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+/****************************************************************************
+**
+** 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 "qstackedlayout.h"
+#include "qlayout_p.h"
+
+#include <qlist.h>
+#include <qwidget.h>
+#include "private/qlayoutengine_p.h"
+
+QT_BEGIN_NAMESPACE
+
+class QStackedLayoutPrivate : public QLayoutPrivate
+{
+ Q_DECLARE_PUBLIC(QStackedLayout)
+public:
+ QStackedLayoutPrivate() : index(-1), stackingMode(QStackedLayout::StackOne) {}
+ QList<QLayoutItem *> list;
+ int index;
+ QStackedLayout::StackingMode stackingMode;
+};
+
+/*!
+ \class QStackedLayout
+
+ \brief The QStackedLayout class provides a stack of widgets where
+ only one widget is visible at a time.
+
+ \ingroup geomanagement
+
+ QStackedLayout can be used to create a user interface similar to
+ the one provided by QTabWidget. There is also a convenience
+ QStackedWidget class built on top of QStackedLayout.
+
+ A QStackedLayout can be populated with a number of child widgets
+ ("pages"). For example:
+
+ \snippet doc/src/snippets/qstackedlayout/main.cpp 0
+ \codeline
+ \snippet doc/src/snippets/qstackedlayout/main.cpp 2
+ \snippet doc/src/snippets/qstackedlayout/main.cpp 3
+
+ QStackedLayout provides no intrinsic means for the user to switch
+ page. This is typically done through a QComboBox or a QListWidget
+ that stores the titles of the QStackedLayout's pages. For
+ example:
+
+ \snippet doc/src/snippets/qstackedlayout/main.cpp 1
+
+ When populating a layout, the widgets are added to an internal
+ list. The indexOf() function returns the index of a widget in that
+ list. The widgets can either be added to the end of the list using
+ the addWidget() function, or inserted at a given index using the
+ insertWidget() function. The removeWidget() function removes the
+ widget at the given index from the layout. The number of widgets
+ contained in the layout, can be obtained using the count()
+ function.
+
+ The widget() function returns the widget at a given index
+ position. The index of the widget that is shown on screen is given
+ by currentIndex() and can be changed using setCurrentIndex(). In a
+ similar manner, the currently shown widget can be retrieved using
+ the currentWidget() function, and altered using the
+ setCurrentWidget() function.
+
+ Whenever the current widget in the layout changes or a widget is
+ removed from the layout, the currentChanged() and widgetRemoved()
+ signals are emitted respectively.
+
+ \sa QStackedWidget, QTabWidget
+*/
+
+/*!
+ \fn void QStackedLayout::currentChanged(int index)
+
+ This signal is emitted whenever the current widget in the layout
+ changes. The \a index specifies the index of the new current
+ widget, or -1 if there isn't a new one (for example, if there
+ are no widgets in the QStackedLayout)
+
+ \sa currentWidget(), setCurrentWidget()
+*/
+
+/*!
+ \fn void QStackedLayout::widgetRemoved(int index)
+
+ This signal is emitted whenever a widget is removed from the
+ layout. The widget's \a index is passed as parameter.
+
+ \sa removeWidget()
+*/
+
+/*!
+ \fn QWidget *QStackedLayout::widget()
+ \internal
+*/
+
+/*!
+ Constructs a QStackedLayout with no parent.
+
+ This QStackedLayout must be installed on a widget later on to
+ become effective.
+
+ \sa addWidget(), insertWidget()
+*/
+QStackedLayout::QStackedLayout()
+ : QLayout(*new QStackedLayoutPrivate, 0, 0)
+{
+}
+
+/*!
+ Constructs a new QStackedLayout with the given \a parent.
+
+ This layout will install itself on the \a parent widget and
+ manage the geometry of its children.
+*/
+QStackedLayout::QStackedLayout(QWidget *parent)
+ : QLayout(*new QStackedLayoutPrivate, 0, parent)
+{
+}
+
+/*!
+ Constructs a new QStackedLayout and inserts it into
+ the given \a parentLayout.
+*/
+QStackedLayout::QStackedLayout(QLayout *parentLayout)
+ : QLayout(*new QStackedLayoutPrivate, parentLayout, 0)
+{
+}
+
+/*!
+ Destroys this QStackedLayout. Note that the layout's widgets are
+ \e not destroyed.
+*/
+QStackedLayout::~QStackedLayout()
+{
+ Q_D(QStackedLayout);
+ qDeleteAll(d->list);
+}
+
+/*!
+ Adds the given \a widget to the end of this layout and returns the
+ index position of the \a widget.
+
+ If the QStackedLayout is empty before this function is called,
+ the given \a widget becomes the current widget.
+
+ \sa insertWidget(), removeWidget(), setCurrentWidget()
+*/
+int QStackedLayout::addWidget(QWidget *widget)
+{
+ Q_D(QStackedLayout);
+ return insertWidget(d->list.count(), widget);
+}
+
+/*!
+ Inserts the given \a widget at the given \a index in this
+ QStackedLayout. If \a index is out of range, the widget is
+ appended (in which case it is the actual index of the \a widget
+ that is returned).
+
+ If the QStackedLayout is empty before this function is called, the
+ given \a widget becomes the current widget.
+
+ Inserting a new widget at an index less than or equal to the current index
+ will increment the current index, but keep the current widget.
+
+ \sa addWidget(), removeWidget(), setCurrentWidget()
+*/
+int QStackedLayout::insertWidget(int index, QWidget *widget)
+{
+ Q_D(QStackedLayout);
+ addChildWidget(widget);
+ index = qMin(index, d->list.count());
+ if (index < 0)
+ index = d->list.count();
+ QWidgetItem *wi = QLayoutPrivate::createWidgetItem(this, widget);
+ d->list.insert(index, wi);
+ invalidate();
+ if (d->index < 0) {
+ setCurrentIndex(index);
+ } else {
+ if (index <= d->index)
+ ++d->index;
+ if (d->stackingMode == StackOne)
+ widget->hide();
+ widget->lower();
+ }
+ return index;
+}
+
+/*!
+ \reimp
+*/
+QLayoutItem *QStackedLayout::itemAt(int index) const
+{
+ Q_D(const QStackedLayout);
+ return d->list.value(index);
+}
+
+// Code that enables proper handling of the case that takeAt() is
+// called somewhere inside QObject destructor (can't call hide()
+// on the object then)
+
+class QtFriendlyLayoutWidget : public QWidget
+{
+public:
+ inline bool wasDeleted() const { return d_ptr->wasDeleted; }
+};
+
+static bool qt_wasDeleted(const QWidget *w) { return static_cast<const QtFriendlyLayoutWidget*>(w)->wasDeleted(); }
+
+
+/*!
+ \reimp
+*/
+QLayoutItem *QStackedLayout::takeAt(int index)
+{
+ Q_D(QStackedLayout);
+ if (index <0 || index >= d->list.size())
+ return 0;
+ QLayoutItem *item = d->list.takeAt(index);
+ if (index == d->index) {
+ d->index = -1;
+ if ( d->list.count() > 0 ) {
+ int newIndex = (index == d->list.count()) ? index-1 : index;
+ setCurrentIndex(newIndex);
+ } else {
+ emit currentChanged(-1);
+ }
+ } else if (index < d->index) {
+ --d->index;
+ }
+ emit widgetRemoved(index);
+ if (item->widget() && !qt_wasDeleted(item->widget()))
+ item->widget()->hide();
+ return item;
+}
+
+/*!
+ \property QStackedLayout::currentIndex
+ \brief the index position of the widget that is visible
+
+ The current index is -1 if there is no current widget.
+
+ \sa currentWidget(), indexOf()
+*/
+void QStackedLayout::setCurrentIndex(int index)
+{
+ Q_D(QStackedLayout);
+ QWidget *prev = currentWidget();
+ QWidget *next = widget(index);
+ if (!next || next == prev)
+ return;
+
+ bool reenableUpdates = false;
+ QWidget *parent = parentWidget();
+
+ if (parent && parent->updatesEnabled()) {
+ reenableUpdates = true;
+ parent->setUpdatesEnabled(false);
+ }
+
+ QWidget *fw = parent ? parent->window()->focusWidget() : 0;
+ if (prev) {
+ prev->clearFocus();
+ if (d->stackingMode == StackOne)
+ prev->hide();
+ }
+
+ d->index = index;
+ next->raise();
+ next->show();
+
+ // try to move focus onto the incoming widget if focus
+ // was somewhere on the outgoing widget.
+
+ if (parent) {
+ if (fw && (prev && prev->isAncestorOf(fw))) { // focus was on old page
+ // look for the best focus widget we can find
+ if (QWidget *nfw = next->focusWidget())
+ nfw->setFocus();
+ else {
+ // second best: first child widget in the focus chain
+ QWidget *i = fw;
+ while ((i = i->nextInFocusChain()) != fw) {
+ if (((i->focusPolicy() & Qt::TabFocus) == Qt::TabFocus)
+ && !i->focusProxy() && i->isVisibleTo(next) && i->isEnabled()
+ && next->isAncestorOf(i)) {
+ i->setFocus();
+ break;
+ }
+ }
+ // third best: incoming widget
+ if (i == fw )
+ next->setFocus();
+ }
+ }
+ }
+ if (reenableUpdates)
+ parent->setUpdatesEnabled(true);
+ emit currentChanged(index);
+}
+
+int QStackedLayout::currentIndex() const
+{
+ Q_D(const QStackedLayout);
+ return d->index;
+}
+
+
+/*!
+ \fn void QStackedLayout::setCurrentWidget(QWidget *widget)
+
+ Sets the current widget to be the specified \a widget. The new
+ current widget must already be contained in this stacked layout.
+
+ \sa setCurrentIndex(), currentWidget()
+ */
+void QStackedLayout::setCurrentWidget(QWidget *widget)
+{
+ int index = indexOf(widget);
+ if (index == -1) {
+ qWarning("QStackedLayout::setCurrentWidget: Widget %p not contained in stack", widget);
+ return;
+ }
+ setCurrentIndex(index);
+}
+
+
+/*!
+ Returns the current widget, or 0 if there are no widgets in this
+ layout.
+
+ \sa currentIndex(), setCurrentWidget()
+*/
+QWidget *QStackedLayout::currentWidget() const
+{
+ Q_D(const QStackedLayout);
+ return d->index >= 0 ? d->list.at(d->index)->widget() : 0;
+}
+
+/*!
+ Returns the widget at the given \a index, or 0 if there is no
+ widget at the given position.
+
+ \sa currentWidget(), indexOf()
+*/
+QWidget *QStackedLayout::widget(int index) const
+{
+ Q_D(const QStackedLayout);
+ if (index < 0 || index >= d->list.size())
+ return 0;
+ return d->list.at(index)->widget();
+}
+
+/*!
+ \property QStackedLayout::count
+ \brief the number of widgets contained in the layout
+
+ \sa currentIndex(), widget()
+*/
+int QStackedLayout::count() const
+{
+ Q_D(const QStackedLayout);
+ return d->list.size();
+}
+
+
+/*!
+ \reimp
+*/
+void QStackedLayout::addItem(QLayoutItem *item)
+{
+ QWidget *widget = item->widget();
+ if (widget) {
+ addWidget(widget);
+ delete item;
+ } else {
+ qWarning("QStackedLayout::addItem: Only widgets can be added");
+ }
+}
+
+/*!
+ \reimp
+*/
+QSize QStackedLayout::sizeHint() const
+{
+ Q_D(const QStackedLayout);
+ QSize s(0, 0);
+ int n = d->list.count();
+
+ for (int i = 0; i < n; ++i)
+ if (QWidget *widget = d->list.at(i)->widget()) {
+ QSize ws(widget->sizeHint());
+ if (widget->sizePolicy().horizontalPolicy() == QSizePolicy::Ignored)
+ ws.setWidth(0);
+ if (widget->sizePolicy().verticalPolicy() == QSizePolicy::Ignored)
+ ws.setHeight(0);
+ s = s.expandedTo(ws);
+ }
+ return s;
+}
+
+/*!
+ \reimp
+*/
+QSize QStackedLayout::minimumSize() const
+{
+ Q_D(const QStackedLayout);
+ QSize s(0, 0);
+ int n = d->list.count();
+
+ for (int i = 0; i < n; ++i)
+ if (QWidget *widget = d->list.at(i)->widget())
+ s = s.expandedTo(qSmartMinSize(widget));
+ return s;
+}
+
+/*!
+ \reimp
+*/
+void QStackedLayout::setGeometry(const QRect &rect)
+{
+ Q_D(QStackedLayout);
+ switch (d->stackingMode) {
+ case StackOne:
+ if (QWidget *widget = currentWidget())
+ widget->setGeometry(rect);
+ break;
+ case StackAll:
+ if (const int n = d->list.count())
+ for (int i = 0; i < n; ++i)
+ if (QWidget *widget = d->list.at(i)->widget())
+ widget->setGeometry(rect);
+ break;
+ }
+}
+
+/*!
+ \enum QStackedLayout::StackingMode
+ \since 4.4
+
+ This enum specifies how the layout handles its child widgets
+ regarding their visibility.
+
+ \value StackOne
+ Only the current widget is visible. This is the default.
+
+ \value StackAll
+ All widgets are visible. The current widget is merely raised.
+*/
+
+
+/*!
+ \property QStackedLayout::stackingMode
+ \brief determines the way visibility of child widgets are handled.
+ \since 4.4
+
+ The default value is StackOne. Setting the property to StackAll
+ allows you to make use of the layout for overlay widgets
+ that do additional drawing on top of other widgets, for example,
+ graphical editors.
+*/
+
+QStackedLayout::StackingMode QStackedLayout::stackingMode() const
+{
+ Q_D(const QStackedLayout);
+ return d->stackingMode;
+}
+
+void QStackedLayout::setStackingMode(StackingMode stackingMode)
+{
+ Q_D(QStackedLayout);
+ if (d->stackingMode == stackingMode)
+ return;
+ d->stackingMode = stackingMode;
+
+ const int n = d->list.count();
+ if (n == 0)
+ return;
+
+ switch (d->stackingMode) {
+ case StackOne:
+ if (const int idx = currentIndex())
+ for (int i = 0; i < n; ++i)
+ if (QWidget *widget = d->list.at(i)->widget())
+ widget->setVisible(i == idx);
+ break;
+ case StackAll: { // Turn overlay on: Make sure all widgets are the same size
+ QRect geometry;
+ if (const QWidget *widget = currentWidget())
+ geometry = widget->geometry();
+ for (int i = 0; i < n; ++i)
+ if (QWidget *widget = d->list.at(i)->widget()) {
+ if (!geometry.isNull())
+ widget->setGeometry(geometry);
+ widget->setVisible(true);
+ }
+ }
+ break;
+ }
+}
+
+QT_END_NAMESPACE
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