qquicktabbar.cpp

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// Copyright (C) 2017 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:significant reason:default
 
#include "qquicktabbar_p.h"
#include "qquicktabbutton_p.h"
#include "qquickcontainer_p_p.h"
 
#include <QtQuick/private/qquickitemview_p.h>
 
QT_BEGIN_NAMESPACE
 
/*!
    \qmltype TabBar
    \inherits Container
//!     \nativetype QQuickTabBar
    \inqmlmodule QtQuick.Controls
    \since 5.7
    \ingroup qtquickcontrols-navigation
    \ingroup qtquickcontrols-containers
    \ingroup qtquickcontrols-focusscopes
    \brief Allows the user to switch between different views or subtasks.
 
    TabBar provides a tab-based navigation model.
 
    \image qtquickcontrols-tabbar-wireframe.webp
           {Tab bar wireframe showing tab navigation}
 
    TabBar is populated with TabButton controls, and can be used together with
    any layout or container control that provides \c currentIndex -property,
    such as \l StackLayout or \l SwipeView
 
    \snippet qtquickcontrols-tabbar.qml 1
 
    As shown above, TabBar is typically populated with a static set of tab buttons
    that are defined inline as children of the tab bar. It is also possible to
    \l {Container::addItem()}{add}, \l {Container::insertItem()}{insert},
    \l {Container::moveItem()}{move}, and \l {Container::removeItem()}{remove}
    items dynamically at run time. The items can be accessed using
    \l {Container::}{itemAt()} or \l {Container::}{contentChildren}.
 
    \include container-currentindex.qdocinc {file} {TabBar} {SwipeView}
 
    \section2 Resizing Tabs
 
    By default, TabBar resizes its buttons to fit the width of the control.
    The available space is distributed equally to each button. The default
    resizing behavior can be overridden by setting an explicit width for the
    buttons.
 
    The following example illustrates how to keep each tab button at their
    implicit size instead of being resized to fit the tabbar:
 
    \image qtquickcontrols-tabbar-explicit.png
           {Tab bar with First, Second, Third tabs at implicit widths}
 
    \snippet qtquickcontrols-tabbar-explicit.qml 1
 
    \section2 Flickable Tabs
 
    If the total width of the buttons exceeds the available width of the tab bar,
    it automatically becomes flickable.
 
    \image qtquickcontrols-tabbar-flickable.png
           {Tab bar in flickable for scrolling many tabs}
 
    \snippet qtquickcontrols-tabbar-flickable.qml 1
 
    \section2 Vertical Tabs
 
    TabBar can be laid out vertically by setting \l orientation to
    \c Qt.Vertical. In that case, the tab buttons are stacked in a vertical
    list, and \l {Resizing Tabs}{resizing} is done based on the available
    height instead of width.
 
    \sa TabButton, {Customizing TabBar}, {Navigation Controls}, {Container Controls},
        {Focus Management in Qt Quick Controls}
*/
 
class QQuickTabBarPrivate : public QQuickContainerPrivate
{
public:
    Q_DECLARE_PUBLIC(QQuickTabBar)
 
    void updateCurrentItem();
    void updateCurrentIndex();
    void updateLayout();
 
    qreal getContentWidth() const override;
    qreal getContentHeight() const override;
 
    void itemGeometryChanged(QQuickItem *item, QQuickGeometryChange change, const QRectF &diff) override;
    void itemImplicitWidthChanged(QQuickItem *item) override;
    void itemImplicitHeightChanged(QQuickItem *item) override;
 
    QPalette defaultPalette() const override { return QQuickTheme::palette(QQuickTheme::TabBar); }
 
    bool updatingLayout = false;
    QQuickTabBar::Position position = QQuickTabBar::Header;
    Qt::Orientation orientation = Qt::Horizontal;
#if QT_CONFIG(wheelevent)
    QPoint accumulatedAngleDelta;
#endif
};
 
class QQuickTabBarAttachedPrivate : public QObjectPrivate
{
    Q_DECLARE_PUBLIC(QQuickTabBarAttached)
 
public:
    static QQuickTabBarAttachedPrivate *get(QQuickTabBarAttached *attached)
    {
        return attached->d_func();
    }
 
    void update(QQuickTabBar *tabBar, int index);
 
    int index = -1;
    QQuickTabBar *tabBar = nullptr;
};
 
void QQuickTabBarPrivate::updateCurrentItem()
{
    QQuickTabButton *button = qobject_cast<QQuickTabButton *>(contentModel->get(currentIndex));
    if (button)
        button->setChecked(true);
}
 
void QQuickTabBarPrivate::updateCurrentIndex()
{
    Q_Q(QQuickTabBar);
    QQuickTabButton *button = qobject_cast<QQuickTabButton *>(q->sender());
    if (button && button->isChecked())
        q->setCurrentIndex(contentModel->indexOf(button, nullptr));
}
 
void QQuickTabBarPrivate::updateLayout()
{
    Q_Q(QQuickTabBar);
    const int count = contentModel->count();
    if (count <= 0 || !contentItem)
        return;
 
    const bool horizontal = orientation == Qt::Horizontal;
    qreal reservedSize = 0;
    int resizableCount = 0;
 
    QList<QQuickItem *> allItems;
    allItems.reserve(count);
 
    for (int i = 0; i < count; ++i) {
        QQuickItem *item = q->itemAt(i);
        if (item) {
            QQuickItemPrivate *p = QQuickItemPrivate::get(item);
            const bool sizeValid = horizontal ? p->widthValid() : p->heightValid();
            if (!sizeValid)
                ++resizableCount;
            else
                reservedSize += horizontal ? item->width() : item->height();
            allItems += item;
        }
    }
 
    const qreal totalSpacing = qMax(0, count - 1) * spacing;
    const qreal availableSize = horizontal ? contentItem->width() : contentItem->height();
    const qreal itemSize = (availableSize - reservedSize - totalSpacing) / qMax(1, resizableCount);
 
    updatingLayout = true;
    for (QQuickItem *item : std::as_const(allItems)) {
        QQuickItemPrivate *p = QQuickItemPrivate::get(item);
        if (horizontal) {
            if (!p->widthValid()) {
                item->setWidth(itemSize);
                p->widthValidFlag = false;
            }
            if (!p->heightValid()) {
                item->setHeight(contentHeight);
                p->heightValidFlag = false;
            } else {
                item->setY((contentHeight - item->height()) / 2);
            }
        } else {
            if (!p->heightValid()) {
                item->setHeight(itemSize);
                p->heightValidFlag = false;
            }
            if (!p->widthValid()) {
                item->setWidth(contentWidth);
                p->widthValidFlag = false;
            } else {
                item->setX((contentWidth - item->width()) / 2);
            }
        }
    }
    updatingLayout = false;
}
 
qreal QQuickTabBarPrivate::getContentWidth() const
{
    if (hasContentWidth)
        return contentWidth;
 
    Q_Q(const QQuickTabBar);
    const int count = contentModel->count();
    if (orientation == Qt::Vertical) {
        qreal maxWidth = 0;
        for (int i = 0; i < count; ++i) {
            QQuickItem *item = q->itemAt(i);
            if (item)
                maxWidth = qMax(maxWidth, item->implicitWidth());
        }
        return maxWidth;
    }
 
    qreal totalWidth = qMax(0, count - 1) * spacing;
    for (int i = 0; i < count; ++i) {
        QQuickItem *item = q->itemAt(i);
        if (item) {
            QQuickItemPrivate *p = QQuickItemPrivate::get(item);
            if (!p->widthValid())
                totalWidth += item->implicitWidth();
            else
                totalWidth += item->width();
        }
    }
    return totalWidth;
}
 
qreal QQuickTabBarPrivate::getContentHeight() const
{
    if (hasContentHeight)
        return contentHeight;
 
    Q_Q(const QQuickTabBar);
    const int count = contentModel->count();
    if (orientation == Qt::Vertical) {
        qreal totalHeight = qMax(0, count - 1) * spacing;
        for (int i = 0; i < count; ++i) {
            QQuickItem *item = q->itemAt(i);
            if (item) {
                QQuickItemPrivate *p = QQuickItemPrivate::get(item);
                if (!p->heightValid())
                    totalHeight += item->implicitHeight();
                else
                    totalHeight += item->height();
            }
        }
        return totalHeight;
    }
 
    qreal maxHeight = 0;
    for (int i = 0; i < count; ++i) {
        QQuickItem *item = q->itemAt(i);
        if (item)
            maxHeight = qMax(maxHeight, item->implicitHeight());
    }
    return maxHeight;
}
 
void QQuickTabBarPrivate::itemGeometryChanged(QQuickItem *item, QQuickGeometryChange change, const QRectF &diff)
{
    QQuickContainerPrivate::itemGeometryChanged(item, change, diff);
    if (!updatingLayout) {
        if (change.sizeChange())
            updateImplicitContentSize();
        updateLayout();
    }
}
 
void QQuickTabBarPrivate::itemImplicitWidthChanged(QQuickItem *item)
{
    QQuickContainerPrivate::itemImplicitWidthChanged(item);
    if (item != contentItem)
        updateImplicitContentWidth();
}
 
void QQuickTabBarPrivate::itemImplicitHeightChanged(QQuickItem *item)
{
    QQuickContainerPrivate::itemImplicitHeightChanged(item);
    if (item != contentItem)
        updateImplicitContentHeight();
}
 
QQuickTabBar::QQuickTabBar(QQuickItem *parent)
    : QQuickContainer(*(new QQuickTabBarPrivate), parent)
{
    Q_D(QQuickTabBar);
    d->changeTypes |= QQuickItemPrivate::Geometry | QQuickItemPrivate::ImplicitWidth | QQuickItemPrivate::ImplicitHeight;
    setFlag(ItemIsFocusScope);
    QObjectPrivate::connect(this, &QQuickTabBar::currentIndexChanged, d, &QQuickTabBarPrivate::updateCurrentItem);
}
 
/*!
    \qmlproperty enumeration QtQuick.Controls::TabBar::position
 
    This property holds the position of the tab bar.
 
    \note If the tab bar is assigned as a header or footer of \l ApplicationWindow
    or \l Page, the appropriate position is set automatically.
 
    Possible values:
    \value TabBar.Header The tab bar is at the top, as a window or page header.
    \value TabBar.Footer The tab bar is at the bottom, as a window or page footer.
 
    The default value is style-specific.
 
    \sa ApplicationWindow::header, ApplicationWindow::footer, Page::header, Page::footer
*/
QQuickTabBar::Position QQuickTabBar::position() const
{
    Q_D(const QQuickTabBar);
    return d->position;
}
 
void QQuickTabBar::setPosition(Position position)
{
    Q_D(QQuickTabBar);
    if (d->position == position)
        return;
 
    d->position = position;
    emit positionChanged();
}
 
/*!
    \since QtQuick.Controls 6.13
    \qmlproperty enumeration QtQuick.Controls::TabBar::orientation
 
    This property holds the orientation of the tab bar.
 
    Possible values:
    \value Qt.Horizontal Horizontal (default)
    \value Qt.Vertical Vertical
 
    \sa horizontal, vertical
*/
Qt::Orientation QQuickTabBar::orientation() const
{
    Q_D(const QQuickTabBar);
    return d->orientation;
}
 
void QQuickTabBar::setOrientation(Qt::Orientation orientation)
{
    Q_D(QQuickTabBar);
    if (d->orientation == orientation)
        return;
 
    d->orientation = orientation;
    d->updateImplicitContentSize();
    if (isComponentComplete())
        polish();
    emit orientationChanged();
}
 
/*!
    \since QtQuick.Controls 6.13
    \qmlproperty bool QtQuick.Controls::TabBar::horizontal
    \readonly
 
    This property holds whether the tab bar is horizontal.
 
    \sa orientation
*/
bool QQuickTabBar::isHorizontal() const
{
    Q_D(const QQuickTabBar);
    return d->orientation == Qt::Horizontal;
}
 
/*!
    \since QtQuick.Controls 6.13
    \qmlproperty bool QtQuick.Controls::TabBar::vertical
    \readonly
 
    This property holds whether the tab bar is vertical.
 
    \sa orientation
*/
bool QQuickTabBar::isVertical() const
{
    Q_D(const QQuickTabBar);
    return d->orientation == Qt::Vertical;
}
 
/*!
    \since QtQuick.Controls 2.2 (Qt 5.9)
    \qmlproperty real QtQuick.Controls::TabBar::contentWidth
 
    This property holds the content width. It is used for calculating the total
    implicit width of the tab bar.
 
    \note This property is available in TabBar since \l{QtQuick.Controls} 2.2 (Qt 5.9),
    but it was promoted to the Container base type in \l{QtQuick.Controls} 2.5 (Qt 5.12).
 
    \sa Container::contentWidth
*/
 
/*!
    \since QtQuick.Controls 2.2 (Qt 5.9)
    \qmlproperty real QtQuick.Controls::TabBar::contentHeight
 
    This property holds the content height. It is used for calculating the total
    implicit height of the tab bar.
 
    \note This property is available in TabBar since \l{QtQuick.Controls} 2.2 (Qt 5.9),
    but it was promoted to the Container base type in \l{QtQuick.Controls} 2.5 (Qt 5.12).
 
    \sa Container::contentHeight
*/
 
QQuickTabBarAttached *QQuickTabBar::qmlAttachedProperties(QObject *object)
{
    return new QQuickTabBarAttached(object);
}
 
void QQuickTabBar::updatePolish()
{
    Q_D(QQuickTabBar);
    QQuickContainer::updatePolish();
    d->updateLayout();
}
 
void QQuickTabBar::componentComplete()
{
    Q_D(QQuickTabBar);
    QQuickContainer::componentComplete();
    d->updateCurrentItem();
    d->updateLayout();
}
 
void QQuickTabBar::geometryChange(const QRectF &newGeometry, const QRectF &oldGeometry)
{
    Q_D(QQuickTabBar);
    QQuickContainer::geometryChange(newGeometry, oldGeometry);
    d->updateLayout();
}
 
bool QQuickTabBar::isContent(QQuickItem *item) const
{
    return qobject_cast<QQuickTabButton *>(item);
}
 
void QQuickTabBar::itemAdded(int index, QQuickItem *item)
{
    Q_D(QQuickTabBar);
    Q_UNUSED(index);
    // Cull the tab so that it stays hidden until the view shows it (QTBUG-55129). Only do this
    // for views, as nothing else would uncull it. A Repeater, for example, does uncull an item when
    // it creates it, but for a tab added after the Repeater was created, that happens before this
    // function is called. If we culled the tab here, it would stay culled, and hence invisible.
    if (qobject_cast<QQuickItemView *>(d->contentItem))
        QQuickItemPrivate::get(item)->setCulled(true);
    if (QQuickTabButton *button = qobject_cast<QQuickTabButton *>(item))
        QObjectPrivate::connect(button, &QQuickTabButton::checkedChanged, d, &QQuickTabBarPrivate::updateCurrentIndex);
    QQuickTabBarAttached *attached = qobject_cast<QQuickTabBarAttached *>(qmlAttachedPropertiesObject<QQuickTabBar>(item));
    if (attached)
        QQuickTabBarAttachedPrivate::get(attached)->update(this, index);
    d->updateImplicitContentSize();
    if (isComponentComplete())
        polish();
}
 
void QQuickTabBar::itemMoved(int index, QQuickItem *item)
{
    QQuickTabBarAttached *attached = qobject_cast<QQuickTabBarAttached *>(qmlAttachedPropertiesObject<QQuickTabBar>(item));
    if (attached)
        QQuickTabBarAttachedPrivate::get(attached)->update(this, index);
}
 
void QQuickTabBar::itemRemoved(int index, QQuickItem *item)
{
    Q_D(QQuickTabBar);
    Q_UNUSED(index);
    if (QQuickTabButton *button = qobject_cast<QQuickTabButton *>(item))
        QObjectPrivate::disconnect(button, &QQuickTabButton::checkedChanged, d, &QQuickTabBarPrivate::updateCurrentIndex);
    QQuickTabBarAttached *attached = qobject_cast<QQuickTabBarAttached *>(qmlAttachedPropertiesObject<QQuickTabBar>(item));
    if (attached)
        QQuickTabBarAttachedPrivate::get(attached)->update(nullptr, -1);
    d->updateImplicitContentSize();
    if (isComponentComplete())
        polish();
}
 
#if QT_CONFIG(wheelevent)
void QQuickTabBar::wheelEvent(QWheelEvent *event)
{
    Q_D(QQuickTabBar);
    QQuickContainer::wheelEvent(event);
    if (d->wheelEnabled) {
        d->accumulatedAngleDelta += event->angleDelta();
        int xSteps = d->accumulatedAngleDelta.x() / QWheelEvent::DefaultDeltasPerStep;
        int ySteps = d->accumulatedAngleDelta.y() / QWheelEvent::DefaultDeltasPerStep;
        if (xSteps > 0 || ySteps > 0) {
            decrementCurrentIndex();
            d->accumulatedAngleDelta = QPoint();
        } else if (xSteps < 0 || ySteps < 0) {
            incrementCurrentIndex();
            d->accumulatedAngleDelta = QPoint();
        }
    }
}
#endif
 
QFont QQuickTabBar::defaultFont() const
{
    return QQuickTheme::font(QQuickTheme::TabBar);
}
 
#if QT_CONFIG(accessibility)
QAccessible::Role QQuickTabBar::accessibleRole() const
{
    return QAccessible::PageTabList;
}
#endif
 
/*!
    \qmlattachedproperty int QtQuick.Controls::TabBar::index
    \since QtQuick.Controls 2.3 (Qt 5.10)
    \readonly
 
    This attached property holds the index of each tab button in the TabBar.
 
    It is attached to each tab button of the TabBar.
*/
 
/*!
    \qmlattachedproperty TabBar QtQuick.Controls::TabBar::tabBar
    \since QtQuick.Controls 2.3 (Qt 5.10)
    \readonly
 
    This attached property holds the tab bar that manages this tab button.
 
    It is attached to each tab button of the TabBar.
*/
 
/*!
    \qmlattachedproperty enumeration QtQuick.Controls::TabBar::position
    \since QtQuick.Controls 2.3 (Qt 5.10)
    \readonly
 
    This attached property holds the position of the tab bar.
 
    It is attached to each tab button of the TabBar.
 
    Possible values:
    \value TabBar.Header The tab bar is at the top, as a window or page header.
    \value TabBar.Footer The tab bar is at the bottom, as a window or page footer.
*/
 
void QQuickTabBarAttachedPrivate::update(QQuickTabBar *newTabBar, int newIndex)
{
    Q_Q(QQuickTabBarAttached);
    const int oldIndex = index;
    const QQuickTabBar *oldTabBar = tabBar;
    const QQuickTabBar::Position oldPos = q->position();
 
    index = newIndex;
    tabBar = newTabBar;
 
    if (oldTabBar != newTabBar) {
        if (oldTabBar)
            QObject::disconnect(oldTabBar, &QQuickTabBar::positionChanged, q, &QQuickTabBarAttached::positionChanged);
        if (newTabBar)
            QObject::connect(newTabBar, &QQuickTabBar::positionChanged, q, &QQuickTabBarAttached::positionChanged);
        emit q->tabBarChanged();
    }
 
    if (oldIndex != newIndex)
        emit q->indexChanged();
    if (oldPos != q->position())
        emit q->positionChanged();
}
 
QQuickTabBarAttached::QQuickTabBarAttached(QObject *parent)
    : QObject(*(new QQuickTabBarAttachedPrivate), parent)
{
}
 
int QQuickTabBarAttached::index() const
{
    Q_D(const QQuickTabBarAttached);
    return d->index;
}
 
QQuickTabBar *QQuickTabBarAttached::tabBar() const
{
    Q_D(const QQuickTabBarAttached);
    return d->tabBar;
}
 
QQuickTabBar::Position QQuickTabBarAttached::position() const
{
    Q_D(const QQuickTabBarAttached);
    if (!d->tabBar)
        return QQuickTabBar::Header;
    return d->tabBar->position();
}
 
QT_END_NAMESPACE
 
#include "moc_qquicktabbar_p.cpp"