ui: filter monospace fonts

* relpaced onw construction with QFontComboBox
* filter monospace font

src/lib_gui/qt/element/QtFontPicker.cpp

@@ -1,14 +1,8 @@
 #include "qt/element/QtFontPicker.h"
 
-#include <QFileDialog>
-#include <QFontDialog>
 #include <QHBoxLayout>
-#include <QLabel>
 #include <QPainter>
-#include <QPushButton>
-#include <QStyleOption>
-#include <QComboBox>
-#include <QFontDatabase>
+#include <QFontComboBox>
 
 #include "qt/element/QtLineEdit.h"
 
@@ -23,32 +17,13 @@ QtFontPicker::QtFontPicker(QWidget *parent)
 	layout->setContentsMargins(1, 1, 1, 1);
 	layout->setAlignment(Qt::AlignTop);
 
-	m_box = new QComboBox();
-	QFontDatabase database;
-	m_box->setFont(QFont("Roboto"));
-	for( QString fam : database.families() )
-	{
-		m_box->addItem(fam);
-	}
+	m_box = new QFontComboBox();
+	m_box->setFontFilters( QFontComboBox::MonospacedFonts );
+	m_box->setEditable(false);
 
-	QLabel* sampleLabel = new QLabel("Font preview:");
-	m_sampleLabel = new QLabel("AaBbCcXxYyZz");
-	layout->addWidget(sampleLabel);
-	layout->addWidget(m_sampleLabel);
-	QBoxLayout* layout1 = new QVBoxLayout();
-	layout1->addWidget(m_box);
-	layout1->addLayout(layout);
+	layout->addWidget(m_box);
 
-	connect(m_box, static_cast<void(QComboBox::*)(const QString &)>(&QComboBox::currentIndexChanged),
-		[=](const QString &family)
-		{
-			if (!family.isEmpty())
-			{
-				m_sampleLabel->setFont(QFont(family));
-			}
-		});
-
-	setLayout(layout1);
+	setLayout(layout);
 	setSizePolicy(sizePolicy().horizontalPolicy(), QSizePolicy::Fixed);
 }
 

src/lib_gui/qt/element/QtFontPicker.h

@@ -3,10 +3,7 @@
 
 #include <QWidget>
 
-class QPushButton;
-class QtLineEdit;
-class QComboBox;
-class QLabel;
+class QFontComboBox;
 
 class QtFontPicker
 	: public QWidget
@@ -22,8 +19,7 @@ public:
 	void setText(QString text);
 
 private:
-	QLabel* m_sampleLabel;
-	QComboBox* m_box;
+	QFontComboBox* m_box;
 };
 
 #endif // QT_FONT_PICKER_H