ui: Delay font face laoding until combobox clicked to speed up preferences display time

src/lib_gui/qt/window/project_wizzard/QtProjectWizzardContentPreferences.cpp

@@ -6,6 +6,7 @@
 #include <QLabel>
 #include <QLineEdit>
 #include <QTextCodec>
+#include <QTimer>
 
 #include "qt/utility/utilityQt.h"
 #include "settings/ApplicationSettings.h"
@@ -45,11 +46,30 @@ void QtProjectWizzardContentPreferences::populate(QGridLayout* layout, int& row)
 	addTitle("USER INTERFACE", layout, row);
 
 	// font face
-	m_fontFace = new QFontComboBox(this);
+	m_fontFacePlaceHolder = new QtComboBoxPlaceHolder();
-	m_fontFace->setFontFilters(QFontComboBox::MonospacedFonts);
+	m_fontFace = new QFontComboBox();
-	m_fontFace->setWritingSystem(QFontDatabase::Latin);
 	m_fontFace->setEditable(false);
-	addLabelAndWidget("Font Face", m_fontFace, layout, row);
+	addLabelAndWidget("Font Face", m_fontFacePlaceHolder, layout, row);
+
+	int rowNum = row;
+	connect(m_fontFacePlaceHolder, &QtComboBoxPlaceHolder::opened,
+		[this, rowNum, layout]()
+		{
+			m_fontFacePlaceHolder->hide();
+
+			QString name = m_fontFace->currentText();
+			m_fontFace->setFontFilters(QFontComboBox::MonospacedFonts);
+			m_fontFace->setWritingSystem(QFontDatabase::Latin);
+			m_fontFace->setCurrentText(name);
+
+			addWidget(m_fontFace, layout, rowNum);
+
+			QTimer::singleShot(10, [this]()
+			{
+				m_fontFace->showPopup();
+			});
+		}
+	);
 	row++;
 
 	// font size
@@ -359,7 +379,10 @@ void QtProjectWizzardContentPreferences::load()
 {
 	ApplicationSettings* appSettings = ApplicationSettings::getInstance().get();
 
-	m_fontFace->setCurrentText(QString::fromStdString(appSettings->getFontName()));
+	QString fontName = QString::fromStdString(appSettings->getFontName());
+	m_fontFace->setCurrentText(fontName);
+	m_fontFacePlaceHolder->addItem(fontName);
+	m_fontFacePlaceHolder->setCurrentText(fontName);
 
 	m_fontSize->setCurrentIndex(appSettings->getFontSize() - appSettings->getFontSizeMin());
 	m_tabWidth->setCurrentIndex(appSettings->getCodeTabWidth() - 1);
@@ -695,13 +718,24 @@ void QtProjectWizzardContentPreferences::addTitle(QString title, QGridLayout* la
 	layout->addWidget(createFormTitle(title), row++, QtProjectWizzardWindow::FRONT_COL, Qt::AlignLeft);
 }
 
-void QtProjectWizzardContentPreferences::addLabelAndWidget(
+void QtProjectWizzardContentPreferences::addLabel(QString label, QGridLayout* layout, int row)
-	QString label, QWidget* widget, QGridLayout* layout, int& row, Qt::Alignment widgetAlignment)
 {
 	layout->addWidget(createFormLabel(label), row, QtProjectWizzardWindow::FRONT_COL, Qt::AlignRight);
+}
+
+void QtProjectWizzardContentPreferences::addWidget(
+	QWidget* widget, QGridLayout* layout, int row, Qt::Alignment widgetAlignment)
+{
 	layout->addWidget(widget, row, QtProjectWizzardWindow::BACK_COL, widgetAlignment);
 }
 
+void QtProjectWizzardContentPreferences::addLabelAndWidget(
+	QString label, QWidget* widget, QGridLayout* layout, int row, Qt::Alignment widgetAlignment)
+{
+	addLabel(label, layout, row);
+	addWidget(widget, layout, row, widgetAlignment);
+}
+
 void QtProjectWizzardContentPreferences::addGap(QGridLayout* layout, int& row)
 {
 	layout->setRowMinimumHeight(row++, 20);

src/lib_gui/qt/window/project_wizzard/QtProjectWizzardContentPreferences.h

@@ -1,18 +1,35 @@
 #ifndef QT_PROJECT_WIZZARD_CONTENT_PREFERENCES_H
 #define QT_PROJECT_WIZZARD_CONTENT_PREFERENCES_H
 
+#include <QComboBox>
+
 #include "qt/element/QtLocationPicker.h"
 #include "qt/element/QtDirectoryListBox.h"
 #include "qt/window/project_wizzard/QtProjectWizzardContent.h"
 #include "utility/path_detector/CombinedPathDetector.h"
 
 class QCheckBox;
-class QComboBox;
 class QFontComboBox;
 class QLabel;
 class QLineEdit;
 
 
+class QtComboBoxPlaceHolder
+	: public QComboBox
+{
+	Q_OBJECT
+
+signals:
+	void opened();
+
+public:
+	virtual void showPopup()
+	{
+		emit opened();
+	}
+};
+
+
 class QtProjectWizzardContentPreferences
 	: public QtProjectWizzardContent
 {
@@ -45,8 +62,10 @@ private:
 	void addMavenPathDetection(QGridLayout* layout, int& row);
 
 	void addTitle(QString title, QGridLayout* layout, int& row);
+	void addLabel(QString label, QGridLayout* layout, int row);
+	void addWidget(QWidget* widget, QGridLayout* layout, int row, Qt::Alignment widgetAlignment = Qt::Alignment());
 	void addLabelAndWidget(
-		QString label, QWidget* widget, QGridLayout* layout, int& row, Qt::Alignment widgetAlignment = Qt::Alignment());
+		QString label, QWidget* widget, QGridLayout* layout, int row, Qt::Alignment widgetAlignment = Qt::Alignment());
 	void addGap(QGridLayout* layout, int& row);
 
 	QCheckBox* addCheckBox(QString label, QString text, QString helpText, QGridLayout* layout, int& row);
@@ -59,6 +78,8 @@ private:
 	QLineEdit* addLineEdit(QString label, QString helpText, QGridLayout* layout, int& row);
 
 	QFontComboBox* m_fontFace;
+	QtComboBoxPlaceHolder* m_fontFacePlaceHolder;
+
 	QComboBox* m_fontSize;
 	QComboBox* m_tabWidth;
 	QComboBox* m_textEncoding;