Modifiers Gallery (#6703)

* Added GalleryDialog

* GalleryDialog improvements:
* Added DnD functionality
* Added "Delete custom shapes" function

src/slic3r/GUI/GalleryDialog.hpp

@@ -0,0 +1,58 @@
+#ifndef slic3r_GalleryDialog_hpp_
+#define slic3r_GalleryDialog_hpp_
+
+#include "GUI_Utils.hpp"
+
+class wxListCtrl;
+class wxImageList;
+
+namespace Slic3r {
+
+namespace GUI {
+
+
+//------------------------------------------
+//          GalleryDialog
+//------------------------------------------
+
+class GalleryDialog : public DPIDialog
+{
+    wxListCtrl*     m_list_ctrl  { nullptr };
+    wxImageList*    m_image_list { nullptr };
+
+    struct Item {
+        std::string name;
+        bool        is_system;
+    };
+    std::vector<Item>   m_selected_items;
+
+    int ID_BTN_ADD_CUSTOM_SHAPE;
+    int ID_BTN_DEL_CUSTOM_SHAPE;
+    int ID_BTN_REPLACE_CUSTOM_PNG;
+
+    void load_label_icon_list();
+    void add_custom_shapes(wxEvent& event);
+    void del_custom_shapes(wxEvent& event);
+    void replace_custom_png(wxEvent& event);
+    void select(wxListEvent& event);
+    void deselect(wxListEvent& event);
+
+    void update();
+
+public:
+    GalleryDialog(wxWindow* parent);
+    ~GalleryDialog();
+
+    void get_input_files(wxArrayString& input_files);
+    bool load_files(const wxArrayString& input_files);
+
+protected:
+    void on_dpi_changed(const wxRect& suggested_rect) override;
+    void on_sys_color_changed() override {};
+};
+
+
+} // namespace GUI
+} // namespace Slic3r
+
+#endif //slic3r_GalleryDialog_hpp_