//! Platform-agnostic interface for writing apps using [`egui`] (epi = egui programming interface).
//!
//! `epi` provides interfaces for window management and serialization.
//!
//! Start by looking at the [`App`] trait, and implement [`App::update`].
#![warn(missing_docs)] // Let's keep `epi` well-documented.
/// This is how your app is created.
///
/// You can use the [`CreationContext`] to setup egui, restore state, setup OpenGL things, etc.
pub type AppCreator = Box<dyn FnOnce(&CreationContext<'_>) -> Box<dyn App>>;
/// Data that is passed to [`AppCreator`] that can be used to setup and initialize your app.
pub struct CreationContext<'s> {
/// The egui Context.
///
/// You can use this to customize the look of egui, e.g to call [`egui::Context::set_fonts`],
/// [`egui::Context::set_visuals`] etc.
pub egui_ctx: egui::Context,
/// Information about the surrounding environment.
pub integration_info: IntegrationInfo,
/// You can use the storage to restore app state(requires the "persistence" feature).
pub storage: Option<&'s dyn Storage>,
/// The [`glow::Context`] allows you to initialize OpenGL resources (e.g. shaders) that
/// you might want to use later from a [`egui::PaintCallback`].
///
/// Only available when compiling with the `glow` feature and using [`Renderer::Glow`].
#[cfg(feature = "glow")]
pub gl: Option<std::sync::Arc<glow::Context>>,
/// The underlying WGPU render state.
///
/// Only available when compiling with the `wgpu` feature and using [`Renderer::Wgpu`].
///
/// Can be used to manage GPU resources for custom rendering with WGPU using [`egui::PaintCallback`]s.
#[cfg(feature = "wgpu")]
pub wgpu_render_state: Option<egui_wgpu::RenderState>,
}
// ----------------------------------------------------------------------------
/// Implement this trait to write apps that can be compiled for both web/wasm and desktop/native using [`eframe`](https://github.com/emilk/egui/tree/master/crates/eframe).
pub trait App {
/// Called each time the UI needs repainting, which may be many times per second.
///
/// Put your widgets into a [`egui::SidePanel`], [`egui::TopBottomPanel`], [`egui::CentralPanel`], [`egui::Window`] or [`egui::Area`].
///
/// The [`egui::Context`] can be cloned and saved if you like.
///
/// To force a repaint, call [`egui::Context::request_repaint`] at any time (e.g. from another thread).
fn update(&mut self, ctx: &egui::Context, frame: &mut Frame);
/// Called on shutdown, and perhaps at regular intervals. Allows you to save state.
///
/// Only called when the "persistence" feature is enabled.
///
/// On web the state is stored to "Local Storage".
/// On native the path is picked using [`directories_next::ProjectDirs::data_dir`](https://docs.rs/directories-next/2.0.0/directories_next/struct.ProjectDirs.html#method.data_dir) which is:
/// * Linux: `/home/UserName/.local/share/APPNAME`
/// * macOS: `/Users/UserName/Library/Application Support/APPNAME`
/// * Windows: `C:\Users\UserName\AppData\Roaming\APPNAME`
///
/// where `APPNAME` is what is given to `eframe::run_native`.
fn save(&mut self, _storage: &mut dyn Storage) {}
/// Called when the user attempts to close the desktop window and/or quit the application.
///
/// By returning `false` the closing will be aborted. To continue the closing return `true`.
///
/// A scenario where this method will be run is after pressing the close button on a native
/// window, which allows you to ask the user whether they want to do something before exiting.
/// See the example at <https://github.com/emilk/egui/blob/master/examples/confirm_exit/> for practical usage.
///
/// It will _not_ be called on the web or when the window is forcefully closed.
#[cfg(not(target_arch = "wasm32"))]
#[doc(alias = "exit")]
#[doc(alias = "quit")]
fn on_close_event(&mut self) -> bool {
true
}
/// Called once on shutdown, after [`Self::save`].
///
/// If you need to abort an exit use [`Self::on_close_event`].
///
/// To get a [`glow`] context you need to compile with the `glow` feature flag,
/// and run eframe with the glow backend.
#[cfg(feature = "glow")]
fn on_exit(&mut self, _gl: Option<&glow::Context>) {}
/// Called once on shutdown, after [`Self::save`].
///
/// If you need to abort an exit use [`Self::on_close_event`].
#[cfg(not(feature = "glow"))]
fn on_exit(&mut self) {}
// ---------
// Settings:
/// Time between automatic calls to [`Self::save`]
fn auto_save_interval(&self) -> std::time::Duration {
std::time::Duration::from_secs(30)
}
/// The size limit of the web app canvas.
///
/// By default the max size is [`egui::Vec2::INFINITY`], i.e. unlimited.
///
/// A large canvas can lead to bad frame rates on some older browsers on some platforms
/// (see <https://bugzilla.mozilla.org/show_bug.cgi?id=1010527#c0>).
fn max_size_points(&self) -> egui::Vec2 {
egui::Vec2::INFINITY
}
/// Background color for the app, e.g. what is sent to `gl.clearColor`.
/// This is the background of your windows if you don't set a central panel.
fn clear_color(&self, _visuals: &egui::Visuals) -> egui::Rgba {
// NOTE: a bright gray makes the shadows of the windows look weird.
// We use a bit of transparency so that if the user switches on the
// `transparent()` option they get immediate results.
egui::Color32::from_rgba_unmultiplied(12, 12, 12, 180).into()
// _visuals.window_fill() would also be a natural choice
}
/// Controls whether or not the native window position and size will be
/// persisted (only if the "persistence" feature is enabled).
fn persist_native_window(&self) -> bool {
true
}
/// Controls whether or not the egui memory (window positions etc) will be
/// persisted (only if the "persistence" feature is enabled).
fn persist_egui_memory(&self) -> bool {
true
}
/// If `true` a warm-up call to [`Self::update`] will be issued where
/// `ctx.memory().everything_is_visible()` will be set to `true`.
///
/// This can help pre-caching resources loaded by different parts of the UI, preventing stutter later on.
///
/// In this warm-up call, all painted shapes will be ignored.
///
/// The default is `false`, and it is unlikely you will want to change this.
fn warm_up_enabled(&self) -> bool {
false
}
/// Called each time after the rendering the UI.
///
/// Can be used to access pixel data with `get_pixels`
fn post_rendering(&mut self, _window_size_px: [u32; 2], _frame: &Frame) {}
}
/// Selects the level of hardware graphics acceleration.
#[cfg(not(target_arch = "wasm32"))]
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum HardwareAcceleration {
/// Require graphics acceleration.
Required,
/// Prefer graphics acceleration, but fall back to software.
Preferred,
/// Do NOT use graphics acceleration.
///
/// On some platforms (MacOS) this is ignored and treated the same as [`Self::Preferred`].
Off,
}
/// Options controlling the behavior of a native window.
///
/// Only a single native window is currently supported.
#[cfg(not(target_arch = "wasm32"))]
#[derive(Clone)]
pub struct NativeOptions {
/// Sets whether or not the window will always be on top of other windows.
pub always_on_top: bool,
/// Show window in maximized mode
pub maximized: bool,
/// On desktop: add window decorations (i.e. a frame around your app)?
/// If false it will be difficult to move and resize the app.
pub decorated: bool,
/// Start in (borderless) fullscreen?
///
/// Default: `false`.
pub fullscreen: bool,
/// On Windows: enable drag and drop support. Drag and drop can
/// not be disabled on other platforms.
///
/// See [winit's documentation][drag_and_drop] for information on why you
/// might want to disable this on windows.
///
/// [drag_and_drop]: https://docs.rs/winit/latest/x86_64-pc-windows-msvc/winit/platform/windows/trait.WindowBuilderExtWindows.html#tymethod.with_drag_and_drop
pub drag_and_drop_support: bool,
/// The application icon, e.g. in the Windows task bar etc.
///
/// This doesn't work on Mac and on Wayland.
/// See <https://docs.rs/winit/latest/winit/window/struct.Window.html#method.set_window_icon> for more.
pub icon_data: Option<IconData>,
/// The initial (inner) position of the native window in points (logical pixels).
pub initial_window_pos: Option<egui::Pos2>,
/// The initial inner size of the native window in points (logical pixels).
pub initial_window_size: Option<egui::Vec2>,
/// The minimum inner window size
pub min_window_size: Option<egui::Vec2>,
/// The maximum inner window size
pub max_window_size: Option<egui::Vec2>,
/// Should the app window be resizable?
pub resizable: bool,
/// On desktop: make the window transparent.
/// You control the transparency with [`App::clear_color()`].
/// You should avoid having a [`egui::CentralPanel`], or make sure its frame is also transparent.
pub transparent: bool,
/// Turn on vertical syncing, limiting the FPS to the display refresh rate.
///
/// The default is `true`.
pub vsync: bool,
/// Set the level of the multisampling anti-aliasing (MSAA).
///
/// Must be a power-of-two. Higher = more smooth 3D.
///
/// A value of `0` turns it off (default).
///
/// `egui` already performs anti-aliasing via "feathering"
/// (controlled by [`egui::epaint::TessellationOptions`]),
/// but if you are embedding 3D in egui you may want to turn on multisampling.
pub multisampling: u16,
/// Sets the number of bits in the depth buffer.
///
/// `egui` doesn't need the depth buffer, so the default value is 0.
pub depth_buffer: u8,
/// Sets the number of bits in the stencil buffer.
///
/// `egui` doesn't need the stencil buffer, so the default value is 0.
pub stencil_buffer: u8,
/// Specify wether or not hardware acceleration is preferred, required, or not.
///
/// Default: [`HardwareAcceleration::Preferred`].
pub hardware_acceleration: HardwareAcceleration,
/// What rendering backend to use.
pub renderer: Renderer,
/// Only used if the `dark-light` feature is enabled:
///
/// Try to detect and follow the system preferred setting for dark vs light mode.
///
/// By default, this is `true` on Mac and Windows, but `false` on Linux
/// due to <https://github.com/frewsxcv/rust-dark-light/issues/17>.
///
/// See also [`Self::default_theme`].
pub follow_system_theme: bool,
/// Which theme to use in case [`Self::follow_system_theme`] is `false`
/// or the `dark-light` feature is disabled.
///
/// Default: [`Theme::Dark`].
pub default_theme: Theme,
/// This controls what happens when you close the main eframe window.
///
/// If `true`, execution will continue after the eframe window is closed.
/// If `false`, the app will close once the eframe window is closed.
///
/// This is `true` by default, and the `false` option is only there
/// so we can revert if we find any bugs.
///
/// This feature was introduced in <https://github.com/emilk/egui/pull/1889>.
///
/// When `true`, [`winit::platform::run_return::EventLoopExtRunReturn::run_return`] is used.
/// When `false`, [`winit::event_loop::EventLoop::run`] is used.
pub run_and_return: bool,
}
#[cfg(not(target_arch = "wasm32"))]
impl Default for NativeOptions {
fn default() -> Self {
Self {
always_on_top: false,
maximized: false,
decorated: true,
fullscreen: false,
drag_and_drop_support: true,
icon_data: None,
initial_window_pos: None,
initial_window_size: None,
min_window_size: None,
max_window_size: None,
resizable: true,
transparent: false,
vsync: true,
multisampling: 0,
depth_buffer: 0,
stencil_buffer: 0,
hardware_acceleration: HardwareAcceleration::Preferred,
renderer: Renderer::default(),
follow_system_theme: cfg!(target_os = "macos") || cfg!(target_os = "windows"),
default_theme: Theme::Dark,
run_and_return: true,
}
}
}
#[cfg(not(target_arch = "wasm32"))]
impl NativeOptions {
/// The theme used by the system.
#[cfg(feature = "dark-light")]
pub fn system_theme(&self) -> Option<Theme> {
if self.follow_system_theme {
crate::profile_scope!("dark_light::detect");
match dark_light::detect() {
dark_light::Mode::Dark => Some(Theme::Dark),
dark_light::Mode::Light => Some(Theme::Light),
}
} else {
None
}
}
/// The theme used by the system.
#[cfg(not(feature = "dark-light"))]
pub fn system_theme(&self) -> Option<Theme> {
None
}
}
// ----------------------------------------------------------------------------
/// Options when using `eframe` in a web page.
#[cfg(target_arch = "wasm32")]
pub struct WebOptions {
/// Try to detect and follow the system preferred setting for dark vs light mode.
///
/// See also [`Self::default_theme`].
///
/// Default: `false`.
pub follow_system_theme: bool,
/// Which theme to use in case [`Self::follow_system_theme`] is `false`
/// or system theme detection fails.
///
/// Default: `Theme::Dark`.
pub default_theme: Theme,
/// Which version of WebGl context to select
///
/// Default: [`WebGlContextOption::BestFirst`].
pub webgl_context_option: WebGlContextOption,
}
#[cfg(target_arch = "wasm32")]
impl Default for WebOptions {
fn default() -> Self {
Self {
follow_system_theme: true,
default_theme: Theme::Dark,
webgl_context_option: WebGlContextOption::BestFirst,
}
}
}
// ----------------------------------------------------------------------------
/// Dark or Light theme.
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
pub enum Theme {
/// Dark mode: light text on a dark background.
Dark,
/// Light mode: dark text on a light background.
Light,
}
impl Theme {
/// Get the egui visuals corresponding to this theme.
///
/// Use with [`egui::Context::set_visuals`].
pub fn egui_visuals(self) -> egui::Visuals {
match self {
Self::Dark => egui::Visuals::dark(),
Self::Light => egui::Visuals::light(),
}
}
}
// ----------------------------------------------------------------------------
/// WebGL Context options
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
pub enum WebGlContextOption {
/// Force Use WebGL1.
WebGl1,
/// Force use WebGL2.
WebGl2,
/// Use WebGl2 first.
BestFirst,
/// Use WebGl1 first
CompatibilityFirst,
}
// ----------------------------------------------------------------------------
/// What rendering backend to use.
///
/// You need to enable the "glow" and "wgpu" features to have a choice.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
#[cfg_attr(feature = "serde", serde(rename_all = "snake_case"))]
pub enum Renderer {
/// Use [`egui_glow`] renderer for [`glow`](https://github.com/grovesNL/glow).
#[cfg(feature = "glow")]
Glow,
/// Use [`egui_wgpu`] renderer for [`wgpu`](https://github.com/gfx-rs/wgpu).
#[cfg(feature = "wgpu")]
Wgpu,
}
impl Default for Renderer {
fn default() -> Self {
#[cfg(feature = "glow")]
return Self::Glow;
#[cfg(not(feature = "glow"))]
#[cfg(feature = "wgpu")]
return Self::Wgpu;
#[cfg(not(feature = "glow"))]
#[cfg(not(feature = "wgpu"))]
compile_error!("eframe: you must enable at least one of the rendering backend features: 'glow' or 'wgpu'");
}
}
impl std::fmt::Display for Renderer {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
#[cfg(feature = "glow")]
Self::Glow => "glow".fmt(f),
#[cfg(feature = "wgpu")]
Self::Wgpu => "wgpu".fmt(f),
}
}
}
impl std::str::FromStr for Renderer {
type Err = String;
fn from_str(name: &str) -> Result<Self, String> {
match name.to_lowercase().as_str() {
#[cfg(feature = "glow")]
"glow" => Ok(Self::Glow),
#[cfg(feature = "wgpu")]
"wgpu" => Ok(Self::Wgpu),
_ => Err(format!("eframe renderer {name:?} is not available. Make sure that the corresponding eframe feature is enabled."))
}
}
}
// ----------------------------------------------------------------------------
/// Image data for an application icon.
#[derive(Clone)]
pub struct IconData {
/// RGBA pixels, unmultiplied.
pub rgba: Vec<u8>,
/// Image width. This should be a multiple of 4.
pub width: u32,
/// Image height. This should be a multiple of 4.
pub height: u32,
}
/// Represents the surroundings of your app.
///
/// It provides methods to inspect the surroundings (are we on the web?),
/// allocate textures, and change settings (e.g. window size).
pub struct Frame {
/// Information about the integration.
pub(crate) info: IntegrationInfo,
/// Where the app can issue commands back to the integration.
pub(crate) output: backend::AppOutput,
/// A place where you can store custom data in a way that persists when you restart the app.
pub(crate) storage: Option<Box<dyn Storage>>,
/// A reference to the underlying [`glow`] (OpenGL) context.
#[cfg(feature = "glow")]
pub(crate) gl: Option<std::sync::Arc<glow::Context>>,
/// Can be used to manage GPU resources for custom rendering with WGPU using [`egui::PaintCallback`]s.
#[cfg(feature = "wgpu")]
pub(crate) wgpu_render_state: Option<egui_wgpu::RenderState>,
}
impl Frame {
/// True if you are in a web environment.
///
/// Equivalent to `cfg!(target_arch = "wasm32")`
#[allow(clippy::unused_self)]
pub fn is_web(&self) -> bool {
cfg!(target_arch = "wasm32")
}
/// Information about the integration.
pub fn info(&self) -> IntegrationInfo {
self.info.clone()
}
/// A place where you can store custom data in a way that persists when you restart the app.
pub fn storage(&self) -> Option<&dyn Storage> {
self.storage.as_deref()
}
/// A place where you can store custom data in a way that persists when you restart the app.
pub fn storage_mut(&mut self) -> Option<&mut (dyn Storage + 'static)> {
self.storage.as_deref_mut()
}
/// A reference to the underlying [`glow`] (OpenGL) context.
///
/// This can be used, for instance, to:
/// * Render things to offscreen buffers.
/// * Read the pixel buffer from the previous frame (`glow::Context::read_pixels`).
/// * Render things behind the egui windows.
///
/// Note that all egui painting is deferred to after the call to [`App::update`]
/// ([`egui`] only collects [`egui::Shape`]s and then eframe paints them all in one go later on).
///
/// To get a [`glow`] context you need to compile with the `glow` feature flag,
/// and run eframe using [`Renderer::Glow`].
#[cfg(feature = "glow")]
pub fn gl(&self) -> Option<&std::sync::Arc<glow::Context>> {
self.gl.as_ref()
}
/// The underlying WGPU render state.
///
/// Only available when compiling with the `wgpu` feature and using [`Renderer::Wgpu`].
///
/// Can be used to manage GPU resources for custom rendering with WGPU using [`egui::PaintCallback`]s.
#[cfg(feature = "wgpu")]
pub fn wgpu_render_state(&self) -> Option<&egui_wgpu::RenderState> {
self.wgpu_render_state.as_ref()
}
/// Tell `eframe` to close the desktop window.
///
/// The window will not close immediately, but at the end of the this frame.
///
/// Calling this will likely result in the app quitting, unless
/// you have more code after the call to [`crate::run_native`].
#[cfg(not(target_arch = "wasm32"))]
#[doc(alias = "exit")]
#[doc(alias = "quit")]
pub fn close(&mut self) {
self.output.close = true;
}
/// Tell `eframe` to close the desktop window.
#[cfg(not(target_arch = "wasm32"))]
#[deprecated = "Renamed `close`"]
pub fn quit(&mut self) {
self.close();
}
/// Set the desired inner size of the window (in egui points).
#[cfg(not(target_arch = "wasm32"))]
pub fn set_window_size(&mut self, size: egui::Vec2) {
self.output.window_size = Some(size);
}
/// Set the desired title of the window.
#[cfg(not(target_arch = "wasm32"))]
pub fn set_window_title(&mut self, title: &str) {
self.output.window_title = Some(title.to_owned());
}
/// Set whether to show window decorations (i.e. a frame around you app).
///
/// If false it will be difficult to move and resize the app.
#[cfg(not(target_arch = "wasm32"))]
pub fn set_decorations(&mut self, decorated: bool) {
self.output.decorated = Some(decorated);
}
/// Turn borderless fullscreen on/off (native only).
#[cfg(not(target_arch = "wasm32"))]
pub fn set_fullscreen(&mut self, fullscreen: bool) {
self.output.fullscreen = Some(fullscreen);
}
/// set the position of the outer window.
#[cfg(not(target_arch = "wasm32"))]
pub fn set_window_pos(&mut self, pos: egui::Pos2) {
self.output.window_pos = Some(pos);
}
/// When called, the native window will follow the
/// movement of the cursor while the primary mouse button is down.
///
/// Does not work on the web.
#[cfg(not(target_arch = "wasm32"))]
pub fn drag_window(&mut self) {
self.output.drag_window = true;
}
/// Set the visibility of the window.
#[cfg(not(target_arch = "wasm32"))]
pub fn set_visible(&mut self, visible: bool) {
self.output.visible = Some(visible);
}
/// for integrations only: call once per frame
pub(crate) fn take_app_output(&mut self) -> backend::AppOutput {
std::mem::take(&mut self.output)
}
}
/// Information about the web environment (if applicable).
#[derive(Clone, Debug)]
#[cfg(target_arch = "wasm32")]
pub struct WebInfo {
/// Information about the URL.
pub location: Location,
}
/// Information about the application's main window, if available.
#[cfg(not(target_arch = "wasm32"))]
#[derive(Clone, Debug)]
pub struct WindowInfo {
/// Coordinates of the window's outer top left corner, relative to the top left corner of the first display.
///
/// Unit: egui points (logical pixels).
///
/// `None` = unknown.
pub position: Option<egui::Pos2>,
/// Are we in fullscreen mode?
pub fullscreen: bool,
/// Window inner size in egui points (logical pixels).
pub size: egui::Vec2,
}
/// Information about the URL.
///
/// Everything has been percent decoded (`%20` -> ` ` etc).
#[cfg(target_arch = "wasm32")]
#[derive(Clone, Debug)]
pub struct Location {
/// The full URL (`location.href`) without the hash.
///
/// Example: `"http://www.example.com:80/index.html?foo=bar"`.
pub url: String,
/// `location.protocol`
///
/// Example: `"http:"`.
pub protocol: String,
/// `location.host`
///
/// Example: `"example.com:80"`.
pub host: String,
/// `location.hostname`
///
/// Example: `"example.com"`.
pub hostname: String,
/// `location.port`
///
/// Example: `"80"`.
pub port: String,
/// The "#fragment" part of "www.example.com/index.html?query#fragment".
///
/// Note that the leading `#` is included in the string.
/// Also known as "hash-link" or "anchor".
pub hash: String,
/// The "query" part of "www.example.com/index.html?query#fragment".
///
/// Note that the leading `?` is NOT included in the string.
///
/// Use [`Self::query_map`] to get the parsed version of it.
pub query: String,
/// The parsed "query" part of "www.example.com/index.html?query#fragment".
///
/// "foo=42&bar%20" is parsed as `{"foo": "42", "bar ": ""}`
pub query_map: std::collections::BTreeMap<String, String>,
/// `location.origin`
///
/// Example: `"http://www.example.com:80"`.
pub origin: String,
}
/// Information about the integration passed to the use app each frame.
#[derive(Clone, Debug)]
pub struct IntegrationInfo {
/// Information about the surrounding web environment.
#[cfg(target_arch = "wasm32")]
pub web_info: WebInfo,
/// Does the OS use dark or light mode?
///
/// `None` means "don't know".
pub system_theme: Option<Theme>,
/// Seconds of cpu usage (in seconds) of UI code on the previous frame.
/// `None` if this is the first frame.
pub cpu_usage: Option<f32>,
/// The OS native pixels-per-point
pub native_pixels_per_point: Option<f32>,
/// The position and size of the native window.
#[cfg(not(target_arch = "wasm32"))]
pub window_info: WindowInfo,
}
// ----------------------------------------------------------------------------
/// A place where you can store custom data in a way that persists when you restart the app.
///
/// On the web this is backed by [local storage](https://developer.mozilla.org/en-US/docs/Web/API/Window/localStorage).
/// On desktop this is backed by the file system.
///
/// See [`CreationContext::storage`] and [`App::save`].
pub trait Storage {
/// Get the value for the given key.
fn get_string(&self, key: &str) -> Option<String>;
/// Set the value for the given key.
fn set_string(&mut self, key: &str, value: String);
/// write-to-disk or similar
fn flush(&mut self);
}
/// Stores nothing.
#[derive(Clone, Default)]
pub(crate) struct DummyStorage {}
impl Storage for DummyStorage {
fn get_string(&self, _key: &str) -> Option<String> {
None
}
fn set_string(&mut self, _key: &str, _value: String) {}
fn flush(&mut self) {}
}
/// Get and deserialize the [RON](https://github.com/ron-rs/ron) stored at the given key.
#[cfg(feature = "ron")]
pub fn get_value<T: serde::de::DeserializeOwned>(storage: &dyn Storage, key: &str) -> Option<T> {
storage
.get_string(key)
.and_then(|value| ron::from_str(&value).ok())
}
/// Serialize the given value as [RON](https://github.com/ron-rs/ron) and store with the given key.
#[cfg(feature = "ron")]
pub fn set_value<T: serde::Serialize>(storage: &mut dyn Storage, key: &str, value: &T) {
match ron::ser::to_string(value) {
Ok(string) => storage.set_string(key, string),
Err(err) => tracing::error!("eframe failed to encode data using ron: {}", err),
}
}
/// [`Storage`] key used for app
pub const APP_KEY: &str = "app";
// ----------------------------------------------------------------------------
/// You only need to look here if you are writing a backend for `epi`.
pub(crate) mod backend {
/// Action that can be taken by the user app.
#[derive(Clone, Debug, Default)]
#[must_use]
pub struct AppOutput {
/// Set to `true` to close the native window (which often quits the app).
#[cfg(not(target_arch = "wasm32"))]
pub close: bool,
/// Set to some size to resize the outer window (e.g. glium window) to this size.
#[cfg(not(target_arch = "wasm32"))]
pub window_size: Option<egui::Vec2>,
/// Set to some string to rename the outer window (e.g. glium window) to this title.
#[cfg(not(target_arch = "wasm32"))]
pub window_title: Option<String>,
/// Set to some bool to change window decorations.
#[cfg(not(target_arch = "wasm32"))]
pub decorated: Option<bool>,
/// Set to some bool to change window fullscreen.
#[cfg(not(target_arch = "wasm32"))] // TODO: implement fullscreen on web
pub fullscreen: Option<bool>,
/// Set to true to drag window while primary mouse button is down.
#[cfg(not(target_arch = "wasm32"))]
pub drag_window: bool,
/// Set to some position to move the outer window (e.g. glium window) to this position
#[cfg(not(target_arch = "wasm32"))]
pub window_pos: Option<egui::Pos2>,
/// Set to some bool to change window visibility.
#[cfg(not(target_arch = "wasm32"))]
pub visible: Option<bool>,
}
}