BugFix Undo history

Force store of first status, and limit number of undo steps (even if huge number of 1000).

src/ActionManager.cpp

@@ -43,24 +43,25 @@
 using namespace tinyxml2;
 
 
-Action::Action(): history_step_(0), history_max_step_(0),
+Action::Action(): history_step_(0), history_max_step_(0), history_min_step_(0),
     snapshot_id_(0), snapshot_node_(nullptr), interpolator_(nullptr), interpolator_node_(nullptr)
 {
 
 }
 
-void Action::init()
+void Action::init(const std::string &label)
 {
     // clean the history
     history_doc_.Clear();
     history_step_ = 0;
-    history_max_step_ = 0;
+    history_min_step_ = 1;
+    history_max_step_ = 1;
 
     // reset snapshot
     snapshot_id_ = 0;
     snapshot_node_ = nullptr;
 
-    store("Session start");
+    store(label);
 }
 
 // must be called in a thread running in parrallel of the rendering
@@ -131,8 +132,12 @@ void captureMixerSession(Session *se, std::string node, std::string label, tinyx
 
 void Action::storeSession(Session *se, std::string label)
 {
-    //
+    // force lock for creation of first step
-    if (!Action::manager().history_access_.try_lock())
+    if (Action::manager().history_step_ < 1)
+        Action::manager().history_access_.lock();
+    // try lock for storing history in normal case
+    // (i.e. priority to realtime performance over storing history)
+    else if (!Action::manager().history_access_.try_lock())
         return;
 
     // incremental naming of history nodes
@@ -146,6 +151,14 @@ void Action::storeSession(Session *se, std::string label)
     }
     Action::manager().history_max_step_ = Action::manager().history_step_;
 
+    // Ensure a maximum amount of stored steps (even very big, just to ensure memory limit)
+    if (Action::manager().history_max_step_ - Action::manager().history_min_step_  > MAX_COUNT_HISTORY) {
+        XMLElement *node = Action::manager().history_doc_.FirstChildElement( HISTORY_NODE(Action::manager().history_min_step_+1).c_str() );
+        if ( node )
+            Action::manager().history_doc_.DeleteChild(node);
+        Action::manager().history_min_step_++;
+    }
+
     // capture current session
     captureMixerSession(se,
                         HISTORY_NODE(Action::manager().history_step_),
@@ -158,9 +171,7 @@ void Action::storeSession(Session *se, std::string label)
 
 void Action::store(const std::string &label)
 {
-    // TODO: set a maximum amount of stored steps? (even very big, just to ensure memory limit)
+    // ignore if no label is given
-
-    // ignore if locked or if no label is given
     if (label.empty())
         return;
 

src/ActionManager.h

@@ -7,6 +7,8 @@
 
 #include <tinyxml2.h>
 
+#define MAX_COUNT_HISTORY 1000
+
 class Session;
 class Interpolator;
 class FrameBufferImage;
@@ -26,7 +28,7 @@ public:
         static Action _instance;
         return _instance;
     }
-    void init ();
+    void init (const std::string &label);
 
     // Undo History
     void store (const std::string &label);
@@ -36,6 +38,7 @@ public:
 
     inline uint current () const { return history_step_; }
     inline uint max () const { return history_max_step_; }
+    inline uint min () const { return history_min_step_; }
     std::string label (uint s) const;
     std::string shortlabel (uint s) const;
     FrameBufferImage *thumbnail (uint s) const;
@@ -66,6 +69,7 @@ private:
     tinyxml2::XMLDocument history_doc_;
     uint history_step_;
     uint history_max_step_;
+    uint history_min_step_;
     std::mutex history_access_;
     static void storeSession(Session *se, std::string label);
     void restore(uint target);

src/Mixer.cpp

@@ -1555,7 +1555,7 @@ void Mixer::swap()
     }
 
     // reset History manager
-    Action::manager().init();
+    Action::manager().init("Session start");
 
     // notification
     if (session_->filename().empty())

src/UserInterfaceManager.cpp

@@ -1064,7 +1064,7 @@ void UserInterface::showMenuEdit()
     bool has_clipboard = (clipboard != nullptr && strlen(clipboard) > 0 && SessionLoader::isClipboard(clipboard));
 
     // UNDO
-    if ( ImGui::MenuItem( MENU_UNDO, SHORTCUT_UNDO, false, Action::manager().current() > 1) )
+    if ( ImGui::MenuItem( MENU_UNDO, SHORTCUT_UNDO, false, Action::manager().current() > Action::manager().min()) )
         Action::manager().undo();
     if ( ImGui::MenuItem( MENU_REDO, SHORTCUT_REDO, false, Action::manager().current() < Action::manager().max()) )
         Action::manager().redo();
@@ -4898,7 +4898,7 @@ void Navigator::RenderMainPannelSession()
         static bool _tooltip = 0;
 
         ImGui::SetCursorPos( ImVec2( pannel_width_ IMGUI_RIGHT_ALIGN, pos_bot.y -ImGui::GetFrameHeight() ));
-        if ( Action::manager().current() > 1 ) {
+        if ( Action::manager().current() > Action::manager().min() ) {
             if ( ImGuiToolkit::IconButton( ICON_FA_UNDO, "Undo" ) )
                 Action::manager().undo();
         } else
@@ -4920,7 +4920,8 @@ void Navigator::RenderMainPannelSession()
             int count_over = 0;
             ImVec2 size = ImVec2( ImGui::GetContentRegionAvailWidth(), ImGui::GetTextLineHeight() );
 
-            for (uint i = Action::manager().max(); i > 0; --i) {
+            for (uint i = Action::manager().max();
+                 i >= Action::manager().min(); --i) {
 
                 if (ImGui::Selectable( Action::manager().shortlabel(i).c_str(), i == Action::manager().current(), ImGuiSelectableFlags_AllowDoubleClick, size )) {
                     // go to on double clic
@@ -4978,7 +4979,7 @@ void Navigator::RenderMainPannelSession()
         if ( Action::manager().max() > 1 ) {
             ImGui::SetCursorPos( ImVec2( pannel_width_ IMGUI_RIGHT_ALIGN, pos_top.y ));
             if (ImGuiToolkit::IconButton( 12, 14, "Clear history"))
-                Action::manager().init();
+                Action::manager().init("Reset");
         }
 
         ImGui::SetCursorPos( ImVec2( pannel_width_ IMGUI_RIGHT_ALIGN, pos_bot.y - 2.f * ImGui::GetFrameHeightWithSpacing()));