view data/model/EventCommands.h @ 1671:82d03c9661f9 single-point

Rework isReady()/getCompletion() on models. Previously the new overhauled models were implementing getCompletion() but inheriting a version of isReady() (from the Model base) that didn't call it, referring only to isOK(). So they were reporting completion as soon as they had begun. Instead hoist getCompletion() to abstract base and call it from Model::isReady().

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006 Chris Cannam.
    
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#ifndef SV_EVENT_COMMANDS_H
#define SV_EVENT_COMMANDS_H

#include "base/Event.h"
#include "base/Command.h"

/**
 * Interface for classes that can be modified through these commands
 */
class EventEditable
{
public:
    virtual void add(Event e) = 0;
    virtual void remove(Event e) = 0;
};

/**
 * Command to add an event to an editable containing events, with undo.
 */
class AddEventCommand : public Command
{
public:
    AddEventCommand(EventEditable *editable, const Event &e, QString name) :
        m_editable(editable), m_event(e), m_name(name) { }

    QString getName() const override { return m_name; }
    Event getEvent() const { return m_event; }

    void execute() override { m_editable->add(m_event); }
    void unexecute() override { m_editable->remove(m_event); }

private:
    EventEditable *m_editable;
    Event m_event;
    QString m_name;
};

/**
 * Command to remove an event from an editable containing events, with
 * undo.
 */
class RemoveEventCommand : public Command
{
public:
    RemoveEventCommand(EventEditable *editable, const Event &e, QString name) :
        m_editable(editable), m_event(e), m_name(name) { }

    QString getName() const override { return m_name; }
    Event getEvent() const { return m_event; }

    void execute() override { m_editable->remove(m_event); }
    void unexecute() override { m_editable->add(m_event); }

private:
    EventEditable *m_editable;
    Event m_event;
    QString m_name;
};

/**
 * Command to add or remove a series of events to or from an editable,
 * with undo. Creates and immediately executes a sub-command for each
 * add/remove requested. Consecutive add/remove pairs for the same
 * point are collapsed.
 */
class ChangeEventsCommand : public MacroCommand
{
public:
    ChangeEventsCommand(EventEditable *editable, QString name) :
        MacroCommand(name), m_editable(editable) { }

    void add(Event e) {
        addCommand(new AddEventCommand(m_editable, e, getName()), true);
    }
    void remove(Event e) {
        addCommand(new RemoveEventCommand(m_editable, e, getName()), true);
    }

    /**
     * Stack an arbitrary other command in the same sequence.
     */
    void addCommand(Command *command) override { addCommand(command, true); }

    /**
     * If any points have been added or deleted, return this
     * command (so the caller can add it to the command history).
     * Otherwise delete the command and return NULL.
     */
    ChangeEventsCommand *finish() {
        if (!m_commands.empty()) {
            return this;
        } else {
            delete this;
            return nullptr;
        }
    }

protected:
    virtual void addCommand(Command *command, bool executeFirst) {
        
        if (executeFirst) command->execute();

        if (m_commands.empty()) {
            MacroCommand::addCommand(command);
            return;
        }
        
        RemoveEventCommand *r =
            dynamic_cast<RemoveEventCommand *>(command);
        AddEventCommand *a =
            dynamic_cast<AddEventCommand *>(*m_commands.rbegin());
        if (r && a) {
            if (a->getEvent() == r->getEvent()) {
                deleteCommand(a);
                return;
            }
        }
        
        MacroCommand::addCommand(command);
    }

    EventEditable *m_editable;
};

#endif