1 files changed, 161 insertions, 0 deletions
diff --git a/src/event-log.h b/src/event-log.h
new file mode 100644
index 0000000..a21792c
--- /dev/null
+++ b/src/event-log.h
@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Author:
+ *   Gustav Broberg <broberg@kth.se>
+ *   Jon A. Cruz <jon@joncruz.org>
+ *
+ * Copyright (c) 2014 Authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef INKSCAPE_EVENT_LOG_H
+#define INKSCAPE_EVENT_LOG_H
+
+#include <gtkmm/treestore.h>
+#include <glibmm/refptr.h>
+#include <gtkmm/treeselection.h>
+#include <gtkmm/treeview.h>
+#include <sigc++/trackable.h>
+
+#include "undo-stack-observer.h"
+#include "event.h"
+
+class SPDocument;
+
+namespace Inkscape {
+
+class EventLogPrivate;
+
+/**
+ * A simple log for maintaining a history of committed, undone and redone events along with their
+ * type. It implements the UndoStackObserver and should be registered with a
+ * CompositeUndoStackObserver for each document. The event log is then notified on all commit, undo
+ * and redo events and will store a representation of them in an internal Gtk::TreeStore.
+ *
+ * Consecutive events of the same type are grouped with the first event as a parent and following
+ * as its children.
+ *
+ * If a Gtk::TreeView is connected to the event log, the TreeView's selection and its nodes
+ * expanded/collapsed state will be updated as events are committed, undone and redone. Whenever
+ * this happens, the event log will block the TreeView's callbacks to prevent circular updates.
+ */
+class EventLog : public UndoStackObserver, public sigc::trackable
+{
+        
+public:
+    typedef Gtk::TreeModel::iterator iterator;
+    typedef Gtk::TreeModel::const_iterator const_iterator;
+
+    EventLog(SPDocument* document);
+    ~EventLog() override;
+
+    /**
+     * Event datatype
+     */
+    struct EventModelColumns : public Gtk::TreeModelColumnRecord
+    {
+        Gtk::TreeModelColumn<Event *> event;
+        Gtk::TreeModelColumn<Glib::ustring> icon_name;
+        Gtk::TreeModelColumn<Glib::ustring> description;
+        Gtk::TreeModelColumn<int> child_count;
+
+        EventModelColumns()
+        { 
+            add(event); add(icon_name); add(description); add(child_count);
+        }
+    };
+
+    // Implementation of Inkscape::UndoStackObserver methods
+
+    /**
+     * Modifies the log's entries and the view's selection when triggered.
+     */
+    void notifyUndoEvent(Event *log) override;
+    void notifyRedoEvent(Event *log) override;
+    void notifyUndoCommitEvent(Event *log) override;
+    void notifyClearUndoEvent() override;
+    void notifyClearRedoEvent() override;
+
+    // Accessor functions
+
+    Glib::RefPtr<Gtk::TreeModel> getEventListStore() const { return _event_list_store; }
+    static const EventModelColumns& getColumns();
+    iterator getCurrEvent() const                          { return _curr_event; }
+    iterator getCurrEventParent() const                    { return _curr_event_parent; }
+
+    void setCurrEvent(iterator event)          { _curr_event = event; }
+    void setCurrEventParent(iterator event)    { _curr_event_parent = event; }
+    void blockNotifications(bool status=true)  { _notifications_blocked = status; }
+    void rememberFileSave()                    { _last_saved = _curr_event; }
+
+    // Callback types for TreeView changes.
+
+    enum CallbackTypes { 
+        CALLB_SELECTION_CHANGE, 
+        CALLB_EXPAND, 
+        CALLB_COLLAPSE, 
+        CALLB_LAST 
+    };
+
+    typedef std::map<const CallbackTypes, sigc::connection> CallbackMap;
+
+    /**
+     * Connect with a TreeView.
+     */
+    void addDialogConnection(Gtk::TreeView *event_list_view, CallbackMap *callback_connections);
+
+    /**
+     * Disconnect from a TreeView.
+     */
+    void removeDialogConnection(Gtk::TreeView *event_list_view, CallbackMap *callback_connections);
+
+    /*
+     * Updates the sensitivity of undo and redo actions.
+     */
+    void updateUndoVerbs();
+
+private:
+    EventLogPrivate *_priv;
+
+    SPDocument *_document;       //< document that is logged
+
+    Glib::RefPtr<Gtk::TreeStore> _event_list_store; 
+
+    iterator _curr_event;        //< current event in _event_list_store
+    iterator _last_event;        //< end position in _event_list_store
+    iterator _curr_event_parent; //< parent to current event, if any
+
+    iterator _last_saved;        //< position where last document save occurred
+
+    bool _notifications_blocked; //< if notifications should be handled
+
+    // Helper functions
+
+    const_iterator _getUndoEvent() const; //< returns the current undoable event or NULL if none
+    const_iterator _getRedoEvent() const; //< returns the current redoable event or NULL if none
+
+    void _clearUndo();  //< erase all previously committed events
+    void _clearRedo();  //< erase all previously undone events
+
+    void checkForVirginity(); //< marks the document as untouched if undo/redo reaches a previously saved state
+
+    // noncopyable, nonassignable
+    EventLog(EventLog const &other) = delete;
+    EventLog& operator=(EventLog const &other) = delete;
+};
+
+} // namespace Inkscape
+
+#endif // INKSCAPE_EVENT_LOG_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :