Reorganization of pgLab project

pglab/catalog/delegates/IconColumnDelegate.cpp

@@ -0,0 +1,58 @@
+#include "catalog/delegates/IconColumnDelegate.h"
+#include <QPainter>
+
+IconColumnDelegate::IconColumnDelegate(QWidget *parent)
+	: QStyledItemDelegate(parent)
+{
+}
+
+IconColumnDelegate::~IconColumnDelegate()
+{
+	clearCache();
+}
+
+void IconColumnDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option,
+						 const QModelIndex &index) const
+{
+	if (index.data().canConvert<QString>()) {
+		auto icon_name = qvariant_cast<QString>(index.data());
+
+
+		QIcon* icon = IconColumnDelegate::getIcon(icon_name);
+		if (icon) {
+			if (option.state & QStyle::State_Selected)
+				painter->fillRect(option.rect, option.palette.highlight());
+			icon->paint(painter, option.rect);
+		}
+		else
+			QStyledItemDelegate::paint(painter, option, index);
+
+	} else {
+		QStyledItemDelegate::paint(painter, option, index);
+	}
+}
+
+QSize IconColumnDelegate::sizeHint(const QStyleOptionViewItem &,
+				   const QModelIndex &) const
+{
+	return QSize(16, 16);
+}
+
+
+void IconColumnDelegate::clearCache()
+{
+	for (auto &e : m_Icons)
+		delete e.second;
+	m_Icons.clear();
+}
+
+QIcon* IconColumnDelegate::getIcon(const QString &name) const
+{
+	auto fr = m_Icons.find(name);
+	if (fr == m_Icons.end()) {
+		// load and insert icon
+		auto icon = new QIcon(name);
+		fr = m_Icons.emplace(name, icon).first;
+	}
+	return fr->second;
+}

pglab/catalog/delegates/IconColumnDelegate.h

@@ -0,0 +1,29 @@
+#ifndef ICONCOLUMNDELEGATE_H
+#define ICONCOLUMNDELEGATE_H
+
+#include <QStyledItemDelegate>
+#include <map>
+
+/** This class asumes that the string values supplies for the column data
+ * can be Resolved by QIcon to an actual icon. Icons are cached and reused.
+ *
+ */
+class IconColumnDelegate: public QStyledItemDelegate {
+public:
+	IconColumnDelegate(QWidget *parent = nullptr);
+	~IconColumnDelegate() override;
+
+	void paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const override;
+	QSize sizeHint(const QStyleOptionViewItem &option,
+					   const QModelIndex &index) const override;
+
+	void clearCache();
+private:
+	using t_IconCache = std::map<QString, QIcon*>;
+
+	mutable t_IconCache m_Icons;
+
+	QIcon* getIcon(const QString &name) const;
+};
+
+#endif // ICONCOLUMNDELEGATE_H