Module conrod::backend::event [−] [src]

The backend for conrod's event system.

Conrod's event system looks like this:

RawEvent -> Ui -> UiEvent -> Widget

The Ui receives RawEvents such as Press and Release via the Ui::handle_event method. It interprets these RawEvents to create higher-level UiEvents such as DoubleClick, WidgetCapturesKeyboard, etc. These UiEvents are stored and then fed to each Widget when Ui::set_widgets is called. At the end of Ui::set_widgets the stored UiEvents are flushed ready for the next incoming RawEvents.

Conrod uses the pistoncore-input crate's Event type as the RawEvent type. There are a few reasons for this:

  1. This Event type already provides a number of useful variants of events that we wish to provide and handle within conrod, and we do not yet see any great need to re-write it and duplicate code.
  2. The Event type is already compatible with all pistoncore-window backends including glfw_window, sdl2_window and glutin_window.
  3. The pistoncore-input crate also provides a GenericEvent trait which allows us to easily provide a blanket implementation of ToRawEvent for all event types that already implement this trait.

Because we use the pistoncore-input Event type, we also re-export its associated data types (Button, ControllerAxisArgs, Key, etc).

The ToRawEvent trait should be implemented for event types that are to be passed to the Ui::handle_event method. As mentioned above, a blanket implementation is already provided for all types that implement pistoncore-input::GenericEvent, so users of glfw_window, sdl2_window and glutin_window need not concern themselves with this trait.

Modules

keyboard

Back-end agnostic keyboard keys.

Structs

ControllerAxisArgs

Components of a controller axis move event. Not guaranteed consistent across backends.
ControllerButton

Components of a controller button event. Not guaranteed consistent across backends.
ModifierKey

Enums

Button

Models different kinds of buttons.
Event

Adds render and update events to input events
Input

Models input events.
Key

Represent a keyboard key. Keycodes follows SDL http://wiki.libsdl.org/SDLKeycodeLookup
Motion

Models different kinds of motion.
MouseButton

Represent a mouse button.

Traits

ToRawEvent

Types that may be converted to the RawEvent type used by conrod to track events happening in the world.

Type Definitions

RawEvent

The event type that is used by conrod to track inputs from the world. This can be thought of as the event type which is supplied by the window backend to drive the state of the Ui forward.