qxtstars.cpp

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/****************************************************************************
 **
 ** Copyright (C) Qxt Foundation. Some rights reserved.
 **
 ** This file is part of the QxtGui module of the Qxt library.
 **
 ** This library is free software; you can redistribute it and/or modify it
 ** under the terms of the Common Public License, version 1.0, as published
 ** by IBM, and/or under the terms of the GNU Lesser General Public License,
 ** version 2.1, as published by the Free Software Foundation.
 **
 ** This file is provided "AS IS", without WARRANTIES OR CONDITIONS OF ANY
 ** KIND, EITHER EXPRESS OR IMPLIED INCLUDING, WITHOUT LIMITATION, ANY
 ** WARRANTIES OR CONDITIONS OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY OR
 ** FITNESS FOR A PARTICULAR PURPOSE.
 **
 ** You should have received a copy of the CPL and the LGPL along with this
 ** file. See the LICENSE file and the cpl1.0.txt/lgpl-2.1.txt files
 ** included with the source distribution for more information.
 ** If you did not receive a copy of the licenses, contact the Qxt Foundation.
 **
 ** <http://libqxt.org>  <foundation@libqxt.org>
 **
 ****************************************************************************/
#include "qxtstars.h"

#include <QStyleOptionSlider>
#include <QPainterPath>
#include <QMouseEvent>
#include <QPainter>

class QxtStarsPrivate : public QxtPrivate<QxtStars>
{
public:
    QXT_DECLARE_PUBLIC(QxtStars);
    QxtStarsPrivate();
    int pixelPosToRangeValue(int pos) const;
    inline int pick(const QPoint& pt) const;
    QStyleOptionSlider getStyleOption() const;
    QSize getStarSize() const;
    int snapBackPosition;
    bool readOnly;
    QSize starSize;
    QPainterPath star;
};

QxtStarsPrivate::QxtStarsPrivate()
        : snapBackPosition(0), readOnly(false)
{
    star.moveTo(14.285716, -43.352104);
    star.lineTo(38.404536, 9.1654726);
    star.lineTo(95.804846, 15.875014);
    star.lineTo(53.310787, 55.042197);
    star.lineTo(64.667306, 111.7065);
    star.lineTo(14.285714, 83.395573);
    star.lineTo(-36.095881, 111.7065);
    star.lineTo(-24.739359, 55.042198);
    star.lineTo(-67.233416, 15.875009);
    star.lineTo(-9.8331075, 9.1654728);
    star.closeSubpath();
}

int QxtStarsPrivate::pixelPosToRangeValue(int pos) const
{
    const QxtStars* p = &qxt_p();
    QStyleOptionSlider opt = getStyleOption();
    QRect gr = p->style()->subControlRect(QStyle::CC_Slider, &opt, QStyle::SC_SliderGroove, p);
    QRect sr = p->style()->subControlRect(QStyle::CC_Slider, &opt, QStyle::SC_SliderHandle, p);
    int sliderMin, sliderMax, sliderLength;

    gr.setSize(qxt_p().sizeHint());
    if (p->orientation() == Qt::Horizontal)
    {
        sliderLength = sr.width();
        sliderMin = gr.x();
        sliderMax = gr.right() - sliderLength + 1;
    }
    else
    {
        sliderLength = sr.height();
        sliderMin = gr.y();
        sliderMax = gr.bottom() - sliderLength + 1;
    }
    return QStyle::sliderValueFromPosition(p->minimum(), p->maximum(), pos - sliderMin,
                                           sliderMax - sliderMin, opt.upsideDown);
}

inline int QxtStarsPrivate::pick(const QPoint& pt) const
{
    return qxt_p().orientation() == Qt::Horizontal ? pt.x() : pt.y();
}

// TODO: get rid of this in Qt 4.3
QStyleOptionSlider QxtStarsPrivate::getStyleOption() const
{
    const QxtStars* p = &qxt_p();
    QStyleOptionSlider opt;
    opt.initFrom(p);
    opt.subControls = QStyle::SC_None;
    opt.activeSubControls = QStyle::SC_None;
    opt.orientation = p->orientation();
    opt.maximum = p->maximum();
    opt.minimum = p->minimum();
    opt.upsideDown = (p->orientation() == Qt::Horizontal) ?
                     (p->invertedAppearance() != (opt.direction == Qt::RightToLeft)) : (!p->invertedAppearance());
    opt.direction = Qt::LeftToRight; // we use the upsideDown option instead
    opt.sliderPosition = p->sliderPosition();
    opt.sliderValue = p->value();
    opt.singleStep = p->singleStep();
    opt.pageStep = p->pageStep();
    if (p->orientation() == Qt::Horizontal)
        opt.state |= QStyle::State_Horizontal;
    return opt;
}

QSize QxtStarsPrivate::getStarSize() const
{
    QSize size = starSize;
    if (!size.isValid() || size.isNull())
    {
        const int width = qxt_p().style()->pixelMetric(QStyle::PM_SmallIconSize);
        size = QSize(width, width);
    }
    return size;
}

QxtStars::QxtStars(QWidget* parent) : QAbstractSlider(parent)
{
    QXT_INIT_PRIVATE(QxtStars);
    setOrientation(Qt::Horizontal);
    setFocusPolicy(Qt::FocusPolicy(style()->styleHint(QStyle::SH_Button_FocusPolicy)));
    setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
    setRange(0, 5);
}

QxtStars::~QxtStars()
{}

bool QxtStars::isReadOnly() const
{
    return qxt_d().readOnly;
}

void QxtStars::setReadOnly(bool readOnly)
{
    if (qxt_d().readOnly != readOnly)
    {
        qxt_d().readOnly = readOnly;
        if (readOnly)
            setFocusPolicy(Qt::NoFocus);
        else
            setFocusPolicy(Qt::FocusPolicy(style()->styleHint(QStyle::SH_Button_FocusPolicy)));
    }
}

QSize QxtStars::starSize() const
{
    return qxt_d().starSize;
}

void QxtStars::setStarSize(const QSize& size)
{
    if (qxt_d().starSize != size)
    {
        qxt_d().starSize = size;
        updateGeometry();
        update();
    }
}

QSize QxtStars::sizeHint() const
{
    return minimumSizeHint();
}

QSize QxtStars::minimumSizeHint() const
{
    QSize size = qxt_d().getStarSize();
    size.rwidth() *= maximum() - minimum();
    if (orientation() == Qt::Vertical)
        size.transpose();
    return size;
}

void QxtStars::paintEvent(QPaintEvent* event)
{
    QAbstractSlider::paintEvent(event);

    QPainter painter(this);
    painter.save();
    painter.setPen(palette().color(QPalette::Text));
    painter.setRenderHint(QPainter::Antialiasing);

    const bool invert = invertedAppearance();
    const QSize size = qxt_d().getStarSize();
    const QRectF star = qxt_d().star.boundingRect();
    painter.scale(size.width() / star.width(), size.height() / star.height());
    const int count = maximum() - minimum();
    if (orientation() == Qt::Horizontal)
    {
        painter.translate(-star.x(), -star.y());
        if (invert != isRightToLeft())
            painter.translate((count - 1) * star.width(), 0);
    }
    else
    {
        painter.translate(-star.x(), -star.y());
        if (!invert)
            painter.translate(0, (count - 1) * star.height());
    }
    for (int i = 0; i < count; ++i)
    {
        if (value() > minimum() + i)
            painter.setBrush(palette().highlight());
        else
            painter.setBrush(palette().base());
        painter.drawPath(qxt_d().star);

        if (orientation() == Qt::Horizontal)
            painter.translate(invert != isRightToLeft() ? -star.width() : star.width(), 0);
        else
            painter.translate(0, invert ? star.height() : -star.height());
    }

    painter.restore();
    if (hasFocus())
    {
        QStyleOptionFocusRect opt;
        opt.initFrom(this);
        opt.rect.setSize(sizeHint());
        style()->drawPrimitive(QStyle::PE_FrameFocusRect, &opt, &painter, this);
    }
}

void QxtStars::keyPressEvent(QKeyEvent* event)
{
    if (qxt_d().readOnly)
    {
        event->ignore();
        return;
    }
    QAbstractSlider::keyPressEvent(event);
}

void QxtStars::mousePressEvent(QMouseEvent* event)
{
    if (qxt_d().readOnly)
    {
        event->ignore();
        return;
    }
    QAbstractSlider::mousePressEvent(event);

    if (maximum() == minimum() || (event->buttons() ^ event->button()))
    {
        event->ignore();
        return;
    }

    event->accept();
    QStyleOptionSlider opt = qxt_d().getStyleOption();
    const QRect sliderRect = style()->subControlRect(QStyle::CC_Slider, &opt, QStyle::SC_SliderHandle, this);
    const QPoint center = sliderRect.center() - sliderRect.topLeft();
    const int pos = qxt_d().pixelPosToRangeValue(qxt_d().pick(event->pos() - center));
    setSliderPosition(pos);
    triggerAction(SliderMove);
    setRepeatAction(SliderNoAction);
    qxt_d().snapBackPosition = pos;
    update();
}

void QxtStars::mouseMoveEvent(QMouseEvent* event)
{
    if (qxt_d().readOnly)
    {
        event->ignore();
        return;
    }
    QAbstractSlider::mouseMoveEvent(event);

    event->accept();
    int newPosition = qxt_d().pixelPosToRangeValue(qxt_d().pick(event->pos()));
    QStyleOptionSlider opt = qxt_d().getStyleOption();
    int m = style()->pixelMetric(QStyle::PM_MaximumDragDistance, &opt, this);
    if (m >= 0)
    {
        QRect r = rect();
        r.adjust(-m, -m, m, m);
        if (!r.contains(event->pos()))
            newPosition = qxt_d().snapBackPosition;
    }
    setSliderPosition(newPosition);
}

void QxtStars::mouseReleaseEvent(QMouseEvent* event)
{
    if (qxt_d().readOnly)
    {
        event->ignore();
        return;
    }
    QAbstractSlider::mouseReleaseEvent(event);

    if (event->buttons())
    {
        event->ignore();
        return;
    }

    event->accept();
    setRepeatAction(SliderNoAction);
}