QEvent(3qt)

📦 version 3.3.8b, in fedora 43, fedora 44

✨ NAME ✨

QEvent — bestie, this is the base class of all event classes, like the mother of every event object out there. Event objects contain event parameters. That's the whole job. 👑

(also this is from the QEvent(3qt) manual, so jot that down 🎀)

🦋 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. That's a whole friend group fr fr 💖

Public Members 💅

  • enum Type — the big list of event types, full tea below ⬇️
  • QEvent ( Type type ) — makes a new event of type type
  • virtual ~QEvent () — destroys it
  • Type type () const — tells you the event type
  • bool spontaneous () const — was it a real system event or nah

And here's the enum Type in all its glory, exactly as it lives:

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 }

💖 DESCRIPTION 💖

So. QEvent is the base class of all event classes. Event objects contain event parameters. Iconic behaviour honestly.

Qt's main event loop (QApplication::exec()) goes and fetches native window system events from the event queue, translates them into QEvents, and sends those translated events off to QObjects. It's giving matchmaker but for signals of the computer variety 💌

In general, events come from the underlying window system (spontaneous() returns TRUE) — but plot twist, you can also manually send events using QApplication::sendEvent() and QApplication::postEvent() (and then spontaneous() returns FALSE). No cap.

QObjects receive events by having their QObject::event() function called. You can reimplement that function in subclasses to customize event handling and add additional event types — QWidget::event() is the famous example, main character energy fr. By default, events are dispatched to event handlers like QObject::timerEvent() and QWidget::mouseMoveEvent(). And QObject::installEventFilter() lets an object intercept events destined for another object. Sneaky. Obsessed. 🙈

The basic QEvent contains only an event type parameter. Subclasses of QEvent contain additional parameters that describe the particular event — that's where the extra lore lives.

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 — buckle up, it's a long list but every single one matters:

  • 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. That's the rule, bestie, don't fight it 💅

🫶 MEMBER FUNCTION DOCUMENTATION 🫶

QEvent::QEvent ( Type type )

Contructs an event object of type type. (yes that's how it's spelled in the original, we keep it, mwah 🍓)

QEvent::~QEvent () [virtual]

Destroys the event. If it was posted, it will be removed from the list of events to be posted. Cleanup era ✨

bool QEvent::spontaneous () const

Returns TRUE if the event originated outside the application, i.e. it is a system event; otherwise returns FALSE. So basically: did the system send this or did you 👀

Type QEvent::type () const

Returns the event type. Short, sweet, iconic.

🌈 SEE ALSO 🌈

Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the license file included in the distribution for a complete license statement.

🧚 AUTHOR 🧚

Generated automatically from the source code. (not me, not you, the machine did it 💀)

💀 BUGS 💀

If you find a bug in Qt, please report it as described in http://doc.trolltech.com/bughowto.html. Good bug reports help us to help you. Thank you. 🫶

The definitive Qt documentation is provided in HTML format; it is located at $QTDIR/doc/html and can be read using Qt Assistant or with a web browser. This man page is provided as a convenience for those users who prefer man pages, although this format is not officially supported by Trolltech.

If you find errors in this manual page, please report them to qt-bugs@trolltech.com. Please include the name of the manual page (qevent.3qt) and the Qt version (3.3.8).

And that's the whole thing, bestie — this one came from Trolltech AS, dated 2 February 2007, and it's the QEvent(3qt) page itself. Slay, go forth and handle your events 💖✨🎀

📦 where this page comes from