feat: iMEX multi-material warning badge, conflict dialog, and mode row UI

- Add warning badge (obj_warning.svg overlay) to the iMEX plate icon when
  a parallel mode is active alongside multi-material objects on the same plate
- Add has_imex_multimaterial_conflict() using get_extruders(true) so only
  filaments actually used on the plate are checked
- Move multi-material caution dialog from reslice() into on_action_slice_plate /
  on_action_slice_all so it fires exactly once per user action and does not
  disrupt GL thumbnail generation during Slice All
- Fix is_imex missing from p->config init key list so on_config_change()
  diff detection correctly triggers refresh_imex_icons()
- Defer imex_changed handling until after set_bed_shape() so m_shape is current
- Replace plain remove button with ScalableButton (imex_remove.svg) in mode rows
- Add EditGCodeDialog launch button per mode row for placeholder browsing

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

resources/images/imex_remove.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16"><line x1="2.5" y1="2.5" x2="13.5" y2="13.5" style="fill:none;stroke:#949494;stroke-linecap:square;stroke-linejoin:round;opacity:1"/><line x1="13.5" y1="2.5" x2="2.5" y2="13.5" style="fill:none;stroke:#949494;stroke-linecap:square;stroke-linejoin:round;opacity:1"/></svg>

src/slic3r/GUI/PartPlate.cpp

@@ -879,8 +879,11 @@ void PartPlate::refresh_imex_icon()
     if (!preset) return;
     bool dual_bbl = preset->is_bbl_vendor() && preset->get_printer_extruder_count() == 2;
     auto* is_imex_opt = preset->printers.get_edited_preset().config.option<ConfigOptionBool>("is_imex");
-    if (is_imex_opt && is_imex_opt->value)
-        calc_vertex_for_icons(dual_bbl ? 7 : 6, m_imex_mode_icon);
+    if (is_imex_opt && is_imex_opt->value) {
+        int imex_slot = dual_bbl ? 7 : 6;
+        calc_vertex_for_icons(imex_slot, m_imex_mode_icon);
+        calc_vertex_for_imex_warn_badge(imex_slot, m_imex_warn_icon);
+    }
 }
 
 // Ensure zone geometry (secondary boxes, collision strips, visual meshes) is up to date.
@@ -920,6 +923,20 @@ bool PartPlate::has_imex_placement_violations()
     return false;
 }
 
+bool PartPlate::has_imex_multimaterial_conflict() const
+{
+    // Condition 1: iMEX is active and the plate mode is non-primary
+    auto* pb = wxGetApp().preset_bundle;
+    if (!pb) return false;
+    auto* is_imex_opt = pb->printers.get_edited_preset().config.option<ConfigOptionBool>("is_imex");
+    if (!is_imex_opt || !is_imex_opt->value) return false;
+    if (get_imex_mode() == "primary") return false;
+
+    // Condition 2: objects on this plate actually use more than one unique filament/extruder
+    std::vector<int> used = get_extruders(true);
+    return used.size() > 1;
+}
+
 void PartPlate::render_imex_zones(bool force_default_color)
 {
     if (force_default_color)
@@ -1237,6 +1254,37 @@ void PartPlate::calc_vertex_for_icons(int index, PickingModel &model)
 	init_raycaster_from_model(model);
 }
 
+// Positions the iMEX multi-material warning badge as a small overlay at the bottom-right
+// corner of the iMEX mode icon.  The icon slot index matches the one used in calc_vertex_for_icons.
+void PartPlate::calc_vertex_for_imex_warn_badge(int imex_icon_index, GLModel &model)
+{
+    model.reset();
+
+    auto  bed_ext  = get_extents(m_shape);
+    Vec2d p        = bed_ext[2];
+    auto  factor   = bed_ext.size()(1) / 200.0;
+    float size     = PARTPLATE_ICON_SIZE     * factor;
+    float gap_left = PARTPLATE_ICON_GAP_LEFT * factor;
+    float gap_y    = PARTPLATE_ICON_GAP_Y    * factor;
+    float gap_top  = PARTPLATE_ICON_GAP_TOP  * factor;
+
+    // Centre of the iMEX mode icon (top-left corner = p after offset)
+    p += Vec2d(gap_left, -1 * (imex_icon_index * (size + gap_y) + gap_top));
+
+    // Badge is half the icon size, anchored to the bottom-right corner of the icon slot
+    float badge = size * 0.55f;
+    Vec2d bp(p(0) + size - badge, p(1) - size);
+
+    ExPolygon poly;
+    poly.contour.append({ scale_(bp(0))        , scale_(bp(1))        });
+    poly.contour.append({ scale_(bp(0) + badge), scale_(bp(1))        });
+    poly.contour.append({ scale_(bp(0) + badge), scale_(bp(1) + badge)});
+    poly.contour.append({ scale_(bp(0))        , scale_(bp(1) + badge)});
+
+    if (!init_model_from_poly(model, poly, GROUND_Z + 0.01f))
+        BOOST_LOG_TRIVIAL(error) << __FUNCTION__ << "Unable to generate geometry for iMEX warn badge\n";
+}
+
 /*
 void PartPlate::calc_vertex_for_icons_background(int icon_count, GLModel &buffer)
 {
@@ -1748,6 +1796,12 @@ void PartPlate::render_icons(bool bottom, bool only_name, int hover_id)
                     } else {
                         render_icon_texture(m_imex_mode_icon.model, m_partplate_list->m_imex_mode_texture);
                     }
+                    // Warning badge: iMEX parallel mode active alongside multi-material objects
+                    if (has_imex_multimaterial_conflict()) {
+                        render_icon_texture(m_imex_warn_icon, m_partplate_list->m_imex_warn_texture);
+                        if (hover_id == (int)PLATE_IMEX_MODE_ID)
+                            show_tooltip(_u8L("Warning: this plate uses a parallel iMEX mode with multi-material objects. Proceed with caution — verify your G-code handles this combination correctly."));
+                    }
                 }
             }
 
@@ -2060,10 +2114,10 @@ void PartPlate::register_raycasters_for_picking(GLCanvas3D &canvas)
     if (dual_bbl)
         register_model_for_picking(canvas, m_plate_filament_map_icon, picking_id_component(PLATE_FILAMENT_MAP_ID));
 
-    // Register IDEX/IQEX mode icon only when IDEX/IQEX is active on the current printer preset.
+    // Register IDEX/IQEX mode icon only when IDEX/IQEX is active and geometry is initialized.
     if (preset) {
         auto* is_imex_opt = preset->printers.get_edited_preset().config.option<ConfigOptionBool>("is_imex");
-        if (is_imex_opt && is_imex_opt->value)
+        if (is_imex_opt && is_imex_opt->value && m_imex_mode_icon.mesh_raycaster)
             register_model_for_picking(canvas, m_imex_mode_icon, picking_id_component(PLATE_IMEX_MODE_ID));
     }
 }
@@ -3753,8 +3807,11 @@ bool PartPlate::set_shape(const Pointfs& shape, const Pointfs& exclude_areas, co
 			calc_vertex_for_icons(dual_bbl ? 6 : 5, m_move_front_icon);
 			{
 				auto* is_imex_opt = preset->printers.get_edited_preset().config.option<ConfigOptionBool>("is_imex");
-				if (is_imex_opt && is_imex_opt->value)
-					calc_vertex_for_icons(dual_bbl ? 7 : 6, m_imex_mode_icon);
+				if (is_imex_opt && is_imex_opt->value) {
+					int imex_slot = dual_bbl ? 7 : 6;
+					calc_vertex_for_icons(imex_slot, m_imex_mode_icon);
+					calc_vertex_for_imex_warn_badge(imex_slot, m_imex_warn_icon);
+				}
 			}
 
 			calc_vertex_for_number(0, false, m_plate_idx_icon);
@@ -4625,6 +4682,14 @@ void PartPlateList::generate_icon_textures()
 		}
 	}
 
+    // iMEX multi-material conflict warning badge
+    {
+        file_name = path + "obj_warning.svg";
+        if (!m_imex_warn_texture.load_from_svg_file(file_name, true, false, false, icon_size)) {
+            BOOST_LOG_TRIVIAL(warning) << __FUNCTION__ << boost::format(":load file %1% failed (iMEX warn badge)") % file_name;
+        }
+    }
+
     // IDEX/IQEX mode icon textures (fall back gracefully if SVG not present yet)
     {
         file_name = path + (m_is_dark ? "plate_imex_mode_dark.svg" : "plate_imex_mode.svg");
@@ -4684,6 +4749,7 @@ void PartPlateList::release_icon_textures()
 	m_plate_name_edit_hovered_texture.reset();
     m_imex_mode_texture.reset();
     m_imex_mode_hovered_texture.reset();
+    m_imex_warn_texture.reset();
 	for (int i = 0;i < MAX_PLATE_COUNT; i++) {
 		m_idx_textures[i].reset();
 	}

src/slic3r/GUI/PartPlate.hpp

@@ -156,6 +156,7 @@ private:
     PickingModel m_plate_name_edit_icon;
     PickingModel m_move_front_icon;
     PickingModel m_imex_mode_icon;
+    GLModel      m_imex_warn_icon;   // warning badge: iMEX parallel mode + multi-material conflict
     GLModel m_plate_idx_icon;
     GLTexture m_texture;
 
@@ -195,6 +196,7 @@ private:
     void calc_vertex_for_number(int index, bool one_number, GLModel &buffer);
     void calc_vertex_for_plate_name_edit_icon(GLTexture *texture, int index, PickingModel &model);
     void calc_vertex_for_icons(int index, PickingModel &model);
+    void calc_vertex_for_imex_warn_badge(int imex_icon_index, GLModel &model);
     // void calc_vertex_for_icons_background(int icon_count, GLModel &buffer);
     void render_background(bool force_default_color = false);
     void render_logo(bool bottom, bool render_cali = true);
@@ -454,6 +456,9 @@ public:
     }
     // Returns true if any instance on this plate overlaps an IDEX/IQEX secondary or collision zone.
     bool has_imex_placement_violations();
+    // Returns true when iMEX parallel mode is active (non-primary) AND the plate
+    // has objects assigned to more than one filament — a combination that warrants caution.
+    bool has_imex_multimaterial_conflict() const;
     // Returns the primary-zone bounding box in mm when an IDEX/IQEX parallel mode is active.
     // Empty (nullopt) when IDEX/IQEX is off or the mode is "primary" (full-bed).
     std::optional<BoundingBoxf> imex_primary_zone() { ensure_imex_zones(); return m_imex_primary_zone_box; }
@@ -637,6 +642,7 @@ class PartPlateList : public ObjectBase
     GLTexture m_plate_name_edit_hovered_texture;
     GLTexture m_imex_mode_texture;
     GLTexture m_imex_mode_hovered_texture;
+    GLTexture m_imex_warn_texture;  // warning badge for iMEX + multi-material conflict
     GLTexture m_idx_textures[MAX_PLATE_COUNT];
     // set render option
     bool render_bedtype_logo = true;

src/slic3r/GUI/Plater.cpp

@@ -4821,7 +4821,8 @@ Plater::priv::priv(Plater *q, MainFrame *main_frame)
         "wipe_tower_rotation_angle", "wipe_tower_cone_angle", "wipe_tower_extra_spacing", "wipe_tower_extra_flow", "wipe_tower_max_purge_speed",
         "wipe_tower_wall_type", "wipe_tower_extra_rib_length","wipe_tower_rib_width","wipe_tower_fillet_wall",
         "wipe_tower_filament",
-        "best_object_pos",  "master_extruder_id"
+        "best_object_pos",  "master_extruder_id",
+        "is_imex"
         }))
     , sidebar(new Sidebar(q))
     , notification_manager(std::make_unique<NotificationManager>(q))
@@ -9781,6 +9782,24 @@ void Plater::priv::on_action_slice_plate(SimpleEvent&)
 {
     if (q != nullptr) {
         BOOST_LOG_TRIVIAL(debug) << __FUNCTION__ << ":received slice plate event\n" ;
+
+        // iMEX parallel mode + multi-material caution check (current plate only)
+        {
+            PartPlate* plate = partplate_list.get_curr_plate();
+            if (plate && plate->has_imex_multimaterial_conflict()) {
+                int plate_num = partplate_list.get_curr_plate_index() + 1;
+                wxString msg = wxString::Format(
+                    _L("Plate %d has an IDEX/IQEX parallel mode active alongside multi-material objects.\n\n"
+                       "Secondary tool heads operate at the firmware level and may not behave as expected with multi-material prints. "
+                       "Proceed with caution and verify your G-code handles this combination correctly.\n\n"
+                       "Continue slicing?"),
+                    plate_num);
+                MessageDialog dlg(q, msg, _L("IDEX/IQEX Multi-Material Caution"), wxICON_WARNING | wxYES | wxNO);
+                if (dlg.ShowModal() != wxID_YES)
+                    return;
+            }
+        }
+
         //BBS update extruder params and speed table before slicing
         const Slic3r::DynamicPrintConfig& config = wxGetApp().preset_bundle->full_config();
         auto& print = q->get_partplate_list().get_current_fff_print();
@@ -9800,6 +9819,32 @@ void Plater::priv::on_action_slice_all(SimpleEvent&)
 {
     if (q != nullptr) {
         BOOST_LOG_TRIVIAL(debug) << __FUNCTION__ << ":received slice project event\n" ;
+
+        // iMEX parallel mode + multi-material caution check (all plates)
+        {
+            std::vector<int> conflict_plates;
+            int plate_count = partplate_list.get_plate_count();
+            for (int i = 0; i < plate_count; ++i) {
+                PartPlate* plate = partplate_list.get_plate(i);
+                if (plate && plate->has_imex_multimaterial_conflict())
+                    conflict_plates.push_back(i + 1); // 1-based for display
+            }
+            if (!conflict_plates.empty()) {
+                wxString plate_list;
+                for (int n : conflict_plates)
+                    plate_list += wxString::Format(" %d", n);
+                wxString msg = wxString::Format(
+                    _L("Plate(s)%s have an IDEX/IQEX parallel mode active alongside multi-material objects.\n\n"
+                       "Secondary tool heads operate at the firmware level and may not behave as expected with multi-material prints. "
+                       "Proceed with caution and verify your G-code handles this combination correctly.\n\n"
+                       "Continue slicing?"),
+                    plate_list);
+                MessageDialog dlg(q, msg, _L("IDEX/IQEX Multi-Material Caution"), wxICON_WARNING | wxYES | wxNO);
+                if (dlg.ShowModal() != wxID_YES)
+                    return;
+            }
+        }
+
         //BBS update extruder params and speed table before slicing
         const Slic3r::DynamicPrintConfig& config = wxGetApp().preset_bundle->full_config();
         auto& print = q->get_partplate_list().get_current_fff_print();
@@ -16180,6 +16225,7 @@ void Plater::on_config_change(const DynamicPrintConfig &config)
 {
     bool update_scheduled = false;
     bool bed_shape_changed = false;
+    bool imex_changed = false;
     //bool print_sequence_changed = false;
     t_config_option_keys diff_keys = p->config->diff(config);
 
@@ -16270,8 +16316,9 @@ void Plater::on_config_change(const DynamicPrintConfig &config)
         }
         // IDEX/IQEX: when is_imex toggles the mode icon needs to be repositioned on every plate.
         // set_shape() short-circuits when the bed geometry is unchanged, so we refresh explicitly.
+        // Defer until after the loop so bed_shape_changed / set_bed_shape() run first if needed.
         else if (opt_key == "is_imex") {
-            p->partplate_list.refresh_imex_icons();
+            imex_changed = true;
             update_scheduled = true;
         }
     }
@@ -16279,6 +16326,16 @@ void Plater::on_config_change(const DynamicPrintConfig &config)
     if (bed_shape_changed)
         set_bed_shape();
 
+    // After any bed-shape or is_imex change, ensure the iMEX mode icon geometry and
+    // raycaster are correct.  set_shape() short-circuits when the bed is unchanged,
+    // so we call refresh_imex_icons() explicitly whenever is_imex is active.
+    // Always done AFTER set_bed_shape() so m_shape is current.
+    if (bed_shape_changed || imex_changed) {
+        auto* is_imex_opt = wxGetApp().preset_bundle->printers.get_edited_preset().config.option<ConfigOptionBool>("is_imex");
+        if (is_imex_opt && is_imex_opt->value)
+            p->partplate_list.refresh_imex_icons();
+    }
+
     config_change_notification(config, std::string("print_sequence"));
 
     if (update_scheduled)

src/slic3r/GUI/Tab.cpp

@@ -4653,17 +4653,34 @@ private:
             sizer->Add(r.name, 0, wxALIGN_CENTER_VERTICAL | wxRIGHT, 6);
         }
         sizer->Add(grid_panel, 0, wxALIGN_CENTER_VERTICAL | wxRIGHT, 6);
-        sizer->Add(r.gcode,   1, wxALIGN_CENTER_VERTICAL | wxRIGHT, 6);
+        sizer->Add(r.gcode,   1, wxALIGN_CENTER_VERTICAL | wxRIGHT, 4);
+
+        // Placeholder search + (for non-primary) delete — stacked vertically
+        auto* btn_col = new wxBoxSizer(wxVERTICAL);
+        wxTextCtrl* gcode_ctrl = r.gcode;
+        auto* ph_btn = new ScalableButton(r.panel, wxID_ANY, "edit", wxEmptyString,
+                                          wxDefaultSize, wxDefaultPosition,
+                                          wxBU_EXACTFIT | wxNO_BORDER, 16);
+        ph_btn->SetToolTip(_L("Edit G-code / browse placeholders"));
+        ph_btn->Bind(wxEVT_BUTTON, [this, gcode_ctrl](wxCommandEvent&) {
+            EditGCodeDialog dlg(this, "imex_mode_gcode", gcode_ctrl->GetValue().ToStdString());
+            if (dlg.ShowModal() == wxID_OK)
+                gcode_ctrl->SetValue(dlg.get_edited_gcode());
+        });
+        btn_col->Add(ph_btn, 0, wxBOTTOM, 2);
 
         if (!is_primary) {
-            auto* rm = new wxButton(r.panel, wxID_ANY, wxT("\u00d7"),
-                                    wxDefaultPosition, wxSize(24, 24), wxBU_EXACTFIT);
+            auto* rm = new ScalableButton(r.panel, wxID_ANY, "imex_remove", wxEmptyString,
+                                          wxDefaultSize, wxDefaultPosition,
+                                          wxBU_EXACTFIT | wxNO_BORDER, 16);
+            rm->SetToolTip(_L("Remove mode"));
             rm->Bind(wxEVT_BUTTON, [this, this_panel](wxCommandEvent&) {
                 remove_row(this_panel);
                 notify();
             });
-            sizer->Add(rm, 0, wxALIGN_CENTER_VERTICAL);
+            btn_col->Add(rm, 0);
         }
+        sizer->Add(btn_col, 0, wxALIGN_CENTER_VERTICAL);
         r.panel->SetSizer(sizer);
 
         m_rows_sizer->Add(r.panel, 0, wxEXPAND | wxBOTTOM, 4);