Class: SDL2::Event

Inherits:
Object
  • Object
show all
Defined in:
ext/sdl2_ext/event.c,
lib/sdl2/event.rb,
ext/sdl2_ext/event.c

Overview

This class represents SDL's events.

All events are represented by the instance of subclasses of this class.

# Introduction of event subsystem Event handling allows your application to receive input from the user. Event handling is initialized (along with video) with a call to:

SDL2.init(SDL2::INIT_VIDEO|SDL2::INIT_EVENTS)

Internally, SDL stores all the events waiting to be handled in an event queue. Using methods like Event.poll, you can observe and handle input events.

The queue is conceptually a sequence of objects of SDL2::Event. You can read an event from the queue with Event.poll and you can process the information from the object.

Note: peep and wait will be implemented later.

Defined Under Namespace

Classes: ControllerAxisMotion, ControllerButton, ControllerButtonDown, ControllerButtonUp, ControllerDevice, ControllerDeviceAdded, ControllerDeviceRemapped, ControllerDeviceRemoved, FingerDown, FingerMotion, FingerUp, JoyAxisMotion, JoyBallMotion, JoyButton, JoyButtonDown, JoyButtonUp, JoyDevice, JoyDeviceAdded, JoyDeviceRemoved, JoyHatMotion, KeyDown, KeyUp, Keyboard, MouseButton, MouseButtonDown, MouseButtonUp, MouseMotion, MouseWheel, Multigesture, Quit, SysWM, TextEditing, TextInput, TouchFinger, Window

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#timestamp ⇒ Integer

timestamp of the event

Returns:

  • (Integer)

#type ⇒ Integer

SDL's internal event type enum

Returns:

  • (Integer)

Class Method Details

.enable=(bool) ⇒ Boolean

Set wheter the event is enable

This method is only available for subclasses of SDL2::Event corresponding to SDL's event types.

Examples:

disable mouse wheel events

SDL2::Event::MouseWheel.enable = false

Parameters:

  • bool (Boolean) —

    true for enabling the event.

Returns:

  • (Boolean)

See Also:



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# File 'ext/sdl2_ext/event.c', line 159

static VALUE Event_s_set_enable(VALUE self, VALUE val)
{
    VALUE event_type = rb_iv_get(self, "event_type");
    if (event_type == Qnil) 
        rb_raise(rb_eArgError, "You cannot enable %s directly", rb_class2name(self));
    SDL_EventState(NUM2INT(event_type), RTEST(val) ? SDL_ENABLE : SDL_DISABLE);
    return val;
}

.enabled? ⇒ Boolean

Get whether the event is enabled.

This method is available for subclasses of SDL2::Event corresponding to SDL's event types.

Returns:

  • (Boolean)

See Also:

  • enabled=


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# File 'ext/sdl2_ext/event.c', line 134

static VALUE Event_s_enabled_p(VALUE self)
{
    VALUE event_type = rb_iv_get(self, "event_type");
    if (event_type == Qnil) {
        rb_warn("You cannot enable %s directly", rb_class2name(self));
        return Qfalse;
    }
    return INT2BOOL(SDL_EventState(NUM2INT(event_type), SDL_QUERY) == SDL_ENABLE);
}

.poll ⇒ SDL2::Event?

Poll for currently pending events.

Returns:

  • (SDL2::Event) —

    next event from the queue

  • (nil) —

    the queue is empty



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# File 'ext/sdl2_ext/event.c', line 116

static VALUE Event_s_poll(VALUE self)
{
    SDL_Event ev;
    if (SDL_PollEvent(&ev)) {
        return Event_new(&ev);
    } else {
        return Qnil;
    }
}

Instance Method Details

#inspect ⇒ String

Returns inspection string.

Returns:

  • (String) —

    inspection string



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# File 'ext/sdl2_ext/event.c', line 216

static VALUE Event_inspect(VALUE self)
{
    SDL_Event* ev; Data_Get_Struct(self, SDL_Event, ev);
    return rb_sprintf("<%s: type=%u timestamp=%u>",
                      rb_obj_classname(self), ev->common.type, ev->common.timestamp);
}

#window ⇒ SDL2::Window

Return the object of Window corresponding to the window_id attribute.

Some subclasses of SDL2::Event have window_id attribute to point the window which creates the event. The type of the window_id attribute is integer, and you need to convert it with Window.find_by_id to get the Window object. This method returns the Window object.

Returns:

Raises:

  • (NoMethodError) —

    raised if the window_id attribute is not present.



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# File 'ext/sdl2_ext/event.c', line 235

static VALUE Event_window(VALUE self)
{
    VALUE window_id = rb_funcall(self, rb_intern("window_id"), 0);
    return find_window_by_id(NUM2UINT(window_id));
}