Implemented em_unit() function for getting of em_unit value from correct parent.

+ Added correct em_unit to Fields

src/slic3r/GUI/Field.cpp

@@ -65,6 +65,9 @@ void Field::PostInitialize()
 		break;
 	}
 
+    // initialize m_unit_value
+    m_em_unit = em_unit(m_parent);
+
 	BUILD();
 }
 
@@ -212,8 +215,8 @@ bool is_defined_input_value(wxWindow* win, const ConfigOptionType& type)
 
 void TextCtrl::BUILD() {
     auto size = wxSize(wxDefaultSize);
-    if (m_opt.height >= 0) size.SetHeight(m_opt.height*wxGetApp().em_unit());
+    if (m_opt.height >= 0) size.SetHeight(m_opt.height*m_em_unit);
-    if (m_opt.width >= 0) size.SetWidth(m_opt.width*wxGetApp().em_unit());
+    if (m_opt.width >= 0) size.SetWidth(m_opt.width*m_em_unit);
 
 	wxString text_value = wxString(""); 
 
@@ -361,8 +364,8 @@ void TextCtrl::rescale()
 {
     Field::rescale();
     auto size = wxSize(wxDefaultSize);
-    if (m_opt.height >= 0) size.SetHeight(m_opt.height*wxGetApp().em_unit());
+    if (m_opt.height >= 0) size.SetHeight(m_opt.height*m_em_unit);
-    if (m_opt.width >= 0) size.SetWidth(m_opt.width*wxGetApp().em_unit());
+    if (m_opt.width >= 0) size.SetWidth(m_opt.width*m_em_unit);
 
     if (size != wxDefaultSize)
     {
@@ -424,8 +427,8 @@ int undef_spin_val = -9999;		//! Probably, It's not necessary
 
 void SpinCtrl::BUILD() {
 	auto size = wxSize(wxDefaultSize);
-    if (m_opt.height >= 0) size.SetHeight(m_opt.height*wxGetApp().em_unit());
+    if (m_opt.height >= 0) size.SetHeight(m_opt.height*m_em_unit);
-    if (m_opt.width >= 0) size.SetWidth(m_opt.width*wxGetApp().em_unit());
+    if (m_opt.width >= 0) size.SetWidth(m_opt.width*m_em_unit);
 
 	wxString	text_value = wxString("");
 	int			default_value = 0;
@@ -529,9 +532,9 @@ void SpinCtrl::rescale()
 }
 
 void Choice::BUILD() {
-    wxSize size(m_width * wxGetApp().em_unit(), -1);
+    wxSize size(m_width * m_em_unit, -1);
-    if (m_opt.height >= 0) size.SetHeight(m_opt.height*wxGetApp().em_unit());
+    if (m_opt.height >= 0) size.SetHeight(m_opt.height*m_em_unit);
-    if (m_opt.width >= 0) size.SetWidth(m_opt.width*wxGetApp().em_unit());
+    if (m_opt.width >= 0) size.SetWidth(m_opt.width*m_em_unit);
 
 	wxBitmapComboBox* temp;	
     if (!m_opt.gui_type.empty() && m_opt.gui_type.compare("select_open") != 0) {
@@ -856,8 +859,8 @@ void Choice::rescale()
 	 */
     field->Clear();
     wxSize size(wxDefaultSize);
-    if (m_opt.height >= 0) size.SetHeight(m_opt.height * wxGetApp().em_unit());
+    if (m_opt.height >= 0) size.SetHeight(m_opt.height * m_em_unit);
-    size.SetWidth((m_opt.width > 0 ? m_opt.width : m_width) * wxGetApp().em_unit());
+    size.SetWidth((m_opt.width > 0 ? m_opt.width : m_width) * m_em_unit);
     
     field->SetSize(size);
 
@@ -885,8 +888,8 @@ void Choice::rescale()
 void ColourPicker::BUILD()
 {
 	auto size = wxSize(wxDefaultSize);
-    if (m_opt.height >= 0) size.SetHeight(m_opt.height*wxGetApp().em_unit());
+    if (m_opt.height >= 0) size.SetHeight(m_opt.height*m_em_unit);
-    if (m_opt.width >= 0) size.SetWidth(m_opt.width*wxGetApp().em_unit());
+    if (m_opt.width >= 0) size.SetWidth(m_opt.width*m_em_unit);
 
 	// Validate the color
 	wxString clr_str(static_cast<const ConfigOptionStrings*>(m_opt.default_value)->get_at(m_opt_idx));
@@ -921,7 +924,7 @@ void PointCtrl::BUILD()
 {
 	auto temp = new wxBoxSizer(wxHORIZONTAL);
 
-    const wxSize field_size(4 * wxGetApp().em_unit(), -1);
+    const wxSize field_size(4 * m_em_unit, -1);
 
 	auto default_pt = static_cast<const ConfigOptionPoints*>(m_opt.default_value)->values.at(0);
 	double val = default_pt(0);
@@ -964,6 +967,16 @@ void PointCtrl::BUILD()
 	y_textctrl->SetToolTip(get_tooltip_text(X+", "+Y));
 }
 
+void PointCtrl::rescale()
+{
+    Field::rescale();
+
+    const wxSize field_size(4 * m_em_unit, -1);
+
+    x_textctrl->SetMinSize(field_size);
+    y_textctrl->SetMinSize(field_size);
+}
+
 void PointCtrl::propagate_value(wxTextCtrl* win)
 {
     if (!win->GetValue().empty()) 
@@ -1009,8 +1022,8 @@ boost::any& PointCtrl::get_value()
 void StaticText::BUILD()
 {
 	auto size = wxSize(wxDefaultSize);
-    if (m_opt.height >= 0) size.SetHeight(m_opt.height*wxGetApp().em_unit());
+    if (m_opt.height >= 0) size.SetHeight(m_opt.height*m_em_unit);
-    if (m_opt.width >= 0) size.SetWidth(m_opt.width*wxGetApp().em_unit());
+    if (m_opt.width >= 0) size.SetWidth(m_opt.width*m_em_unit);
 
     const wxString legend(static_cast<const ConfigOptionString*>(m_opt.default_value)->value);
     auto temp = new wxStaticText(m_parent, wxID_ANY, legend, wxDefaultPosition, size, wxST_ELLIPSIZE_MIDDLE);
@@ -1029,8 +1042,8 @@ void StaticText::rescale()
     Field::rescale();
 
     auto size = wxSize(wxDefaultSize);
-    if (m_opt.height >= 0) size.SetHeight(m_opt.height*wxGetApp().em_unit());
+    if (m_opt.height >= 0) size.SetHeight(m_opt.height*m_em_unit);
-    if (m_opt.width >= 0) size.SetWidth(m_opt.width*wxGetApp().em_unit());
+    if (m_opt.width >= 0) size.SetWidth(m_opt.width*m_em_unit);
 
     if (size != wxDefaultSize)
     {

src/slic3r/GUI/Field.hpp

@@ -220,6 +220,9 @@ public:
     virtual void rescale() {
         m_Undo_to_sys_btn->rescale();
         m_Undo_btn->rescale();
+
+        // update em_unit value
+        m_em_unit = em_unit(m_parent);
     }
 
 protected:
@@ -241,6 +244,8 @@ protected:
 	// current value
 	boost::any			m_value;
 
+    int                 m_em_unit;
+
     bool    bEnterPressed = false;
     
 	friend class OptionsGroup;
@@ -432,6 +437,8 @@ public:
 	void			set_value(const boost::any& value, bool change_event = false);
 	boost::any&		get_value() override;
 
+    void            rescale() override;
+
 	void			enable() override {
 		x_textctrl->Enable();
 		y_textctrl->Enable(); }

src/slic3r/GUI/wxExtensions.cpp

@@ -18,6 +18,7 @@
 #include "GUI_ObjectList.hpp"
 #include "libslic3r/GCode/PreviewData.hpp"
 #include "I18N.hpp"
+#include "GUI_Utils.hpp"
 
 using Slic3r::GUI::from_u8;
 
@@ -420,6 +421,27 @@ void PrusaCollapsiblePaneMSW::Collapse(bool collapse)
 }
 #endif //__WXMSW__
 
+/* Function for getting of em_unit value from correct parent.
+ * In most of cases it is m_em_unit value from GUI_App,
+ * but for DPIDialogs it's its own value. 
+ * This value will be used to correct rescale after moving between 
+ * Displays with different HDPI */
+int em_unit(wxWindow* win)
+{
+    if (win) {
+        // get TopLevelWindow for some window
+        wxWindow* top_win = win;
+        while (!top_win->IsTopLevel())
+            top_win = top_win->GetParent();
+
+        Slic3r::GUI::DPIDialog* dlg = dynamic_cast<Slic3r::GUI::DPIDialog*>(top_win);
+        if (dlg)
+            // An analog of em_unit value from GUI_App.
+            return 10 * dlg->scale_factor();
+    }
+    
+    return Slic3r::GUI::wxGetApp().em_unit();
+}
 
 // If an icon has horizontal orientation (width > height) call this function with is_horizontal = true
 wxBitmap create_scaled_bitmap(wxWindow *win, const std::string& bmp_name_in, const int px_cnt/* = 16*/, const bool is_horizontal /* = false*/)
@@ -436,7 +458,7 @@ wxBitmap create_scaled_bitmap(wxWindow *win, const std::string& bmp_name_in, con
     unsigned int height, width = height = 0;
     unsigned int& scale_base = is_horizontal ? width : height;
 
-    scale_base = (unsigned int)(Slic3r::GUI::wxGetApp().em_unit() * px_cnt * 0.1f + 0.5f);
+    scale_base = (unsigned int)(em_unit(win) * px_cnt * 0.1f + 0.5f);
 
     std::string bmp_name = bmp_name_in;
     boost::replace_last(bmp_name, ".png", "");

src/slic3r/GUI/wxExtensions.hpp

@@ -31,6 +31,8 @@ wxMenuItem* append_submenu(wxMenu* menu, wxMenu* sub_menu, int id, const wxStrin
 wxMenuItem* append_menu_radio_item(wxMenu* menu, int id, const wxString& string, const wxString& description, 
     std::function<void(wxCommandEvent& event)> cb, wxEvtHandler* event_handler);
 
+int em_unit(wxWindow* win);
+
 wxBitmap create_scaled_bitmap(wxWindow *win, const std::string& bmp_name, const int px_cnt = 16, const bool is_horizontal = false);
 
 class wxCheckListBoxComboPopup : public wxCheckListBox, public wxComboPopup