From cb255bc7d1041a2f84efc42b36eaaedac0255b92 Mon Sep 17 00:00:00 2001
From: Jeff Wang <jeff.wang@utexas.edu>
Date: Thu, 4 Apr 2019 02:04:20 -0400
Subject: [PATCH] fix quitting

---
 qt_gui/calculator.cpp | 9 ++++++++-
 qt_gui/calculator.h   | 1 +
 qt_gui/main.cpp       | 6 ++++++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/qt_gui/calculator.cpp b/qt_gui/calculator.cpp
index 7c3305b..c864d8e 100644
--- a/qt_gui/calculator.cpp
+++ b/qt_gui/calculator.cpp
@@ -19,11 +19,18 @@ Calculator::Calculator(QObject *parent) :
 }
 
 Calculator::~Calculator(){
-	ExitCalcMain = 1;
+	quit();
 	while (!calc_thread.isFinished()); //TODO: timeout
 	while (!lcd_thread.isFinished()); //TODO: timeout
 }
 
+void Calculator::quit(){
+	ExitCalcMain = 1;
+	LcdAvailable.release();
+	KeysAvailable.release();
+	qDebug() << "quitting...";
+}
+
 void Calculator::buttonClicked(const QString& in) {
 	QStringList split = in.split(",");
 	int8_t row = split[0].toInt();
diff --git a/qt_gui/calculator.h b/qt_gui/calculator.h
index 79c11cf..876dc4a 100644
--- a/qt_gui/calculator.h
+++ b/qt_gui/calculator.h
@@ -52,6 +52,7 @@ signals:
 public slots:
 	void buttonClicked(const QString& in);
 	void updateLcd();
+	void quit();
 
 private:
 	CalcMainThread calc_thread;
diff --git a/qt_gui/main.cpp b/qt_gui/main.cpp
index 2ed7d21..196633a 100644
--- a/qt_gui/main.cpp
+++ b/qt_gui/main.cpp
@@ -8,15 +8,21 @@ int main(int argc, char** argv)
 {
 	QApplication app(argc, argv);
 
+	//QML engine
 	QQmlApplicationEngine engine;
 	engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
 	
+	//calculator
 	Calculator calculator;
 	engine.rootContext()->setContextProperty("_calculator", &calculator);
 
+	//fixed-width font for LCD
 	QFont fixedFont = QFontDatabase::systemFont(QFontDatabase::FixedFont);
 	fixedFont.setStyleHint(QFont::TypeWriter);
 	engine.rootContext()->setContextProperty("_fixedFont", fixedFont);
 
+	//handle quit
+	QObject::connect(&app, &QApplication::aboutToQuit, &calculator, &Calculator::quit);
+
 	return app.exec();
 }