/playercontrols.cpp
@@ -45,6 +45,7 @@
 #include <QStyle>
 #include <QToolButton>
 #include <QComboBox>
+#include <QAudio>
 
 PlayerControls::PlayerControls(QWidget *parent)
     : QWidget(parent)
@@ -87,7 +88,7 @@ PlayerControls::PlayerControls(QWidget *parent)
     volumeSlider = new QSlider(Qt::Horizontal, this);
     volumeSlider->setRange(0, 100);
 
-    connect(volumeSlider, SIGNAL(sliderMoved(int)), this, SIGNAL(changeVolume(int)));
+    connect(volumeSlider, SIGNAL(valueChanged(int)), this, SLOT(onVolumeSliderValueChanged()));
 
     rateBox = new QComboBox(this);
     rateBox->addItem("0.5x", QVariant(0.5));
@@ -138,13 +139,20 @@ void PlayerControls::setState(QMediaPlayer::State state)
 
 int PlayerControls::volume() const
 {
-    return volumeSlider ? volumeSlider->value() : 0;
+    qreal linearVolume =  QAudio::convertVolume(volumeSlider->value() / qreal(100),
+                                                QAudio::CubicVolumeScale,
+                                                QAudio::LinearVolumeScale);
+
+    return qRound(linearVolume * 100);
 }
 
 void PlayerControls::setVolume(int volume)
 {
-    if (volumeSlider)
-        volumeSlider->setValue(volume);
+    qreal cubicVolume = QAudio::convertVolume(volume / qreal(100),
+                                               QAudio::LinearVolumeScale,
+                                               QAudio::CubicVolumeScale);
+
+    volumeSlider->setValue(qRound(cubicVolume * 100));
 }
 
 bool PlayerControls::isMuted() const
@@ -203,3 +211,8 @@ void PlayerControls::updateRate()
 {
     emit changeRate(playbackRate());
 }
+
+void PlayerControls::onVolumeSliderValueChanged()
+{
+    emit changeVolume(volume());
+}
diff --git a/examples/multimediawidgets/player/playercontrols.h b/examples/multimediawidgets/player/playercontrols.h
index 0ab195faa..d29a06d6c 100644
--- a/examples/multimediawidgets/player/playercontrols.h
+++ b/examples/multimediawidgets/player/playercontrols.h
@@ -82,6 +82,7 @@ private slots:
     void playClicked();
     void muteClicked();
     void updateRate();
+    void onVolumeSliderValueChanged();
 
 private:
     QMediaPlayer::State playerState;