qgraphicslinearlayout.cpp

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// Copyright (C) 2016 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
 
#include "qapplication.h"
 
#include "qwidget.h"
#include "qgraphicslayout_p.h"
#include "qgraphicslayoutitem.h"
#include "qgraphicslinearlayout.h"
#include "qgraphicswidget.h"
#include "qgraphicsgridlayoutengine_p.h"
#include "qgraphicslayoutstyleinfo_p.h"
#include "qscopedpointer.h"
#ifdef QT_DEBUG
#include <QtCore/qdebug.h>
#endif
 
QT_BEGIN_NAMESPACE
 
class QGraphicsLinearLayoutPrivate : public QGraphicsLayoutPrivate
{
public:
    QGraphicsLinearLayoutPrivate(Qt::Orientation orientation)
        : orientation(orientation)
    { }
 
    void removeGridItem(QGridLayoutItem *gridItem);
    QGraphicsLayoutStyleInfo *styleInfo() const;
    void fixIndex(int *index) const;
    int gridRow(int index) const;
    int gridColumn(int index) const;
 
    Qt::Orientation orientation;
    mutable QScopedPointer<QGraphicsLayoutStyleInfo> m_styleInfo;
    QGraphicsGridLayoutEngine engine;
};
 
void QGraphicsLinearLayoutPrivate::removeGridItem(QGridLayoutItem *gridItem)
{
    int index = gridItem->firstRow(orientation);
    engine.removeItem(gridItem);
    engine.removeRows(index, 1, orientation);
}
 
void QGraphicsLinearLayoutPrivate::fixIndex(int *index) const
{
    int count = engine.rowCount(orientation);
    if (uint(*index) > uint(count))
        *index = count;
}
 
int QGraphicsLinearLayoutPrivate::gridRow(int index) const
{
    if (orientation == Qt::Horizontal)
        return 0;
    return int(qMin(uint(index), uint(engine.rowCount())));
}
 
int QGraphicsLinearLayoutPrivate::gridColumn(int index) const
{
    if (orientation == Qt::Vertical)
        return 0;
    return int(qMin(uint(index), uint(engine.columnCount())));
}
 
QGraphicsLayoutStyleInfo *QGraphicsLinearLayoutPrivate::styleInfo() const
{
    if (!m_styleInfo)
        m_styleInfo.reset(new QGraphicsLayoutStyleInfo(this));
    return m_styleInfo.data();
}
 
QGraphicsLinearLayout::QGraphicsLinearLayout(Qt::Orientation orientation, QGraphicsLayoutItem *parent)
    : QGraphicsLayout(*new QGraphicsLinearLayoutPrivate(orientation), parent)
{
}
 
QGraphicsLinearLayout::QGraphicsLinearLayout(QGraphicsLayoutItem *parent)
    : QGraphicsLayout(*new QGraphicsLinearLayoutPrivate(Qt::Horizontal), parent)
{
}
 
QGraphicsLinearLayout::~QGraphicsLinearLayout()
{
    for (int i = count() - 1; i >= 0; --i) {
        QGraphicsLayoutItem *item = itemAt(i);
        // The following lines can be removed, but this removes the item
        // from the layout more efficiently than the implementation of
        // ~QGraphicsLayoutItem.
        removeAt(i);
        if (item) {
            item->setParentLayoutItem(nullptr);
            if (item->ownedByLayout())
                delete item;
        }
    }
}
 
void QGraphicsLinearLayout::setOrientation(Qt::Orientation orientation)
{
    Q_D(QGraphicsLinearLayout);
    if (orientation != d->orientation) {
        d->engine.transpose();
        d->orientation = orientation;
        invalidate();
    }
}
 
Qt::Orientation QGraphicsLinearLayout::orientation() const
{
    Q_D(const QGraphicsLinearLayout);
    return d->orientation;
}
 
void QGraphicsLinearLayout::insertItem(int index, QGraphicsLayoutItem *item)
{
    Q_D(QGraphicsLinearLayout);
    if (!item) {
        qWarning("QGraphicsLinearLayout::insertItem: cannot insert null item");
        return;
    }
    if (item == this) {
        qWarning("QGraphicsLinearLayout::insertItem: cannot insert itself");
        return;
    }
    d->addChildLayoutItem(item);
 
    Q_ASSERT(item);
    d->fixIndex(&index);
    d->engine.insertRow(index, d->orientation);
    QGraphicsGridLayoutEngineItem *gridEngineItem = new QGraphicsGridLayoutEngineItem(item, d->gridRow(index), d->gridColumn(index), 1, 1, { });
    d->engine.insertItem(gridEngineItem, index);
    invalidate();
}
 
void QGraphicsLinearLayout::insertStretch(int index, int stretch)
{
    Q_D(QGraphicsLinearLayout);
    d->fixIndex(&index);
    d->engine.insertRow(index, d->orientation);
    d->engine.setRowStretchFactor(index, stretch, d->orientation);
    invalidate();
}
 
void QGraphicsLinearLayout::removeItem(QGraphicsLayoutItem *item)
{
    Q_D(QGraphicsLinearLayout);
    if (QGraphicsGridLayoutEngineItem *gridItem = d->engine.findLayoutItem(item)) {
        item->setParentLayoutItem(nullptr);
        d->removeGridItem(gridItem);
        delete gridItem;
        invalidate();
    }
}
 
void QGraphicsLinearLayout::removeAt(int index)
{
    Q_D(QGraphicsLinearLayout);
    if (index < 0 || index >= d->engine.itemCount()) {
        qWarning("QGraphicsLinearLayout::removeAt: invalid index %d", index);
        return;
    }
 
    if (QGraphicsGridLayoutEngineItem *gridItem = static_cast<QGraphicsGridLayoutEngineItem*>(d->engine.itemAt(index))) {
        if (QGraphicsLayoutItem *layoutItem = gridItem->layoutItem())
            layoutItem->setParentLayoutItem(nullptr);
        d->removeGridItem(gridItem);
        delete gridItem;
        invalidate();
    }
}
 
void QGraphicsLinearLayout::setSpacing(qreal spacing)
{
    Q_D(QGraphicsLinearLayout);
    if (spacing < 0) {
        qWarning("QGraphicsLinearLayout::setSpacing: invalid spacing %g", spacing);
        return;
    }
    d->engine.setSpacing(spacing, Qt::Horizontal | Qt::Vertical);
    invalidate();
}
 
qreal QGraphicsLinearLayout::spacing() const
{
    Q_D(const QGraphicsLinearLayout);
    return d->engine.spacing(d->orientation, d->styleInfo());
}
 
void QGraphicsLinearLayout::setItemSpacing(int index, qreal spacing)
{
    Q_D(QGraphicsLinearLayout);
    d->engine.setRowSpacing(index, spacing, d->orientation);
    invalidate();
}
qreal QGraphicsLinearLayout::itemSpacing(int index) const
{
    Q_D(const QGraphicsLinearLayout);
    return d->engine.rowSpacing(index, d->orientation);
}
 
void QGraphicsLinearLayout::setStretchFactor(QGraphicsLayoutItem *item, int stretch)
{
    Q_D(QGraphicsLinearLayout);
    if (!item) {
        qWarning("QGraphicsLinearLayout::setStretchFactor: cannot assign"
                 " a stretch factor to a null item");
        return;
    }
    if (stretchFactor(item) == stretch)
        return;
    d->engine.setStretchFactor(item, stretch, d->orientation);
    invalidate();
}
 
int QGraphicsLinearLayout::stretchFactor(QGraphicsLayoutItem *item) const
{
    Q_D(const QGraphicsLinearLayout);
    if (!item) {
        qWarning("QGraphicsLinearLayout::setStretchFactor: cannot return"
                 " a stretch factor for a null item");
        return 0;
    }
    return d->engine.stretchFactor(item, d->orientation);
}
 
void QGraphicsLinearLayout::setAlignment(QGraphicsLayoutItem *item, Qt::Alignment alignment)
{
    Q_D(QGraphicsLinearLayout);
    if (this->alignment(item) == alignment)
        return;
    d->engine.setAlignment(item, alignment);
    invalidate();
}
 
Qt::Alignment QGraphicsLinearLayout::alignment(QGraphicsLayoutItem *item) const
{
    Q_D(const QGraphicsLinearLayout);
    return d->engine.alignment(item);
}
 
#if 0 // ###
QSizePolicy::ControlTypes QGraphicsLinearLayout::controlTypes(LayoutSide side) const
{
    return d->engine.controlTypes(side);
}
#endif
 
int QGraphicsLinearLayout::count() const
{
    Q_D(const QGraphicsLinearLayout);
    return d->engine.itemCount();
}
 
QGraphicsLayoutItem *QGraphicsLinearLayout::itemAt(int index) const
{
    Q_D(const QGraphicsLinearLayout);
    if (index < 0 || index >= d->engine.itemCount()) {
        qWarning("QGraphicsLinearLayout::itemAt: invalid index %d", index);
        return nullptr;
    }
    QGraphicsLayoutItem *item = nullptr;
    if (QGraphicsGridLayoutEngineItem *gridItem = static_cast<QGraphicsGridLayoutEngineItem *>(d->engine.itemAt(index)))
        item = gridItem->layoutItem();
    return item;
}
 
void QGraphicsLinearLayout::setGeometry(const QRectF &rect)
{
    Q_D(QGraphicsLinearLayout);
    QGraphicsLayout::setGeometry(rect);
    QRectF effectiveRect = geometry();
    qreal left, top, right, bottom;
    getContentsMargins(&left, &top, &right, &bottom);
    Qt::LayoutDirection visualDir = d->visualDirection();
    d->engine.setVisualDirection(visualDir);
    if (visualDir == Qt::RightToLeft)
        qSwap(left, right);
    effectiveRect.adjust(+left, +top, -right, -bottom);
#ifdef QGRIDLAYOUTENGINE_DEBUG
    if (qt_graphicsLayoutDebug()) {
        static int counter = 0;
        qDebug() << counter++ << "QGraphicsLinearLayout::setGeometry - " << rect;
        dump(1);
    }
#endif
    d->engine.setGeometries(effectiveRect, d->styleInfo());
#ifdef QGRIDLAYOUTENGINE_DEBUG
    if (qt_graphicsLayoutDebug()) {
        qDebug("post dump");
        dump(1);
    }
#endif
}
 
QSizeF QGraphicsLinearLayout::sizeHint(Qt::SizeHint which, const QSizeF &constraint) const
{
    Q_D(const QGraphicsLinearLayout);
    qreal left, top, right, bottom;
    getContentsMargins(&left, &top, &right, &bottom);
    const QSizeF extraMargins(left + right, top + bottom);
    return d->engine.sizeHint(which , constraint - extraMargins, d->styleInfo()) + extraMargins;
}
 
void QGraphicsLinearLayout::invalidate()
{
    Q_D(QGraphicsLinearLayout);
    d->engine.invalidate();
    if (d->m_styleInfo)
        d->m_styleInfo->invalidate();
    QGraphicsLayout::invalidate();
}
 
void QGraphicsLinearLayout::dump(int indent) const
{
#ifdef QGRIDLAYOUTENGINE_DEBUG
    if (qt_graphicsLayoutDebug()) {
        Q_D(const QGraphicsLinearLayout);
        qDebug("%*s%s layout", indent, "",
               d->orientation == Qt::Horizontal ? "Horizontal" : "Vertical");
        d->engine.dump(indent + 1);
    }
#else
    Q_UNUSED(indent);
#endif
}
 
QT_END_NAMESPACE