src/gui/widgets/qprogressbar.cpp

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/****************************************************************************
**
** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
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**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
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****************************************************************************/

#include "qprogressbar.h"
#ifndef QT_NO_PROGRESSBAR
#include <qevent.h>
#include <qpainter.h>
#include <qstylepainter.h>
#include <qstyleoption.h>
#include <private/qwidget_p.h>
#ifndef QT_NO_ACCESSIBILITY
#include <qaccessible.h>
#endif
#include <limits.h>

class QProgressBarPrivate : public QWidgetPrivate
{
    Q_DECLARE_PUBLIC(QProgressBar)
public:
    QProgressBarPrivate();
    void init();

    int minimum;
    int maximum;
    int value;
    Qt::Alignment alignment;
    uint textVisible : 1;
    int lastPaintedValue;
    Qt::Orientation orientation;
    bool invertedAppearance;
    QProgressBar::Direction textDirection;
    QString format;
    QStyleOptionProgressBarV2 getStyleOption() const;
    inline int bound(int val) const { return qMax(minimum-1, qMin(maximum, val)); }
    bool repaintRequired() const;
};

QProgressBarPrivate::QProgressBarPrivate()
    : minimum(0), maximum(100), value(-1), alignment(Qt::AlignLeft), textVisible(true),
      lastPaintedValue(-1), orientation(Qt::Horizontal), invertedAppearance(false),
      textDirection(QProgressBar::TopToBottom), format(QLatin1String("%p%"))
{
}

void QProgressBarPrivate::init()
{
    Q_Q(QProgressBar);
    QSizePolicy sp(QSizePolicy::Expanding, QSizePolicy::Fixed);
    if (orientation == Qt::Vertical)
        sp.transpose();
    q->setSizePolicy(sp);
    q->setAttribute(Qt::WA_WState_OwnSizePolicy, false);
}

QStyleOptionProgressBarV2 QProgressBarPrivate::getStyleOption() const
{
    QStyleOptionProgressBarV2 opt;
    opt.init(q_func());

    opt.minimum = minimum;
    opt.maximum = maximum;
    opt.progress = value;
    opt.textAlignment = alignment;
    opt.textVisible = textVisible;
    opt.text = q_func()->text();
    opt.orientation = orientation;
    opt.invertedAppearance = invertedAppearance;
    opt.bottomToTop = (textDirection == QProgressBar::BottomToTop);

    return opt;
}

bool QProgressBarPrivate::repaintRequired() const
{
    Q_Q(const QProgressBar);
    if (value == lastPaintedValue)
        return false;

    int valueDifference = qAbs(value - lastPaintedValue);

    // Check if the text needs to be repainted
    if ((value == minimum || value == maximum)
            || (textVisible && valueDifference >= qAbs((maximum - minimum) / 100)))
        return true;

    // Check if the bar needs to be repainted
    QStyleOptionProgressBarV2 opt = getStyleOption();
    int cw = q->style()->pixelMetric(QStyle::PM_ProgressBarChunkWidth, &opt, q);
    QRect groove  = q->style()->subElementRect(QStyle::SE_ProgressBarGroove, &opt, q);
    // This expression is basically
    // (valueDifference / (maximum - minimum) > cw / groove.width())
    // transformed to avoid integer division.
    return (valueDifference * groove.width() > cw * (maximum - minimum));
}

QProgressBar::QProgressBar(QWidget *parent)
    : QWidget(*(new QProgressBarPrivate), parent, 0)
{
    d_func()->init();
}

void QProgressBar::reset()
{
    Q_D(QProgressBar);
    d->value = d->minimum - 1;
    if (d->minimum == INT_MIN)
        d->value = INT_MIN;
    repaint();
}

void QProgressBar::setMinimum(int minimum)
{
    setRange(minimum, qMax(d_func()->maximum, minimum));
}

int QProgressBar::minimum() const
{
    return d_func()->minimum;
}


void QProgressBar::setMaximum(int maximum)
{
    setRange(qMin(d_func()->minimum, maximum), maximum);
}

int QProgressBar::maximum() const
{
    return d_func()->maximum;
}

void QProgressBar::setValue(int value)
{
    Q_D(QProgressBar);
    if (d->value == value
            || ((value > d->maximum || value < d->minimum)
                && (d->maximum != 0 || d->minimum != 0)))
        return;
    d->value = value;
    emit valueChanged(value);
#ifndef QT_NO_ACCESSIBILITY
    QAccessible::updateAccessibility(this, 0, QAccessible::ValueChanged);
#endif
    if (d->repaintRequired())
        repaint();
}

int QProgressBar::value() const
{
    return d_func()->value;
}

void QProgressBar::setRange(int minimum, int maximum)
{
    Q_D(QProgressBar);
    d->minimum = minimum;
    d->maximum = qMax(minimum, maximum);
    if ( d->value <(d->minimum-1) || d->value > d->maximum)
        reset();
}
void QProgressBar::setTextVisible(bool visible)
{
    Q_D(QProgressBar);
    if (d->textVisible != visible) {
        d->textVisible = visible;
        repaint();
    }
}

bool QProgressBar::isTextVisible() const
{
    return d_func()->textVisible;
}

void QProgressBar::setAlignment(Qt::Alignment alignment)
{
    if (d_func()->alignment != alignment) {
        d_func()->alignment = alignment;
        repaint();
    }
}

Qt::Alignment QProgressBar::alignment() const
{
    return d_func()->alignment;
}

void QProgressBar::paintEvent(QPaintEvent *)
{
    QStylePainter paint(this);
    QStyleOptionProgressBarV2 opt = d_func()->getStyleOption();
    paint.drawControl(QStyle::CE_ProgressBar, opt);
    d_func()->lastPaintedValue = d_func()->value;
}

QSize QProgressBar::sizeHint() const
{
    ensurePolished();
    QFontMetrics fm = fontMetrics();
    QStyleOptionProgressBarV2 opt = d_func()->getStyleOption();
    int cw = style()->pixelMetric(QStyle::PM_ProgressBarChunkWidth, &opt, this);
    QSize size = QSize(cw * 7 + fm.width(QLatin1Char('0')) * 4, fm.height() + 8);
    if (opt.orientation == Qt::Vertical)
        size.transpose();
    return style()->sizeFromContents(QStyle::CT_ProgressBar, &opt, size, this);
}

QSize QProgressBar::minimumSizeHint() const
{
    QSize size;
    if (orientation() == Qt::Horizontal)
        size = QSize(sizeHint().width(), fontMetrics().height() + 2);
    else
        size = QSize(fontMetrics().height() + 2, sizeHint().height());
    return size;
}

QString QProgressBar::text() const
{
    Q_D(const QProgressBar);
    if (d->maximum == 0 || d->value < d->minimum
            || (d->value == INT_MIN && d->minimum == INT_MIN))
        return QString();

    int totalSteps = d->maximum - d->minimum;

    QString result = d->format;
    result.replace(QLatin1String("%m"), QString::fromLatin1("%1").arg(totalSteps));
    result.replace(QLatin1String("%v"), QString::fromLatin1("%1").arg(d->value));

    // If max and min are equal and we get this far, it means that the
    // progress bar has one step and that we are on that step. Return
    // 100% here in order to avoid division by zero further down.
    if (totalSteps == 0) {
        result.replace(QLatin1String("%p"), QString::fromLatin1("%1").arg(100));
        return result;
    }

    int progress = d->value - d->minimum;
    // Get the values down to something usable.
    if (totalSteps > INT_MAX / 1000) {
        progress /= 1000;
        totalSteps /= 1000;
    }

    result.replace(QLatin1String("%p"), QString::fromLatin1("%1").arg((progress * 100) / totalSteps));
    return result;
}

void QProgressBar::setOrientation(Qt::Orientation orientation)
{
    Q_D(QProgressBar);
    if (d->orientation == orientation)
        return;
    d->orientation = orientation;
    if (!testAttribute(Qt::WA_WState_OwnSizePolicy)) {
        QSizePolicy sp = sizePolicy();
        sp.transpose();
        setSizePolicy(sp);
        setAttribute(Qt::WA_WState_OwnSizePolicy, false);
    }
    update();
    updateGeometry();
}

Qt::Orientation QProgressBar::orientation() const
{
    Q_D(const QProgressBar);
    return d->orientation;
}

void QProgressBar::setInvertedAppearance(bool invert)
{
    Q_D(QProgressBar);
    d->invertedAppearance = invert;
    update();
}

bool QProgressBar::invertedAppearance()
{
    Q_D(QProgressBar);
    return d->invertedAppearance;
}

void QProgressBar::setTextDirection(QProgressBar::Direction textDirection)
{
    Q_D(QProgressBar);
    d->textDirection = textDirection;
    update();
}

QProgressBar::Direction QProgressBar::textDirection()
{
    Q_D(QProgressBar);
    return d->textDirection;
}

bool QProgressBar::event(QEvent *e)
{
    return QWidget::event(e);
}

void QProgressBar::setFormat(const QString &format)
{
    Q_D(QProgressBar);
    d->format = format;
}

QString QProgressBar::format() const
{
    Q_D(const QProgressBar);
    return d->format;
}

#endif // QT_NO_PROGRESSBAR

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