source: trunk/src/gui/dialogs/qdialog.cpp@ 5

/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Qt Software Information ([email protected])
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** 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 1.0, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at [email protected].
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qdialog.h"


#include "qevent.h"
#include "qdesktopwidget.h"
#include "qpushbutton.h"
#include "qapplication.h"
#include "qlayout.h"
#include "qsizegrip.h"
#include "qwhatsthis.h"
#include "qmenu.h"
#include "qcursor.h"
#include "private/qdialog_p.h"
#ifndef QT_NO_ACCESSIBILITY
#include "qaccessible.h"
#endif
#if defined(Q_OS_WINCE)
#include "qt_windows.h"
#include "qmenubar.h"
#include "qpointer.h"
#include "qguifunctions_wince.h"
extern bool qt_wince_is_mobile();     //defined in qguifunctions_wce.cpp
extern bool qt_wince_is_smartphone(); //is defined in qguifunctions_wce.cpp
#elif defined(Q_WS_X11)
#  include "../kernel/qt_x11_p.h"
#endif

#ifndef SPI_GETSNAPTODEFBUTTON
#  define SPI_GETSNAPTODEFBUTTON  95
#endif

QT_BEGIN_NAMESPACE

/*!
    \class QDialog
    \brief The QDialog class is the base class of dialog windows.

    \ingroup dialogs
    \ingroup abstractwidgets
    \mainclass

    A dialog window is a top-level window mostly used for short-term
    tasks and brief communications with the user. QDialogs may be
    modal or modeless. QDialogs can
    provide a \link #return return
    value\endlink, and they can have \link #default default
    buttons\endlink. QDialogs can also have a QSizeGrip in their
    lower-right corner, using setSizeGripEnabled().

    Note that QDialog (an any other widget that has type Qt::Dialog) uses
    the parent widget slightly differently from other classes in Qt. A
    dialog is always a top-level widget, but if it has a parent, its
    default location is centered on top of the parent's top-level widget
    (if it is not top-level itself). It will also share the parent's
    taskbar entry.

    Use the overload of the QWidget::setParent() function to change
    the ownership of a QDialog widget. This function allows you to
    explicitly set the window flags of the reparented widget; using
    the overloaded function will clear the window flags specifying the
    window-system properties for the widget (in particular it will
    reset the Qt::Dialog flag).

    \section1 Modal Dialogs

    A \bold{modal} dialog is a dialog that blocks input to other
    visible windows in the same application. Dialogs that are used to
    request a file name from the user or that are used to set
    application preferences are usually modal. Dialogs can be
    \l{Qt::ApplicationModal}{application modal} (the default) or
    \l{Qt::WindowModal}{window modal}.

    When an application modal dialog is opened, the user must finish
    interacting with the dialog and close it before they can access
    any other window in the application. Window modal dialogs only
    block access to the window associated with the dialog, allowing
    the user to continue to use other windows in an application.

    The most common way to display a modal dialog is to call its
    exec() function. When the user closes the dialog, exec() will
    provide a useful \link #return return value\endlink. Typically,
    to get the dialog to close and return the appropriate value, we
    connect a default button, e.g. \gui OK, to the accept() slot and a
    \gui Cancel button to the reject() slot.
    Alternatively you can call the done() slot with \c Accepted or
    \c Rejected.

    An alternative is to call setModal(true) or setWindowModality(),
    then show(). Unlike exec(), show() returns control to the caller
    immediately. Calling setModal(true) is especially useful for
    progress dialogs, where the user must have the ability to interact
    with the dialog, e.g.  to cancel a long running operation. If you
    use show() and setModal(true) together to perform a long operation,
    you must call QApplication::processEvents() periodically during
    processing to enable the user to interact with the dialog. (See
    QProgressDialog.)

    \section1 Modeless Dialogs

    A \bold{modeless} dialog is a dialog that operates
    independently of other windows in the same application. Find and
    replace dialogs in word-processors are often modeless to allow the
    user to interact with both the application's main window and with
    the dialog.

    Modeless dialogs are displayed using show(), which returns control
    to the caller immediately.

    If you invoke the \l{QWidget::show()}{show()} function after hiding
    a dialog, the dialog will be displayed in its original position. This is
    because the window manager decides the position for windows that
    have not been explicitly placed by the programmer. To preserve the
    position of a dialog that has been moved by the user, save its position
    in your \l{QWidget::closeEvent()}{closeEvent()}  handler and then
    move the dialog to that position, before showing it again.

    \target default
    \section1 Default Button

    A dialog's \e default button is the button that's pressed when the
    user presses Enter (Return). This button is used to signify that
    the user accepts the dialog's settings and wants to close the
    dialog. Use QPushButton::setDefault(), QPushButton::isDefault()
    and QPushButton::autoDefault() to set and control the dialog's
    default button.

    \target escapekey
    \section1 Escape Key

    If the user presses the Esc key in a dialog, QDialog::reject()
    will be called. This will cause the window to close: The \link
    QCloseEvent close event \endlink cannot be \link
    QCloseEvent::ignore() ignored \endlink.

    \section1 Extensibility

    Extensibility is the ability to show the dialog in two ways: a
    partial dialog that shows the most commonly used options, and a
    full dialog that shows all the options. Typically an extensible
    dialog will initially appear as a partial dialog, but with a
    \gui More toggle button. If the user presses the \gui More button down,
    the dialog is expanded. The \l{Extension Example} shows how to achieve
    extensible dialogs using Qt.

    \target return
    \section1 Return Value (Modal Dialogs)

    Modal dialogs are often used in situations where a return value is
    required, e.g. to indicate whether the user pressed \gui OK or
    \gui Cancel. A dialog can be closed by calling the accept() or the
    reject() slots, and exec() will return \c Accepted or \c Rejected
    as appropriate. The exec() call returns the result of the dialog.
    The result is also available from result() if the dialog has not
    been destroyed.

    In order to modify your dialog's close behavior, you can reimplement
    the functions accept(), reject() or done(). The
    \l{QWidget::closeEvent()}{closeEvent()} function should only be
    reimplemented to preserve the dialog's position or to override the
    standard close or reject behavior.

    \target examples
    \section1 Code Examples

    A modal dialog:

    \snippet doc/src/snippets/dialogs/dialogs.cpp 1

    A modeless dialog:

    \snippet doc/src/snippets/dialogs/dialogs.cpp 0

    \sa QDialogButtonBox, QTabWidget, QWidget, QProgressDialog,
        {fowler}{GUI Design Handbook: Dialogs, Standard}, {Extension Example},
        {Standard Dialogs Example}
*/

/*! \enum QDialog::DialogCode

    The value returned by a modal dialog.

    \value Accepted
    \value Rejected
*/

/*!
  \property QDialog::sizeGripEnabled
  \brief whether the size grip is enabled

  A QSizeGrip is placed in the bottom-right corner of the dialog when this
  property is enabled. By default, the size grip is disabled.
*/


/*!