Chris@1648: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@1648: 
Chris@1648: /*
Chris@1648:     Sonic Visualiser
Chris@1648:     An audio file viewer and annotation editor.
Chris@1648:     Centre for Digital Music, Queen Mary, University of London.
Chris@1648:     This file copyright 2006 Chris Cannam.
Chris@1648:     
Chris@1648:     This program is free software; you can redistribute it and/or
Chris@1648:     modify it under the terms of the GNU General Public License as
Chris@1648:     published by the Free Software Foundation; either version 2 of the
Chris@1648:     License, or (at your option) any later version.  See the file
Chris@1648:     COPYING included with this distribution for more information.
Chris@1648: */
Chris@1648: 
Chris@1648: #ifndef SV_EVENT_COMMANDS_H
Chris@1648: #define SV_EVENT_COMMANDS_H
Chris@1648: 
Chris@1648: #include "base/Event.h"
Chris@1648: #include "base/Command.h"
Chris@1648: 
Chris@1648: /**
Chris@1648:  * Interface for classes that can be modified through these commands
Chris@1648:  */
Chris@1648: class EventEditable
Chris@1648: {
Chris@1648: public:
Chris@1648:     virtual void add(Event e) = 0;
Chris@1648:     virtual void remove(Event e) = 0;
Chris@1648: };
Chris@1648: 
Chris@1648: /**
Chris@1648:  * Command to add an event to an editable containing events, with undo.
Chris@1648:  */
Chris@1648: class AddEventCommand : public Command
Chris@1648: {
Chris@1648: public:
Chris@1648:     AddEventCommand(EventEditable *editable, const Event &e, QString name) :
Chris@1648:         m_editable(editable), m_event(e), m_name(name) { }
Chris@1648: 
Chris@1648:     QString getName() const override { return m_name; }
Chris@1648:     Event getEvent() const { return m_event; }
Chris@1648: 
Chris@1648:     void execute() override { m_editable->add(m_event); }
Chris@1648:     void unexecute() override { m_editable->remove(m_event); }
Chris@1648: 
Chris@1648: private:
Chris@1648:     EventEditable *m_editable;
Chris@1648:     Event m_event;
Chris@1648:     QString m_name;
Chris@1648: };
Chris@1648: 
Chris@1648: /**
Chris@1648:  * Command to remove an event from an editable containing events, with
Chris@1648:  * undo.
Chris@1648:  */
Chris@1648: class RemoveEventCommand : public Command
Chris@1648: {
Chris@1648: public:
Chris@1648:     RemoveEventCommand(EventEditable *editable, const Event &e, QString name) :
Chris@1648:         m_editable(editable), m_event(e), m_name(name) { }
Chris@1648: 
Chris@1648:     QString getName() const override { return m_name; }
Chris@1648:     Event getEvent() const { return m_event; }
Chris@1648: 
Chris@1648:     void execute() override { m_editable->remove(m_event); }
Chris@1648:     void unexecute() override { m_editable->add(m_event); }
Chris@1648: 
Chris@1648: private:
Chris@1648:     EventEditable *m_editable;
Chris@1648:     Event m_event;
Chris@1648:     QString m_name;
Chris@1648: };
Chris@1648: 
Chris@1648: /**
Chris@1648:  * Command to add or remove a series of events to or from an editable,
Chris@1648:  * with undo. Creates and immediately executes a sub-command for each
Chris@1648:  * add/remove requested. Consecutive add/remove pairs for the same
Chris@1648:  * point are collapsed.
Chris@1648:  */
Chris@1648: class ChangeEventsCommand : public MacroCommand
Chris@1648: {
Chris@1648: public:
Chris@1648:     ChangeEventsCommand(EventEditable *editable, QString name) :
Chris@1648:         MacroCommand(name), m_editable(editable) { }
Chris@1648: 
Chris@1648:     void add(Event e) {
Chris@1648:         addCommand(new AddEventCommand(m_editable, e, getName()), true);
Chris@1648:     }
Chris@1648:     void remove(Event e) {
Chris@1648:         addCommand(new RemoveEventCommand(m_editable, e, getName()), true);
Chris@1648:     }
Chris@1648: 
Chris@1648:     /**
Chris@1648:      * Stack an arbitrary other command in the same sequence.
Chris@1648:      */
Chris@1648:     void addCommand(Command *command) override { addCommand(command, true); }
Chris@1648: 
Chris@1648:     /**
Chris@1648:      * If any points have been added or deleted, return this
Chris@1648:      * command (so the caller can add it to the command history).
Chris@1648:      * Otherwise delete the command and return NULL.
Chris@1648:      */
Chris@1648:     ChangeEventsCommand *finish() {
Chris@1648:         if (!m_commands.empty()) {
Chris@1648:             return this;
Chris@1648:         } else {
Chris@1648:             delete this;
Chris@1648:             return nullptr;
Chris@1648:         }
Chris@1648:     }
Chris@1648: 
Chris@1648: protected:
Chris@1648:     virtual void addCommand(Command *command, bool executeFirst) {
Chris@1648:         
Chris@1648:         if (executeFirst) command->execute();
Chris@1648: 
Chris@1648:         if (m_commands.empty()) {
Chris@1648:             MacroCommand::addCommand(command);
Chris@1648:             return;
Chris@1648:         }
Chris@1648:         
Chris@1648:         RemoveEventCommand *r =
Chris@1648:             dynamic_cast<RemoveEventCommand *>(command);
Chris@1648:         AddEventCommand *a =
Chris@1648:             dynamic_cast<AddEventCommand *>(*m_commands.rbegin());
Chris@1648:         if (r && a) {
Chris@1648:             if (a->getEvent() == r->getEvent()) {
Chris@1648:                 deleteCommand(a);
Chris@1648:                 return;
Chris@1648:             }
Chris@1648:         }
Chris@1648:         
Chris@1648:         MacroCommand::addCommand(command);
Chris@1648:     }
Chris@1648: 
Chris@1648:     EventEditable *m_editable;
Chris@1648: };
Chris@1648: 
Chris@1648: #endif