From 20ebc0c334c33229b402513a202f26794f7ef3cc Mon Sep 17 00:00:00 2001
From: Louis-Joseph Fournier <louisjoseph.fournier@gmail.com>
Date: Tue, 29 Dec 2015 21:32:57 +0100
Subject: [PATCH] Sailfish: prevent screen blanking

---
 Tuner.pro             |  2 +-
 harbour-sailtuner.pro |  2 +-
 src/Tuner.cpp         | 27 +++++++++++++++++++++++++++
 src/Tuner.hpp         |  3 ++-
 4 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/Tuner.pro b/Tuner.pro
index c542b86..752f6ec 100644
--- a/Tuner.pro
+++ b/Tuner.pro
@@ -1,4 +1,4 @@
-QT += qml quick gui multimedia
+QT += qml quick gui multimedia dbus
 TARGET = Tuner
 
 CONFIG += c++11
diff --git a/harbour-sailtuner.pro b/harbour-sailtuner.pro
index dc9ce70..066ffe2 100644
--- a/harbour-sailtuner.pro
+++ b/harbour-sailtuner.pro
@@ -1,4 +1,4 @@
-QT += qml quick gui multimedia
+QT += qml quick gui multimedia dbus
 TARGET = harbour-sailtuner
 
 CONFIG += c++11 sailfishapp sailfishapp_i18n
diff --git a/src/Tuner.cpp b/src/Tuner.cpp
index d043298..11bf8b6 100644
--- a/src/Tuner.cpp
+++ b/src/Tuner.cpp
@@ -3,6 +3,8 @@
 
 #include <QCoreApplication>
 #include <QUrl>
+#include <QDBusConnection>
+#include <QDBusInterface>
 
 #include "Tuner.hpp"
 
@@ -12,6 +14,21 @@ using namespace std;
 static double a10[] = { 1        , -2.99214602,  2.98432286, -0.99217678 };
 static double b10[] = { 0.99608071, -2.98824212,  2.98824212, -0.99608071 };
 
+// function to prevent screen blank
+
+static void blank_prevent(bool prevent)
+{
+	cerr << __func__ << endl;
+	QDBusConnection system = QDBusConnection::connectToBus(QDBusConnection::SystemBus, "system");
+	QDBusInterface interface("com.nokia.mce", "/com/nokia/mce/request", "com.nokia.mce.request", system);
+
+	if (prevent) {
+		interface.call(QLatin1String("req_display_blanking_pause"));
+	} else {
+		interface.call(QLatin1String("req_display_cancel_blanking_pause"));
+	}
+}
+
 Tuner::Tuner()
 {
 	running = false;
@@ -53,6 +70,8 @@ Tuner::~Tuner()
 void Tuner::Start()
 {
 	cerr << __func__ << endl;
+	nb_sample_running = 0;
+	blank_prevent(true);
 	high_filter->Clear();
 	cross->Clear();
 	recorder->record();
@@ -66,6 +85,7 @@ void Tuner::Stop()
 	running = false;
 	recorder->stop();
 	runningChanged();
+	blank_prevent(false);
 }
 
 void Tuner::ComputeFrame(int16_t v)
@@ -83,6 +103,8 @@ void Tuner::AudioCb(const QAudioBuffer &buffer)
 
 void Tuner::AudioAnalyse(const int16_t *ptr, int nb_frame)
 {
+	nb_sample_running += nb_frame;
+
 	while (nb_frame--) ComputeFrame(*ptr++);
 
 	if (freq != cross->Freq()) {
@@ -98,6 +120,11 @@ void Tuner::AudioAnalyse(const int16_t *ptr, int nb_frame)
 			//std::cerr << note << " " << scale->NoteName(note) << std::endl;
 		}
 	}
+
+	if (nb_sample_running >= nbSamplePreventRunning && running) {
+		nb_sample_running = 0;
+		blank_prevent(true);
+	}
 }
 
 bool Tuner::GetRunning()
diff --git a/src/Tuner.hpp b/src/Tuner.hpp
index a1548fc..be6cdb4 100644
--- a/src/Tuner.hpp
+++ b/src/Tuner.hpp
@@ -25,12 +25,13 @@ class Tuner : public QObject {
 
 	bool running;
 	double freq, deviation;
-	int note, octave;
+	int note, octave, nb_sample_running;
 
 	static const int rate = 16000;
 	static const int defaultNbFrame = 1024;
 	static const int defaultFreqMin = 50;
 	static const int defaultFreqMax = 2000;
+	static const int nbSamplePreventRunning = rate * 40; // 40 seconds
 
 	inline void ComputeFrame(int16_t v);