mobile/UI: remember the system default font size

We need to do this before the preferences are loaded, or the system
default size is lost. Given that our other sizes are all relative to
this value, that would be a problem.

With this we can now ensure that we always have the right font size for
smaller, regular, and larger theme settings.

Also removes some obsolete commented out code.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

core/metrics.cpp

@@ -24,7 +24,6 @@ IconMetrics::IconMetrics() :
 QFont defaultModelFont()
 {
 	QFont font;
-//	font.setPointSizeF(font.pointSizeF() * 0.8);
 	return font;
 }
 

core/qt-gui.h

@@ -10,7 +10,7 @@ void set_non_bt_addresses();
 
 #if defined(SUBSURFACE_MOBILE)
 #include <QQuickWindow>
-void run_mobile_ui();
+void run_mobile_ui(double initial_font_size);
 #else
 void run_ui();
 #endif

mobile-widgets/themeinterface.cpp

@@ -56,13 +56,7 @@ ThemeInterface::ThemeInterface()
 	// get current theme
 	m_currentTheme = qPrefDisplay::theme();
 	update_theme();
-
+	m_basePointSize = -1.0; // simply a placeholder to declare 'this isn't set, yet'
-	// check system font and create QFontInfo in order to reliably get the point size
-	QFontInfo qfi(defaultModelFont());
-	m_basePointSize = qfi.pointSize();
-
-	// set initial font size
-	set_currentScale(qPrefDisplay::mobile_scale());
 }
 
 void ThemeInterface::set_currentTheme(const QString &theme)
@@ -73,6 +67,12 @@ void ThemeInterface::set_currentTheme(const QString &theme)
 	emit currentThemeChanged();
 }
 
+void ThemeInterface::setInitialFontSize(double fontSize)
+{
+	m_basePointSize = fontSize;
+	set_currentScale(qPrefDisplay::mobile_scale());
+}
+
 double ThemeInterface::currentScale()
 {
 	return qPrefDisplay::mobile_scale();
@@ -80,17 +80,17 @@ double ThemeInterface::currentScale()
 
 void ThemeInterface::set_currentScale(double newScale)
 {
+	static bool needSignals = true; // make sure the signals fire the first time
+
 	if (!IS_FP_SAME(newScale, qPrefDisplay::mobile_scale())) {
-		double factor = newScale / qPrefDisplay::mobile_scale();
 		qPrefDisplay::set_mobile_scale(newScale);
 		emit currentScaleChanged();
-
+		needSignals = true;
-		// Set current font size
-		m_basePointSize *= factor;
-		defaultModelFont().setPointSizeF(m_basePointSize);
 	}
+	if (needSignals) {
 		// adjust all used font sizes
-	m_regularPointSize = m_basePointSize;
+		m_regularPointSize = m_basePointSize * newScale;
+		defaultModelFont().setPointSizeF(m_regularPointSize);
 		emit regularPointSizeChanged();
 
 		m_headingPointSize = m_regularPointSize * 1.2;
@@ -101,6 +101,9 @@ void ThemeInterface::set_currentScale(double newScale)
 
 		m_titlePointSize = m_regularPointSize * 1.5;
 		emit titlePointSizeChanged();
+
+		needSignals = false;
+	}
 }
 
 void ThemeInterface::update_theme()

mobile-widgets/themeinterface.h

@@ -37,6 +37,7 @@ class ThemeInterface : public QObject {
 public:
 	static ThemeInterface *instance();
 	double currentScale();
+	void setInitialFontSize(double fontSize);
 
 public slots:
 	void set_currentTheme(const QString &theme);

subsurface-helper.cpp

@@ -69,7 +69,7 @@ void exit_ui()
 }
 
 #ifdef SUBSURFACE_MOBILE
-void run_mobile_ui()
+void run_mobile_ui(double initial_font_size)
 {
 #if defined(Q_OS_ANDROID)
 	// work around an odd interaction between the OnePlus flavor of Android and Qt font handling
@@ -127,9 +127,13 @@ void run_mobile_ui()
 	ctxt->setContextProperty("diveModel", MobileModels::instance()->listModel());
 	set_non_bt_addresses();
 
+	// we need to setup the initial font size before the QML UI is instantiated
+	ThemeInterface *themeInterface = ThemeInterface::instance();
+	themeInterface->setInitialFontSize(initial_font_size);
+
 	ctxt->setContextProperty("connectionListModel", &connectionListModel);
 	ctxt->setContextProperty("logModel", MessageHandlerModel::self());
-	ctxt->setContextProperty("subsurfaceTheme", ThemeInterface::instance());
+	ctxt->setContextProperty("subsurfaceTheme", themeInterface);
 
 	qmlRegisterUncreatableType<QMLManager>("org.subsurfacedivelog.mobile",1,0,"ExportType","Enum is not a type");
 

subsurface-mobile-main.cpp

@@ -19,6 +19,7 @@
 #include "core/settings/qPrefCloudStorage.h"
 
 #include <QApplication>
+#include <QFont>
 #include <QLocale>
 #include <QLoggingCategory>
 #include <QStringList>
@@ -60,6 +61,9 @@ int main(int argc, char **argv)
 
 	parse_xml_init();
 	taglist_init_global();
+
+	// grab the system font size before we overwrite this when we load preferences
+	double initial_font_size = QGuiApplication::font().pointSizeF();
 	init_ui();
 	if (prefs.default_file_behavior == LOCAL_DEFAULT_FILE)
 		set_filename(prefs.default_filename);
@@ -76,7 +80,7 @@ int main(int argc, char **argv)
 	init_proxy();
 
 	if (!quit)
-		run_mobile_ui();
+		run_mobile_ui(initial_font_size);
 	exit_ui();
 	taglist_free(g_tag_list);
 	parse_xml_exit();