src/gui/kernel/qtooltip.cpp

Go to the documentation of this file.

/****************************************************************************
**
** 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:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at sales@trolltech.com.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include <qapplication.h>
#include <qdesktopwidget.h>
#include <qevent.h>
#include <qhash.h>
#include <qlabel.h>
#include <qpointer.h>
#include <qstyle.h>
#include <qstyleoption.h>
#include <qstylepainter.h>
#include <qtimer.h>
#include <qtooltip.h>
#include <private/qeffects_p.h>
#include <qtextdocument.h>

#ifndef QT_NO_TOOLTIP

class QTipLabel : public QLabel
{
    Q_OBJECT
public:
    QTipLabel(const QString& text, QWidget* parent);
    ~QTipLabel();
    static QTipLabel *instance;

    bool eventFilter(QObject *, QEvent *);

    QBasicTimer hideTimer, deleteTimer;

    void hideTip();
    void setTipRect(QWidget *w, const QRect &r);
protected:
    void enterEvent(QEvent*){hideTip();}
    void timerEvent(QTimerEvent *e);
    void paintEvent(QPaintEvent *e);

private:
    QWidget *widget;
    QRect rect;
};

QTipLabel *QTipLabel::instance = 0;

QTipLabel::QTipLabel(const QString& text, QWidget* parent)
    : QLabel(parent, Qt::ToolTip), widget(0)
{
    delete instance;
    instance = this;
    ensurePolished();
    setMargin(1 + style()->pixelMetric(QStyle::PM_ToolTipLabelFrameWidth, 0, this));
    setFrameStyle(QFrame::NoFrame);
    setAlignment(Qt::AlignLeft);
    setIndent(1);
    setWordWrap(Qt::mightBeRichText(text));
    setText(text);

    QFontMetrics fm(font());
    QSize extra(1, 0);
    // Make it look good with the default ToolTip font on Mac, which has a small descent.
    if (fm.descent() == 2 && fm.ascent() >= 11)
        ++extra.rheight();

    resize(sizeHint() + extra);
    qApp->installEventFilter(this);

    int time = 10000 + 40 * qMax(0, text.length()-100);
    hideTimer.start(time, this);
    setWindowOpacity(style()->styleHint(QStyle::SH_ToolTipLabel_Opacity, 0, this) / 255.0);
    setPalette(QToolTip::palette());
}

void QTipLabel::paintEvent(QPaintEvent *ev)
{
    QStylePainter p(this);
    QStyleOptionFrame opt;
    opt.init(this);
    p.drawPrimitive(QStyle::PE_PanelTipLabel, opt);
    p.end();

    QLabel::paintEvent(ev);
}

QTipLabel::~QTipLabel()
{
    instance = 0;
}

void QTipLabel::hideTip()
{
    hide();
    // timer based deletion to prevent animation
    deleteTimer.start(250, this);
}

void QTipLabel::setTipRect(QWidget *w, const QRect &r)
{
    if (w) {
        widget = w;
        rect = r;
    }
}

void QTipLabel::timerEvent(QTimerEvent *e)
{
    if (e->timerId() == hideTimer.timerId())
        hideTip();
    else if (e->timerId() == deleteTimer.timerId())
        delete this;
}

bool QTipLabel::eventFilter(QObject *o, QEvent *e)
{
    switch (e->type()) {
    case QEvent::KeyPress:
    case QEvent::KeyRelease: {
        int key = static_cast<QKeyEvent *>(e)->key();
        Qt::KeyboardModifiers mody = static_cast<QKeyEvent *>(e)->modifiers();

        if ((mody & Qt::KeyboardModifierMask)
            || (key == Qt::Key_Shift || key == Qt::Key_Control
                || key == Qt::Key_Alt || key == Qt::Key_Meta))
            break;
    }
    case QEvent::Leave:
    case QEvent::WindowActivate:
    case QEvent::WindowDeactivate:
    case QEvent::MouseButtonPress:
    case QEvent::MouseButtonRelease:
    case QEvent::MouseButtonDblClick:
    case QEvent::FocusIn:
    case QEvent::FocusOut:
    case QEvent::Wheel:
        hideTip();
        break;

    case QEvent::MouseMove:
        if (o == widget && !rect.isNull() && !rect.contains(static_cast<QMouseEvent*>(e)->pos()))
            hideTip();
    default:
        break;
    }
    return false;
}

void QToolTip::showText(const QPoint &pos, const QString &text, QWidget *w, const QRect &rect)
{
    if (QTipLabel::instance && QTipLabel::instance->text() == text)
        return; /* this is NOT a bug, if the text doesn't change, you
                 don't want the tool tips to move. If you divide your
                 widget in different parts that show the same tool
                 tip, you must handle that yourself. Simple hide the
                 tip (by showing an empty string) and show the new
                 one. */

    if (text.isEmpty()) {
        if (QTipLabel::instance)
            QTipLabel::instance->hideTip();
        return;
    }

#ifndef QT_NO_EFFECTS
    bool preventAnimation = (QTipLabel::instance != 0);
#endif
    int scr;
    if (QApplication::desktop()->isVirtualDesktop())
        scr = QApplication::desktop()->screenNumber(pos);
    else
        scr = QApplication::desktop()->screenNumber(w);

#ifdef Q_WS_MAC
    QRect screen = QApplication::desktop()->availableGeometry(scr);
#else
    QRect screen = QApplication::desktop()->screenGeometry(scr);
#endif

    QTipLabel *label = new QTipLabel(text, QApplication::desktop()->screen(scr));
    if (!rect.isNull() && !w) {
        qWarning("QToolTip::showText: Cannot pass null widget if rect is set");
    } else {
        label->setTipRect(w, rect);
    }

    label->setObjectName(QLatin1String("qtooltip_label"));

    QPoint p = pos;
    p += QPoint(2,
#ifdef Q_WS_WIN
                24
#else
                16
#endif
        );
    if (p.x() + label->width() > screen.x() + screen.width())
        p.rx() -= 4 + label->width();
    if (p.y() + label->height() > screen.y() + screen.height())
        p.ry() -= 24 + label->height();
    if (p.y() < screen.y())
        p.setY(screen.y());
    if (p.x() + label->width() > screen.x() + screen.width())
        p.setX(screen.x() + screen.width() - label->width());
    if (p.x() < screen.x())
        p.setX(screen.x());
    if (p.y() + label->height() > screen.y() + screen.height())
        p.setY(screen.y() + screen.height() - label->height());
    label->move(p);

#ifndef QT_NO_EFFECTS
    if ( QApplication::isEffectEnabled(Qt::UI_AnimateTooltip) == false || preventAnimation)
        label->show();
    else if (QApplication::isEffectEnabled(Qt::UI_FadeTooltip)) {
        qFadeEffect(label);
    }
    else
        qScrollEffect(label);
#else
    label->show();
#endif

}

void QToolTip::showText(const QPoint &pos, const QString &text, QWidget *w)
{
    QToolTip::showText(pos, text, w, QRect());
}


Q_GLOBAL_STATIC_WITH_ARGS(QPalette, tooltip_palette, (Qt::black, QColor(255,255,220),
                                                      QColor(96,96,96), Qt::black, Qt::black,
                                                      Qt::black, QColor(255,255,220)))


QPalette QToolTip::palette()
{
    return *tooltip_palette();
}

QFont QToolTip::font()
{
    return QApplication::font("QTipLabel");
}

void QToolTip::setPalette(const QPalette &palette)
{
    *tooltip_palette() = palette;
}

void QToolTip::setFont(const QFont &font)
{
    QApplication::setFont(font, "QTipLabel");
}


#include "qtooltip.moc"
#endif // QT_NO_TOOLTIP

---