Polishing of NotificationManager:

Fixed pairing of PrintObjects with slicing warning notifications.
Removed or commented out dead code.
Added documentation.

src/libslic3r/Print.cpp

@@ -577,6 +577,16 @@ void Print::config_diffs(
     }
 }
 
+std::vector<ObjectID> Print::print_object_ids() const 
+{ 
+    std::vector<ObjectID> out; 
+    // Reserve one more for the caller to append the ID of the Print itself.
+    out.reserve(m_objects.size() + 1);
+    for (const PrintObject *print_object : m_objects)
+        out.emplace_back(print_object->id());
+    return out;
+}
+
 Print::ApplyStatus Print::apply(const Model &model, DynamicPrintConfig new_full_config)
 {
 #ifdef _DEBUG

src/libslic3r/Print.hpp

@@ -370,6 +370,8 @@ public:
     // a cancellation callback is executed to stop the background processing before the operation.
     void                clear() override;
     bool                empty() const override { return m_objects.empty(); }
+    // List of existing PrintObject IDs, to remove notifications for non-existent IDs.
+    std::vector<ObjectID> print_object_ids() const override;
 
     ApplyStatus         apply(const Model &model, DynamicPrintConfig config) override;
 

src/libslic3r/PrintBase.hpp

@@ -348,6 +348,8 @@ public:
     // The Print is empty either after clear() or after apply() over an empty model,
     // or after apply() over a model, where no object is printable (all outside the print volume).
     virtual bool            empty() const = 0;
+    // List of existing PrintObject IDs, to remove notifications for non-existent IDs.
+    virtual std::vector<ObjectID> print_object_ids() const = 0;
 
     // Validate the print, return empty string if valid, return error if process() cannot (or should not) be started.
     virtual std::string     validate() const { return std::string(); }

src/libslic3r/SLAPrint.cpp

@@ -175,6 +175,16 @@ static std::vector<SLAPrintObject::Instance> sla_instances(const ModelObject &mo
     return instances;
 }
 
+std::vector<ObjectID> SLAPrint::print_object_ids() const 
+{ 
+    std::vector<ObjectID> out;
+    // Reserve one more for the caller to append the ID of the Print itself.
+    out.reserve(m_objects.size() + 1);
+    for (const SLAPrintObject *print_object : m_objects)
+        out.emplace_back(print_object->id());
+    return out;
+}
+
 SLAPrint::ApplyStatus SLAPrint::apply(const Model &model, DynamicPrintConfig config)
 {
 #ifdef _DEBUG

src/libslic3r/SLAPrint.hpp

@@ -420,6 +420,8 @@ public:
 
     void                clear() override;
     bool                empty() const override { return m_objects.empty(); }
+    // List of existing PrintObject IDs, to remove notifications for non-existent IDs.
+    std::vector<ObjectID> print_object_ids() const;
     ApplyStatus         apply(const Model &model, DynamicPrintConfig config) override;
     void                set_task(const TaskParams &params) override;
     void                process() override;