qlayout.cpp

奇趣公司比较新的qt/emd版本

}

/*!
    \reimp
*/
bool QLayout::isEmpty() const
{
    int i = 0;
    QLayoutItem *item = itemAt(i);
    while (item) {
        if (!item->isEmpty())
            return false;
        ++i;
        item = itemAt(i);
    }
    return true;
}

/*!
    \reimp
*/
void QLayout::setGeometry(const QRect &r)
{
    Q_D(QLayout);
    d->rect = r;
}

/*!
    \reimp
*/
QRect QLayout::geometry() const
{
    Q_D(const QLayout);
    return d->rect;
}

/*!
    \reimp
*/
void QLayout::invalidate()
{
    Q_D(QLayout);
    d->rect = QRect();
    update();
}

static bool removeWidgetRecursively(QLayoutItem *li, QWidget *w)
{
    QLayout *lay = li->layout();
    if (!lay)
        return false;
    int i = 0;
    QLayoutItem *child;
    while ((child = lay->itemAt(i))) {
        if (child->widget() == w) {
            delete lay->takeAt(i);
            lay->invalidate();
            return true;
        } else if (removeWidgetRecursively(child, w)) {
            return true;
        } else {
            ++i;
        }
    }
    return false;
}


void QLayoutPrivate::doResize(const QSize &r)
{
    Q_Q(QLayout);
    int mbh = menuBarHeightForWidth(menubar, r.width());
    QWidget *mw = q->parentWidget();
    QRect rect = mw->testAttribute(Qt::WA_LayoutOnEntireRect) ? mw->rect() : mw->contentsRect();
    rect.setTop(rect.top() + mbh);
    q->setGeometry(rect);
#ifndef QT_NO_MENUBAR
    if (menubar)
        menubar->setGeometry(0,0,r.width(), mbh);
#endif
}


/*!
    \internal
    Performs child widget layout when the parent widget is
    resized.  Also handles removal of widgets. \a e is the
    event
*/
void QLayout::widgetEvent(QEvent *e)
{
    Q_D(QLayout);
    if (!d->enabled)
        return;

    switch (e->type()) {
    case QEvent::Resize:
        if (d->activated) {
            QResizeEvent *r = (QResizeEvent *)e;
            d->doResize(r->size());
        } else {
            activate();
        }
        break;
    case QEvent::ChildRemoved:
        {
            QChildEvent *c = (QChildEvent *)e;
            if (c->child()->isWidgetType()) {
                QWidget *w = (QWidget *)c->child();
#ifndef QT_NO_MENUBAR
                if (w == d->menubar)
                    d->menubar = 0;
#endif
                removeWidgetRecursively(this, w);
            }
        }
        break;
#ifdef QT3_SUPPORT
    case QEvent::ChildInserted:
        if (d->topLevel && d->autoNewChild) {
            QChildEvent *c = (QChildEvent *)e;
            if (c->child()->isWidgetType()) {
                QWidget *w = (QWidget *)c->child();
                if (!w->isWindow()) {
#if !defined(QT_NO_MENUBAR) && !defined(QT_NO_TOOLBAR)
                    if (qobject_cast<QMenuBar*>(w) && !::qobject_cast<QToolBar*>(w->parentWidget())) {
                        d->menubar = (QMenuBar *)w;
                        invalidate();
                    } else
#endif
                        addItem(new QWidgetItem(w));
                }
            }
        }
        break;
    case QEvent::LayoutHint:
        d->activated = false;
        // fall through
#endif
    case QEvent::LayoutRequest:
        activate();
        break;
    default:
        break;
    }
}

/*!
    \reimp
*/
void QLayout::childEvent(QChildEvent *e)
{
    Q_D(QLayout);
    if (!d->enabled)
        return;

    if (e->type() == QEvent::ChildRemoved) {
        QChildEvent *c = (QChildEvent*)e;
        int i = 0;

        QLayoutItem *item;
        while ((item = itemAt(i))) {
            if (item == static_cast<QLayout*>(c->child())) {
                takeAt(i);
                invalidate();
                break;
            } else {
                ++i;
            }
        }
    }
}

/*!
  \internal
  Also takes contentsMargins and menu bar into account.
*/
int QLayout::totalHeightForWidth(int w) const
{
    Q_D(const QLayout);
    int side=0, top=0;
    if (d->topLevel) {
        QWidget *parent = parentWidget();
        parent->ensurePolished();
        QWidgetPrivate *wd = parent->d_func();
        side += wd->leftmargin + wd->rightmargin;
        top += wd->topmargin + wd->bottommargin;
    }
    int h = heightForWidth(w - side) + top;
#ifndef QT_NO_MENUBAR
    h += menuBarHeightForWidth(d->menubar, w);
#endif
    return h;
}

/*!
  \internal
  Also takes contentsMargins and menu bar into account.
*/
QSize QLayout::totalMinimumSize() const
{
    Q_D(const QLayout);
    int side=0, top=0;
    if (d->topLevel) {
        QWidget *pw = parentWidget();
        pw->ensurePolished();
        QWidgetPrivate *wd = pw->d_func();
        side += wd->leftmargin + wd->rightmargin;
        top += wd->topmargin + wd->bottommargin;
    }

    QSize s = minimumSize();
#ifndef QT_NO_MENUBAR
    top += menuBarHeightForWidth(d->menubar, s.width() + side);
#endif
    return s + QSize(side, top);
}

/*!
  \internal
  Also takes contentsMargins and menu bar into account.
*/
QSize QLayout::totalSizeHint() const
{
    Q_D(const QLayout);
    int side=0, top=0;
    if (d->topLevel) {
        QWidget *pw = parentWidget();
        pw->ensurePolished();
        QWidgetPrivate *wd = pw->d_func();
        side += wd->leftmargin + wd->rightmargin;
        top += wd->topmargin + wd->bottommargin;
    }

    QSize s = sizeHint();
    if (hasHeightForWidth())
        s.setHeight(heightForWidth(s.width() + side));
#ifndef QT_NO_MENUBAR
    top += menuBarHeightForWidth(d->menubar, s.width());
#endif
    return s + QSize(side, top);
}

/*!
  \internal
  Also takes contentsMargins and menu bar into account.
*/
QSize QLayout::totalMaximumSize() const
{
    Q_D(const QLayout);
    int side=0, top=0;
    if (d->topLevel) {
        QWidget *pw = parentWidget();
        pw->ensurePolished();
        QWidgetPrivate *wd = pw->d_func();
        side += wd->leftmargin + wd->rightmargin;
        top += wd->topmargin + wd->bottommargin;
    }

    QSize s = maximumSize();
#ifndef QT_NO_MENUBAR
    top += menuBarHeightForWidth(d->menubar, s.width());
#endif

    if (d->topLevel)
        s = QSize(qMin(s.width() + side, QLAYOUTSIZE_MAX),
                   qMin(s.height() + top, QLAYOUTSIZE_MAX));
    return s;
}

/*!
  \internal
  Destroys the layout, deleting all child layouts.
  Geometry management stops when a top-level layout is deleted.

  The layout classes will probably be fatally confused if you delete
  a sublayout.
*/
QLayout::~QLayout()
{
    Q_D(QLayout);
    /*
      This function may be called during the QObject destructor,
      when the parent no longer is a QWidget.
    */
    if (d->topLevel && parent() && parent()->isWidgetType() &&
         ((QWidget*)parent())->layout() == this)
        ((QWidget*)parent())->d_func()->layout = 0;
}

#ifdef QT3_SUPPORT
/*!
    Removes and deletes all items in this layout.
*/
void QLayout::deleteAllItems()
{
    QLayoutItem *l;
    while ((l = takeAt(0)))
        delete l;
}
#endif

/*!
    This function is called from \c addLayout() or \c insertLayout() functions in
    subclasses to add layout \a l as a sub-layout.

    The only scenario in which you need to call it directly is if you
    implement a custom layout that supports nested layouts.

    \sa QBoxLayout::addLayout(), QBoxLayout::insertLayout(), QGridLayout::addLayout()
*/
void QLayout::addChildLayout(QLayout *l)
{
    if (l->parent()) {
        qWarning("QLayout::addChildLayout: layout \"%s\" already has a parent",
                 l->objectName().toLocal8Bit().data());
        return;
    }
    l->setParent(this);

    if (QWidget *mw = parentWidget()) {
        l->d_func()->reparentChildWidgets(mw);
    }

}

#ifdef QT_DEBUG
static bool layoutDebug()
{
    static int checked_env = -1;
    if(checked_env == -1)
        checked_env = !!qgetenv("QT_LAYOUT_DEBUG").toInt();

    return checked_env;
}
#endif

void QLayoutPrivate::reparentChildWidgets(QWidget *mw)
{
    Q_Q(QLayout);
    int n =  q->count();

#ifndef QT_NO_MENUBAR
    if (menubar && menubar->parentWidget() != mw) {
        menubar->setParent(mw);
    }
#endif
    bool mwVisible = mw && mw->isVisible();
    for (int i = 0; i < n; ++i) {
        QLayoutItem *item = q->itemAt(i);
        if (QWidget *w = item->widget()) {
            QWidget *pw = w->parentWidget();
#ifdef QT_DEBUG
            if (pw && pw != mw && layoutDebug()) {
                qWarning("QLayout::addChildLayout: widget %s \"%s\" in wrong parent; moved to correct parent",
                         w->metaObject()->className(), w->objectName().toLocal8Bit().data());
            }
#endif
            bool needShow = mwVisible && !(w->isHidden() && w->testAttribute(Qt::WA_WState_ExplicitShowHide));
            if (pw != mw)
                w->setParent(mw);
            if (needShow)
                QMetaObject::invokeMethod(w, "_q_showIfNotHidden", Qt::QueuedConnection); //show later
        } else if (QLayout *l = item->layout()) {
            l->d_func()->reparentChildWidgets(mw);
        }
    }
}

/*!
    This function is called from \c addWidget() functions in
    subclasses to add \a w as a child widget.

    If \a w is already in a layout, this function will give a warning
    and remove \a w from the layout. This function must therefore be
    called before adding \a w to the layout's data structure.
*/
void QLayout::addChildWidget(QWidget *w)
{
    QWidget *mw = parentWidget();
    QWidget *pw = w->parentWidget();

    //Qt::WA_LaidOut is never reset. It only means that the widget at some point has
    //been in a layout.
    if (pw && w->testAttribute(Qt::WA_LaidOut)) {
        QLayout *l = pw->layout();
        if (l && removeWidgetRecursively(l, w)) {
#ifdef QT_DEBUG
            if (layoutDebug())
                qWarning("QLayout::addChildWidget: %s \"%s\" is already in a layout; moved to new layout",
                         w->metaObject()->className(), w->objectName().toLocal8Bit().data());
#endif
        }
    }
    if (pw && mw && pw != mw) {
#ifdef QT_DEBUG
            if (layoutDebug())
                qWarning("QLayout::addChildWidget: %s \"%s\" in wrong parent; moved to correct parent",
                         w->metaObject()->className(), w->objectName().toLocal8Bit().data());
#endif
        pw = 0;
    }
    bool needShow = mw && mw->isVisible() && !(w->isHidden() && w->testAttribute(Qt::WA_WState_ExplicitShowHide));
    if (!pw && mw)
        w->setParent(mw);
    w->setAttribute(Qt::WA_LaidOut);
    if (needShow)
        QMetaObject::invokeMethod(w, "_q_showIfNotHidden", Qt::QueuedConnection); //show later
}

#ifdef QT3_SUPPORT
/*!
  \compat

    Sets this layout's parent widget to a fixed size with width \a w
    and height \a h, stopping the user from resizing it, and also
    prevents the layout from resizing it, even if the layout's size
    hint should change. Does nothing if this is not a top-level
    layout (i.e., if parent()->isWidgetType()).

    As a special case, if both \a w and \a h are 0, then the layout's
    current sizeHint() is used.

    Use \c setResizeMode(Fixed) to stop the widget from being resized
    by the user, while still allowing the layout to resize it when
    the sizeHint() changes.

    Use \c setResizeMode(FreeResize) to allow the user to resize the
    widget, while preventing the layout from resizing it.

*/
void QLayout::freeze(int w, int h)
{
    Q_D(QLayout);
    if (!d->topLevel)
        return;
    if (w <= 0 || h <= 0) {
        QSize s = totalSizeHint();
        w = s.width();
        h = s.height();
    }
    setSizeConstraint(SetNoConstraint); // layout will not change min/max size
    QWidget *parent = parentWidget();
    if (parent)
        parent->setFixedSize(w, h);
}

#endif







/*!
    Tells the geometry manager to place the menu bar \a widget at the
    top of parentWidget(), outside QWidget::contentsMargins(). All
    child widgets are placed below the bottom edge of the menu bar.
*/
void QLayout::setMenuBar(QWidget *widget)
{
    Q_D(QLayout);
    if (widget)
        addChildWidget(widget);
    d->menubar = widget;
}

/*!
    Returns the menu bar set for this layout, or 0 if no menu bar is
    set.
*/

QWidget *QLayout::menuBar() const
{
    Q_D(const QLayout);
    return d->menubar;
}


/*!
    Returns the minimum size of this layout. This is the smallest
    size that the layout can have while still respecting the
    specifications.

    The returned value doesn't include the space required by
    QWidget::setContentsMargins() or menuBar().

    The default implementation allows unlimited resizing.
*/
QSize QLayout::minimumSize() const
{
    return QSize(0, 0);
}

/*!
    Returns the maximum size of this layout. This is the largest size
    that the layout can have while still respecting the
    specifications.

    The returned value doesn't include the space required by
    QWidget::setContentsMargins() or menuBar().

    The default implementation allows unlimited resizing.
*/
QSize QLayout::maximumSize() const
{
    return QSize(QLAYOUTSIZE_MAX, QLAYOUTSIZE_MAX);
}

/*!
    Returns whether this layout can make use of more space than
    sizeHint(). A value of Qt::Vertical or Qt::Horizontal means that
    it wants to grow in only one dimension, whereas Qt::Vertical |
    Qt::Horizontal means that it wants to grow in both dimensions.

    The default implementation returns Qt::Horizontal | Qt::Vertical.
    Subclasses reimplement it to return a meaningful value based on
    their child widgets's \l{QSizePolicy}{size policies}.