10.1 Event Types

An event is data generated asynchronously by the X server as a result of some device activity or as side effects of a request sent by an Xlib function. Device-related events propagate from the source window to ancestor windows until some client application has selected that event type or until the event is explicitly discarded. The X server generally sends an event to a client application only if the client has specifically asked to be informed of that event type, typically by setting the event-mask attribute of the window. The mask can also be set when you create a window or by changing the window's event-mask. You can also mask out events that would propagate to ancestor windows by manipulating the do-not-propagate mask of the window's attributes. However, MappingNotify events are always sent to all clients.

An event type describes a specific event generated by the X server. For each event type, a corresponding constant name is defined in X11/X.h, which is used when referring to an event type. The following table lists the event category and its associated event type or types. The processing associated with these events is discussed in section "Event Processing Overview".

Event Category	Event Type
Keyboard events	KeyPress, KeyRelease
Pointer events	ButtonPress, ButtonRelease, MotionNotify
Window crossing events	EnterNotify, LeaveNotify
Input focus events	FocusIn, FocusOut
Keymap state notification event	KeymapNotify
Exposure events	Expose, GraphicsExpose, NoExpose
Structure control events	CirculateRequest, ConfigureRequest, MapRequest, ResizeRequest
Window state notification events	CirculateNotify, ConfigureNotify, CreateNotify, DestroyNotify, GravityNotify, MapNotify, MappingNotify, ReparentNotify, UnmapNotify, VisibilityNotify
Colormap state notification event	ColormapNotify
Client communication events	ClientMessage, PropertyNotify, SelectionClear, SelectionNotify, SelectionRequest

Next: Event Structures

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Christophe Tronche, [email protected]