1.55.3 Send methods

event ->has_modifier: modifier

Succeeds if the event satisfies the condition of the argument modifier object.

A modifier may be created by conversion from a name consisting of the letters’s’(shift),’c’(control) and’m’(meta). The empty name demands all modifier keys to be up. See modifier<-convert for details.

The following tests whether the shift key of the current event is depressed (and the control- and meta-keys are not depressed).

send(@event, has_modifier, s).

See also

- modifier<-convert
- class modifier

event ->initialise: id=event_id, origin=[window|frame], x=[int], y=[int], button_mask=[int], time=[int]

Create an event from the specified parameters. Events are seldomly generated explicitly by the application code. All optional arguments default to their value of the last processed event. See also graphical->generate_event.

See also

graphical->generate_event

event ->inside: [graphical]

Succeeds if event is in the event-sensitive area of the argument graphical (see graphical->in_event_area).

If the argument is a window it checks whether the event is in the client area of the window.

Defaults: The default graphical is the event<-receiver.

See also

- area->in
- graphical->in_event_area

event ->is_a: super=event_id

Succeed if the event matches the specifier. The event-specifiers are organised in a hierarchy, represented by @event_tree. This method succeeds if event<-id is at or below the specified node in @event_hierarchy.

This test is the common way to test the identity of events. It is used by handler objects. Note that class gesture provides a more advanced mechanism to deal with mouse events.

ASCII events (event<-id is an integer) are organised as follows:

ascii
    control
        0..31|127
    printable
        32..126
    meta
        128..255

The demo tool Events displays @event-hierarchy.

See also

- event-id
- class event_tree
- object->recogniser

event ->is_down:

Succeeds if the event describes a button-down of any of the existing mouse-buttons.

See also

event->is_up

event ->is_drag:

Test if event is a button-drag event. A drag event is a loc_move event with one of the pointer-buttons depressed.

event ->is_up:

Succeeds if the event represents a release of one of the mouse-buttons. See also event->is_down.

See also

event->is_down

event ->post: to=graphical, recogniser=[recogniser]

This method is the central function for delivering events to graphical objects. This method takes care of automatically grabbing the event-focus on mouse-down events. See also class gesture.

It may also be used to forward events to other graphicals. It performs the following steps:

• Bind @event to the receiving event object
• Bind event<-receiver to the argument graphical
• If the recogniser is @default, invoke graphical->event to the argument graphical. Otherwise invoke recogniser->event on the argument recogniser. The latter mechanism is used when a device->event posts an event to its focus and window<-focus_recogniser is not @nil.
• If the event, nor the receiver of the event is freed and the event is accepted and
• The event<-window has no window<-focus and
• The event is a event->is_down event and
• graphical is displayed on event<-window

  invoke `window ->focus: graphical, @nil, @default, <-button`

  See also

  - event-receiver
  - @event
  - graphical->generate_event
  - device->event
  - device->event
  - window->focus