qtah-cpp-qt6-0.9.1: cpp/event.hpp

#ifndef QTAH_EVENT_HPP
#define QTAH_EVENT_HPP

// This file is part of Qtah.
//
// Copyright 2015-2023 The Qtah Authors.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#include <QEvent>
#include <QGraphicsItem>
#include <QObject>
#include <QPainter>
#include <QStyleOptionGraphicsItem>
#include <QWidget>
#include "b_callback.hpp"

namespace qtah {
namespace event {

class EventListener : public QObject {
    Q_OBJECT

public:
    EventListener(
        QObject *parent,
        CallbackPtrQObjectPtrQEventBool eventCallback,
        CallbackVoid deletedCallback) :
        QObject(parent),
        eventCallback_(eventCallback),
        deletedCallback_(deletedCallback),
        notifyDeleted_(true) {
        parent->installEventFilter(this);
    }

    ~EventListener() {
        parent()->removeEventFilter(this);
        if (notifyDeleted_) {
            deletedCallback_();
        }
    }

    virtual bool eventFilter(QObject* receiver, QEvent* event) {
        return eventCallback_(receiver, event);
    }

    void doNotNotifyOnDelete() {
        notifyDeleted_ = false;
    }

private:
    CallbackPtrQObjectPtrQEventBool eventCallback_;
    CallbackVoid deletedCallback_;
    bool notifyDeleted_;
};

class SceneEventListener : public QGraphicsItem {

public:
    SceneEventListener(
        QGraphicsItem *parent,
        CallbackPtrQGraphicsItemPtrQEventBool eventCallback,
        CallbackVoid deletedCallback) :
        QGraphicsItem(parent),
        eventCallback_(eventCallback),
        deletedCallback_(deletedCallback),
        notifyDeleted_(true) {
        parent->installSceneEventFilter(this);
    }

    ~SceneEventListener() {
        parentItem()->removeSceneEventFilter(this);
        if (notifyDeleted_) {
            deletedCallback_();
        }
    }

    virtual bool sceneEventFilter(QGraphicsItem* receiver, QEvent* event) {
        return eventCallback_(receiver, event);
    }

    void doNotNotifyOnDelete() {
        notifyDeleted_ = false;
    }

    virtual QRectF boundingRect() const { return QRectF(); }
    virtual void paint(QPainter*, const QStyleOptionGraphicsItem*, QWidget* = 0) { return; }

private:
    CallbackPtrQGraphicsItemPtrQEventBool eventCallback_;
    CallbackVoid deletedCallback_;
    bool notifyDeleted_;
};

}  // namespace event
}  // namespace qtah

#endif // QTAH_EVENT_HPP