q3listview.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

}


/*!
    Sets this item's height to \a height pixels. This implicitly
    changes totalHeight(), too.

    Note that a font change causes this height to be overwritten
    unless you reimplement setup().

    For best results in Windows style we suggest using an even number
    of pixels.

    \sa height() totalHeight() isOpen()
*/

void Q3ListViewItem::setHeight(int height)
{
    if (ownHeight != height) {
        if (visible)
            ownHeight = height;
        else
            ownHeight = 0;
        invalidateHeight();
    }
}


/*!
    Invalidates the cached total height of this item, including all
    open children.

    \sa setHeight() height() totalHeight()
*/

void Q3ListViewItem::invalidateHeight()
{
    if (maybeTotalHeight < 0)
        return;
    maybeTotalHeight = -1;
    if (parentItem && parentItem->isOpen())
        parentItem->invalidateHeight();
}


/*!
    Opens or closes an item, i.e. shows or hides an item's children.

    If \a o is true all child items are shown initially. The user can
    hide them by clicking the \bold{-} icon to the left of the item.
    If \a o is false, the children of this item are initially hidden.
    The user can show them by clicking the \bold{+} icon to the left
    of the item.

    \sa height() totalHeight() isOpen()
*/

void Q3ListViewItem::setOpen(bool o)
{
    if (o == (bool)open || !enabled)
        return;
    open = o;

    // If no children to show simply emit signals and return
    if (!nChildren) {
        Q3ListView *lv = listView();
        if (lv && this != lv->d->r) {
            if (o)
                emit lv->expanded(this);
            else
                emit lv->collapsed(this);
#ifndef QT_NO_ACCESSIBILITY
            QAccessible::updateAccessibility(lv->viewport(), indexOfItem(this), QAccessible::StateChanged);
#endif
        }
        return;
    }
    invalidateHeight();

    if (!configured) {
        Q3ListViewItem * l = this;
        QStack<Q3ListViewItem *> s;
        while(l) {
            if (l->open && l->childItem) {
                s.push(l->childItem);
            } else if (l->childItem) {
                // first invisible child is unconfigured
                Q3ListViewItem * c = l->childItem;
                while(c) {
                    c->configured = false;
                    c = c->siblingItem;
                }
            }
            l->configured = true;
            l->setup();
            l = (l == this) ? 0 : l->siblingItem;
            if (!l && !s.isEmpty())
                l = s.pop();
        }
    }

    Q3ListView *lv = listView();

    if (open && lv)
        enforceSortOrder();

    if (isVisible() && lv && lv->d && !lv->d->drawables.isEmpty())
        lv->buildDrawableList();

    if (lv && this != lv->d->r) {
        if (o)
            emit lv->expanded(this);
        else
            emit lv->collapsed(this);
#ifndef QT_NO_ACCESSIBILITY
        QAccessible::updateAccessibility(lv->viewport(), indexOfItem(this), QAccessible::StateChanged);
#endif
    }
}


/*!
    This virtual function is called before the first time Q3ListView
    needs to know the height or any other graphical attribute of this
    object, and whenever the font, GUI style, or colors of the list
    view change.

    The default calls widthChanged() and sets the item's height to the
    height of a single line of text in the list view's font. (If you
    use icons, multi-line text, etc., you will probably need to call
    setHeight() yourself or reimplement it.)
*/

void Q3ListViewItem::setup()
{
    widthChanged();
    Q3ListView *lv = listView();

    int ph = 0;
    int h = 0;
    if (lv) {
        for (int i = 0; i < lv->d->column.size(); ++i) {
            if (pixmap(i))
                ph = qMax(ph, pixmap(i)->height());
        }

        if (mlenabled) {
            h = ph;
            for (int c = 0; c < lv->columns(); ++c) {
                int lines = text(c).count(QChar('\n')) + 1;
                int tmph = lv->d->fontMetricsHeight
                           + lv->fontMetrics().lineSpacing() * (lines - 1);
                h = qMax(h, tmph);
            }
            h += 2*lv->itemMargin();
        } else {
            h = qMax(lv->d->fontMetricsHeight, ph) + 2*lv->itemMargin();
        }
    }

    h = qMax(h, QApplication::globalStrut().height());

    if (h % 2 > 0)
        h++;
    setHeight(h);
}




/*!
    This virtual function is called whenever the user presses the mouse
    on this item or presses Space on it.

    \sa activatedPos()
*/

void Q3ListViewItem::activate()
{
}


/*!
    When called from a reimplementation of activate(), this function
    gives information on how the item was activated. Otherwise the
    behavior is undefined.

    If activate() was caused by a mouse press, the function sets \a
    pos to where the user clicked and returns true; otherwise it
    returns false and does not change \a pos.

    \a pos is relative to the top-left corner of this item.

    \sa activate()
*/

bool Q3ListViewItem::activatedPos(QPoint &pos)
{
    if (activatedByClick)
        pos = activatedP;
    return activatedByClick;
}


/*!
    \fn bool Q3ListViewItem::isSelectable() const

    Returns true if the item is selectable (as it is by default);
    otherwise returns false

    \sa setSelectable()
*/


/*!
    Sets this items to be selectable if \a enable is true (the
    default) or not to be selectable if \a enable is false.

    The user is not able to select a non-selectable item using either
    the keyboard or the mouse. The application programmer still can
    though, e.g. using setSelected().

    \sa isSelectable()
*/

void Q3ListViewItem::setSelectable(bool enable)
{
    selectable = enable;
}


/*!
    \fn bool Q3ListViewItem::isExpandable() const

    Returns true if this item is expandable even when it has no
    children; otherwise returns false.
*/

/*!
    Sets this item to be expandable even if it has no children if \a
    enable is true, and to be expandable only if it has children if \a
    enable is false (the default).

    The dirview example uses this in the canonical fashion. It checks
    whether the directory is empty in setup() and calls
    setExpandable(true) if not; in setOpen() it reads the contents of
    the directory and inserts items accordingly. This strategy means
    that dirview can display the entire file system without reading
    very much at startup.

    Note that root items are not expandable by the user unless
    Q3ListView::setRootIsDecorated() is set to true.

    \sa setSelectable()
*/

void Q3ListViewItem::setExpandable(bool enable)
{
    expandable = enable;
}


/*!
    Makes sure that this object's children are sorted appropriately.

    This only works if every item from the root item down to this item
    is already sorted.

    \sa sortChildItems()
*/

void Q3ListViewItem::enforceSortOrder() const
{
    Q3ListView *lv = listView();
    if (!lv || lv && (lv->d->clearing || lv->d->sortcolumn == Unsorted))
        return;
    if (parentItem &&
         (parentItem->lsc != lsc || parentItem->lso != lso))
        ((Q3ListViewItem *)this)->sortChildItems((int)parentItem->lsc,
                                                 (bool)parentItem->lso);
    else if (!parentItem &&
              ((int)lsc != lv->d->sortcolumn || (bool)lso != lv->d->ascending))
        ((Q3ListViewItem *)this)->sortChildItems(lv->d->sortcolumn, lv->d->ascending);
}


/*!
    \fn bool Q3ListViewItem::isSelected() const

    Returns true if this item is selected; otherwise returns false.

    \sa setSelected() Q3ListView::setSelected() Q3ListView::selectionChanged()
*/


/*!
    If \a s is true this item is selected; otherwise it is deselected.

    This function does not maintain any invariants or repaint anything
    -- Q3ListView::setSelected() does that.

    \sa height() totalHeight()
*/

void Q3ListViewItem::setSelected(bool s)
{
    bool old = selected;

    Q3ListView *lv = listView();
    if (lv && lv->selectionMode() != Q3ListView::NoSelection) {
        if (s && isSelectable())
            selected = true;
        else
            selected = false;

#ifndef QT_NO_ACCESSIBILITY
        if (old != (bool)selected) {
            int ind = indexOfItem(this);
            QAccessible::updateAccessibility(lv->viewport(), ind, QAccessible::StateChanged);
            QAccessible::updateAccessibility(lv->viewport(), ind, selected ? QAccessible::SelectionAdd : QAccessible::SelectionRemove);
        }
#else
        Q_UNUSED(old);
#endif
    }
}

/*!
    Returns the total height of this object, including any visible
    children. This height is recomputed lazily and cached for as long
    as possible.

    Functions which can affect the total height are, setHeight() which
    is used to set an item's height, setOpen() to show or hide an
    item's children, and invalidateHeight() to invalidate the cached
    height.

    \sa height()
*/

int Q3ListViewItem::totalHeight() const
{
    if (!visible)
        return 0;
    if (maybeTotalHeight >= 0)
        return maybeTotalHeight;
    Q3ListViewItem * that = (Q3ListViewItem *)this;
    if (!that->configured) {
        that->configured = true;
        that->setup(); // ### virtual non-const function called in const
    }
    that->maybeTotalHeight = that->ownHeight;

    if (!that->isOpen() || !that->childCount())
        return that->ownHeight;

    Q3ListViewItem * child = that->childItem;
    while (child != 0) {
        that->maybeTotalHeight += child->totalHeight();
        child = child->siblingItem;
    }
    return that->maybeTotalHeight;
}


/*!
    Returns the text in column \a column, or an empty string if there is
    no text in that column.

    \sa key() paintCell()
*/

QString Q3ListViewItem::text(int column) const
{
    Q3ListViewPrivate::ItemColumnInfo * l
        = (Q3ListViewPrivate::ItemColumnInfo*) columns;

    while(column && l) {
        l = l->next;
        column--;
    }

    return l ? l->text : QString();
}


/*!
    Sets the text in column \a column to \a text, if \a column is a
    valid column number and \a text is different from the existing
    text.

    If the text() function has been reimplemented, this function may
    be a no-op.

    \sa text() key()
*/

void Q3ListViewItem::setText(int column, const QString &text)
{
    if (column < 0)
        return;

    Q3ListViewPrivate::ItemColumnInfo * l
        = (Q3ListViewPrivate::ItemColumnInfo*) columns;
    if (!l) {
        l = new Q3ListViewPrivate::ItemColumnInfo;
        columns = (void*)l;
    }
    for(int c = 0; c < column; c++) {
        if (!l->next)
            l->next = new Q3ListViewPrivate::ItemColumnInfo;
        l = l->next;
    }
    if (l->text == text)
        return;

    int oldLc = 0;
    int newLc = 0;
    if (mlenabled) {
        if (!l->text.isEmpty())
            oldLc = l->text.count(QChar('\n')) + 1;
        if (!text.isEmpty())
            newLc = text.count(QChar('\n')) + 1;
    }

    l->dirty = true;
    l->text = text;
    if (column == (int)lsc)
        lsc = Unsorted;

    if (mlenabled && oldLc != newLc)
        setup();
    else
        widthChanged(column);

    Q3ListView * lv = listView();
    if (lv) {
        lv->triggerUpdate();
#ifndef QT_NO_ACCESSIBILITY
        if (lv->isVisible())
            QAccessible::updateAccessibility(lv->viewport(), indexOfItem(this), QAccessible::NameChanged);
#endif
    }
}


/*!
    Sets the pixmap in column \a column to \a pm, if \a pm is non-null
    and different from the current pixmap, and if \a column is
    non-negative.

    \sa pixmap() setText()
*/

void Q3ListViewItem::setPixmap(int column, const QPixmap & pm)
{
    if (column < 0)