qgridlayout.cpp

奇趣公司比较新的qt/emd版本

    bool reverse = ((r.bottom() > rect.bottom()) || (r.bottom() == rect.bottom()
                                                     && ((r.right() > rect.right()) != visualHReversed)));
    int n = things.size();
    for (i = 0; i < n; ++i) {
        QGridBox *box = things.at(reverse ? n-i-1 : i);
        int r2 = box->toRow(rr);
        int c2 = box->toCol(cc);

        int x = colData.at(box->col).pos;
        int y = rData.at(box->row).pos;
        int x2p = colData.at(c2).pos + colData.at(c2).size; // x2+1
        int y2p = rData.at(r2).pos + rData.at(r2).size;    // y2+1
        int w = x2p - x;
        int h = y2p - y;

        if (visualHReversed)
            x = r.left() + r.right() - x - w + 1;
        if (vReversed)
            y = r.top() + r.bottom() - y - h + 1;

        box->setGeometry(QRect(x, y, w, h));
    }
}

QRect QGridLayoutPrivate::cellRect(int row, int col) const
{
    if (row < 0 || row >= rr || col < 0 || col >= cc)
        return QRect();

    const QVector<QLayoutStruct> *rDataPtr;
    if (has_hfw && hfwData)
        rDataPtr = hfwData;
    else
        rDataPtr = &rowData;
    return QRect(colData.at(col).pos, rDataPtr->at(row).pos,
                 colData.at(col).size, rDataPtr->at(row).size);
}

/*!
    \class QGridLayout

    \brief The QGridLayout class lays out widgets in a grid.

    \ingroup geomanagement
    \ingroup appearance
    \mainclass

    QGridLayout takes the space made available to it (by its parent
    layout or by the parentWidget()), divides it up into rows and
    columns, and puts each widget it manages into the correct cell.

    Columns and rows behave identically; we will discuss columns, but
    there are equivalent functions for rows.

    Each column has a minimum width and a stretch factor. The minimum
    width is the greatest of that set using setColumnMinimumWidth() and the
    minimum width of each widget in that column. The stretch factor is
    set using setColumnStretch() and determines how much of the available
    space the column will get over and above its necessary minimum.

    Normally, each managed widget or layout is put into a cell of its
    own using addWidget(). It is also possible for a widget to occupy
    multiple cells using the row and column spanning overloads of
    addItem() and addWidget(). If you do this, QGridLayout will guess
    how to distribute the size over the columns/rows (based on the
    stretch factors).

    To remove a widget from a layout, call remove(). Calling
    QWidget::hide() on a widget also effectively removes the widget
    from the layout until QWidget::show() is called.

    This illustration shows a fragment of a dialog with a five-column,
    three-row grid (the grid is shown overlaid in magenta):

    \image gridlayout.png A grid layout

    Columns 0, 2 and 4 in this dialog fragment are made up of a
    QLabel, a QLineEdit, and a QListBox. Columns 1 and 3 are
    placeholders made with setColumnMinimumWidth(). Row 0 consists of three
    QLabel objects, row 1 of three QLineEdit objects and row 2 of
    three QListBox objects. We used placeholder columns (1 and 3) to
    get the right amount of space between the columns.

    Note that the columns and rows are not equally wide or tall. If
    you want two columns to have the same width, you must set their
    minimum widths and stretch factors to be the same yourself. You do
    this using setColumnMinimumWidth() and setColumnStretch().

    If the QGridLayout is not the top-level layout (i.e. does not
    manage all of the widget's area and children), you must add it to
    its parent layout when you create it, but before you do anything
    with it. The normal way to add a layout is by calling
    addLayout() on the parent layout.

    Once you have added your layout you can start putting widgets and
    other layouts into the cells of your grid layout using
    addWidget(), addItem(), and addLayout().

    QGridLayout also includes two margin widths: the margin() and the
    spacing(). The margin is the width of the reserved space along
    each of the QGridLayout's four sides. The spacing is the width of
    the automatically allocated spacing between neighboring boxes.

    The default margin() and spacing() values are provided by the
    style. The default margin Qt styles specify is 9 for child
    widgets and 11 for windows. The spacing defaults to the same as
    the margin width for a top-level layout, or to the same as the
    parent layout.

    \sa QBoxLayout, QStackedLayout, {Layout Classes}, {Basic Layouts Example}
*/


/*!
    Constructs a new QGridLayout with parent widget, \a parent.  The
    layout has one row and one column initially, and will expand when
    new items are inserted.
*/
QGridLayout::QGridLayout(QWidget *parent)
    : QLayout(*new QGridLayoutPrivate, 0, parent)
{
    Q_D(QGridLayout);
    d->expand(1, 1);
}

/*!
    Constructs a new grid layout.

    You must insert this grid into another layout. You can insert
    widgets and layouts into this layout at any time, but laying out
    will not be performed before this is inserted into another layout.
*/
QGridLayout::QGridLayout()
    : QLayout(*new QGridLayoutPrivate, 0, 0)
{
    Q_D(QGridLayout);
    d->expand(1, 1);
}


#ifdef QT3_SUPPORT
/*!
  \obsolete
    Constructs a new QGridLayout with \a nRows rows, \a nCols columns
    and parent widget, \a  parent. \a parent may not be 0. The grid
    layout is called \a name.

    \a margin is the number of pixels between the edge of the widget
    and its managed children. \a space is the default number of pixels
    between cells. If \a space is -1, the value of \a margin is used.
*/
QGridLayout::QGridLayout(QWidget *parent, int nRows, int nCols, int margin,
                         int space, const char *name)
    : QLayout(*new QGridLayoutPrivate, 0, parent)
{
    Q_D(QGridLayout);
    d->expand(nRows, nCols);
    setMargin(margin);
    setSpacing(space < 0 ? margin : space);
    setObjectName(QString::fromAscii(name));
}

/*!
    \obsolete

    Constructs a new grid with \a nRows rows and \a nCols columns. If
    \a spacing is -1, this QGridLayout inherits its parent's
    spacing(); otherwise \a spacing is used. The grid layout is called
    \a name.

    You must insert this grid into another layout. You can insert
    widgets and layouts into this layout at any time, but laying out
    will not be performed before this is inserted into another layout.
*/
QGridLayout::QGridLayout(QLayout *parentLayout, int nRows, int nCols,
                         int spacing, const char *name)
    : QLayout(*new QGridLayoutPrivate, parentLayout, 0)
{
    Q_D(QGridLayout);
    d->expand(nRows, nCols);
    setSpacing(spacing);
    setObjectName(QString::fromAscii(name));
}

/*!
    \obsolete

    Constructs a new grid with \a nRows rows and \a nCols columns. If
    \a spacing is -1, this QGridLayout inherits its parent's
    spacing(); otherwise \a spacing is used. The grid layout is called
    \a name.

    You must insert this grid into another layout. You can insert
    widgets and layouts into this layout at any time, but laying out
    will not be performed before this is inserted into another layout.
*/
QGridLayout::QGridLayout(int nRows, int nCols, int spacing, const char *name)
    : QLayout(*new QGridLayoutPrivate, 0, 0)
{
    Q_D(QGridLayout);
    d->expand(nRows, nCols);
    setSpacing(spacing);
    setObjectName(QString::fromAscii(name));
}
#endif


/*!
\internal (mostly)

Sets the positioning mode used by addItem(). If \a orient is
Qt::Horizontal, this layout is expanded to \a n columns, and items
will be added columns-first. Otherwise it is expanded to \a n rows and
items will be added rows-first.
*/

void QGridLayout::setDefaultPositioning(int n, Qt::Orientation orient)
{
    Q_D(QGridLayout);
    if (orient == Qt::Horizontal) {
        d->expand(1, n);
        d->addVertical = false;
    } else {
        d->expand(n,1);
        d->addVertical = true;
    }
}


/*!
    Destroys the grid layout. Geometry management is terminated if
    this is a top-level grid.

    The layout's widgets aren't destroyed.
*/
QGridLayout::~QGridLayout()
{
    Q_D(QGridLayout);
    d->deleteAll();
}

/*!
    \property QGridLayout::horizontalSpacing
    \brief the spacing between widgets that are laid out side by side
    \since 4.3

    If no value is explicitly set, the layout's horizontal spacing is
    inherited from the parent layout, or from the style settings for
    the parent widget.

    \sa verticalSpacing, QStyle::pixelMetric(), {QStyle::}{PM_LayoutHorizontalSpacing}
*/
void QGridLayout::setHorizontalSpacing(int spacing)
{
    Q_D(QGridLayout);
    d->horizontalSpacing = spacing;
    invalidate();
}

int QGridLayout::horizontalSpacing() const
{
    Q_D(const QGridLayout);
    if (d->horizontalSpacing >= 0) {
        return d->horizontalSpacing;
    } else {
        return qSmartSpacing(this, QStyle::PM_LayoutHorizontalSpacing);
    }
}

/*!
    \property QGridLayout::verticalSpacing
    \brief the spacing between widgets that are laid out on top of each other
    \since 4.3

    If no value is explicitly set, the layout's vertical spacing is
    inherited from the parent layout, or from the style settings for
    the parent widget.

    \sa horizontalSpacing, QStyle::pixelMetric(), {QStyle::}{PM_LayoutHorizontalSpacing}
*/
void QGridLayout::setVerticalSpacing(int spacing)
{
    Q_D(QGridLayout);
    d->verticalSpacing = spacing;
    invalidate();
}

int QGridLayout::verticalSpacing() const
{
    Q_D(const QGridLayout);
    if (d->verticalSpacing >= 0) {
        return d->verticalSpacing;
    } else {
        return qSmartSpacing(this, QStyle::PM_LayoutVerticalSpacing);
    }
}

/*!
    This function sets both the vertical and horizontal spacing to
    \a spacing.

    \sa setVerticalSpacing(), setHorizontalSpacing()
*/
void QGridLayout::setSpacing(int spacing)
{
    Q_D(QGridLayout);
    d->horizontalSpacing = d->verticalSpacing = spacing;
    invalidate();
}

/*!
    If the vertical spacing is equal to the horizontal spacing,
    this function returns that value; otherwise it return -1.

    \sa setSpacing(), verticalSpacing(), horizontalSpacing()
*/
int QGridLayout::spacing() const
{
    int hSpacing = horizontalSpacing();
    if (hSpacing == verticalSpacing()) {
        return hSpacing;
    } else {
        return -1;
    }
}

/*!
    Returns the number of rows in this grid.
*/
int QGridLayout::rowCount() const
{
    Q_D(const QGridLayout);
    return d->numRows();
}

/*!
    Returns the number of columns in this grid.
*/
int QGridLayout::columnCount() const
{
    Q_D(const QGridLayout);
    return d->numCols();
}

/*!
    \reimp
*/
QSize QGridLayout::sizeHint() const
{
    Q_D(const QGridLayout);
    QSize result(d->sizeHint(horizontalSpacing(), verticalSpacing()));
    int left, top, right, bottom;
    d->effectiveMargins(&left, &top, &right, &bottom);
    result += QSize(left + right, top + bottom);
    return result;
}

/*!
    \reimp
*/
QSize QGridLayout::minimumSize() const
{
    Q_D(const QGridLayout);
    QSize result(d->minimumSize(horizontalSpacing(), verticalSpacing()));
    int left, top, right, bottom;
    d->effectiveMargins(&left, &top, &right, &bottom);
    result += QSize(left + right, top + bottom);
    return result;
}

/*!
    \reimp
*/
QSize QGridLayout::maximumSize() const
{
    Q_D(const QGridLayout);

    QSize s = d->maximumSize(horizontalSpacing(), verticalSpacing());
    int left, top, right, bottom;
    d->effectiveMargins(&left, &top, &right, &bottom);
    s += QSize(left + right, top + bottom);
    s = s.boundedTo(QSize(QLAYOUTSIZE_MAX, QLAYOUTSIZE_MAX));
    if (alignment() & Qt::AlignHorizontal_Mask)
        s.setWidth(QLAYOUTSIZE_MAX);
    if (alignment() & Qt::AlignVertical_Mask)
        s.setHeight(QLAYOUTSIZE_MAX);
    return s;
}

/*!
    \reimp
*/
bool QGridLayout::hasHeightForWidth() const
{
    return ((QGridLayout*)this)->d_func()->hasHeightForWidth(horizontalSpacing(), verticalSpacing());
}

/*!
    \reimp
*/
int QGridLayout::heightForWidth(int w) const
{
    Q_D(const QGridLayout);
    QGridLayoutPrivate *dat = const_cast<QGridLayoutPrivate *>(d);
    return dat->heightForWidth(w, horizontalSpacing(), verticalSpacing());
}

/*!
    \reimp
*/
int QGridLayout::minimumHeightForWidth(int w) const
{
    Q_D(const QGridLayout);
    QGridLayoutPrivate *dat = const_cast<QGridLayoutPrivate *>(d);
    return dat->minimumHeightForWidth(w, horizontalSpacing(), verticalSpacing());
}

#ifdef QT3_SUPPORT
/*!
    \compat

    Searches for widget \a w in this layout (not including child
    layouts). If \a w is found, it sets \c{*}\a{row} and
    \c{*}\a{column} to the row and column that the widget
    occupies and returns true; otherwise returns false.

    If the widget spans multiple rows/columns, the top-left cell
    is returned.

    Use indexOf() and getItemPosition() instead.
*/
bool QGridLayout::findWidget(QWidget* w, int *row, int *column)
{
    Q_D(QGridLayout);
    int index = indexOf(w);
    if (index < 0)
        return false;
    int dummy1, dummy2;
    d->getItemPosition(index, row, column, &dummy1, &dummy2);
    return true;
}
#endif
/*!
    \reimp
*/
int QGridLayout::count() const
{
    Q_D(const QGridLayout);
    return d->count();
}


/*!
    \reimp
*/
QLayoutItem *QGridLayout::itemAt(int index) const
{
    Q_D(const QGridLayout);
    return d->itemAt(index);
}


/*!
    \reimp
*/