qtabwidget.cpp

奇趣公司比较新的qt/emd版本

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#include "qtabwidget.h"

#ifndef QT_NO_TABWIDGET
#include "private/qwidget_p.h"
#include "qapplication.h"
#include "qbitmap.h"
#include "qdesktopwidget.h"
#include "qevent.h"
#include "qlayout.h"
#include "qstackedwidget.h"
#include "qstyle.h"
#include "qstyleoption.h"
#include "qstylepainter.h"
#include "qtabbar.h"
#include "qtoolbutton.h"

/*!
    \class QTabWidget
    \brief The QTabWidget class provides a stack of tabbed widgets.

    \ingroup organizers
    \ingroup advanced
    \mainclass

    A tab widget provides a tab bar (see QTabBar) and a "page area"
    that is used to display pages related to each tab. By default, the
    tab bar is shown above the page area, but different configurations
    are available (see \l{TabPosition}). Each tab is associated with a
    different widget (called a page). Only the current page is shown in
    the page area; all the other pages are hidden. The user can show a
    different page by clicking on its tab or by pressing its
    Alt+\e{letter} shortcut if it has one.

    The normal way to use QTabWidget is to do the following:
    \list 1
    \i Create a QTabWidget.
    \i Create a QWidget for each of the pages in the tab dialog, but
       do not specify parent widgets for them.
    \i Insert child widgets into the page widget, using layouts to
       position them as normal.
    \i Call addTab() or insertTab() to put the page widgets into the
       tab widget, giving each tab a suitable label with an optional
       keyboard shortcut.
    \endlist

    The position of the tabs is defined by \l tabPosition, their shape
    by \l tabShape.

    The signal currentChanged() is emitted when the user selects a
    page.

    The current page index is available as currentIndex(), the current
    page widget with currentWidget().  You can retrieve a pointer to a
    page widget with a given index using widget(), and can find the
    index position of a widget with indexOf(). Use setCurrentWidget()
    or setCurrentIndex() to show a particular page.

    You can change a tab's text and icon using setTabText() or
    setTabIcon(). A tab and its associated page can be removed with
    removeTab().

    Each tab is either enabled or disabled at any given time (see
    setTabEnabled()). If a tab is enabled, the tab text is drawn
    normally and the user can select that tab. If it is disabled, the
    tab is drawn in a different way and the user cannot select that
    tab. Note that even if a tab is disabled, the page can still be
    visible, for example if all of the tabs happen to be disabled.

    Tab widgets can be a very good way to split up a complex dialog.
    An alternative is to use a QStackedWidget for which you provide some
    means of navigating between pages, for example, a QToolBar or a
    QListWidget.

    Most of the functionality in QTabWidget is provided by a QTabBar
    (at the top, providing the tabs) and a QStackedWidget (most of the
    area, organizing the individual pages).

    \table 100%
    \row \o \inlineimage windowsxp-tabwidget.png Screenshot of a Windows XP style tab widget
         \o \inlineimage macintosh-tabwidget.png Screenshot of a Macintosh style tab widget
         \o \inlineimage plastique-tabwidget.png Screenshot of a Plastique style tab widget
    \row \o A Windows XP style tab widget.
         \o A Macintosh style tab widget.
         \o A Plastique style tab widget.
    \endtable

    \sa QTabBar, QStackedWidget, QToolBox, {Tab Dialog Example}
*/

/*!
    \enum QTabWidget::TabPosition

    This enum type defines where QTabWidget draws the tab row:

    \value North  The tabs are drawn above the pages.
    \value South  The tabs are drawn below the pages.
    \value West  The tabs are drawn to the left of the pages.
    \value East  The tabs are drawn to the right of the pages.
    \omitvalue Bottom
    \omitvalue Top
*/

/*!
    \enum QTabWidget::TabShape

    This enum type defines the shape of the tabs:
    \value Rounded  The tabs are drawn with a rounded look. This is the default
                    shape.
    \value Triangular  The tabs are drawn with a triangular look.
*/

/*!
    \fn void QTabWidget::selected(const QString &tabLabel)

    This signal is emitted whenever a tab is selected (raised),
    including during the first show().

    You can normally use currentChanged() instead.
*/

/*!
    \fn void QTabWidget::currentChanged(int index)

    This signal is emitted whenever the current page index changes.
    The parameter is the new current page \a index position.

    \sa currentWidget() currentIndex
*/


class QTabWidgetPrivate : public QWidgetPrivate
{
    Q_DECLARE_PUBLIC(QTabWidget)

public:
    QTabWidgetPrivate();
    ~QTabWidgetPrivate();
    void updateTabBarPosition();
    void _q_showTab(int);
    void _q_removeTab(int);
    void init();

    QTabBar *tabs;
    QStackedWidget *stack;
    QRect panelRect;
    bool dirty;
    QTabWidget::TabPosition pos;
    QTabWidget::TabShape shape;
    int alignment;
    QWidget *leftCornerWidget;
    QWidget *rightCornerWidget;
};

QTabWidgetPrivate::QTabWidgetPrivate()
    : tabs(0), stack(0), dirty(true),
      pos(QTabWidget::North), shape(QTabWidget::Rounded),
      leftCornerWidget(0), rightCornerWidget(0)
{}

QTabWidgetPrivate::~QTabWidgetPrivate()
{}

void QTabWidgetPrivate::init()
{
    Q_Q(QTabWidget);

    stack = new QStackedWidget(q);
    stack->setObjectName(QLatin1String("qt_tabwidget_stackedwidget"));
    stack->setLineWidth(0);
    // hack so that QMacStyle::layoutSpacing() can detect tab widget pages
    stack->setSizePolicy(QSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred, QSizePolicy::TabWidget));

    QObject::connect(stack, SIGNAL(widgetRemoved(int)), q, SLOT(_q_removeTab(int)));
    QTabBar *tabBar = new QTabBar(q);
    tabBar->setObjectName(QLatin1String("qt_tabwidget_tabbar"));
    tabBar->setDrawBase(false);
    q->setTabBar(tabBar);

#ifdef Q_OS_TEMP
    pos = QTabWidget::South;
#endif

    q->setSizePolicy(QSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding, 
                                 QSizePolicy::TabWidget));
#ifdef QT_KEYPAD_NAVIGATION
    if (QApplication::keypadNavigationEnabled())
        q->setFocusPolicy(Qt::NoFocus);
    else
#endif
    q->setFocusPolicy(Qt::TabFocus);
    q->setFocusProxy(tabs);
}

/*!
    Initialize \a option with the values from this QTabWidget. This method is useful
    for subclasses when they need a QStyleOptionTabWidgetFrame, but don't want to fill
    in all the information themselves.

    \sa QStyleOption::initFrom() QTabBar::initStyleOption()
*/
void QTabWidget::initStyleOption(QStyleOptionTabWidgetFrame *option) const
{
    if (!option)
        return;

    Q_D(const QTabWidget);
    option->initFrom(this);

    int exth = style()->pixelMetric(QStyle::PM_TabBarBaseHeight, 0, this);
    QSize t(0, d->stack->frameWidth());
    if (d->tabs->isVisibleTo(const_cast<QTabWidget *>(this)))
        t = d->tabs->sizeHint();

    if (d->rightCornerWidget)
        option->rightCornerWidgetSize
            = d->rightCornerWidget->sizeHint().boundedTo(t - QSize(exth, exth));
    else
        option->rightCornerWidgetSize = QSize(0, 0);

    if (d->leftCornerWidget)
        option->leftCornerWidgetSize
                            = d->leftCornerWidget->sizeHint().boundedTo(t - QSize(exth, exth));
    else
        option->leftCornerWidgetSize = QSize(0, 0);

    switch (d->pos) {
    case QTabWidget::North:
        option->shape = d->shape == QTabWidget::Rounded ? QTabBar::RoundedNorth
                                                        : QTabBar::TriangularNorth;
        break;
    case QTabWidget::South:
        option->shape = d->shape == QTabWidget::Rounded ? QTabBar::RoundedSouth
                                                        : QTabBar::TriangularSouth;
        break;
    case QTabWidget::West:
        option->shape = d->shape == QTabWidget::Rounded ? QTabBar::RoundedWest
                                                        : QTabBar::TriangularWest;
        break;
    case QTabWidget::East:
        option->shape = d->shape == QTabWidget::Rounded ? QTabBar::RoundedEast
                                                        : QTabBar::TriangularEast;
        break;
    }
    option->tabBarSize = t;
}

/*!
    Constructs a tabbed widget with parent \a parent.
*/
QTabWidget::QTabWidget(QWidget *parent)
    : QWidget(*new QTabWidgetPrivate, parent, 0)
{
    Q_D(QTabWidget);
    d->init();
}

#ifdef QT3_SUPPORT
/*!
    Use one of the constructors that doesn't take the \a name
    argument and then use setObjectName() instead.
*/
QTabWidget::QTabWidget(QWidget *parent, const char *name, Qt::WindowFlags f)
    : QWidget(*new QTabWidgetPrivate, parent, f)
{
    Q_D(QTabWidget);
    setObjectName(QString::fromAscii(name));
    d->init();
}
#endif

/*!
    Destroys the tabbed widget.
*/
QTabWidget::~QTabWidget()
{
}

/*!
    \fn int QTabWidget::addTab(QWidget *page, const QString &label)

    Adds a tab with the given \a page and \a label to the tab widget,
    and returns the index of the tab in the tab bar.

    If the tab's \a label contains an ampersand, the letter following
    the ampersand is used as a shortcut for the tab, e.g. if the
    label is "Bro\&wse" then Alt+W becomes a shortcut which will
    move the focus to this tab.

    \note If you call addTab() after show(), the layout system will try
    to adjust to the changes in it's widgets hierarchy and may cause
    flicker. To prevent this, you can set the QWidget::updatesEnabled
    property to false prior to changes; remember to set the property
    to true when the changes are done, making the widget receive paint
    events again.

    \sa insertTab()
*/
int QTabWidget::addTab(QWidget *child, const QString &label)
{
    return insertTab(-1, child, label);
}


/*!
    \fn int QTabWidget::addTab(QWidget *page, const QIcon &icon, const QString &label)
    \overload

    Adds a tab with the given \a page, \a icon, and \a label to the tab
    widget, and returns the index of the tab in the tab bar.

    This function is the same as addTab(), but with an additional \a
    icon.
*/
int QTabWidget::addTab(QWidget *child, const QIcon& icon, const QString &label)
{
    return insertTab(-1, child, icon, label);
}


/*!
    \fn int QTabWidget::insertTab(int index, QWidget *page, const QString &label)

    Inserts a tab with the given \a label and \a page into the tab
    widget at the specified \a index, and returns the index of the
    inserted tab in the tab bar.

    The label is displayed in the tab and may vary in appearance depending
    on the configuration of the tab widget.

    If the tab's \a label contains an ampersand, the letter following
    the ampersand is used as a shortcut for the tab, e.g. if the
    label is "Bro\&wse" then Alt+W becomes a shortcut which will
    move the focus to this tab.

    If \a index is out of range, the tab is simply appended.
    Otherwise it is inserted at the specified position.

    If the QTabWidget was empty before this function is called, the
    new page becomes the current page. Inserting a new tab at an index
    less than or equal to the current index will increment the current
    index, but keep the current page.

    \note If you call insertTab() after show(), the layout system will try
    to adjust to the changes in it's widgets hierarchy and may cause
    flicker. To prevent this, you can set the QWidget::updatesEnabled
    property to false prior to changes; remember to set the property
    to true when the changes are done, making the widget receive paint
    events again.

    \sa addTab()
*/
int QTabWidget::insertTab(int index, QWidget *w, const QString &label)
{
    return insertTab(index, w, QIcon(), label);
}


/*!
    \fn int QTabWidget::insertTab(int index, QWidget *page, const QIcon& icon, const QString &label)
    \overload

    Inserts a tab with the given \a label, \a page, and \a icon into
    the tab widget at the specified \a index, and returns the index of the
    inserted tab in the tab bar.

    This function is the same as insertTab(), but with an additional
    \a icon.
*/
int QTabWidget::insertTab(int index, QWidget *w, const QIcon& icon, const QString &label)
{
    Q_D(QTabWidget);
    if(!w)
        return -1;
    index = d->tabs->insertTab(index, icon, label);
    d->stack->insertWidget(index, w);
    setUpLayout();
    tabInserted(index);
    return index;
}


/*!
    Defines a new \a label for the page at position \a index's tab.

    If the provided text contains an ampersand character ('&'), a
    shortcut is automatically created for it. The character that
    follows the '&' will be used as the shortcut key. Any previous
    shortcut will be overwritten, or cleared if no shortcut is defined
    by the text. See the \l {QShortcut#mnemonic}{QShortcut}
    documentation for details (to display an actual ampersand, use
    '&&').

*/
void QTabWidget::setTabText(int index, const QString &label)