- Qt 5.5
- Qt WebEngine Widgets
- WebEngine Tab Browser Example
- searchlineedit.cpp Example File
- Qt 5.5.1 Reference Documentation

# searchlineedit.cpp Example File

browser/searchlineedit.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the demonstration applications of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:LGPL$
    ** 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 http://www.qt.io/terms-conditions. For further
    ** information use the contact form at http://www.qt.io/contact-us.
    **
    ** GNU Lesser General Public License Usage
    ** Alternatively, this file may be used under the terms of the GNU Lesser
    ** General Public License version 2.1 as published by the Free Software
    ** Foundation and appearing in the file LICENSE.LGPL included in the
    ** packaging of this file. Please review the following information to
    ** ensure the GNU Lesser General Public License version 2.1 requirements
    ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
    **
    ** As a special exception, The Qt Company gives you certain additional
    ** rights. These rights are described in The Qt Company LGPL Exception
    ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
    **
    ** GNU General Public License Usage
    ** Alternatively, this file may be used under the terms of the GNU
    ** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be
    ** met: http://www.gnu.org/copyleft/gpl.html.
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    ** $QT_END_LICENSE$
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    ****************************************************************************/

    #include "searchlineedit.h"

    #include <QtGui/QPainter>
    #include <QtGui/QMouseEvent>
    #include <QtWidgets/QMenu>
    #include <QtWidgets/QStyle>
    #include <QtWidgets/QStyleOptionFrameV2>

    ClearButton::ClearButton(QWidget *parent)
      : QAbstractButton(parent)
    {
    #ifndef QT_NO_CURSOR
        setCursor(Qt::ArrowCursor);
    #endif // QT_NO_CURSOR
        setToolTip(tr("Clear"));
        setVisible(false);
        setFocusPolicy(Qt::NoFocus);
    }

    void ClearButton::paintEvent(QPaintEvent *event)
    {
        Q_UNUSED(event);
        QPainter painter(this);
        int height = this->height();

        painter.setRenderHint(QPainter::Antialiasing, true);
        painter.setBrush(isDown()
                         ? palette().color(QPalette::Dark)
                         : palette().color(QPalette::Mid));
        painter.setPen(painter.brush().color());
        int size = width();
        int offset = size / 5;
        int radius = size - offset * 2;
        painter.drawEllipse(offset, offset, radius, radius);

        painter.setPen(palette().color(QPalette::Base));
        int border = offset * 2;
        painter.drawLine(border, border, width() - border, height - border);
        painter.drawLine(border, height - border, width() - border, border);
    }

    void ClearButton::textChanged(const QString &text)
    {
        setVisible(!text.isEmpty());
    }

    /*
        Search icon on the left hand side of the search widget
        When a menu is set a down arrow appears
     */
    class SearchButton : public QAbstractButton {
    public:
        SearchButton(QWidget *parent = 0);
        void paintEvent(QPaintEvent *event);
        QMenu *m_menu;

    protected:
        void mousePressEvent(QMouseEvent *event);
    };

    SearchButton::SearchButton(QWidget *parent)
      : QAbstractButton(parent),
        m_menu(0)
    {
        setObjectName(QLatin1String("SearchButton"));
    #ifndef QT_NO_CURSOR
        setCursor(Qt::ArrowCursor);
    #endif //QT_NO_CURSOR
        setFocusPolicy(Qt::NoFocus);
    }

    void SearchButton::mousePressEvent(QMouseEvent *event)
    {
        if (m_menu && event->button() == Qt::LeftButton) {
            QWidget *p = parentWidget();
            if (p) {
                QPoint r = p->mapToGlobal(QPoint(0, p->height()));
                m_menu->exec(QPoint(r.x() + height() / 2, r.y()));
            }
            event->accept();
        }
        QAbstractButton::mousePressEvent(event);
    }

    void SearchButton::paintEvent(QPaintEvent *event)
    {
        Q_UNUSED(event);
        QPainterPath myPath;

        int radius = (height() / 5) * 2;
        QRect circle(height() / 3 - 1, height() / 4, radius, radius);
        myPath.addEllipse(circle);

        myPath.arcMoveTo(circle, 300);
        QPointF c = myPath.currentPosition();
        int diff = height() / 7;
        myPath.lineTo(qMin(width() - 2, (int)c.x() + diff), c.y() + diff);

        QPainter painter(this);
        painter.setRenderHint(QPainter::Antialiasing, true);
        painter.setPen(QPen(Qt::darkGray, 2));
        painter.drawPath(myPath);

        if (m_menu) {
            QPainterPath dropPath;
            dropPath.arcMoveTo(circle, 320);
            QPointF c = dropPath.currentPosition();
            c = QPointF(c.x() + 3.5, c.y() + 0.5);
            dropPath.moveTo(c);
            dropPath.lineTo(c.x() + 4, c.y());
            dropPath.lineTo(c.x() + 2, c.y() + 2);
            dropPath.closeSubpath();
            painter.setPen(Qt::darkGray);
            painter.setBrush(Qt::darkGray);
            painter.setRenderHint(QPainter::Antialiasing, false);
            painter.drawPath(dropPath);
        }
        painter.end();
    }

    /*
        SearchLineEdit is an enhanced QLineEdit
        - A Search icon on the left with optional menu
        - When there is no text and doesn't have focus an "inactive text" is displayed
        - When there is text a clear button is displayed on the right hand side
     */
    SearchLineEdit::SearchLineEdit(QWidget *parent) : ExLineEdit(parent),
        m_searchButton(new SearchButton(this))
    {
        connect(lineEdit(), SIGNAL(textChanged(QString)),
                this, SIGNAL(textChanged(QString)));
        setLeftWidget(m_searchButton);
        m_inactiveText = tr("Search");

        QSizePolicy policy = sizePolicy();
        setSizePolicy(QSizePolicy::Preferred, policy.verticalPolicy());
    }

    void SearchLineEdit::paintEvent(QPaintEvent *event)
    {
        if (lineEdit()->text().isEmpty() && !hasFocus() && !m_inactiveText.isEmpty()) {
            ExLineEdit::paintEvent(event);
            QStyleOptionFrameV2 panel;
            initStyleOption(&panel);
            QRect r = style()->subElementRect(QStyle::SE_LineEditContents, &panel, this);
            QFontMetrics fm = fontMetrics();
            int horizontalMargin = lineEdit()->x();
            QRect lineRect(horizontalMargin + r.x(), r.y() + (r.height() - fm.height() + 1) / 2,
                           r.width() - 2 * horizontalMargin, fm.height());
            QPainter painter(this);
            painter.setPen(palette().brush(QPalette::Disabled, QPalette::Text).color());
            painter.drawText(lineRect, Qt::AlignLeft|Qt::AlignVCenter, m_inactiveText);
        } else {
            ExLineEdit::paintEvent(event);
        }
    }

    void SearchLineEdit::resizeEvent(QResizeEvent *event)
    {
        updateGeometries();
        ExLineEdit::resizeEvent(event);
    }

    void SearchLineEdit::updateGeometries()
    {
        int menuHeight = height();
        int menuWidth = menuHeight + 1;
        if (!m_searchButton->m_menu)
            menuWidth = (menuHeight / 5) * 4;
        m_searchButton->resize(QSize(menuWidth, menuHeight));
    }

    QString SearchLineEdit::inactiveText() const
    {
        return m_inactiveText;
    }

    void SearchLineEdit::setInactiveText(const QString &text)
    {
        m_inactiveText = text;
    }

    void SearchLineEdit::setMenu(QMenu *menu)
    {
        if (m_searchButton->m_menu)
            m_searchButton->m_menu->deleteLater();
        m_searchButton->m_menu = menu;
        updateGeometries();
    }

    QMenu *SearchLineEdit::menu() const
    {
        if (!m_searchButton->m_menu) {
            m_searchButton->m_menu = new QMenu(m_searchButton);
            if (isVisible())
                (const_cast<SearchLineEdit*>(this))->updateGeometries();
        }
        return m_searchButton->m_menu;
    }