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** Copyright (C) 2016 The Qt Company Ltd.
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#include "GUI/coregui/Views/CommonWidgets/detailsbutton.h"
#include "GUI/coregui/utils/hostosinfo.h"

#include <QGraphicsOpacityEffect>
#include <QGuiApplication>
#include <QPaintEvent>
#include <QPainter>
#include <QPropertyAnimation>
#include <QStyleOption>

using namespace Utils;

namespace
{
const bool FlatProjectsMode(false);
const QColor DetailsButtonBackgroundColorHover("#eff0f1");
} // namespace

FadingWidget::FadingWidget(QWidget* parent)
    : FadingPanel(parent), m_opacityEffect(new QGraphicsOpacityEffect)
{
    m_opacityEffect->setOpacity(0);
    setGraphicsEffect(m_opacityEffect);

    // Workaround for issue with QGraphicsEffect. GraphicsEffect
    // currently clears with Window color. Remove if flickering
    // no longer occurs on fade-in
    QPalette pal;
    pal.setBrush(QPalette::All, QPalette::Window, Qt::transparent);
    setPalette(pal);
}

void FadingWidget::setOpacity(qreal value)
{
    m_opacityEffect->setOpacity(value);
}

void FadingWidget::fadeTo(qreal value)
{
    QPropertyAnimation* animation = new QPropertyAnimation(m_opacityEffect, "opacity");
    animation->setDuration(200);
    animation->setEndValue(value);
    animation->start(QAbstractAnimation::DeleteWhenStopped);
}

qreal FadingWidget::opacity()
{
    return m_opacityEffect->opacity();
}

DetailsButton::DetailsButton(QWidget* parent) : QAbstractButton(parent), m_fader(0)
{
    setCheckable(true);
    setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Minimum);
    setText(tr("Details"));
}

QSize DetailsButton::sizeHint() const
{
    // TODO: Adjust this when icons become available!

#if QT_VERSION >= QT_VERSION_CHECK(5, 11, 0)
    const int w = fontMetrics().horizontalAdvance(text()) + 32;
#else
    const int w = fontMetrics().width(text()) + 32;
#endif
    if (GUI_OS_Utils::HostOsInfo::isMacHost())
        return QSize(w, 34);
    return QSize(w, 22);
}

bool DetailsButton::event(QEvent* e)
{
    switch (e->type()) {
    case QEvent::Enter: {
        QPropertyAnimation* animation = new QPropertyAnimation(this, "fader");
        animation->setDuration(200);
        animation->setEndValue(1.0);
        animation->start(QAbstractAnimation::DeleteWhenStopped);
    } break;
    case QEvent::Leave: {
        QPropertyAnimation* animation = new QPropertyAnimation(this, "fader");
        animation->setDuration(200);
        animation->setEndValue(0.0);
        animation->start(QAbstractAnimation::DeleteWhenStopped);
    } break;
    default:
        return QAbstractButton::event(e);
    }
    return false;
}

void DetailsButton::paintEvent(QPaintEvent* e)
{
    QWidget::paintEvent(e);

    QPainter p(this);

    // draw hover animation
    if (!GUI_OS_Utils::HostOsInfo::isMacHost() && !isDown() && m_fader > 0) {
        QColor c = DetailsButtonBackgroundColorHover;
        c.setAlpha(int(m_fader * c.alpha()));

        QRect r = rect();
        if (!FlatProjectsMode)
            r.adjust(1, 1, -2, -2);
        p.fillRect(r, c);
    }

    if (isChecked()) {
        if (m_checkedPixmap.isNull()
            || m_checkedPixmap.size() / m_checkedPixmap.devicePixelRatio() != contentsRect().size())
            m_checkedPixmap = cacheRendering(contentsRect().size(), true);
        p.drawPixmap(contentsRect(), m_checkedPixmap);
    } else {
        if (m_uncheckedPixmap.isNull()
            || m_uncheckedPixmap.size() / m_uncheckedPixmap.devicePixelRatio()
                   != contentsRect().size())
            m_uncheckedPixmap = cacheRendering(contentsRect().size(), false);
        p.drawPixmap(contentsRect(), m_uncheckedPixmap);
    }
    if (isDown()) {
        p.setPen(Qt::NoPen);
        p.setBrush(QColor(0, 0, 0, 20));
        p.drawRoundedRect(rect().adjusted(1, 1, -1, -1), 1, 1);
    }
    if (hasFocus()) {
        QStyleOptionFocusRect option;
        option.initFrom(this);
        style()->drawPrimitive(QStyle::PE_FrameFocusRect, &option, &p, this);
    }
}

QPixmap DetailsButton::cacheRendering(const QSize& size, bool checked)
{
    const qreal pixelRatio = devicePixelRatio();
    QPixmap pixmap(size * pixelRatio);
    pixmap.setDevicePixelRatio(pixelRatio);
    pixmap.fill(Qt::transparent);
    QPainter p(&pixmap);
    p.setRenderHint(QPainter::Antialiasing, true);
    p.translate(0.5, 0.5);

    if (!FlatProjectsMode) {
        QLinearGradient lg;
        lg.setCoordinateMode(QGradient::ObjectBoundingMode);
        lg.setFinalStop(0, 1);
        if (!checked) {
            lg.setColorAt(0, QColor(0, 0, 0, 10));
            lg.setColorAt(1, QColor(0, 0, 0, 16));
        } else {
            lg.setColorAt(0, QColor(255, 255, 255, 0));
            lg.setColorAt(1, QColor(255, 255, 255, 50));
        }
        p.setBrush(lg);
        p.setPen(QColor(255, 255, 255, 140));
        p.drawRoundedRect(1, 1, size.width() - 3, size.height() - 3, 1, 1);
        p.setPen(QPen(QColor(0, 0, 0, 40)));
        p.drawLine(0, 1, 0, size.height() - 2);
        if (checked)
            p.drawLine(1, size.height() - 1, size.width() - 1, size.height() - 1);
    } else {
        p.setPen(Qt::NoPen);
        p.drawRoundedRect(0, 0, size.width(), size.height(), 1, 1);
    }

    p.setPen(palette().color(QPalette::Text));

    QRect textRect = p.fontMetrics().boundingRect(text());
    textRect.setWidth(textRect.width() + 15);
    textRect.setHeight(textRect.height() + 4);
    textRect.moveCenter(rect().center());

    p.drawText(textRect, Qt::AlignLeft | Qt::AlignVCenter, text());

    int arrowsize = 15;
    QStyleOption arrowOpt;
    arrowOpt.initFrom(this);
    QPalette pal = arrowOpt.palette;
    pal.setBrush(QPalette::All, QPalette::Text, QColor(0, 0, 0));
    arrowOpt.rect =
        QRect(size.width() - arrowsize - 6, height() / 2 - arrowsize / 2, arrowsize, arrowsize);
    arrowOpt.palette = pal;
    style()->drawPrimitive(checked ? QStyle::PE_IndicatorArrowUp : QStyle::PE_IndicatorArrowDown,
                           &arrowOpt, &p, this);
    return pixmap;
}
