6 releases
0.1.16 | Sep 24, 2024 |
---|---|
0.1.15 | Sep 19, 2024 |
#289 in Graphics APIs
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Used in 3 crates
2MB
41K
SLoC
rio-window
Rio window is a fork of Winit maintained only for Rio terminal.
lib.rs
:
Winit is a cross-platform window creation and event loop management library.
Building windows
Before you can create a Window
, you first need to build an EventLoop
. This is done with
the EventLoop::new()
function.
use rio_window::event_loop::EventLoop;
let event_loop = EventLoop::new().unwrap();
Then you create a Window
with create_window
.
Event handling
Once a Window
has been created, it will generate different events. A Window
object can
generate WindowEvent
s when certain input events occur, such as a cursor moving over the
window or a key getting pressed while the window is focused. Devices can generate
DeviceEvent
s, which contain unfiltered event data that isn't specific to a certain window.
Some user activity, like mouse movement, can generate both a WindowEvent
and a
DeviceEvent
. You can also create and handle your own custom Event::UserEvent
s, if
desired.
You can retrieve events by calling EventLoop::run_app()
. This function will
dispatch events for every Window
that was created with that particular EventLoop
, and
will run until exit()
is used, at which point Event::LoopExiting
.
Winit no longer uses a EventLoop::poll_events() -> impl Iterator<Event>
-based event loop
model, since that can't be implemented properly on some platforms (e.g web, iOS) and works
poorly on most other platforms. However, this model can be re-implemented to an extent with
[^1]. See that method's documentation for more reasons about why
it's discouraged beyond compatibility reasons.
use rio_window::application::ApplicationHandler;
use rio_window::event::WindowEvent;
use rio_window::event_loop::{ActiveEventLoop, ControlFlow, EventLoop};
use rio_window::window::{Window, WindowId};
#[derive(Default)]
struct App {
window: Option<Window>,
}
impl ApplicationHandler for App {
fn resumed(&mut self, event_loop: &ActiveEventLoop) {
self.window = Some(event_loop.create_window(Window::default_attributes()).unwrap());
}
fn window_event(&mut self, event_loop: &ActiveEventLoop, id: WindowId, event: WindowEvent) {
match event {
WindowEvent::CloseRequested => {
println!("The close button was pressed; stopping");
event_loop.exit();
},
WindowEvent::RedrawRequested => {
// Redraw the application.
//
// It's preferable for applications that do not render continuously to render in
// this event rather than in AboutToWait, since rendering in here allows
// the program to gracefully handle redraws requested by the OS.
// Draw.
// Queue a RedrawRequested event.
//
// You only need to call this if you've determined that you need to redraw in
// applications which do not always need to. Applications that redraw continuously
// can render here instead.
self.window.as_ref().unwrap().request_redraw();
}
_ => (),
}
}
}
let event_loop = EventLoop::new().unwrap();
// ControlFlow::Poll continuously runs the event loop, even if the OS hasn't
// dispatched any events. This is ideal for games and similar applications.
event_loop.set_control_flow(ControlFlow::Poll);
// ControlFlow::Wait pauses the event loop if no events are available to process.
// This is ideal for non-game applications that only update in response to user
// input, and uses significantly less power/CPU time than ControlFlow::Poll.
event_loop.set_control_flow(ControlFlow::Wait);
let mut app = App::default();
event_loop.run_app(&mut app);
WindowEvent
has a WindowId
member. In multi-window environments, it should be
compared to the value returned by Window::id()
to determine which Window
dispatched the event.
Drawing on the window
Winit doesn't directly provide any methods for drawing on a Window
. However, it allows you
to retrieve the raw handle of the window and display (see the platform
module and/or the
raw_window_handle
and raw_display_handle
methods), which in turn allows
you to create an OpenGL/Vulkan/DirectX/Metal/etc. context that can be used to render graphics.
Note that many platforms will display garbage data in the window's client area if the
application doesn't render anything to the window by the time the desktop compositor is ready to
display the window to the user. If you notice this happening, you should create the window with
visible
set to false
and explicitly make
the window visible only once you're ready to render into it.
UI scaling
UI scaling is important, go read the docs for the [dpi
] crate for an
introduction.
All of Winit's functions return physical types, but can take either logical or physical coordinates as input, allowing you to use the most convenient coordinate system for your particular application.
Winit will dispatch a ScaleFactorChanged
event whenever a window's scale factor has changed.
This can happen if the user drags their window from a standard-resolution monitor to a high-DPI
monitor or if the user changes their DPI settings. This allows you to rescale your application's
UI elements and adjust how the platform changes the window's size to reflect the new scale
factor. If a window hasn't received a ScaleFactorChanged
event, its scale factor
can be found by calling window.scale_factor()
.
Cargo Features
Winit provides the following Cargo features:
x11
(enabled by default): On Unix platforms, enables the X11 backend.wayland
(enabled by default): On Unix platforms, enables the Wayland backend.
See the platform
module for documentation on platform-specific cargo
features.
[^1]: EventLoopExtPumpEvents::pump_app_events()
is only available on Windows, macOS, Android, X11 and Wayland.
Dependencies
~0.5–18MB
~263K SLoC