Require less clicks to change filament in object list (#12603)

* reduces number of clicks to change filament in objectlist

* dont set minimum width in dropdown if use_content_width == true

---------

Co-authored-by: Hanno Witzleb <hannowitzleb@gmail.com>
Co-authored-by: yw4z <ywsyildiz@gmail.com>

src/slic3r/GUI/Widgets/ComboBox.cpp

@@ -241,6 +241,23 @@ void ComboBox::DoDeleteOneItem(unsigned int pos)
     drop.Invalidate(true);
 }
 
+void ComboBox::ForceDropdownOpen()
+{
+    if (!IsEnabled())
+        return;
+
+    if (!drop_down) {
+        drop.need_sync = true;
+        drop.messureSize();
+        drop.autoPosition();
+        drop_down = true;
+        drop.Popup(&drop);
+
+        wxCommandEvent e(wxEVT_COMBOBOX_DROPDOWN);
+        GetEventHandler()->ProcessEvent(e);
+    }
+}
+
 unsigned int ComboBox::GetCount() const { return items.size(); }
 
 void ComboBox::set_replace_text(wxString text, wxString image_name)

src/slic3r/GUI/Widgets/ComboBox.hpp

@@ -76,6 +76,9 @@ public:
     void     SetItemBitmap(unsigned int n, wxBitmap const &bitmap);
     bool     is_drop_down(){return drop_down;}
     void     DeleteOneItem(unsigned int pos) { DoDeleteOneItem(pos); }
+
+    void ForceDropdownOpen();
+
 protected:
     virtual int  DoInsertItems(const wxArrayStringsAdapter &items,
                                unsigned int                 pos,

src/slic3r/GUI/Widgets/DropDown.cpp

@@ -525,7 +525,7 @@ void DropDown::messureSize()
     }
     if (!align_icon) iconSize.x = 0;
     wxSize szContent = textSize;
-    if (szContent.x < FromDIP(120))
+    if (szContent.x < FromDIP(120) && !use_content_width)
         szContent.x = FromDIP(120);
     szContent.x += 10;
     if (check_bitmap.bmp().IsOk()) {