From c1778a8fee75a478c7532430d0a4bb0b56e59c68 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sat, 30 Dec 2023 23:03:15 -0500
Subject: [PATCH] Reintroduce Qt5 support.

---
 OSBindings/Qt/clksignal.pro  |  5 +++--
 OSBindings/Qt/mainwindow.cpp | 25 ++++++++++++++++++++++++-
 OSBindings/Qt/mainwindow.h   | 13 ++++++++++++-
 3 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/OSBindings/Qt/clksignal.pro b/OSBindings/Qt/clksignal.pro
index 3353d979e..8b3c3b8e2 100644
--- a/OSBindings/Qt/clksignal.pro
+++ b/OSBindings/Qt/clksignal.pro
@@ -1,4 +1,5 @@
-QT += core gui multimedia widgets openglwidgets
+QT += core gui multimedia widgets
+greaterThan(5, QT_MAJOR_VERSION) QT += openglwidgets
 
 # Be specific about C++17 but also try the vaguer C++1z for older
 # versions of Qt.
@@ -25,7 +26,7 @@ DEFINES += IGNORE_APPLE
 QMAKE_CXXFLAGS_RELEASE += -DNDEBUG
 
 # Generate warnings for any use of APIs deprecated prior to Qt 7.0.0.
-# Development was performed against Qt 6.6.1.
+# Development was performed against Qt 6.6.1 and Qt 5.15.2
 DEFINES += QT_DEPRECATED_WARNINGS
 DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x070000
 
diff --git a/OSBindings/Qt/mainwindow.cpp b/OSBindings/Qt/mainwindow.cpp
index d0b9a53e9..7e4df42f6 100644
--- a/OSBindings/Qt/mainwindow.cpp
+++ b/OSBindings/Qt/mainwindow.cpp
@@ -2,14 +2,17 @@
 #include "settings.h"
 #include "timer.h"
 
+#include <QtGlobal>
+
 #include <QObject>
 #include <QStandardPaths>
 
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
 #include <QAudioDevice>
 #include <QMediaDevices>
+#endif
 
 #include <QtWidgets>
-#include <QtGlobal>
 
 #include <cstdio>
 
@@ -317,16 +320,32 @@ void MainWindow::launchMachine() {
 		static constexpr size_t samplesPerBuffer = 256;	// TODO: select this dynamically.
 		const auto speaker = audio_producer->get_speaker();
 		if(speaker) {
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
 			QAudioDevice device(QMediaDevices::defaultAudioOutput());
 			if(true) {  // TODO: how to check that audio output is available in Qt6?
 				QAudioFormat idealFormat = device.preferredFormat();
+#else
+			const QAudioDeviceInfo &defaultDeviceInfo = QAudioDeviceInfo::defaultOutputDevice();
+			if(!defaultDeviceInfo.isNull()) {
+				QAudioFormat idealFormat = defaultDeviceInfo.preferredFormat();
+#endif
 
 				// Use the ideal format's sample rate, provide stereo as long as at least two channels
 				// are available, and — at least for now — assume a good buffer size.
 				audioIsStereo = (idealFormat.channelCount() > 1) && speaker->get_is_stereo();
+
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
 				audioIs8bit = idealFormat.sampleFormat() == QAudioFormat::UInt8;
+#else
+				audioIs8bit = idealFormat.sampleSize() < 16;
+#endif
+
 				idealFormat.setChannelCount(1 + int(audioIsStereo));
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
 				idealFormat.setSampleFormat(audioIs8bit ? QAudioFormat::UInt8 : QAudioFormat::Int16);
+#else
+				idealFormat.setSampleSize(audioIs8bit ? 8 : 16);
+#endif
 
 				speaker->set_output_rate(idealFormat.sampleRate(), samplesPerBuffer, audioIsStereo);
 				speaker->set_delegate(this);
@@ -334,7 +353,11 @@ void MainWindow::launchMachine() {
 				audioThread.start();
 				audioThread.performAsync([&] {
 					// Create an audio output.
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
 					audioOutput = std::make_unique<QAudioSink>(device, idealFormat);
+#else
+					audioOutput = std::make_unique<QAudioOutput>(idealFormat);
+#endif
 
 					// Start the output. The additional `audioBuffer` is meant to minimise latency,
 					// believe it or not, given Qt's semantics.
diff --git a/OSBindings/Qt/mainwindow.h b/OSBindings/Qt/mainwindow.h
index a1aa5e80b..f2dd530fa 100644
--- a/OSBindings/Qt/mainwindow.h
+++ b/OSBindings/Qt/mainwindow.h
@@ -1,7 +1,14 @@
 #ifndef MAINWINDOW_H
 #define MAINWINDOW_H
 
-#include <QAudioSink>
+#include <QtGlobal>
+
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+	#include <QAudioSink>
+#else
+	#include <QAudioOutput>
+#endif
+
 #include <QMainWindow>
 
 #include <memory>
@@ -70,7 +77,11 @@ class MainWindow : public QMainWindow, public Outputs::Speaker::Speaker::Delegat
 		std::unique_ptr<Machine::DynamicMachine> machine;
 		std::mutex machineMutex;
 
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
 		std::unique_ptr<QAudioSink> audioOutput;
+#else
+		std::unique_ptr<QAudioOutput> audioOutput;
+#endif
 		bool audioIs8bit = false, audioIsStereo = false;
 		void speaker_did_complete_samples(Outputs::Speaker::Speaker *speaker, const std::vector<int16_t> &buffer) override;
 		AudioBuffer audioBuffer;