Hide preamp in EQ when Phonon backend does not support it.

Prevents some confusion.

BUG: 324976

src/EngineController.cpp

@@ -156,7 +156,7 @@ EngineController::initializePhonon()
 
     // Add an equalizer effect if available
     QList<EffectDescription> effects = BackendCapabilities::availableAudioEffects();
-    QRegExp equalizerRegExp( QString( "equalizer.*%1.*bands" ).arg( s_equalizerBandsCount ),
+    QRegExp equalizerRegExp( QString( "equalizer.*%1.*bands" ).arg( s_equalizerBandsNum ),
                              Qt::CaseInsensitive );
     foreach( const EffectDescription &description, effects )
     {
@@ -165,7 +165,7 @@ EngineController::initializePhonon()
 
         QScopedPointer<Effect> equalizer( new Effect( description, this ) );
         int parameterCount = equalizer->parameters().count();
-        if( parameterCount == s_equalizerBandsCount || parameterCount == s_equalizerBandsCount + 1 )
+        if( parameterCount == s_equalizerBandsNum || parameterCount == s_equalizerBandsNum + 1 )
         {
             debug() << "Established Phonon equalizer effect with" << parameterCount
                     << "parameters.";
@@ -884,7 +884,7 @@ EngineController::eqUpdate() //SLOT
         QListIterator<int> equalizerParametersIt( equalizerParametersCfg );
         double scaledVal; // Scaled value to set from universal -100 - 100 range to plugin scale
         // Checking if preamp is present in equalizer parameters
-        if( equalizerParameters.size() == s_equalizerBandsCount )
+        if( equalizerParameters.size() == s_equalizerBandsNum )
         {
             // If pre-amp is not present then skip the first element of equalizer gain
             if( equalizerParametersIt.hasNext() )

src/EngineController.h

@@ -40,7 +40,7 @@
 #include <Phonon/EffectParameter>
 #include <phonon/audiodataoutput.h>
 
-static const int s_equalizerBandsCount = 10; // Number of equalizer parameters excluding Preamp
+static const int s_equalizerBandsNum = 10; // Number of equalizer parameters excluding Preamp
 
 class Fadeouter;
 namespace Capabilities { class MultiPlayableCapability; class MultiSourceCapability; }

src/dialogs/EqualizerDialog.cpp

@@ -89,16 +89,21 @@ EqualizerDialog::EqualizerDialog( QWidget* parent )
 
     // Ask engine for maximum gain value and compute scale to display values
     mValueScale = The::engineController()->eqMaxGain();
-    QString mlblText = i18n( "%0\ndB" ).arg( QString::number( mValueScale, 'f', 1 ) );
+    const QString mlblText = i18n( "%0\ndB" ).arg( QString::number( mValueScale, 'f', 1 ) );
     eqMaxEq->setText( QString("+") + mlblText );
     eqMinEq->setText( QString("-") + mlblText );
 
     // Ask engine for band frequencies and set labels
-    QStringList equalizerBandFreq = The::engineController()->eqBandsFreq();
+    const QStringList equalizerBandFreq = The::engineController()->eqBandsFreq();
     QStringListIterator i( equalizerBandFreq );
-    // Checking if preamp is present
-    if( equalizerBandFreq.size() == s_equalizerBandsCount )
-        eqPreampSlider->setDisabled( true );
+
+    // Check if preamp is supported by Phonon backend
+    if( equalizerBandFreq.size() == s_equalizerBandsNum ) {
+        // Preamp not supported, so hide its slider
+        eqPreampLabel->hide();
+        eqPreampSlider->hide();
+        eqPreampValue->hide();
+    }
     else if( i.hasNext() ) // If preamp is present then skip its label as it is hard-coded in UI
         i.next();
     foreach( QLabel* mLabel, m_bandLabels )