logic: remember graph zoom level on restart (issue #801) (#1099)

src/lib/settings/ApplicationSettings.cpp

@@ -678,6 +678,16 @@ void ApplicationSettings::setLastFilepickerLocation(const FilePath& path)
 	setValue<std::wstring>("user/last_filepicker_location", path.wstr());
 }
 
+float ApplicationSettings::getGraphZoomLevel() const
+{
+	return getValue<float>("user/graph_zoom_level", 1.0f);
+}
+
+void ApplicationSettings::setGraphZoomLevel(float zoomLevel)
+{
+	setValue<float>("user/graph_zoom_level", zoomLevel);
+}
+
 int ApplicationSettings::getPluginPort() const
 {
 	return getValue<int>("network/plugin_port", 6666);

src/lib/settings/ApplicationSettings.h

@@ -181,6 +181,9 @@ class ApplicationSettings: public Settings
 	FilePath getLastFilepickerLocation() const;
 	void setLastFilepickerLocation(const FilePath& path);
 
+	float getGraphZoomLevel() const;
+	void setGraphZoomLevel(float zoomLevel);
+
 	// network
 	int getPluginPort() const;
 	void setPluginPort(const int pluginPort);

src/lib_gui/qt/graphics/QtGraphicsView.cpp

@@ -37,7 +37,7 @@
 QtGraphicsView::QtGraphicsView(GraphFocusHandler* focusHandler, QWidget* parent)
 	: QGraphicsView(parent)
 	, m_focusHandler(focusHandler)
-	, m_zoomFactor(1.0f)
+	, m_zoomFactor(ApplicationSettings::getInstance()->getGraphZoomLevel())
 	, m_appZoomFactor(1.0f)
 	, m_zoomInButtonSpeed(20.0f)
 	, m_zoomOutButtonSpeed(-20.0f)
@@ -835,6 +835,10 @@ void QtGraphicsView::setZoomFactor(float zoomFactor)
 {
 	m_zoomFactor = zoomFactor;
 
+	std::shared_ptr<ApplicationSettings> settings = ApplicationSettings::getInstance();
+	settings->setGraphZoomLevel(zoomFactor);
+	settings->save();
+
 	m_zoomState->setText(QString::number(int(m_zoomFactor * 100)) + "%");
 	updateTransform();