src: refactored UI elements and graphics file structure

* split QtIconButton into multiple files
* moved graph elements from view to graphics
* structured elements into sub directories

src/lib_gui/qt/element/button/QtIconStateButton.h

@@ -0,0 +1,49 @@
+#ifndef QT_ICON_STATE_BUTTON_H
+#define QT_ICON_STATE_BUTTON_H
+
+#include <QPushButton>
+
+#include "FilePath.h"
+
+class QtIconStateButton
+	: public QPushButton
+{
+	Q_OBJECT
+
+public:
+	enum ButtonState
+	{
+		STATE_DEFAULT,
+		STATE_HOVERED,
+		STATE_DISABLED
+	};
+
+	struct State
+	{
+		FilePath iconPath;
+		QColor color;
+	};
+
+	QtIconStateButton(QWidget* parent = nullptr);
+
+	void addState(ButtonState buttonState, const FilePath& iconPath, QColor color = Qt::transparent);
+
+	void hoverIn();
+	void hoverOut();
+
+signals:
+	void hoveredIn(QPushButton*);
+	void hoveredOut(QPushButton*);
+
+protected:
+	void changeEvent(QEvent *event);
+	void enterEvent(QEvent *event);
+	void leaveEvent(QEvent *event);
+
+private:
+	void setState(State state);
+
+	std::map<ButtonState, State> m_states;
+};
+
+#endif // QT_ICON_STATE_BUTTON_H