create stopable job which could be repeatedly run

src/slic3r/GUI/Jobs/EmbossJob.cpp

@@ -13,9 +13,10 @@
 using namespace Slic3r;
 using namespace GUI;
 
+
 namespace Priv {
 
-static void process(std::unique_ptr<EmbossData> input);
+static void process(std::unique_ptr<EmbossData> input, StopCondition is_stop);
 static void finalize(const EmbossData &input, const indexed_triangle_set &result);
 
 // TODO: move to objec list utils
@@ -23,10 +24,9 @@ static void select_volume(ModelVolume *volume);
 
 } // namespace Priv
 
-EmbossJob::EmbossJob() : ReRunJob<EmbossData>(Priv::process) {}
+EmbossJob::EmbossJob() : StopableJob<EmbossData>(Priv::process) {}
 
-
-void Priv::process(std::unique_ptr<EmbossData> input)
+void Priv::process(std::unique_ptr<EmbossData> input, StopCondition is_stop)
 {
     // only for sure
     assert(input != nullptr);
@@ -34,14 +34,16 @@ void Priv::process(std::unique_ptr<EmbossData> input)
     // check if exist valid font
     if (input->font == nullptr) return;
 
-    // Do NOT process empty string
     const TextConfiguration &cfg  = input->text_configuration;
     const std::string &      text = cfg.text;
+    // Do NOT process empty string
     if (text.empty()) return;
 
     const FontProp &prop = cfg.font_prop;
     ExPolygons shapes = Emboss::text2shapes(*input->font, text.c_str(), prop);
 
+    if (is_stop()) return;
+
     // exist 2d shape made by text ?
     // (no shape means that font hasn't any of text symbols)
     if (shapes.empty()) return;
@@ -49,7 +51,9 @@ void Priv::process(std::unique_ptr<EmbossData> input)
     float scale    = prop.size_in_mm / input->font->ascent;
     auto  projectZ = std::make_unique<Emboss::ProjectZ>(prop.emboss / scale);
     Emboss::ProjectScale project(std::move(projectZ), scale);
-    auto  its = std::make_unique<indexed_triangle_set>(Emboss::polygons2model(shapes, project));
+    auto   its = std::make_unique<indexed_triangle_set>(Emboss::polygons2model(shapes, project));
+
+    if (is_stop()) return;
 
     // for sure that some object is created from shape
     if (its->indices.empty()) return;
@@ -72,9 +76,11 @@ void Priv::process(std::unique_ptr<EmbossData> input)
         {}
     };
     Data *data = new Data(std::move(input), std::move(its));
+    // How to proof that call, will be done on exit?
     wxGetApp().plater()->CallAfter([data]() {
-        Priv::finalize(*data->input, *data->result);
-        delete data;
+        // because of finalize exception delete must be in ScopeGuard
+        ScopeGuard sg([data]() { delete data; }); 
+        Priv::finalize(*data->input, *data->result);        
     });
 }
 

src/slic3r/GUI/Jobs/EmbossJob.hpp

@@ -17,7 +17,8 @@ namespace Slic3r::GUI {
 // inspired by Job.hpp
 // All public function can be call only from UI thread
 // Mechanism to stack processing and do only last one
-template<typename TIn> class ReRunJob
+template<typename TIn> 
+class ReRunJob
 {
     std::mutex           m_next_mutex;
     std::unique_ptr<TIn> m_input_next = nullptr;
@@ -77,6 +78,91 @@ public:
     }
 };
 
+using StopCondition = std::function<bool(void)>;
+// add stop ability
+template<typename TIn> class StopableJob
+{
+    std::mutex           m_mutex;
+    std::unique_ptr<TIn> m_input_next = nullptr;
+
+    std::thread m_thread;
+    // indicate checking of new input.
+    bool m_running = false;
+    bool m_stop = false;
+
+    
+    using Func = std::function<void(std::unique_ptr<TIn>, StopCondition)>;
+    Func m_func;
+
+public:
+    StopableJob(Func func) : m_func(func) {}
+    virtual ~StopableJob() { 
+        stop();
+        join();
+    }
+
+    void re_run(std::unique_ptr<TIn> input)
+    {
+        if (input == nullptr) return;
+        {
+            // keep access to next input
+            std::lock_guard lg(m_mutex);
+            if (m_running) {
+                // when runnig
+                m_stop       = true;
+                m_input_next = std::move(input);
+                return; // on end of run will be used new input
+            }
+            m_running = true;
+            m_stop    = false;
+        }
+        if (m_thread.joinable()) m_thread.join();
+        // at this moment is not running --> stoped
+        assert(m_input_next == nullptr);
+        try { // Execute the job
+            m_thread = std::thread(
+                [this](std::unique_ptr<TIn> input) {
+                    do {
+                        m_func(std::move(input), [this]() { return is_stoping(); });
+
+                        std::lock_guard lg(m_mutex);
+                        m_stop = false;
+                        // this is not while (end)condition because of lock guard
+                        if (m_input_next == nullptr) {
+                            m_running = false;
+                            return;
+                        }
+                        input        = std::move(m_input_next);                        
+                        m_input_next = nullptr;
+                    } while (true);
+                },
+                std::move(input));
+        } catch (std::exception &) {}
+    }
+
+    bool is_running()
+    {
+        std::lock_guard lg(m_mutex);
+        return m_running;
+    }
+    bool is_stoping()
+    {
+        std::lock_guard lg(m_mutex);
+        return m_stop;
+    }
+    void stop() { 
+        std::lock_guard lg(m_mutex);
+        m_input_next = nullptr;
+        m_stop = true; 
+    }
+    // blocking until stop, 
+    void join(int timeout_ms = 0)
+    {
+        if (m_thread.joinable()) m_thread.join();
+        assert(!m_running);
+    }
+};
+
 struct EmbossData
 {
     // Pointer on Data of font (glyph shapes)
@@ -91,7 +177,7 @@ struct EmbossData
     int object_idx;
 };
 
-class EmbossJob : public ReRunJob<EmbossData>
+class EmbossJob : public StopableJob<EmbossData>
 {
 public:
     EmbossJob();