Provide status messages on splash screen when loading (LMMS#1696)

include/Engine.h

@@ -27,6 +27,9 @@
 #define ENGINE_H
 
 #include <QtCore/QMap>
+#include <QtCore/QString>
+#include <QtCore/QObject>
+
 
 #include "export.h"
 
@@ -39,8 +42,9 @@ class Song;
 class Ladspa2LMMS;
 
 
-class EXPORT Engine
+class EXPORT Engine : public QObject
 {
+	Q_OBJECT
 public:
 	static void init();
 	static void destroy();
@@ -94,6 +98,18 @@ class EXPORT Engine
 		return s_pluginFileHandling;
 	}
 
+	static inline Engine * inst()
+	{
+		if( s_instanceOfMe == NULL )
+		{
+			s_instanceOfMe = new Engine();
+		}
+		return s_instanceOfMe;
+	}
+
+signals:
+	void initProgress(const QString &msg);
+
 
 private:
 	// small helper function which sets the pointer to NULL before actually deleting
@@ -120,6 +136,9 @@ class EXPORT Engine
 
 	static QMap<QString, QString> s_pluginFileHandling;
 
+	// even though most methods are static, an instance is needed for Qt slots/signals
+	static Engine * s_instanceOfMe;
+
 	static void initPluginFileHandling();
 
 	friend class GuiApplication;

include/GuiApplication.h

@@ -25,8 +25,12 @@
 #ifndef GUIAPPLICATION_H
 #define GUIAPPLICATION_H
 
+#include <QtCore/QObject>
+
 #include "export.h"
 
+class QSplashScreen;
+
 class AutomationEditorWindow;
 class BBEditor;
 class ControllerRackView;
@@ -36,8 +40,9 @@ class PianoRollWindow;
 class ProjectNotes;
 class SongEditorWindow;
 
-class EXPORT GuiApplication
+class EXPORT GuiApplication : public QObject
 {
+	Q_OBJECT;
 public:
 	explicit GuiApplication();
 	~GuiApplication();
@@ -53,6 +58,9 @@ class EXPORT GuiApplication
 	AutomationEditorWindow* automationEditor() { return m_automationEditor; }
 	ControllerRackView* getControllerRackView() { return m_controllerRackView; }
 
+public slots:
+	void displayInitProgress(const QString &msg);
+
 private:
 	static GuiApplication* s_instance;
 
@@ -64,6 +72,7 @@ class EXPORT GuiApplication
 	PianoRollWindow* m_pianoRoll;
 	ProjectNotes* m_projectNotes;
 	ControllerRackView* m_controllerRackView;
+	QSplashScreen* m_splashScreen;
 };
 
 #define gui GuiApplication::instance()

src/core/Engine.cpp

@@ -52,11 +52,16 @@ QMap<QString, QString> Engine::s_pluginFileHandling;
 
 void Engine::init()
 {
+	Engine *engine = inst();
+
+	emit engine->initProgress(tr("Generating wavetables"));
 	// generate (load from file) bandlimited wavetables
 	BandLimitedWave::generateWaves();
 
+	emit engine->initProgress(tr("Locating plugins"));
 	initPluginFileHandling();
 
+	emit engine->initProgress(tr("Initializing data structures"));
 	s_projectJournal = new ProjectJournal;
 	s_mixer = new Mixer;
 	s_song = new Song;
@@ -67,11 +72,13 @@ void Engine::init()
 
 	s_projectJournal->setJournalling( true );
 
+	emit engine->initProgress(tr("Opening audio and midi devices"));
 	s_mixer->initDevices();
 
 	PresetPreviewPlayHandle::init();
 	s_dummyTC = new DummyTrackContainer;
 
+	emit engine->initProgress(tr("Launching mixer threads"));
 	s_mixer->startProcessing();
 }
 
@@ -142,3 +149,4 @@ void Engine::initPluginFileHandling()
 }
 
 
+Engine * Engine::s_instanceOfMe = NULL;

src/gui/GuiApplication.cpp

@@ -49,6 +49,7 @@ GuiApplication* GuiApplication::instance()
 	return s_instance;
 }
 
+
 GuiApplication::GuiApplication()
 {
 	// Init style and palette
@@ -63,16 +64,22 @@ GuiApplication::GuiApplication()
 
 	// Show splash screen
 	QSplashScreen splashScreen( embed::getIconPixmap( "splash" ) );
+	m_splashScreen = &splashScreen;
 	splashScreen.show();
 	splashScreen.showMessage( MainWindow::tr( "Version %1" ).arg( LMMS_VERSION ),
 								Qt::AlignRight | Qt::AlignBottom, Qt::white );
 	qApp->processEvents();
 
+	connect(Engine::inst(), SIGNAL(initProgress(const QString&)), 
+		this, SLOT(displayInitProgress(const QString&)));
+
 	// Init central engine which handles all components of LMMS
 	Engine::init();
 
 	s_instance = this;
 
+	displayInitProgress("Preparing UI");
+
 	m_mainWindow = new MainWindow;
 
 	m_songEditor = new SongEditorWindow(Engine::getSong());
@@ -85,10 +92,21 @@ GuiApplication::GuiApplication()
 
 	m_mainWindow->finalize();
 	splashScreen.finish(m_mainWindow);
+
+	m_splashScreen = nullptr;
 }
 
 GuiApplication::~GuiApplication()
 {
 	InstrumentTrackView::cleanupWindowCache();
 	s_instance = nullptr;
 }
+
+
+void GuiApplication::displayInitProgress(const QString &msg)
+{
+	if (m_splashScreen != nullptr)
+	{
+		m_splashScreen->showMessage(msg, Qt::AlignLeft | Qt::AlignBottom, Qt::white);
+	}
+}