--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/gui/graphicsview/qgraphicslinearlayout.cpp Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,559 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*!
+ \class QGraphicsLinearLayout
+ \brief The QGraphicsLinearLayout class provides a horizontal or vertical
+ layout for managing widgets in Graphics View.
+ \since 4.4
+ \ingroup graphicsview-api
+
+ The default orientation for a linear layout is Qt::Horizontal. You can
+ choose a vertical orientation either by calling setOrientation(), or by
+ passing Qt::Vertical to QGraphicsLinearLayout's constructor.
+
+ The most common way to use QGraphicsLinearLayout is to construct an object
+ on the heap with no parent, add widgets and layouts by calling addItem(),
+ and finally assign the layout to a widget by calling
+ QGraphicsWidget::setLayout().
+
+ \snippet doc/src/snippets/code/src_gui_graphicsview_qgraphicslinearlayout.cpp 0
+
+ You can add widgets, layouts, stretches (addStretch(), insertStretch() or
+ setStretchFactor()), and spacings (setItemSpacing()) to a linear
+ layout. The layout takes ownership of the items. In some cases when the layout
+ item also inherits from QGraphicsItem (such as QGraphicsWidget) there will be a
+ ambiguity in ownership because the layout item belongs to two ownership hierarchies.
+ See the documentation of QGraphicsLayoutItem::setOwnedByLayout() how to handle
+ this.
+ You can access each item in the layout by calling count() and itemAt(). Calling
+ removeAt() or removeItem() will remove an item from the layout, without
+ destroying it.
+
+ \section1 Size Hints and Size Policies in QGraphicsLinearLayout
+
+ QGraphicsLinearLayout respects each item's size hints and size policies,
+ and when the layout contains more space than the items can fill, each item
+ is arranged according to the layout's alignment for that item. You can set
+ an alignment for each item by calling setAlignment(), and check the
+ alignment for any item by calling alignment(). By default, items are
+ centered both vertically and horizontally.
+
+ \section1 Spacing within QGraphicsLinearLayout
+
+ Between the items, the layout distributes some space. The actual amount of
+ space depends on the managed widget's current style, but the common
+ spacing is 4. You can also set your own spacing by calling setSpacing(),
+ and get the current spacing value by calling spacing(). If you want to
+ configure individual spacing for your items, you can call setItemSpacing().
+
+ \section1 Stretch Factor in QGraphicsLinearLayout
+
+ You can assign a stretch factor to each item to control how much space it
+ will get compared to the other items. By default, two identical widgets
+ arranged in a linear layout will have the same size, but if the first
+ widget has a stretch factor of 1 and the second widget has a stretch
+ factor of 2, the first widget will get 1/3 of the available space, and the
+ second will get 2/3.
+
+ QGraphicsLinearLayout calculates the distribution of sizes by adding up
+ the stretch factors of all items, and then dividing the available space
+ accordingly. The default stretch factor is 0 for all items; a factor of 0
+ means the item does not have any defined stretch factor; effectively this
+ is the same as setting the stretch factor to 1. The stretch factor only
+ applies to the available space in the lengthwise direction of the layout
+ (following its orientation). If you want to control both the item's
+ horizontal and vertical stretch, you can use QGraphicsGridLayout instead.
+
+ \section1 QGraphicsLinearLayout Compared to Other Layouts
+
+ QGraphicsLinearLayout is very similar to QVBoxLayout and QHBoxLayout, but
+ in contrast to these classes, it is used to manage QGraphicsWidget and
+ QGraphicsLayout instead of QWidget and QLayout.
+
+ \sa QGraphicsGridLayout, QGraphicsWidget
+*/
+
+#include "qapplication.h"
+
+#ifndef QT_NO_GRAPHICSVIEW
+
+#include "qwidget.h"
+#include "qgraphicslayout_p.h"
+#include "qgraphicslayoutitem.h"
+#include "qgraphicslinearlayout.h"
+#include "qgraphicswidget.h"
+#include "qgridlayoutengine_p.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);
+ QLayoutStyleInfo styleInfo() const;
+ void fixIndex(int *index) const;
+ int gridRow(int index) const;
+ int gridColumn(int index) const;
+
+ Qt::Orientation orientation;
+ QGridLayoutEngine engine;
+};
+
+void QGraphicsLinearLayoutPrivate::removeGridItem(QGridLayoutItem *gridItem)
+{
+ int index = gridItem->firstRow(orientation);
+ engine.removeItem(gridItem);
+ engine.removeRow(index, 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())));
+}
+
+QLayoutStyleInfo QGraphicsLinearLayoutPrivate::styleInfo() const
+{
+ static QWidget *wid = 0;
+ if (!wid)
+ wid = new QWidget;
+ QGraphicsItem *item = parentItem();
+ QStyle *style = (item && item->isWidget()) ? static_cast<QGraphicsWidget*>(item)->style() : QApplication::style();
+ return QLayoutStyleInfo(style, wid);
+}
+
+/*!
+ Constructs a QGraphicsLinearLayout instance. You can pass the
+ \a orientation for the layout, either horizontal or vertical, and
+ \a parent is passed to QGraphicsLayout's constructor.
+*/
+QGraphicsLinearLayout::QGraphicsLinearLayout(Qt::Orientation orientation, QGraphicsLayoutItem *parent)
+ : QGraphicsLayout(*new QGraphicsLinearLayoutPrivate(orientation), parent)
+{
+}
+
+/*!
+ Constructs a QGraphicsLinearLayout instance using Qt::Horizontal
+ orientation. \a parent is passed to QGraphicsLayout's constructor.
+*/
+QGraphicsLinearLayout::QGraphicsLinearLayout(QGraphicsLayoutItem *parent)
+ : QGraphicsLayout(*new QGraphicsLinearLayoutPrivate(Qt::Horizontal), parent)
+{
+}
+
+/*!
+ Destroys the QGraphicsLinearLayout object.
+*/
+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(0);
+ if (item->ownedByLayout())
+ delete item;
+ }
+ }
+}
+
+/*!
+ Change the layout orientation to \a orientation. Changing the layout
+ orientation will automatically invalidate the layout.
+
+ \sa orientation()
+*/
+void QGraphicsLinearLayout::setOrientation(Qt::Orientation orientation)
+{
+ Q_D(QGraphicsLinearLayout);
+ if (orientation != d->orientation) {
+ d->engine.transpose();
+ d->orientation = orientation;
+ invalidate();
+ }
+}
+
+/*!
+ Returns the layout orientation.
+ \sa setOrientation()
+ */
+Qt::Orientation QGraphicsLinearLayout::orientation() const
+{
+ Q_D(const QGraphicsLinearLayout);
+ return d->orientation;
+}
+
+/*!
+ \fn void QGraphicsLinearLayout::addItem(QGraphicsLayoutItem *item)
+
+ This convenience function is equivalent to calling
+ insertItem(-1, \a item).
+*/
+
+/*!
+ \fn void QGraphicsLinearLayout::addStretch(int stretch)
+
+ This convenience function is equivalent to calling
+ insertStretch(-1, \a stretch).
+*/
+
+/*!
+ Inserts \a item into the layout at \a index, or before any item that is
+ currently at \a index.
+
+ \sa addItem(), itemAt(), insertStretch(), setItemSpacing()
+*/
+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);
+ new QGridLayoutItem(&d->engine, item, d->gridRow(index), d->gridColumn(index), 1, 1, 0, index);
+ invalidate();
+}
+
+/*!
+ Inserts a stretch of \a stretch at \a index, or before any item that is
+ currently at \a index.
+
+ \sa addStretch(), setStretchFactor(), setItemSpacing(), insertItem()
+*/
+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();
+}
+
+/*!
+ Removes \a item from the layout without destroying it. Ownership of
+ \a item is transferred to the caller.
+
+ \sa removeAt(), insertItem()
+*/
+void QGraphicsLinearLayout::removeItem(QGraphicsLayoutItem *item)
+{
+ Q_D(QGraphicsLinearLayout);
+ if (QGridLayoutItem *gridItem = d->engine.findLayoutItem(item)) {
+ item->setParentLayoutItem(0);
+ d->removeGridItem(gridItem);
+ delete gridItem;
+ invalidate();
+ }
+}
+
+/*!
+ Removes the item at \a index without destroying it. Ownership of the item
+ is transferred to the caller.
+
+ \sa removeItem(), insertItem()
+*/
+void QGraphicsLinearLayout::removeAt(int index)
+{
+ Q_D(QGraphicsLinearLayout);
+ if (index < 0 || index >= d->engine.itemCount()) {
+ qWarning("QGraphicsLinearLayout::removeAt: invalid index %d", index);
+ return;
+ }
+ if (QGridLayoutItem *gridItem = d->engine.itemAt(index)) {
+ if (QGraphicsLayoutItem *layoutItem = gridItem->layoutItem())
+ layoutItem->setParentLayoutItem(0);
+ d->removeGridItem(gridItem);
+ delete gridItem;
+ invalidate();
+ }
+}
+
+/*!
+ Sets the layout's spacing to \a spacing. Spacing refers to the
+ vertical and horizontal distances between items.
+
+ \sa setItemSpacing(), setStretchFactor(), QGraphicsGridLayout::setSpacing()
+*/
+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();
+}
+
+/*!
+ Returns the layout's spacing. Spacing refers to the
+ vertical and horizontal distances between items.
+
+ \sa setSpacing()
+ */
+qreal QGraphicsLinearLayout::spacing() const
+{
+ Q_D(const QGraphicsLinearLayout);
+ return d->engine.spacing(d->styleInfo(), d->orientation);
+}
+
+/*!
+ Sets the spacing after item at \a index to \a spacing.
+*/
+void QGraphicsLinearLayout::setItemSpacing(int index, qreal spacing)
+{
+ Q_D(QGraphicsLinearLayout);
+ d->engine.setRowSpacing(index, spacing, d->orientation);
+ invalidate();
+}
+/*!
+ Returns the spacing after item at \a index.
+*/
+qreal QGraphicsLinearLayout::itemSpacing(int index) const
+{
+ Q_D(const QGraphicsLinearLayout);
+ return d->engine.rowSpacing(index, d->orientation);
+}
+
+/*!
+ Sets the stretch factor for \a item to \a stretch. If an item's stretch
+ factor changes, this function will invalidate the layout.
+
+ Setting \a stretch to 0 removes the stretch factor from the item, and is
+ effectively equivalent to setting \a stretch to 1.
+
+ \sa stretchFactor()
+*/
+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();
+}
+
+/*!
+ Returns the stretch factor for \a item. The default stretch factor is 0,
+ meaning that the item has no assigned stretch factor.
+
+ \sa setStretchFactor()
+*/
+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);
+}
+
+/*!
+ Sets the alignment of \a item to \a alignment. If \a item's alignment
+ changes, the layout is automatically invalidated.
+
+ \sa alignment(), invalidate()
+*/
+void QGraphicsLinearLayout::setAlignment(QGraphicsLayoutItem *item, Qt::Alignment alignment)
+{
+ Q_D(QGraphicsLinearLayout);
+ if (this->alignment(item) == alignment)
+ return;
+ d->engine.setAlignment(item, alignment);
+ invalidate();
+}
+
+/*!
+ Returns the alignment for \a item. The default alignment is
+ Qt::AlignCenter.
+
+ The alignment decides how the item is positioned within its assigned space
+ in the case where there's more space available in the layout than the
+ widgets can occupy.
+
+ \sa setAlignment()
+*/
+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
+
+/*!
+ \reimp
+*/
+int QGraphicsLinearLayout::count() const
+{
+ Q_D(const QGraphicsLinearLayout);
+ return d->engine.itemCount();
+}
+
+/*!
+ \reimp
+ When iterating from 0 and up, it will return the items in the visual arranged order.
+*/
+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 0;
+ }
+ QGraphicsLayoutItem *item = 0;
+ if (QGridLayoutItem *gridItem = d->engine.itemAt(index))
+ item = gridItem->layoutItem();
+ return item;
+}
+
+/*!
+ \reimp
+*/
+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 QT_DEBUG
+ if (qt_graphicsLayoutDebug()) {
+ static int counter = 0;
+ qDebug() << counter++ << "QGraphicsLinearLayout::setGeometry - " << rect;
+ dump(1);
+ }
+#endif
+ d->engine.setGeometries(d->styleInfo(), effectiveRect);
+#ifdef QT_DEBUG
+ if (qt_graphicsLayoutDebug()) {
+ qDebug() << "post dump";
+ dump(1);
+ }
+#endif
+}
+
+/*!
+ \reimp
+*/
+QSizeF QGraphicsLinearLayout::sizeHint(Qt::SizeHint which, const QSizeF &constraint) const
+{
+ Q_D(const QGraphicsLinearLayout);
+ qreal left, top, right, bottom;
+ getContentsMargins(&left, &top, &right, &bottom);
+ return d->engine.sizeHint(d->styleInfo(), which , constraint) + QSizeF(left + right, top + bottom);
+}
+
+/*!
+ \reimp
+*/
+void QGraphicsLinearLayout::invalidate()
+{
+ Q_D(QGraphicsLinearLayout);
+ d->engine.invalidate();
+ QGraphicsLayout::invalidate();
+}
+
+#ifdef QT_DEBUG
+void QGraphicsLinearLayout::dump(int indent) const
+{
+ if (qt_graphicsLayoutDebug()) {
+ Q_D(const QGraphicsLinearLayout);
+ qDebug("%*s%s layout", indent, "",
+ d->orientation == Qt::Horizontal ? "Horizontal" : "Vertical");
+ d->engine.dump(indent + 1);
+ }
+}
+#endif
+
+QT_END_NAMESPACE
+
+#endif //QT_NO_GRAPHICSVIEW