Clean project structure.

src/ui_elements/widgets/Button.h

@@ -1,46 +0,0 @@
-#pragma once
-
-#include "Widget.h"
-#include "Color.h"
-
-#include <functional>
-#include <string>
-
-class PaintEvent;
-class MouseEvent;
-class TextNode;
-
-class Button : public Widget
-{
-public:
-    using clickFunc = std::function<void(Widget* self)>;
-
-    Button();
-
-    ~Button();
-
-    static std::unique_ptr<Button> Create();
-
-    void setLabel(const std::string& text);
-
-    void setOnClickFunction(clickFunc func);
-
-protected:
-    void onMyMouseEvent(const MouseEvent* event) override;
-
-    bool isDirty() const override;
-    void doPaint(const PaintEvent* event) override;
-
-    void updateLabel(const PaintEvent* event);
-
-private:
-    std::string mLabel;
-    clickFunc mClickFunc;
-    Color mCachedColor;
-    Color mClickedColor;
-
-    std::unique_ptr<TextNode> mTextNode;
-    bool mContentDirty{true};
-};
-
-using ButtonUPtr = std::unique_ptr<Button>;