qt5base-lts/examples/widgets/graphicsview/embeddeddialogs/customproxy.cpp

/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the demonstration applications of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
**   * Redistributions of source code must retain the above copyright
**     notice, this list of conditions and the following disclaimer.
**   * Redistributions in binary form must reproduce the above copyright
**     notice, this list of conditions and the following disclaimer in
**     the documentation and/or other materials provided with the
**     distribution.
**   * Neither the name of The Qt Company Ltd nor the names of its
**     contributors may be used to endorse or promote products derived
**     from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "customproxy.h"

#include <QGraphicsScene>
#include <QPainter>
#include <QStyleOptionGraphicsItem>

CustomProxy::CustomProxy(QGraphicsItem *parent, Qt::WindowFlags wFlags)
    : QGraphicsProxyWidget(parent, wFlags), timeLine(new QTimeLine(250, this))
{
    connect(timeLine, &QTimeLine::valueChanged,
            this, &CustomProxy::updateStep);
    connect(timeLine, &QTimeLine::stateChanged,
            this, &CustomProxy::stateChanged);
}

QRectF CustomProxy::boundingRect() const
{
    return QGraphicsProxyWidget::boundingRect().adjusted(0, 0, 10, 10);
}

void CustomProxy::paintWindowFrame(QPainter *painter, const QStyleOptionGraphicsItem *option,
                                   QWidget *widget)
{
    const QColor color(0, 0, 0, 64);

    QRectF r = windowFrameRect();
    QRectF right(r.right(), r.top() + 10, 10, r.height() - 10);
    QRectF bottom(r.left() + 10, r.bottom(), r.width(), 10);
    bool intersectsRight = right.intersects(option->exposedRect);
    bool intersectsBottom = bottom.intersects(option->exposedRect);
    if (intersectsRight && intersectsBottom) {
        QPainterPath path;
        path.addRect(right);
        path.addRect(bottom);
        painter->setPen(Qt::NoPen);
        painter->setBrush(color);
        painter->drawPath(path);
    } else if (intersectsBottom) {
        painter->fillRect(bottom, color);
    } else if (intersectsRight) {
        painter->fillRect(right, color);
    }

    QGraphicsProxyWidget::paintWindowFrame(painter, option, widget);
}

void CustomProxy::hoverEnterEvent(QGraphicsSceneHoverEvent *event)
{
    QGraphicsProxyWidget::hoverEnterEvent(event);
    scene()->setActiveWindow(this);
    if (qFuzzyCompare(timeLine->currentValue(), 1))
        zoomIn();
}

void CustomProxy::hoverLeaveEvent(QGraphicsSceneHoverEvent *event)
{
    QGraphicsProxyWidget::hoverLeaveEvent(event);
    if (!popupShown
            && (timeLine->direction() != QTimeLine::Backward || qFuzzyIsNull(timeLine->currentValue()))) {
        zoomOut();
    }
}

bool CustomProxy::sceneEventFilter(QGraphicsItem *watched, QEvent *event)
{
    if (watched->isWindow()
            && (event->type() == QEvent::UngrabMouse || event->type() == QEvent::GrabMouse)) {
        popupShown = watched->isVisible();
        if (!popupShown && !isUnderMouse())
            zoomOut();
    }
    return QGraphicsProxyWidget::sceneEventFilter(watched, event);
}

QVariant CustomProxy::itemChange(GraphicsItemChange change, const QVariant &value)
{
    if (change == ItemChildAddedChange || change == ItemChildRemovedChange) {
        if (change == ItemChildAddedChange) {
            currentPopup = qvariant_cast<QGraphicsItem *>(value);
            currentPopup->setCacheMode(ItemCoordinateCache);
            if (scene())
                currentPopup->installSceneEventFilter(this);
        } else if (scene()) {
            currentPopup->removeSceneEventFilter(this);
            currentPopup = nullptr;
        }
    } else if (currentPopup && change == ItemSceneHasChanged) {
        currentPopup->installSceneEventFilter(this);
    }
    return QGraphicsProxyWidget::itemChange(change, value);
}

void CustomProxy::updateStep(qreal step)
{
    QRectF r = boundingRect();
    setTransform(QTransform()
                 .translate(r.width() / 2, r.height() / 2)
                 .rotate(step * 30, Qt::XAxis)
                 .rotate(step * 10, Qt::YAxis)
                 .rotate(step * 5, Qt::ZAxis)
                 .scale(1 + 1.5 * step, 1 + 1.5 * step)
                 .translate(-r.width() / 2, -r.height() / 2));
}

void CustomProxy::stateChanged(QTimeLine::State state)
{
    if (state == QTimeLine::Running) {
        if (timeLine->direction() == QTimeLine::Forward)
            setCacheMode(ItemCoordinateCache);
    } else if (state == QTimeLine::NotRunning) {
        if (timeLine->direction() == QTimeLine::Backward)
            setCacheMode(DeviceCoordinateCache);
    }
}

void CustomProxy::zoomIn()
{
    if (timeLine->direction() != QTimeLine::Forward)
        timeLine->setDirection(QTimeLine::Forward);
    if (timeLine->state() == QTimeLine::NotRunning)
        timeLine->start();
}

void CustomProxy::zoomOut()
{
    if (timeLine->direction() != QTimeLine::Backward)
        timeLine->setDirection(QTimeLine::Backward);
    if (timeLine->state() == QTimeLine::NotRunning)
        timeLine->start();
}