GdkEvent

Direct subclasses

None.

Description

A GdkEvent is one of the continual stream of events that help make up the GTK main loop. Events crossing a widget indicate some form of activity - generally, but not exclusively, user activity.

There are 32 different kinds of GdkEvent, each of which has only the properties appropriate to it exposed. Those differences are keyed using an enumerated value known as GdkEventType, which is a type property of both GdkEventAny and GdkEvent itself. Confused yet? That'll be because GdkEvent has a union structure, which is unique in GTK+ programming, and because the type property is intentionally accessible both through $event->type and through $any->type.

Each event carries GdkEventType and GdkEventAny information. Beyond that, the properties that can be accessed within an event depend completely on its type. See the table below for details.

The types of event that can be captured by an object depend on the GdkEventMask or masks that are in effect on that object. Each GTK widget is created with a set of these flags; this base set can be added to or limited within PHP-GTK using set_events() or add_events() as appropriate. The masks required by each event type are also listed in the table below, where applicable.

See also: GtkEventBox, add_events() , set_events() , and the section on events in the Userguide.

Further reading: The relevant chapter of Havoc Pennington's GTK+ / Gnome Application Development provides an in-depth overview of GDK events. It's aimed at C programmers, but is easy to read despite that caveat.

Table 10. GdkEvent properties

GdkEventType	property	GdkEventMask
GDK_NOTHING GDK_DELETE GDK_DESTROY
GDK_EXPOSE	expose	GDK_EXPOSURE_MASK
GDK_MOTION_NOTIFY	motion	GDK_POINTER_MOTION_MASK GDK_BUTTON1_MOTION_MASK GDK_BUTTON2_MOTION_MASK GDK_BUTTON3_MOTION_MASK
GDK_BUTTON_PRESS GDK_2BUTTON_PRESS GDK_3BUTTON_PRESS GDK_BUTTON_RELEASE	button	GDK_BUTTON_PRESS_MASK GDK_BUTTON_RELEASE_MASK
GDK_KEY_PRESS GDK_KEY_RELEASE	key	GDK_KEY_PRESS_MASK GDK_KEY_RELEASE_MASK
GDK_ENTER_NOTIFY GDK_LEAVE_NOTIFY	crossing	GDK_ENTER_NOTIFY_MASK GDK_LEAVE_NOTIFY_MASK
GDK_FOCUS_CHANGE	focus_change	GDK_FOCUS_CHANGE_MASK
GDK_CONFIGURE	configure
GDK_MAP GDK_UNMAP
GDK_PROPERTY_NOTIFY	property	GDK_PROPERTY_CHANGE_MASK
GDK_SELECTION_CLEAR GDK_SELECTION_REQUEST GDK_SELECTION_NOTIFY	selection
GDK_PROXIMITY_IN GDK_PROXIMITY_OUT	proximity	GDK_PROXIMITY_IN_MASK GDK_PROXIMITY_OUT_MASK
GDK_DRAG_ENTER GDK_DRAG_LEAVE GDK_DRAG_MOTION GDK_DRAG_STATUS GDK_DROP_START GDK_DROP_FINISH	dnd
GDK_CLIENT_EVENT	client
GDK_VISIBILITY_NOTIFY	visibility	GDK_VISIBILITY_NOTIFY_MASK
GDK_NO_EXPOSE	no_expose