qabstractbutton.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

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**
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#include "qabstractbutton.h"
#include "qbuttongroup.h"
#include "qabstractbutton_p.h"
#include "qevent.h"
#include "qpainter.h"
#include "qapplication.h"
#include "qstyle.h"
#include "qaction.h"
#ifndef QT_NO_ACCESSIBILITY
#include "qaccessible.h"
#endif

#define AUTO_REPEAT_DELAY  300
#define AUTO_REPEAT_PERIOD 100


/*!
\class QAbstractButton qabstractbutton.h

\brief The QAbstractButton class is the abstract base class of
button widgets, providing functionality common to buttons.

\ingroup abstractwidgets

This class implements an \e abstract button.
Subclasses of this class handle user actions, and specify how the button
is drawn.

QAbstractButton provides support for both push buttons and checkable
(toggle) buttons. Checkable buttons are implemented in the QRadioButton
and QCheckBox classes. Push buttons are implemented in the
QPushButton and QToolButton classes; these also provide toggle
behavior if required.

Any button can display a label containing text and an icon. setText()
sets the text; setIcon() sets the icon. If a button is disabled, its label
is changed to give the button a "disabled" appearance.

If the button is a text button with a string containing an ampersand (\&),
QAbstractButton creates an automatic shortcut key, called a mnemonic, that may
change based on the button translation. The following code creates
a push button labelled "Ro\underline{c}k & Roll" (where the c is underlined):

\code
    QPushButton *button = new QPushButton(tr("Ro&ck && Roll"), this);
\endcode

In this example, the shortcut \key Alt+C is assigned to the button, so that when
the user presses \key Alt+C the button will call animateClick().

You can also set a custom shortcut key using the setShortcut()
function. This is useful mostly for buttons that do not have any
text, because they have no automatic shortcut.

\code
    button->setIcon(QIcon(":/images/print.png"));
    button->setShortcut(tr("Alt+F7"));
\endcode

All of the buttons provided by Qt (QPushButton, QToolButton,
QCheckBox, and QRadioButton) can display both \l text and \l{icon}{icons}.

A button can be made the default button in a dialog are provided by
QPushButton::setDefault() and QPushButton::setAutoDefault().

QAbstractButton provides most of the states used for buttons:

\list

\i isDown() indicates whether the button is \e pressed down.

\i isChecked() indicates whether the button is \e checked.  Only
checkable buttons can be checked and unchecked (see below).

\i isEnabled() indicates whether the button can be pressed by the
user.

\i setAutoRepeat() sets whether the button will auto-repeat if the
user holds it down.

\i setCheckable() sets whether the button is a toggle button or not.

\endlist

The difference between isDown() and isChecked() is as follows.
When the user clicks a toggle button to check it, the button is first
\e pressed then released into the \e checked state. When the user
clicks it again (to uncheck it), the button moves first to the
\e pressed state, then to the \e unchecked state (isChecked() and
isDown() are both false).

QAbstractButton provides five signals:

\list 1

\i pressed() is emitted when the left mouse button is pressed while
the mouse cursor is inside the button.

\i released() is emitted when the left mouse button is released.

\i clicked() is emitted when the button is first pressed and then
released when the shortcut key is typed, or when animateClick()
is called.

\i toggled(bool) is emitted when the state of a toggle button
changes.

\endlist

To subclass QAbstractButton, you must reimplement at least
paintEvent() to draw the button's outline and its text or pixmap. It
is generally advisable to reimplement sizeHint() as well, and
sometimes hitButton() (to determine whether a button press is within
the button). For buttons with more than two states (like tri-state
buttons), you will also have to reimplement checkStateSet() and
nextCheckState().

\sa QButtonGroup
*/

QAbstractButtonPrivate::QAbstractButtonPrivate()
    :
#ifndef QT_NO_SHORTCUT
    shortcutId(0),
#endif
    checkable(false), checked(false), autoRepeat(false), autoExclusive(false),
    down(false), blockRefresh(false)
#ifndef QT_NO_BUTTONGROUP
    , group(0)
#endif
{}

#ifndef QT_NO_BUTTONGROUP

class QButtonGroupPrivate: public QObjectPrivate
{
    Q_DECLARE_PUBLIC(QButtonGroup)

public:
    QButtonGroupPrivate():exclusive(true){}
    QList<QAbstractButton *> buttonList;
    QPointer<QAbstractButton> checkedButton;
    void notifyChecked(QAbstractButton *button);
    bool exclusive;
    QMap<QAbstractButton*, int> mapping;
};

QButtonGroup::QButtonGroup(QObject *parent)
    : QObject(*new QButtonGroupPrivate, parent)
{
}

QButtonGroup::~QButtonGroup()
{
    Q_D(QButtonGroup);
    for (int i = 0; i < d->buttonList.count(); ++i)
        d->buttonList.at(i)->d_func()->group = 0;
}


bool QButtonGroup::exclusive() const
{
    Q_D(const QButtonGroup);
    return d->exclusive;
}

void QButtonGroup::setExclusive(bool exclusive)
{
    Q_D(QButtonGroup);
    d->exclusive = exclusive;
}

/*!
    Adds the given \a button to the end of the group's internal list of buttons.

    \sa removeButton()
*/
void QButtonGroup::addButton(QAbstractButton *button)
{
    addButton(button, -1);
}

void QButtonGroup::addButton(QAbstractButton *button, int id)
{
    Q_D(QButtonGroup);
    if (QButtonGroup *previous = button->d_func()->group)
        if (previous && previous != this)
            previous->removeButton(button);
    button->d_func()->group = this;
    d->buttonList.append(button);
    if (id != -1)
        d->mapping[button] = id;
    if (d->exclusive && button->isChecked())
        button->d_func()->notifyChecked();
}

void QButtonGroup::removeButton(QAbstractButton *button)
{
    Q_D(QButtonGroup);
    if (d->checkedButton == button)
        d->checkedButton = 0;
    if (button->d_func()->group == this) {
        button->d_func()->group = 0;
        d->buttonList.removeAll(button);
    }
}

QList<QAbstractButton*> QButtonGroup::buttons() const
{
    Q_D(const QButtonGroup);
    return d->buttonList;
}

QAbstractButton *QButtonGroup::checkedButton() const
{
    Q_D(const QButtonGroup);
    return d->checkedButton;
}

QAbstractButton *QButtonGroup::button(int id) const
{
    Q_D(const QButtonGroup);
    return d->mapping.key(id);
}

void QButtonGroup::setId(QAbstractButton *button, int id)
{
    Q_D(QButtonGroup);
    if (button && id != -1)
        d->mapping[button] = id;
}

int QButtonGroup::id(QAbstractButton *button) const
{
    Q_D(const QButtonGroup);
    return d->mapping.value(button, -1);
}

int QButtonGroup::checkedId() const
{
    Q_D(const QButtonGroup);
    return d->mapping.value(d->checkedButton, -1);
}

#endif // QT_NO_BUTTONGROUP

QList<QAbstractButton *>QAbstractButtonPrivate::queryButtonList() const
{
#ifndef QT_NO_BUTTONGROUP
    if (group)
        return group->d_func()->buttonList;
#endif

    Q_Q(const QAbstractButton);
    QList<QAbstractButton*>candidates;
    if (q->parentWidget() && autoExclusive) {
        candidates =  qFindChildren<QAbstractButton *>(q->parentWidget());
        for (int i = candidates.count() - 1; i >= 0; --i) {
            QAbstractButton *candidate = candidates.at(i);
            if (!candidate->autoExclusive()
#ifndef QT_NO_BUTTONGROUP
                || candidate->group()
#endif
                )
                candidates.removeAt(i);
        }
    }
    return candidates;
}

QAbstractButton *QAbstractButtonPrivate::queryCheckedButton() const
{
#ifndef QT_NO_BUTTONGROUP
    if (group)
        return group->d_func()->checkedButton;
#endif

    Q_Q(const QAbstractButton);
    QList<QAbstractButton *> buttonList = queryButtonList();
    if (buttonList.count() == 1) // no group
        return 0;

    for (int i = 0; i < buttonList.count(); ++i) {
        QAbstractButton *b = buttonList.at(i);
        if (b->d_func()->checked && b != q)
            return b;
    }
    return checked  ? const_cast<QAbstractButton *>(q) : 0;
}

void QAbstractButtonPrivate::notifyChecked()
{
#ifndef QT_NO_BUTTONGROUP
    Q_Q(QAbstractButton);
    if (group) {
        QAbstractButton *previous = group->d_func()->checkedButton;
        group->d_func()->checkedButton = q;
        if (group->d_func()->exclusive && previous && previous != q)
            previous->nextCheckState();
    } else
#endif
    if (autoExclusive) {
        if (QAbstractButton *b = queryCheckedButton())
            b->setChecked(false);
    }
}

void QAbstractButtonPrivate::moveFocus(int key)
{
    QList<QAbstractButton *> buttonList = queryButtonList();;
#ifndef QT_NO_BUTTONGROUP
    bool exclusive = group ? group->d_func()->exclusive : autoExclusive;
#else
    bool exclusive = autoExclusive;
#endif
    QWidget *f = qApp->focusWidget();
    QAbstractButton *fb = ::qobject_cast<QAbstractButton *>(f);
    if (!fb || !buttonList.contains(fb))
        return;

    QAbstractButton *candidate = 0;
    int bestScore = -1;
    QRect fGeometry = f->geometry();

    QPoint goal(f->mapToGlobal(fGeometry.center()));

    for (int i = 0; i < buttonList.count(); ++i) {
        QAbstractButton *button = buttonList.at(i);
        if (button != f && button->isEnabled()) {
            QRect buttonGeometry = button->geometry();
            QPoint p(button->mapToGlobal(buttonGeometry.center()));
            int score = (p.y() - goal.y())*(p.y() - goal.y()) +
                        (p.x() - goal.x())*(p.x() - goal.x());
            bool betterScore = score < bestScore || !candidate;
            switch(key) {
            case Qt::Key_Up:
                if (p.y() < goal.y() && betterScore) {
                    if (qAbs(p.x() - goal.x()) < qAbs(p.y() - goal.y())) {
                        candidate = button;
                        bestScore = score;
                    } else if (buttonGeometry.x() == fGeometry.x()) {
                        candidate = button;
                        bestScore = score/2;
                    }
                }
                break;
            case Qt::Key_Down:
                if (p.y() > goal.y() && betterScore) {
                    if (qAbs(p.x() - goal.x()) < qAbs(p.y() - goal.y())) {
                        candidate = button;
                        bestScore = score;
                    } else if (buttonGeometry.x() == fGeometry.x()) {
                        candidate = button;
                        bestScore = score/2;
                    }
                }
                break;
            case Qt::Key_Left:
                if (p.x() < goal.x() && betterScore) {
                    if (qAbs(p.y() - goal.y()) < qAbs(p.x() - goal.x())) {
                        candidate = button;
                        bestScore = score;
                    } else if (buttonGeometry.y() == fGeometry.y()) {
                        candidate = button;
                        bestScore = score/2;
                    }
                }
                break;
            case Qt::Key_Right:
                if (p.x() > goal.x() && betterScore) {
                    if (qAbs(p.y() - goal.y()) < qAbs(p.x() - goal.x())) {
                        candidate = button;
                        bestScore = score;
                    } else if (buttonGeometry.y() == fGeometry.y()) {
                        candidate = button;
                        bestScore = score/2;
                    }
                }
                break;
            }
        }
    }

    if (exclusive
#ifdef QT_KEYPAD_NAVIGATION
        && !QApplication::keypadNavigationEnabled()
#endif
        && candidate
        && fb->d_func()->checked
        && candidate->d_func()->checkable)
        candidate->click();

    if (candidate) {
        if (key == Qt::Key_Up || key == Qt::Key_Left)
            candidate->setFocus(Qt::BacktabFocusReason);
        else
            candidate->setFocus(Qt::TabFocusReason);
    }
}

void QAbstractButtonPrivate::fixFocusPolicy()
{
    Q_Q(QAbstractButton);

    QList<QAbstractButton *> buttonList = queryButtonList();
    for (int i = 0; i < buttonList.count(); ++i) {
        QAbstractButton *b = buttonList.at(i);
        if (!b->isCheckable())