logic: reduce access to filesystem while indexing

* use canonical filepath cache in cxx indexer
* made constructors of FilePath explicit
* use FilePath at more places instead of string
* forward declares FilePath wherever possible

src/lib_gui/qt/view/QtBookmarkView.cpp

@@ -88,7 +88,7 @@ void QtBookmarkView::setCreateButtonState(const CreateButtonState& state)
 			m_createButtonState = state;
 
 			m_createBookmarkButton->setIcon(utility::createButtonIcon(
-				ResourcePaths::getGuiPath() + "bookmark_view/images/edit_bookmark_icon.png",
+				ResourcePaths::getGuiPath().str() + "bookmark_view/images/edit_bookmark_icon.png",
 				"search/button"
 			));
 
@@ -105,7 +105,7 @@ void QtBookmarkView::setCreateButtonState(const CreateButtonState& state)
 				m_createBookmarkButton->setEnabled(true);
 
 				m_createBookmarkButton->setIcon(utility::createButtonIcon(
-					ResourcePaths::getGuiPath() + "bookmark_view/images/bookmark_active.png",
+					ResourcePaths::getGuiPath().str() + "bookmark_view/images/bookmark_active.png",
 					"search/button"
 				));
 			}
@@ -240,7 +240,7 @@ void QtBookmarkView::displayBookmarkEditor(std::shared_ptr<Bookmark> bookmark, c
 
 void QtBookmarkView::setStyleSheet()
 {
-	m_widget->setStyleSheet(utility::getStyleSheet(ResourcePaths::getGuiPath() + "bookmark_view/bookmark_view.css").c_str());
+	m_widget->setStyleSheet(utility::getStyleSheet(ResourcePaths::getGuiPath().concat(FilePath("bookmark_view/bookmark_view.css"))).c_str());
 }
 
 void QtBookmarkView::refreshStyle()
@@ -251,12 +251,12 @@ void QtBookmarkView::refreshStyle()
 	m_showBookmarksButton->setFixedHeight(height);
 
 	m_createBookmarkButton->setIcon(utility::createButtonIcon(
-		ResourcePaths::getGuiPath() + "bookmark_view/images/edit_bookmark_icon.png",
+		ResourcePaths::getGuiPath().str() + "bookmark_view/images/edit_bookmark_icon.png",
 		"search/button"
 	));
 
 	m_showBookmarksButton->setIcon(utility::createButtonIcon(
-		ResourcePaths::getGuiPath() + "bookmark_view/images/bookmark_list_icon.png",
+		ResourcePaths::getGuiPath().str() + "bookmark_view/images/bookmark_list_icon.png",
 		"search/button"
 	));
 }

src/lib_gui/qt/view/QtCodeView.cpp

@@ -267,7 +267,7 @@ void QtCodeView::setStyleSheet() const
 {
 	utility::setWidgetBackgroundColor(m_widget, ColorScheme::getInstance()->getColor("code/background"));
 
-	std::string styleSheet = utility::getStyleSheet(ResourcePaths::getGuiPath() + "code_view/code_view.css");
+	std::string styleSheet = utility::getStyleSheet(ResourcePaths::getGuiPath().concat(FilePath("code_view/code_view.css")));
 
 	m_widget->setStyleSheet(styleSheet.c_str());
 }

src/lib_gui/qt/view/QtErrorView.cpp

@@ -50,7 +50,7 @@ QtErrorView::QtErrorView(ViewLayout* viewLayout)
 	, m_setErrorIdFunctor(std::bind(&QtErrorView::doSetErrorId, this, std::placeholders::_1))
 	, m_ignoreRowSelection(false)
 {
-	s_errorIcon = QIcon(QString((ResourcePaths::getGuiPath() + "/indexing_dialog/error.png").c_str()));
+	s_errorIcon = QIcon(QString((ResourcePaths::getGuiPath().str() + "/indexing_dialog/error.png").c_str()));
 }
 
 QtErrorView::~QtErrorView()

src/lib_gui/qt/view/QtGraphView.cpp

@@ -441,12 +441,12 @@ void QtGraphView::updateTrailButtons()
 	}
 
 	m_backwardTrailButton->setIcon(utility::createButtonIcon(
-		ResourcePaths::getGuiPath() + "graph_view/images/" + backwardImagePath,
+		ResourcePaths::getGuiPath().str() + "graph_view/images/" + backwardImagePath,
 		"search/button"
 	));
 
 	m_forwardTrailButton->setIcon(utility::createButtonIcon(
-		ResourcePaths::getGuiPath() + "graph_view/images/" + forwardImagePath,
+		ResourcePaths::getGuiPath().str() + "graph_view/images/" + forwardImagePath,
 		"search/button"
 	));
 }
@@ -646,19 +646,19 @@ void QtGraphView::doRefreshView()
 
 	QtGraphicsView* view = getView();
 
-	std::string css = utility::getStyleSheet(ResourcePaths::getGuiPath() + "graph_view/graph_view.css");
+	std::string css = utility::getStyleSheet(ResourcePaths::getGuiPath().concat(FilePath("graph_view/graph_view.css")));
 	view->setStyleSheet(css.c_str());
 	view->setAppZoomFactor(GraphViewStyle::getZoomFactor());
 
 	m_trailWidget->setStyleSheet(css.c_str());
 
 	m_expandButton->setIcon(utility::createButtonIcon(
-		ResourcePaths::getGuiPath() + "graph_view/images/graph.png",
+		ResourcePaths::getGuiPath().str() + "graph_view/images/graph.png",
 		"search/button"
 	));
 
 	m_collapseButton->setIcon(utility::createButtonIcon(
-		ResourcePaths::getGuiPath() + "graph_view/images/graph_arrow.png",
+		ResourcePaths::getGuiPath().str() + "graph_view/images/graph_arrow.png",
 		"search/button"
 	));
 

src/lib_gui/qt/view/QtLogView.cpp

@@ -216,7 +216,7 @@ void QtLogView::setStyleSheet() const
 	//m_showNonIndexedFatals->setPalette(palette);
 
 	widget->setStyleSheet(
-		utility::getStyleSheet(ResourcePaths::getGuiPath() + "error_view/error_view.css").c_str()
+		utility::getStyleSheet(ResourcePaths::getGuiPath().concat(FilePath("error_view/error_view.css"))).c_str()
 	);
 
 	m_table->updateRows();

src/lib_gui/qt/view/QtRefreshView.cpp

@@ -41,5 +41,5 @@ void QtRefreshView::doRefreshView()
 
 void QtRefreshView::setStyleSheet()
 {
-	m_widget->setStyleSheet(utility::getStyleSheet(ResourcePaths::getGuiPath() + "refresh_view/refresh_view.css").c_str());
+	m_widget->setStyleSheet(utility::getStyleSheet(ResourcePaths::getGuiPath().concat(FilePath("refresh_view/refresh_view.css"))).c_str());
 }

src/lib_gui/qt/view/QtSearchView.cpp

@@ -93,7 +93,7 @@ void QtSearchView::doSetAutocompletionList(const std::vector<SearchMatch>& autoc
 
 void QtSearchView::setStyleSheet()
 {
-	std::string css = utility::getStyleSheet(ResourcePaths::getGuiPath() + "search_view/search_view.css");
+	std::string css = utility::getStyleSheet(ResourcePaths::getGuiPath().concat(FilePath("search_view/search_view.css")));
 
 	m_widget->setStyleSheet(css.c_str());
 

src/lib_gui/qt/view/QtTabbedView.cpp

@@ -68,6 +68,6 @@ void QtTabbedView::setStyleSheet()
 	utility::setWidgetBackgroundColor(QtViewWidgetWrapper::getWidgetOfView(this), ColorScheme::getInstance()->getColor("tab/background"));
 
 	m_widget->setStyleSheet(
-		utility::getStyleSheet(ResourcePaths::getGuiPath() + "tabbed_view/tabbed_view.css").c_str()
+		utility::getStyleSheet(ResourcePaths::getGuiPath().concat(FilePath("tabbed_view/tabbed_view.css"))).c_str()
 	);
 }

src/lib_gui/qt/view/QtUndoRedoView.cpp

@@ -37,7 +37,7 @@ void QtUndoRedoView::refreshView()
 
 void QtUndoRedoView::setStyleSheet()
 {
-	m_widget->setStyleSheet(utility::getStyleSheet(ResourcePaths::getGuiPath() + "undoredo_view/undoredo_view.css").c_str());
+	m_widget->setStyleSheet(utility::getStyleSheet(ResourcePaths::getGuiPath().concat(FilePath("undoredo_view/undoredo_view.css"))).c_str());
 }
 
 void QtUndoRedoView::doRefreshView()

src/lib_gui/qt/view/graphElements/QtGraphNode.cpp

@@ -428,7 +428,7 @@ void QtGraphNode::setStyle(const GraphViewStyle::NodeStyle& style)
 
 	if (style.hasHatching)
 	{
-		QtDeviceScaledPixmap pattern((ResourcePaths::getGuiPath() + "graph_view/images/pattern.png").c_str());
+		QtDeviceScaledPixmap pattern((ResourcePaths::getGuiPath().str() + "graph_view/images/pattern.png").c_str());
 		pattern.scaleToHeight(12);
 		QPixmap pixmap = utility::colorizePixmap(pattern.pixmap(), style.color.hatching.c_str());
 

src/lib_gui/qt/view/graphElements/QtGraphNodeAccess.cpp

@@ -47,7 +47,7 @@ QtGraphNodeAccess::QtGraphNodeAccess(AccessKind accessKind)
 	if (iconFileName.size() > 0)
 	{
 		QtDeviceScaledPixmap pixmap(
-			QString::fromStdString(ResourcePaths::getGuiPath() + "graph_view/images/" + iconFileName + ".png"));
+			QString::fromStdString(ResourcePaths::getGuiPath().str() + "graph_view/images/" + iconFileName + ".png"));
 		pixmap.scaleToHeight(m_accessIconSize);
 
 		m_accessIcon = new QGraphicsPixmapItem(pixmap.pixmap(), this);

src/lib_gui/qt/view/graphElements/QtGraphNodeData.cpp

@@ -1,5 +1,6 @@
 #include "qt/view/graphElements/QtGraphNodeData.h"
 
+#include "utility/file/FilePath.h"
 #include "utility/messaging/type/MessageActivateNodes.h"
 #include "utility/messaging/type/MessageDeactivateEdge.h"
 #include "utility/messaging/type/MessageFocusIn.h"

src/lib_gui/qt/view/graphElements/QtGraphNodeData.h

@@ -1,10 +1,10 @@
 #ifndef QT_GRAPH_NODE_DATA_H
 #define QT_GRAPH_NODE_DATA_H
 
-#include "utility/file/FilePath.h"
-
 #include "qt/view/graphElements/QtGraphNode.h"
 
+class FilePath;
+
 class QtGraphNodeData
 	: public QtGraphNode
 {

src/lib_gui/qt/view/graphElements/QtGraphNodeExpandToggle.cpp

@@ -26,7 +26,7 @@ QtGraphNodeExpandToggle::QtGraphNodeExpandToggle(bool expanded, int invisibleSub
 	m_icon->setTransformationMode(Qt::SmoothTransformation);
 	m_icon->setShapeMode(QGraphicsPixmapItem::BoundingRectShape);
 
-	QtDeviceScaledPixmap pixmap((ResourcePaths::getGuiPath() + "graph_view/images/arrow.png").c_str());
+	QtDeviceScaledPixmap pixmap((ResourcePaths::getGuiPath().str() + "graph_view/images/arrow.png").c_str());
 	pixmap.scaleToHeight(iconHeight);
 
 	if (invisibleSubNodeCount)