Fix: moving with text object(not volume) over build plate by canvas dragging

src/libslic3r/Model.cpp

@@ -1397,6 +1397,25 @@ void ModelObject::clone_for_cut(ModelObject** obj)
     (*obj)->input_file.clear();
 }
 
+bool ModelVolume::is_the_only_one_part() const 
+{
+    if (m_type != ModelVolumeType::MODEL_PART)
+        return false;
+    if (object == nullptr)
+        return false;
+    for (const ModelVolume *v : object->volumes) {
+        if (v == nullptr)
+            continue;
+        // is this volume?
+        if (v->id() == this->id())
+            continue;
+        // exist another model part in object?
+        if (v->type() == ModelVolumeType::MODEL_PART)
+            return false;
+    }
+    return true;
+}
+
 void ModelVolume::reset_extra_facets()
 {
     this->supported_facets.reset();

src/libslic3r/Model.hpp

@@ -835,6 +835,7 @@ public:
 	bool                is_support_blocker()    const { return m_type == ModelVolumeType::SUPPORT_BLOCKER; }
 	bool                is_support_modifier()   const { return m_type == ModelVolumeType::SUPPORT_BLOCKER || m_type == ModelVolumeType::SUPPORT_ENFORCER; }
     bool                is_text()               const { return text_configuration.has_value(); }
+    bool                is_the_only_one_part() const; // behave like an object
     t_model_material_id material_id() const { return m_material_id; }
     void                reset_extra_facets();
     void                apply_tolerance();

src/slic3r/GUI/Gizmos/GLGizmoEmboss.cpp

@@ -1169,7 +1169,8 @@ void GLGizmoEmboss::close()
         m_volume->text_configuration.has_value() &&
         priv::is_text_empty(m_text)) {
         Plater &p = *wxGetApp().plater();
-        if (is_text_object(m_volume)) {
+        // is the text object?
+        if (m_volume->is_the_only_one_part()) {
             // delete whole object
             p.remove(m_parent.get_selection().get_object_idx());
         } else {
@@ -1912,7 +1913,7 @@ void GLGizmoEmboss::draw_font_list()
 
 void GLGizmoEmboss::draw_model_type()
 {
-    bool is_last_solid_part = is_text_object(m_volume);
+    bool is_last_solid_part = m_volume->is_the_only_one_part();
     std::string title = _u8L("Text is to object");
     if (is_last_solid_part) {
         ImVec4 color{.5f, .5f, .5f, 1.f};
@@ -2945,7 +2946,7 @@ void GLGizmoEmboss::draw_advanced()
     // input surface distance
     bool allowe_surface_distance = 
         !m_volume->text_configuration->style.prop.use_surface &&
-        !is_text_object(m_volume);    
+        !m_volume->is_the_only_one_part();
     std::optional<float> &distance = font_prop.distance;
     float prev_distance = distance.has_value() ? *distance : .0f,
           min_distance = -2 * font_prop.emboss,
@@ -3336,17 +3337,6 @@ bool priv::draw_button(const IconManager::VIcons &icons, IconType type, bool dis
     );
 }
 
-bool GLGizmoEmboss::is_text_object(const ModelVolume *text) {
-    if (text == nullptr) return false;
-    if (!text->text_configuration.has_value()) return false;
-    if (text->type() != ModelVolumeType::MODEL_PART) return false;
-    for (const ModelVolume *v : text->get_object()->volumes) {
-        if (v == text) continue;
-        if (v->type() == ModelVolumeType::MODEL_PART) return false;
-    }
-    return true;
-}
-
 /////////////
 // priv namespace implementation
 ///////////////

src/slic3r/GUI/Gizmos/GLGizmoEmboss.hpp

@@ -328,15 +328,6 @@ private:
 
     // only temporary solution
     static const std::string M_ICON_FILENAME;
-
-public:
-    /// <summary>
-    /// Check if text is last solid part of object
-    /// TODO: move to emboss gui utils
-    /// </summary>
-    /// <param name="text">Model volume of Text</param>
-    /// <returns>True when object otherwise False</returns>
-    static bool is_text_object(const ModelVolume *text);
 };
 
 } // namespace Slic3r::GUI

src/slic3r/GUI/SurfaceDrag.cpp

@@ -116,6 +116,10 @@ bool on_mouse_surface_drag(const wxMouseEvent         &mouse_event,
         if (object == nullptr || instance == nullptr || volume == nullptr)
             return false;
 
+        // allowed drag&drop by canvas for object
+        if (volume->is_the_only_one_part())
+            return false;
+
         const ModelVolumePtrs &volumes = object->volumes;
         std::vector<size_t>    allowed_volumes_id;
         if (volumes.size() > 1) {