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diff --git a/src/widgets/graphicsview/qgraphicslayoutitem.cpp b/src/widgets/graphicsview/qgraphicslayoutitem.cpp new file mode 100644 index 0000000000..c064e01502 --- /dev/null +++ b/src/widgets/graphicsview/qgraphicslayoutitem.cpp @@ -0,0 +1,935 @@ +/**************************************************************************** +** +** Copyright (C) 2011 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. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qglobal.h" + +#ifndef QT_NO_GRAPHICSVIEW + +#include "qgraphicslayout.h" +#include "qgraphicsscene.h" +#include "qgraphicslayoutitem.h" +#include "qgraphicslayoutitem_p.h" +#include "qwidget.h" +#include "qgraphicswidget.h" + +#include <QtDebug> + +QT_BEGIN_NAMESPACE + +/* + COMBINE_SIZE() is identical to combineSize(), except that it + doesn't evaluate 'size' unless necessary. +*/ +#define COMBINE_SIZE(result, size) \ + do { \ + if ((result).width() < 0 || (result).height() < 0) \ + combineSize((result), (size)); \ + } while (false) + +static void combineSize(QSizeF &result, const QSizeF &size) +{ + if (result.width() < 0) + result.setWidth(size.width()); + if (result.height() < 0) + result.setHeight(size.height()); +} + +static void boundSize(QSizeF &result, const QSizeF &size) +{ + if (size.width() >= 0 && size.width() < result.width()) + result.setWidth(size.width()); + if (size.height() >= 0 && size.height() < result.height()) + result.setHeight(size.height()); +} + +static void expandSize(QSizeF &result, const QSizeF &size) +{ + if (size.width() >= 0 && size.width() > result.width()) + result.setWidth(size.width()); + if (size.height() >= 0 && size.height() > result.height()) + result.setHeight(size.height()); +} + +static void normalizeHints(qreal &minimum, qreal &preferred, qreal &maximum, qreal &descent) +{ + if (minimum >= 0 && maximum >= 0 && minimum > maximum) + minimum = maximum; + + if (preferred >= 0) { + if (minimum >= 0 && preferred < minimum) { + preferred = minimum; + } else if (maximum >= 0 && preferred > maximum) { + preferred = maximum; + } + } + + if (minimum >= 0 && descent > minimum) + descent = minimum; +} + +/*! + \internal +*/ +QGraphicsLayoutItemPrivate::QGraphicsLayoutItemPrivate(QGraphicsLayoutItem *par, bool layout) + : parent(par), userSizeHints(0), isLayout(layout), ownedByLayout(false), graphicsItem(0) +{ +} + +/*! + \internal +*/ +QGraphicsLayoutItemPrivate::~QGraphicsLayoutItemPrivate() +{ + // Remove any lazily allocated data + delete[] userSizeHints; +} + +/*! + \internal +*/ +void QGraphicsLayoutItemPrivate::init() +{ + sizeHintCacheDirty = true; + sizeHintWithConstraintCacheDirty = true; +} + +/*! + \internal +*/ +QSizeF *QGraphicsLayoutItemPrivate::effectiveSizeHints(const QSizeF &constraint) const +{ + Q_Q(const QGraphicsLayoutItem); + QSizeF *sizeHintCache; + const bool hasConstraint = constraint.width() >= 0 || constraint.height() >= 0; + if (hasConstraint) { + if (!sizeHintWithConstraintCacheDirty && constraint == cachedConstraint) + return cachedSizeHintsWithConstraints; + sizeHintCache = cachedSizeHintsWithConstraints; + } else { + if (!sizeHintCacheDirty) + return cachedSizeHints; + sizeHintCache = cachedSizeHints; + } + + for (int i = 0; i < Qt::NSizeHints; ++i) { + sizeHintCache[i] = constraint; + if (userSizeHints) + combineSize(sizeHintCache[i], userSizeHints[i]); + } + + QSizeF &minS = sizeHintCache[Qt::MinimumSize]; + QSizeF &prefS = sizeHintCache[Qt::PreferredSize]; + QSizeF &maxS = sizeHintCache[Qt::MaximumSize]; + QSizeF &descentS = sizeHintCache[Qt::MinimumDescent]; + + normalizeHints(minS.rwidth(), prefS.rwidth(), maxS.rwidth(), descentS.rwidth()); + normalizeHints(minS.rheight(), prefS.rheight(), maxS.rheight(), descentS.rheight()); + + // if the minimum, preferred and maximum sizes contradict each other + // (e.g. the minimum is larger than the maximum) we give priority to + // the maximum size, then the minimum size and finally the preferred size + COMBINE_SIZE(maxS, q->sizeHint(Qt::MaximumSize, maxS)); + combineSize(maxS, QSizeF(QWIDGETSIZE_MAX, QWIDGETSIZE_MAX)); + expandSize(maxS, prefS); + expandSize(maxS, minS); + boundSize(maxS, QSizeF(QWIDGETSIZE_MAX, QWIDGETSIZE_MAX)); + + COMBINE_SIZE(minS, q->sizeHint(Qt::MinimumSize, minS)); + expandSize(minS, QSizeF(0, 0)); + boundSize(minS, prefS); + boundSize(minS, maxS); + + COMBINE_SIZE(prefS, q->sizeHint(Qt::PreferredSize, prefS)); + expandSize(prefS, minS); + boundSize(prefS, maxS); + + // Not supported yet + // COMBINE_SIZE(descentS, q->sizeHint(Qt::MinimumDescent, constraint)); + + if (hasConstraint) { + cachedConstraint = constraint; + sizeHintWithConstraintCacheDirty = false; + } else { + sizeHintCacheDirty = false; + } + return sizeHintCache; +} + + +/*! + \internal + + Returns the parent item of this layout, or 0 if this layout is + not installed on any widget. + + If this is the item that the layout is installed on, it will return "itself". + + If the layout is a sub-layout, this function returns the parent + widget of the parent layout. + + Note that it will traverse up the layout item hierarchy instead of just calling + QGraphicsItem::parentItem(). This is on purpose. + + \sa parent() +*/ +QGraphicsItem *QGraphicsLayoutItemPrivate::parentItem() const +{ + Q_Q(const QGraphicsLayoutItem); + + const QGraphicsLayoutItem *parent = q; + while (parent && parent->isLayout()) { + parent = parent->parentLayoutItem(); + } + return parent ? parent->graphicsItem() : 0; +} + +/*! + \internal + + Ensures that userSizeHints is allocated. + This function must be called before any dereferencing. +*/ +void QGraphicsLayoutItemPrivate::ensureUserSizeHints() +{ + if (!userSizeHints) + userSizeHints = new QSizeF[Qt::NSizeHints]; +} + +/*! + \internal + + Sets the user size hint \a which to \a size. Use an invalid size to unset the size hint. + */ +void QGraphicsLayoutItemPrivate::setSize(Qt::SizeHint which, const QSizeF &size) +{ + Q_Q(QGraphicsLayoutItem); + + if (userSizeHints) { + if (size == userSizeHints[which]) + return; + } else if (size.width() < 0 && size.height() < 0) { + return; + } + + ensureUserSizeHints(); + userSizeHints[which] = size; + q->updateGeometry(); +} + +/*! + \internal + + Sets the width of the user size hint \a which to \a width. + */ +void QGraphicsLayoutItemPrivate::setSizeComponent( + Qt::SizeHint which, SizeComponent component, qreal value) +{ + Q_Q(QGraphicsLayoutItem); + ensureUserSizeHints(); + qreal &userValue = (component == Width) + ? userSizeHints[which].rwidth() + : userSizeHints[which].rheight(); + if (value == userValue) + return; + userValue = value; + q->updateGeometry(); +} + + +bool QGraphicsLayoutItemPrivate::hasHeightForWidth() const +{ + Q_Q(const QGraphicsLayoutItem); + if (isLayout) { + const QGraphicsLayout *l = static_cast<const QGraphicsLayout *>(q); + for (int i = l->count() - 1; i >= 0; --i) { + if (QGraphicsLayoutItemPrivate::get(l->itemAt(i))->hasHeightForWidth()) + return true; + } + } else if (QGraphicsItem *item = q->graphicsItem()) { + if (item->isWidget()) { + QGraphicsWidget *w = static_cast<QGraphicsWidget *>(item); + if (w->layout()) { + return QGraphicsLayoutItemPrivate::get(w->layout())->hasHeightForWidth(); + } + } + } + return q->sizePolicy().hasHeightForWidth(); +} + +bool QGraphicsLayoutItemPrivate::hasWidthForHeight() const +{ + Q_Q(const QGraphicsLayoutItem); + if (isLayout) { + const QGraphicsLayout *l = static_cast<const QGraphicsLayout *>(q); + for (int i = l->count() - 1; i >= 0; --i) { + if (QGraphicsLayoutItemPrivate::get(l->itemAt(i))->hasWidthForHeight()) + return true; + } + } else if (QGraphicsItem *item = q->graphicsItem()) { + if (item->isWidget()) { + QGraphicsWidget *w = static_cast<QGraphicsWidget *>(item); + if (w->layout()) { + return QGraphicsLayoutItemPrivate::get(w->layout())->hasWidthForHeight(); + } + } + } + return q->sizePolicy().hasWidthForHeight(); +} + +/*! + \class QGraphicsLayoutItem + \brief The QGraphicsLayoutItem class can be inherited to allow your custom + items to be managed by layouts. + \since 4.4 + \ingroup graphicsview-api + + QGraphicsLayoutItem is an abstract class that defines a set of virtual + functions describing sizes, size policies, and size hints for any object + arranged by QGraphicsLayout. The API contains functions relevant + for both the item itself and for the user of the item as most of + QGraphicsLayoutItem's functions are also part of the subclass' public API. + + In most cases, existing layout-aware classes such as QGraphicsWidget and + QGraphicsLayout already provide the functionality you require. However, + subclassing these classes will enable you to create both graphical + elements that work well with layouts (QGraphicsWidget) or custom layouts + (QGraphicsLayout). + + \section1 Subclassing QGraphicsLayoutItem + + If you create a subclass of QGraphicsLayoutItem and reimplement its + virtual functions, you will enable the layout to resize and position your + item along with other QGraphicsLayoutItems including QGraphicsWidget + and QGraphicsLayout. + + You can start by reimplementing important functions: the protected + sizeHint() function, as well as the public setGeometry() + function. If you want your items to be aware of immediate geometry + changes, you can also reimplement updateGeometry(). + + The geometry, size hint, and size policy affect the item's size and + position. Calling setGeometry() will always resize and reposition the item + immediately. Normally, this function is called by QGraphicsLayout after + the layout has been activated, but it can also be called by the item's user + at any time. + + The sizeHint() function returns the item' minimum, preferred and maximum + size hints. You can override these properties by calling setMinimumSize(), + setPreferredSize() or setMaximumSize(). You can also use functions such as + setMinimumWidth() or setMaximumHeight() to set only the width or height + component if desired. + + The effectiveSizeHint() function, on the other hand, returns a size hint + for any given Qt::SizeHint, and guarantees that the returned size is bound + to the minimum and maximum sizes and size hints. You can set the item's + vertical and horizontal size policy by calling setSizePolicy(). The + sizePolicy property is used by the layout system to describe how this item + prefers to grow or shrink. + + \section1 Nesting QGraphicsLayoutItems + + QGraphicsLayoutItems can be nested within other QGraphicsLayoutItems, + similar to layouts that can contain sublayouts. This is done either by + passing a QGraphicsLayoutItem pointer to QGraphicsLayoutItem's + protected constructor, or by calling setParentLayoutItem(). The + parentLayoutItem() function returns a pointer to the item's layoutItem + parent. If the item's parent is 0 or if the parent does not inherit + from QGraphicsItem, the parentLayoutItem() function then returns 0. + isLayout() returns true if the QGraphicsLayoutItem subclass is itself a + layout, or false otherwise. + + Qt uses QGraphicsLayoutItem to provide layout functionality in the + \l{Graphics View Framework}, but in the future its use may spread + throughout Qt itself. + + \sa QGraphicsWidget, QGraphicsLayout, QGraphicsLinearLayout, + QGraphicsGridLayout +*/ + +/*! + Constructs the QGraphicsLayoutItem object. \a parent becomes the object's + parent. If \a isLayout is true the item is a layout, otherwise + \a isLayout is false. +*/ +QGraphicsLayoutItem::QGraphicsLayoutItem(QGraphicsLayoutItem *parent, bool isLayout) + : d_ptr(new QGraphicsLayoutItemPrivate(parent, isLayout)) +{ + Q_D(QGraphicsLayoutItem); + d->init(); + d->sizePolicy = QSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred); + d->q_ptr = this; +} + +/*! + \internal +*/ +QGraphicsLayoutItem::QGraphicsLayoutItem(QGraphicsLayoutItemPrivate &dd) + : d_ptr(&dd) +{ + Q_D(QGraphicsLayoutItem); + d->init(); + d->q_ptr = this; +} + +/*! + Destroys the QGraphicsLayoutItem object. +*/ +QGraphicsLayoutItem::~QGraphicsLayoutItem() +{ + QGraphicsLayoutItem *parentLI = parentLayoutItem(); + if (parentLI && parentLI->isLayout()) { + QGraphicsLayout *lay = static_cast<QGraphicsLayout*>(parentLI); + // this is not optimal + for (int i = lay->count() - 1; i >= 0; --i) { + if (lay->itemAt(i) == this) { + lay->removeAt(i); + break; + } + } + } +} + +/*! + \fn virtual QSizeF QGraphicsLayoutItem::sizeHint(Qt::SizeHint which, const QSizeF &constraint) const = 0; + + This pure virtual function returns the size hint for \a which of the + QGraphicsLayoutItem, using the width or height of \a constraint to + constrain the output. + + Reimplement this function in a subclass of QGraphicsLayoutItem to + provide the necessary size hints for your items. + + \sa effectiveSizeHint() +*/ + +/*! + Sets the size policy to \a policy. The size policy describes how the item + should grow horizontally and vertically when arranged in a layout. + + QGraphicsLayoutItem's default size policy is (QSizePolicy::Fixed, + QSizePolicy::Fixed, QSizePolicy::DefaultType), but it is common for + subclasses to change the default. For example, QGraphicsWidget defaults + to (QSizePolicy::Preferred, QSizePolicy::Preferred, + QSizePolicy::DefaultType). + + \sa sizePolicy(), QWidget::sizePolicy() +*/ +void QGraphicsLayoutItem::setSizePolicy(const QSizePolicy &policy) +{ + Q_D(QGraphicsLayoutItem); + if (d->sizePolicy == policy) + return; + d->sizePolicy = policy; + updateGeometry(); +} + +/*! + \overload + + This function is equivalent to calling + setSizePolicy(QSizePolicy(\a hPolicy, \a vPolicy, \a controlType)). + + \sa sizePolicy(), QWidget::sizePolicy() +*/ +void QGraphicsLayoutItem::setSizePolicy(QSizePolicy::Policy hPolicy, + QSizePolicy::Policy vPolicy, + QSizePolicy::ControlType controlType) +{ + setSizePolicy(QSizePolicy(hPolicy, vPolicy, controlType)); +} + +/*! + Returns the current size policy. + + \sa setSizePolicy(), QWidget::sizePolicy() +*/ +QSizePolicy QGraphicsLayoutItem::sizePolicy() const +{ + Q_D(const QGraphicsLayoutItem); + return d->sizePolicy; +} + +/*! + Sets the minimum size to \a size. This property overrides sizeHint() for + Qt::MinimumSize and ensures that effectiveSizeHint() will never return + a size smaller than \a size. In order to unset the minimum size, use an + invalid size. + + \sa minimumSize(), maximumSize(), preferredSize(), Qt::MinimumSize, + sizeHint(), setMinimumWidth(), setMinimumHeight() +*/ +void QGraphicsLayoutItem::setMinimumSize(const QSizeF &size) +{ + d_ptr->setSize(Qt::MinimumSize, size); +} + +/*! + \fn QGraphicsLayoutItem::setMinimumSize(qreal w, qreal h) + + This convenience function is equivalent to calling + setMinimumSize(QSizeF(\a w, \a h)). + + \sa minimumSize(), setMaximumSize(), setPreferredSize(), sizeHint() +*/ + +/*! + Returns the minimum size. + + \sa setMinimumSize(), preferredSize(), maximumSize(), Qt::MinimumSize, + sizeHint() +*/ +QSizeF QGraphicsLayoutItem::minimumSize() const +{ + return effectiveSizeHint(Qt::MinimumSize); +} + +/*! + Sets the minimum width to \a width. + + \sa minimumWidth(), setMinimumSize(), minimumSize() +*/ +void QGraphicsLayoutItem::setMinimumWidth(qreal width) +{ + d_ptr->setSizeComponent(Qt::MinimumSize, d_ptr->Width, width); +} + +/*! + Sets the minimum height to \a height. + + \sa minimumHeight(), setMinimumSize(), minimumSize() +*/ +void QGraphicsLayoutItem::setMinimumHeight(qreal height) +{ + d_ptr->setSizeComponent(Qt::MinimumSize, d_ptr->Height, height); +} + + +/*! + Sets the preferred size to \a size. This property overrides sizeHint() for + Qt::PreferredSize and provides the default value for effectiveSizeHint(). + In order to unset the preferred size, use an invalid size. + + \sa preferredSize(), minimumSize(), maximumSize(), Qt::PreferredSize, + sizeHint() +*/ +void QGraphicsLayoutItem::setPreferredSize(const QSizeF &size) +{ + d_ptr->setSize(Qt::PreferredSize, size); +} + +/*! + \fn QGraphicsLayoutItem::setPreferredSize(qreal w, qreal h) + + This convenience function is equivalent to calling + setPreferredSize(QSizeF(\a w, \a h)). + + \sa preferredSize(), setMaximumSize(), setMinimumSize(), sizeHint() +*/ + +/*! + Returns the preferred size. + + \sa setPreferredSize(), minimumSize(), maximumSize(), Qt::PreferredSize, + sizeHint() +*/ +QSizeF QGraphicsLayoutItem::preferredSize() const +{ + return effectiveSizeHint(Qt::PreferredSize); +} + +/*! + Sets the preferred height to \a height. + + \sa preferredWidth(), setPreferredSize(), preferredSize() +*/ +void QGraphicsLayoutItem::setPreferredHeight(qreal height) +{ + d_ptr->setSizeComponent(Qt::PreferredSize, d_ptr->Height, height); +} + +/*! + Sets the preferred width to \a width. + + \sa preferredHeight(), setPreferredSize(), preferredSize() +*/ +void QGraphicsLayoutItem::setPreferredWidth(qreal width) +{ + d_ptr->setSizeComponent(Qt::PreferredSize, d_ptr->Width, width); +} + +/*! + Sets the maximum size to \a size. This property overrides sizeHint() for + Qt::MaximumSize and ensures that effectiveSizeHint() will never return a + size larger than \a size. In order to unset the maximum size, use an + invalid size. + + \sa maximumSize(), minimumSize(), preferredSize(), Qt::MaximumSize, + sizeHint() +*/ +void QGraphicsLayoutItem::setMaximumSize(const QSizeF &size) +{ + d_ptr->setSize(Qt::MaximumSize, size); +} + +/*! + \fn QGraphicsLayoutItem::setMaximumSize(qreal w, qreal h) + + This convenience function is equivalent to calling + setMaximumSize(QSizeF(\a w, \a h)). + + \sa maximumSize(), setMinimumSize(), setPreferredSize(), sizeHint() +*/ + +/*! + Returns the maximum size. + + \sa setMaximumSize(), minimumSize(), preferredSize(), Qt::MaximumSize, + sizeHint() +*/ +QSizeF QGraphicsLayoutItem::maximumSize() const +{ + return effectiveSizeHint(Qt::MaximumSize); +} + +/*! + Sets the maximum width to \a width. + + \sa maximumWidth(), setMaximumSize(), maximumSize() +*/ +void QGraphicsLayoutItem::setMaximumWidth(qreal width) +{ + d_ptr->setSizeComponent(Qt::MaximumSize, d_ptr->Width, width); +} + +/*! + Sets the maximum height to \a height. + + \sa maximumHeight(), setMaximumSize(), maximumSize() +*/ +void QGraphicsLayoutItem::setMaximumHeight(qreal height) +{ + d_ptr->setSizeComponent(Qt::MaximumSize, d_ptr->Height, height); +} + +/*! + \fn qreal QGraphicsLayoutItem::minimumWidth() const + + Returns the minimum width. + + \sa setMinimumWidth(), setMinimumSize(), minimumSize() +*/ + +/*! + \fn qreal QGraphicsLayoutItem::minimumHeight() const + + Returns the minimum height. + + \sa setMinimumHeight(), setMinimumSize(), minimumSize() +*/ + +/*! + \fn qreal QGraphicsLayoutItem::preferredWidth() const + + Returns the preferred width. + + \sa setPreferredWidth(), setPreferredSize(), preferredSize() +*/ + +/*! + \fn qreal QGraphicsLayoutItem::preferredHeight() const + + Returns the preferred height. + + \sa setPreferredHeight(), setPreferredSize(), preferredSize() +*/ + +/*! + \fn qreal QGraphicsLayoutItem::maximumWidth() const + + Returns the maximum width. + + \sa setMaximumWidth(), setMaximumSize(), maximumSize() +*/ + +/*! + \fn qreal QGraphicsLayoutItem::maximumHeight() const + + Returns the maximum height. + + \sa setMaximumHeight(), setMaximumSize(), maximumSize() +*/ + +/*! + \fn virtual void QGraphicsLayoutItem::setGeometry(const QRectF &rect) + + This virtual function sets the geometry of the QGraphicsLayoutItem to + \a rect, which is in parent coordinates (e.g., the top-left corner of \a rect + is equivalent to the item's position in parent coordinates). + + You must reimplement this function in a subclass of QGraphicsLayoutItem to + receive geometry updates. The layout will call this function when it does a + rearrangement. + + If \a rect is outside of the bounds of minimumSize and maximumSize, it + will be adjusted to its closest size so that it is within the legal + bounds. + + \sa geometry() +*/ +void QGraphicsLayoutItem::setGeometry(const QRectF &rect) +{ + Q_D(QGraphicsLayoutItem); + QSizeF effectiveSize = rect.size().expandedTo(effectiveSizeHint(Qt::MinimumSize)) + .boundedTo(effectiveSizeHint(Qt::MaximumSize)); + d->geom = QRectF(rect.topLeft(), effectiveSize); +} + +/*! + \fn QRectF QGraphicsLayoutItem::geometry() const + + Returns the item's geometry (e.g., position and size) as a + QRectF. This function is equivalent to QRectF(pos(), size()). + + \sa setGeometry() +*/ +QRectF QGraphicsLayoutItem::geometry() const +{ + Q_D(const QGraphicsLayoutItem); + return d->geom; +} + +/*! + This virtual function provides the \a left, \a top, \a right and \a bottom + contents margins for this QGraphicsLayoutItem. The default implementation + assumes all contents margins are 0. The parameters point to values stored + in qreals. If any of the pointers is 0, that value will not be updated. + + \sa QGraphicsWidget::setContentsMargins() +*/ +void QGraphicsLayoutItem::getContentsMargins(qreal *left, qreal *top, qreal *right, qreal *bottom) const +{ + if (left) + *left = 0; + if (top) + *top = 0; + if (right) + *right = 0; + if (bottom) + *bottom = 0; +} + +/*! + Returns the contents rect in local coordinates. + + The contents rect defines the subrectangle used by an associated layout + when arranging subitems. This function is a convenience function that + adjusts the item's geometry() by its contents margins. Note that + getContentsMargins() is a virtual function that you can reimplement to + return the item's contents margins. + + \sa getContentsMargins(), geometry() +*/ +QRectF QGraphicsLayoutItem::contentsRect() const +{ + qreal left, top, right, bottom; + getContentsMargins(&left, &top, &right, &bottom); + return QRectF(QPointF(), geometry().size()).adjusted(+left, +top, -right, -bottom); +} + +/*! + Returns the effective size hint for this QGraphicsLayoutItem. + + \a which is the size hint in question. + \a constraint is an optional argument that defines a special constrain + when calculating the effective size hint. By default, \a constraint is + QSizeF(-1, -1), which means there is no constraint to the size hint. + + If you want to specify the widget's size hint for a given width or height, + you can provide the fixed dimension in \a constraint. This is useful for + widgets that can grow only either vertically or horizontally, and need to + set either their width or their height to a special value. + + For example, a text paragraph item fit into a column width of 200 may + grow vertically. You can pass QSizeF(200, -1) as a constraint to get a + suitable minimum, preferred and maximum height). + + You can adjust the effective size hint by reimplementing sizeHint() + in a QGraphicsLayoutItem subclass, or by calling one of the following + functions: setMinimumSize(), setPreferredSize, or setMaximumSize() + (or a combination of both). + + This function caches each of the size hints and guarantees that + sizeHint() will be called only once for each value of \a which - unless + \a constraint is not specified and updateGeometry() has been called. + + \sa sizeHint() +*/ +QSizeF QGraphicsLayoutItem::effectiveSizeHint(Qt::SizeHint which, const QSizeF &constraint) const +{ + Q_D(const QGraphicsLayoutItem); + + if (!d->userSizeHints && constraint.isValid()) + return constraint; + + // ### should respect size policy??? + return d_ptr->effectiveSizeHints(constraint)[which]; +} + +/*! + This virtual function discards any cached size hint information. You + should always call this function if you change the return value of the + sizeHint() function. Subclasses must always call the base implementation + when reimplementing this function. + + \sa effectiveSizeHint() +*/ +void QGraphicsLayoutItem::updateGeometry() +{ + Q_D(QGraphicsLayoutItem); + d->sizeHintCacheDirty = true; + d->sizeHintWithConstraintCacheDirty = true; +} + +/*! + Returns the parent of this QGraphicsLayoutItem, or 0 if there is no parent, + or if the parent does not inherit from QGraphicsLayoutItem + (QGraphicsLayoutItem is often used through multiple inheritance with + QObject-derived classes). + + \sa setParentLayoutItem() +*/ +QGraphicsLayoutItem *QGraphicsLayoutItem::parentLayoutItem() const +{ + return d_func()->parent; +} + +/*! + Sets the parent of this QGraphicsLayoutItem to \a parent. + + \sa parentLayoutItem() +*/ +void QGraphicsLayoutItem::setParentLayoutItem(QGraphicsLayoutItem *parent) +{ + d_func()->parent = parent; +} + +/*! + Returns true if this QGraphicsLayoutItem is a layout (e.g., is inherited + by an object that arranges other QGraphicsLayoutItem objects); otherwise + returns false. + + \sa QGraphicsLayout +*/ +bool QGraphicsLayoutItem::isLayout() const +{ + return d_func()->isLayout; +} + +/*! + \since 4.6 + + Returns whether a layout should delete this item in its destructor. + If its true, then the layout will delete it. If its false, then it is + assumed that another object has the ownership of it, and the layout won't + delete this item. + + If the item inherits both QGraphicsItem and QGraphicsLayoutItem (such + as QGraphicsWidget does) the item is really part of two ownership + hierarchies. This property informs what the layout should do with its + child items when it is destructed. In the case of QGraphicsWidget, it + is preferred that when the layout is deleted it won't delete its children + (since they are also part of the graphics item hierarchy). + + By default this value is initialized to false in QGraphicsLayoutItem, + but it is overridden by QGraphicsLayout to return true. This is because + QGraphicsLayout is not normally part of the QGraphicsItem hierarchy, so the + parent layout should delete it. + Subclasses might override this default behaviour by calling + setOwnedByLayout(true). + + \sa setOwnedByLayout() +*/ +bool QGraphicsLayoutItem::ownedByLayout() const +{ + return d_func()->ownedByLayout; +} +/*! + \since 4.6 + + Sets whether a layout should delete this item in its destructor or not. + \a ownership must be true to in order for the layout to delete it. + \sa ownedByLayout() +*/ +void QGraphicsLayoutItem::setOwnedByLayout(bool ownership) +{ + d_func()->ownedByLayout = ownership; +} + +/*! + * Returns the QGraphicsItem that this layout item represents. + * For QGraphicsWidget it will return itself. For custom items it can return an + * aggregated value. + * + * \sa setGraphicsItem() + */ +QGraphicsItem *QGraphicsLayoutItem::graphicsItem() const +{ + return d_func()->graphicsItem; +} + +/*! + * If the QGraphicsLayoutItem represents a QGraphicsItem, and it wants to take + * advantage of the automatic reparenting capabilities of QGraphicsLayout it + * should set this value. + * Note that if you delete \a item and not delete the layout item, you are + * responsible of calling setGraphicsItem(0) in order to avoid having a + * dangling pointer. + * + * \sa graphicsItem() + */ +void QGraphicsLayoutItem::setGraphicsItem(QGraphicsItem *item) +{ + d_func()->graphicsItem = item; +} + +QT_END_NAMESPACE + +#endif //QT_NO_GRAPHICSVIEW |