Events
Functions for handling events from the window system
This section describes functions dealing with events from the window system.
In GTK+ applications the events are handled automatically in
gtk_main_do_event() and passed on to the appropriate widgets, so these
functions are rarely needed. Though some of the fields in the
Event Structures are useful.
Event Structures
The structs used for each type of event.
Specifies the type of the event.
Do not confuse these events with the signals that GTK+ widgets emit.
Although many of these events result in corresponding signals being emitted,
the events are often transformed or filtered along the way.
@GDK_NOTHING: a special code to indicate a null event.
@GDK_DELETE: the window manager has requested that the toplevel window be
hidden or destroyed, usually when the user clicks on a special icon in the
title bar.
@GDK_DESTROY: the window has been destroyed.
@GDK_EXPOSE: all or part of the window has become visible and needs to be
redrawn.
@GDK_MOTION_NOTIFY: the pointer (usually a mouse) has moved.
@GDK_BUTTON_PRESS: a mouse button has been pressed.
@GDK_2BUTTON_PRESS: a mouse button has been double-clicked (clicked twice
within a short period of time). Note that each click also generates a
%GDK_BUTTON_PRESS event.
@GDK_3BUTTON_PRESS: a mouse button has been clicked 3 times in a short period
of time. Note that each click also generates a %GDK_BUTTON_PRESS event.
@GDK_BUTTON_RELEASE: a mouse button has been released.
@GDK_KEY_PRESS: a key has been pressed.
@GDK_KEY_RELEASE: a key has been released.
@GDK_ENTER_NOTIFY: the pointer has entered the window.
@GDK_LEAVE_NOTIFY: the pointer has left the window.
@GDK_FOCUS_CHANGE: the keyboard focus has entered or left the window.
@GDK_CONFIGURE: the size, position or stacking order of the window has changed.
Note that GTK+ discards these events for %GDK_WINDOW_CHILD windows.
@GDK_MAP: the window has been mapped.
@GDK_UNMAP: the window has been unmapped.
@GDK_PROPERTY_NOTIFY: a property on the window has been changed or deleted.
@GDK_SELECTION_CLEAR: the application has lost ownership of a selection.
@GDK_SELECTION_REQUEST: another application has requested a selection.
@GDK_SELECTION_NOTIFY: a selection has been received.
@GDK_PROXIMITY_IN: an input device has moved into contact with a sensing
surface (e.g. a touchscreen or graphics tablet).
@GDK_PROXIMITY_OUT: an input device has moved out of contact with a sensing
surface.
@GDK_DRAG_ENTER: the mouse has entered the window while a drag is in progress.
@GDK_DRAG_LEAVE: the mouse has left the window while a drag is in progress.
@GDK_DRAG_MOTION: the mouse has moved in the window while a drag is in
progress.
@GDK_DRAG_STATUS: the status of the drag operation initiated by the window
has changed.
@GDK_DROP_START: a drop operation onto the window has started.
@GDK_DROP_FINISHED: the drop operation initiated by the window has completed.
@GDK_CLIENT_EVENT: a message has been received from another application.
@GDK_VISIBILITY_NOTIFY: the window visibility status has changed.
@GDK_NO_EXPOSE: indicates that the source region was completely available
when parts of a drawable were copied. This is not very useful.
@GDK_SCROLL: the scroll wheel was turned
@GDK_WINDOW_STATE: the state of a window has changed. See #GdkWindowState
for the possible window states
@GDK_SETTING: a setting has been modified.
@GDK_OWNER_CHANGE: the owner of a selection has changed. This event type
was added in 2.6
@GDK_GRAB_BROKEN: a pointer or keyboard grab was broken. This event type
was added in 2.8.
@GDK_DAMAGE: the content of the window has been changed. This event type
was added in 2.14.
@GDK_EVENT_LAST: marks the end of the GdkEventType enumeration. Added in 2.18
A set of bit-flags to indicate which events a window is to receive.
Most of these masks map onto one or more of the #GdkEventType event types
above.
%GDK_POINTER_MOTION_HINT_MASK is a special mask which is used to reduce the
number of %GDK_MOTION_NOTIFY events received. Normally a %GDK_MOTION_NOTIFY
event is received each time the mouse moves. However, if the application
spends a lot of time processing the event (updating the display, for example),
it can lag behind the position of the mouse. When using
%GDK_POINTER_MOTION_HINT_MASK, fewer %GDK_MOTION_NOTIFY events will be sent,
some of which are marked as a hint (the is_hint member is %TRUE).
To receive more motion events after a motion hint event, the application
needs to asks for more, by calling gdk_event_request_motions().
@GDK_EXPOSURE_MASK: receive expose events
@GDK_POINTER_MOTION_MASK: receive all pointer motion events
@GDK_POINTER_MOTION_HINT_MASK: see the explanation above
@GDK_BUTTON_MOTION_MASK: receive pointer motion events while any button is pressed
@GDK_BUTTON1_MOTION_MASK: receive pointer motion events while 1 button is pressed
@GDK_BUTTON2_MOTION_MASK: receive pointer motion events while 2 button is pressed
@GDK_BUTTON3_MOTION_MASK: receive pointer motion events while 3 button is pressed
@GDK_BUTTON_PRESS_MASK: receive button press events
@GDK_BUTTON_RELEASE_MASK: receive button release events
@GDK_KEY_PRESS_MASK: receive key press events
@GDK_KEY_RELEASE_MASK: receive key release events
@GDK_ENTER_NOTIFY_MASK: receive window enter events
@GDK_LEAVE_NOTIFY_MASK: receive window leave events
@GDK_FOCUS_CHANGE_MASK: receive focus change events
@GDK_STRUCTURE_MASK: receive events about window configuration change
@GDK_PROPERTY_CHANGE_MASK: receive property change events
@GDK_VISIBILITY_NOTIFY_MASK: receive visibility change events
@GDK_PROXIMITY_IN_MASK: receive proximity in events
@GDK_PROXIMITY_OUT_MASK: receive proximity out events
@GDK_SUBSTRUCTURE_MASK: receive events about window configuration changes of
child windows
@GDK_SCROLL_MASK: receive scroll events
@GDK_ALL_EVENTS_MASK: the combination of all the above event masks.
Represents the current time, and can be used anywhere a time is expected.
This is the priority that events from the X server are given in the
GLib Main Loop.
This is the priority that the idle handler processing window updates
is given in the GLib Main Loop.
@Returns:
@Returns:
@Returns:
@event:
@type:
@Returns:
@event:
@Returns:
@event: a #GdkEvent.
@event:
@Returns:
@event:
@state:
@Returns:
@event:
@axis_use:
@value:
@Returns:
@event:
@x_win:
@y_win:
@Returns:
@event:
@x_root:
@y_root:
@Returns:
@event:
@func:
@data:
@notify:
Specifies the type of function passed to gdk_event_handler_set() to handle
all GDK events.
@event: the #GdkEvent to process.
@data: user data set when the event handler was installed with
gdk_event_handler_set().
@event:
@winid:
@Returns:
@display:
@event:
@winid:
@Returns:
@event:
@message_type:
@func:
@data:
@Returns:
@show_events:
@event:
@screen:
@event:
@Returns:
@name:
@value:
@Returns: