NAME
QEvent − The base class of all event classes. Event objects contain event parameters
SYNOPSIS
#include <qevent.h>
Inherits Qt.
Inherited by QTimerEvent, QMouseEvent, QWheelEvent, QTabletEvent, QKeyEvent, QFocusEvent, QPaintEvent, QMoveEvent, QResizeEvent, QCloseEvent, QIconDragEvent, QShowEvent, QHideEvent, QContextMenuEvent, QIMEvent, QDropEvent, QDragLeaveEvent, QChildEvent, and QCustomEvent.
Public Members
<li class=fn>enum Type { None = 0, Timer = 1, MouseButtonPress = 2, MouseButtonRelease = 3, MouseButtonDblClick = 4, MouseMove = 5, KeyPress = 6, KeyRelease = 7, FocusIn = 8, FocusOut = 9, Enter = 10, Leave = 11, Paint = 12, Move = 13, Resize = 14, Create = 15, Destroy = 16, Show = 17, Hide = 18, Close = 19, Quit = 20, Reparent = 21, ShowMinimized = 22, ShowNormal = 23, WindowActivate = 24, WindowDeactivate = 25, ShowToParent = 26, HideToParent = 27, ShowMaximized = 28, ShowFullScreen = 29, Accel = 30, Wheel = 31, AccelAvailable = 32, CaptionChange = 33, IconChange = 34, ParentFontChange = 35, ApplicationFontChange = 36, ParentPaletteChange = 37, ApplicationPaletteChange = 38, PaletteChange = 39, Clipboard = 40, Speech = 42, SockAct = 50, AccelOverride = 51, DeferredDelete = 52, DragEnter = 60, DragMove = 61, DragLeave = 62, Drop = 63, DragResponse = 64, ChildInserted = 70, ChildRemoved = 71, LayoutHint = 72, ShowWindowRequest = 73, WindowBlocked = 74, WindowUnblocked = 75, ActivateControl = 80, DeactivateControl = 81, ContextMenu = 82, IMStart = 83, IMCompose = 84, IMEnd = 85, Accessibility = 86, TabletMove = 87, LocaleChange = 88, LanguageChange = 89, LayoutDirectionChange = 90, Style = 91, TabletPress = 92, TabletRelease = 93, OkRequest = 94, HelpRequest = 95, WindowStateChange = 96, IconDrag = 97, User = 1000, MaxUser = 65535 } <li class=fn>QEvent ( Type type ) <li class=fn>virtual ~QEvent () <li class=fn>Type type () const <li class=fn>bool spontaneous () const
DESCRIPTION
The QEvent class is the base class of all event classes. Event objects contain event parameters.
Qt’s main event loop (QApplication::exec()) fetches native window system events from the event queue, translates them into QEvents and sends the translated events to QObjects.
In general, events come from the underlying window system (spontaneous() returns TRUE) but it is also possible to manually send events using QApplication::sendEvent() and QApplication::postEvent() (spontaneous() returns FALSE).
QObjects receive events by having their QObject::event() function called. The function can be reimplemented in subclasses to customize event handling and add additional event types; QWidget::event() is a notable example. By default, events are dispatched to event handlers like QObject::timerEvent() and QWidget::mouseMoveEvent(). QObject::installEventFilter() allows an object to intercept events destined for another object.
The basic QEvent contains only an event type parameter. Subclasses of QEvent contain additional parameters that describe the particular event.
See also QObject::event(), QObject::installEventFilter(), QWidget::event(), QApplication::sendEvent(), QApplication::postEvent(), QApplication::processEvents(), Environment Classes, and Event Classes.
Member Type Documentation
QEvent::Type
This enum type defines the
valid event types in Qt. The event types and the specialized
classes for each type are these:
QEvent::None - Not an event.
QEvent::Accessibility - Accessibility information is
requested
QEvent::Timer - Regular timer events, QTimerEvent.
QEvent::MouseButtonPress - Mouse press, QMouseEvent.
QEvent::MouseButtonRelease - Mouse release,
QMouseEvent.
QEvent::MouseButtonDblClick - Mouse press again,
QMouseEvent.
QEvent::MouseMove - Mouse move, QMouseEvent.
QEvent::KeyPress - Key press (including Shift, for
example), QKeyEvent.
QEvent::KeyRelease - Key release, QKeyEvent.
QEvent::IMStart - The start of input method
composition, QIMEvent.
QEvent::IMCompose - Input method composition is taking
place, QIMEvent.
QEvent::IMEnd - The end of input method composition,
QIMEvent.
QEvent::FocusIn - Widget gains keyboard focus,
QFocusEvent.
QEvent::FocusOut - Widget loses keyboard focus,
QFocusEvent.
QEvent::Enter - Mouse enters widget’s boundaries.
QEvent::Leave - Mouse leaves widget’s boundaries.
QEvent::Paint - Screen update necessary, QPaintEvent.
QEvent::Move - Widget’s position changed,
QMoveEvent.
QEvent::Resize - Widget’s size changed,
QResizeEvent.
QEvent::Show - Widget was shown on screen, QShowEvent.
QEvent::Hide - Widget was hidden, QHideEvent.
QEvent::ShowToParent - A child widget has been shown.
QEvent::HideToParent - A child widget has been hidden.
QEvent::Close - Widget was closed (permanently),
QCloseEvent.
QEvent::ShowNormal - Widget should be shown normally
(obsolete).
QEvent::ShowMaximized - Widget should be shown
maximized (obsolete).
QEvent::ShowMinimized - Widget should be shown
minimized (obsolete).
QEvent::ShowFullScreen - Widget should be shown
full-screen (obsolete).
QEvent::ShowWindowRequest - Widget’s window
should be shown (obsolete).
QEvent::DeferredDelete - The object will be deleted
after it has
cleaned up.
QEvent::Accel - Key press in child for shortcut key
handling,
QKeyEvent.
QEvent::Wheel - Mouse wheel rolled, QWheelEvent.
QEvent::ContextMenu - Context popup menu,
QContextMenuEvent
QEvent::AccelOverride - Key press in child, for
overriding shortcut key
handling, QKeyEvent.
QEvent::AccelAvailable - internal.
QEvent::WindowActivate - Window was activated.
QEvent::WindowDeactivate - Window was deactivated.
QEvent::CaptionChange - Widget’s caption changed.
QEvent::IconChange - Widget’s icon changed.
QEvent::ParentFontChange - Font of the parent widget
changed.
QEvent::ApplicationFontChange - Default application
font changed.
QEvent::PaletteChange - Palette of the widget changed.
QEvent::ParentPaletteChange - Palette of the parent
widget changed.
QEvent::ApplicationPaletteChange - Default application
palette changed.
QEvent::Clipboard - Clipboard contents have changed.
QEvent::SockAct - Socket activated, used to implement
QSocketNotifier.
QEvent::DragEnter - A drag-and-drop enters widget,
QDragEnterEvent.
QEvent::DragMove - A drag-and-drop is in progress,
QDragMoveEvent.
QEvent::DragLeave - A drag-and-drop leaves widget,
QDragLeaveEvent.
QEvent::Drop - A drag-and-drop is completed,
QDropEvent.
QEvent::DragResponse - Internal event used by Qt on
some platforms.
QEvent::ChildInserted - Object gets a child,
QChildEvent.
QEvent::ChildRemoved - Object loses a child,
QChildEvent.
QEvent::LayoutHint - Widget child has changed layout
properties.
QEvent::ActivateControl - Internal event used by Qt on
some platforms.
QEvent::DeactivateControl - Internal event used by Qt
on some
platforms.
QEvent::LanguageChange - The application translation
changed,
QTranslator
QEvent::LayoutDirectionChange - The direction of
layouts changed
QEvent::LocaleChange - The system locale changed
QEvent::Quit - Reserved.
QEvent::Create - Reserved.
QEvent::Destroy - Reserved.
QEvent::Reparent - Reserved.
QEvent::Speech - Reserved for speech input.
QEvent::TabletMove - A Wacom Tablet Move Event.
QEvent::Style - Internal use only
QEvent::TabletPress - A Wacom Tablet Press Event
QEvent::TabletRelease - A Wacom Tablet Release Event
QEvent::OkRequest - Internal event used by Qt on some
platforms.
QEvent::HelpRequest - Internal event used by Qt on some
platforms.
QEvent::IconDrag - Internal event used by Qt on some
platforms when
proxy icon is dragged.
QEvent::WindowStateChange - The window’s state,
i.e. minimized,
maximized or full-screen, has changed. See
QWidget::windowState().
QEvent::WindowBlocked - The window is modally blocked
QEvent::WindowUnblocked - The window leaves modal
blocking
QEvent::User - User defined event.
QEvent::MaxUser - Last user event id.
User events should have values between User and MaxUser inclusive.
MEMBER FUNCTION DOCUMENTATION
QEvent::QEvent ( Type type )
Contructs an event object of type type.
QEvent::~QEvent () [virtual]
Destroys the event. If it was posted, it will be removed from the list of events to be posted.
bool QEvent::spontaneous () const
Returns TRUE if the event originated outside the application, i.e. it is a system event; otherwise returns FALSE.
Type QEvent::type () const
Returns the event type.
SEE ALSO
http://doc.trolltech.com/qevent.html http://www.trolltech.com/faq/tech.html
COPYRIGHT
Copyright 1992-2001 Trolltech AS, http://www.trolltech.com. See the license file included in the distribution for a complete license statement.
AUTHOR
Generated automatically from the source code.
BUGS
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