diff --git a/crates/gpui2/src/app.rs b/crates/gpui2/src/app.rs index 35df72769b..57ea79afbe 100644 --- a/crates/gpui2/src/app.rs +++ b/crates/gpui2/src/app.rs @@ -38,7 +38,10 @@ use util::http::{self, HttpClient}; pub struct App(Arc>); +/// Represents an application before it is fully launched. Once your app is +/// configured, you'll start the app with `App::run`. impl App { + /// Builds an app with the given asset source. pub fn production(asset_source: Arc) -> Self { Self(AppContext::new( current_platform(), @@ -47,6 +50,8 @@ impl App { )) } + /// Start the application. The provided callback will be called once the + /// app is fully launched. pub fn run(self, on_finish_launching: F) where F: 'static + FnOnce(&mut MainThread), @@ -60,6 +65,8 @@ impl App { })); } + /// Register a handler to be invoked when the platform instructs the application + /// to open one or more URLs. pub fn on_open_urls(&self, mut callback: F) -> &Self where F: 'static + FnMut(Vec, &mut AppContext), @@ -203,6 +210,8 @@ impl AppContext { }) } + /// Quit the application gracefully. Handlers registered with `ModelContext::on_app_quit` + /// will be given 100ms to complete before exiting. pub fn quit(&mut self) { let mut futures = Vec::new(); @@ -230,6 +239,8 @@ impl AppContext { self.app_metadata.clone() } + /// Schedules all windows in the application to be redrawn. This can be called + /// multiple times in an update cycle and still result in a single redraw. pub fn refresh(&mut self) { self.pending_effects.push_back(Effect::Refresh); } @@ -302,6 +313,9 @@ impl AppContext { self.pending_effects.push_back(effect); } + /// Called at the end of AppContext::update to complete any side effects + /// such as notifying observers, emitting events, etc. Effects can themselves + /// cause effects, so we continue looping until all effects are processed. fn flush_effects(&mut self) { loop { self.release_dropped_entities(); @@ -348,6 +362,9 @@ impl AppContext { } } + /// Repeatedly called during `flush_effects` to release any entities whose + /// reference count has become zero. We invoke any release observers before dropping + /// each entity. fn release_dropped_entities(&mut self) { loop { let dropped = self.entities.take_dropped(); @@ -365,6 +382,9 @@ impl AppContext { } } + /// Repeatedly called during `flush_effects` to handle a focused handle being dropped. + /// For now, we simply blur the window if this happens, but we may want to support invoking + /// a window blur handler to restore focus to some logical element. fn release_dropped_focus_handles(&mut self) { let window_ids = self.windows.keys().collect::>(); for window_id in window_ids { @@ -448,6 +468,8 @@ impl AppContext { callback(self); } + /// Creates an `AsyncAppContext`, which can be cloned and has a static lifetime + /// so it can be held across `await` points. pub fn to_async(&self) -> AsyncAppContext { AsyncAppContext { app: unsafe { mem::transmute(self.this.clone()) }, @@ -455,10 +477,14 @@ impl AppContext { } } + /// Obtains a reference to the executor, which can be used to spawn futures. pub fn executor(&self) -> &Executor { &self.executor } + /// Runs the given closure on the main thread, where interaction with the platform + /// is possible. The given closure will be invoked with a `MainThread`, which + /// has platform-specific methods that aren't present on `AppContext`. pub fn run_on_main( &mut self, f: impl FnOnce(&mut MainThread) -> R + Send + 'static, @@ -479,6 +505,11 @@ impl AppContext { } } + /// Spawns the future returned by the given function on the main thread, where interaction with + /// the platform is possible. The given closure will be invoked with a `MainThread`, + /// which has platform-specific methods that aren't present on `AsyncAppContext`. The future will be + /// polled exclusively on the main thread. + // todo!("I think we need somehow to prevent the MainThread from implementing Send") pub fn spawn_on_main( &self, f: impl FnOnce(MainThread) -> F + Send + 'static, @@ -491,6 +522,8 @@ impl AppContext { self.executor.spawn_on_main(move || f(MainThread(cx))) } + /// Spawns the future returned by the given function on the thread pool. The closure will be invoked + /// with AsyncAppContext, which allows the application state to be accessed across await points. pub fn spawn(&self, f: impl FnOnce(AsyncAppContext) -> Fut + Send + 'static) -> Task where Fut: Future + Send + 'static, @@ -503,20 +536,25 @@ impl AppContext { }) } + /// Schedules the given function to be run at the end of the current effect cycle, allowing entities + /// that are currently on the stack to be returned to the app. pub fn defer(&mut self, f: impl FnOnce(&mut AppContext) + 'static + Send) { self.push_effect(Effect::Defer { callback: Box::new(f), }); } + /// Accessor for the application's asset source, which is provided when constructing the `App`. pub fn asset_source(&self) -> &Arc { &self.asset_source } + /// Accessor for the text system. pub fn text_system(&self) -> &Arc { &self.text_system } + /// The current text style. Which is composed of all the style refinements provided to `with_text_style`. pub fn text_style(&self) -> TextStyle { let mut style = TextStyle::default(); for refinement in &self.text_style_stack { @@ -525,10 +563,12 @@ impl AppContext { style } + /// Check whether a global of the given type has been assigned. pub fn has_global(&self) -> bool { self.globals_by_type.contains_key(&TypeId::of::()) } + /// Access the global of the given type. Panics if a global for that type has not been assigned. pub fn global(&self) -> &G { self.globals_by_type .get(&TypeId::of::()) @@ -537,12 +577,14 @@ impl AppContext { .unwrap() } + /// Access the global of the given type if a value has been assigned. pub fn try_global(&self) -> Option<&G> { self.globals_by_type .get(&TypeId::of::()) .map(|any_state| any_state.downcast_ref::().unwrap()) } + /// Access the global of the given type mutably. Panics if a global for that type has not been assigned. pub fn global_mut(&mut self) -> &mut G { let global_type = TypeId::of::(); self.push_effect(Effect::NotifyGlobalObservers { global_type }); @@ -553,6 +595,8 @@ impl AppContext { .unwrap() } + /// Access the global of the given type mutably. A default value is assigned if a global of this type has not + /// yet been assigned. pub fn default_global(&mut self) -> &mut G { let global_type = TypeId::of::(); self.push_effect(Effect::NotifyGlobalObservers { global_type }); @@ -563,12 +607,15 @@ impl AppContext { .unwrap() } + /// Set the value of the global of the given type. pub fn set_global(&mut self, global: G) { let global_type = TypeId::of::(); self.push_effect(Effect::NotifyGlobalObservers { global_type }); self.globals_by_type.insert(global_type, Box::new(global)); } + /// Update the global of the given type with a closure. Unlike `global_mut`, this method provides + /// your closure with mutable access to the `AppContext` and the global simultaneously. pub fn update_global(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R { let mut global = self.lease_global::(); let result = f(&mut global, self); @@ -576,6 +623,7 @@ impl AppContext { result } + /// Register a callback to be invoked when a global of the given type is updated. pub fn observe_global( &mut self, mut f: impl FnMut(&mut Self) + Send + 'static, @@ -589,6 +637,7 @@ impl AppContext { ) } + /// Move the global of the given type to the stack. pub(crate) fn lease_global(&mut self) -> GlobalLease { GlobalLease::new( self.globals_by_type @@ -598,6 +647,7 @@ impl AppContext { ) } + /// Restore the global of the given type after it is moved to the stack. pub(crate) fn end_global_lease(&mut self, lease: GlobalLease) { let global_type = TypeId::of::(); self.push_effect(Effect::NotifyGlobalObservers { global_type }); @@ -612,11 +662,13 @@ impl AppContext { self.text_style_stack.pop(); } + /// Register key bindings. pub fn bind_keys(&mut self, bindings: impl IntoIterator) { self.keymap.lock().add_bindings(bindings); self.pending_effects.push_back(Effect::Refresh); } + /// Register a global listener for actions invoked via the keyboard. pub fn on_action(&mut self, listener: impl Fn(&A, &mut Self) + Send + 'static) { self.global_action_listeners .entry(TypeId::of::()) @@ -629,10 +681,12 @@ impl AppContext { })); } + /// Register an action type to allow it to be referenced in keymaps. pub fn register_action_type(&mut self) { self.action_builders.insert(A::qualified_name(), A::build); } + /// Construct an action based on its name and parameters. pub fn build_action( &mut self, name: &str, @@ -645,6 +699,8 @@ impl AppContext { (build)(params) } + /// Halt propagation of a mouse event, keyboard event, or action. This prevents listeners + /// that have not yet been invoked from receiving the event. pub fn stop_propagation(&mut self) { self.propagate_event = false; } @@ -654,6 +710,9 @@ impl Context for AppContext { type EntityContext<'a, T> = ModelContext<'a, T>; type Result = T; + /// Build an entity that is owned by the application. The given function will be invoked with + /// a `ModelContext` and must return an object representing the entity. A `Handle` will be returned + /// which can be used to access the entity in a context. fn entity( &mut self, build_entity: impl FnOnce(&mut Self::EntityContext<'_, T>) -> T, @@ -665,6 +724,8 @@ impl Context for AppContext { }) } + /// Update the entity referenced by the given handle. The function is passed a mutable reference to the + /// entity along with a `ModelContext` for the entity. fn update_entity( &mut self, handle: &Handle, @@ -690,30 +751,37 @@ where self.0.borrow().platform.borrow_on_main_thread() } + /// Instructs the platform to activate the application by bringing it to the foreground. pub fn activate(&self, ignoring_other_apps: bool) { self.platform().activate(ignoring_other_apps); } + /// Writes data to the platform clipboard. pub fn write_to_clipboard(&self, item: ClipboardItem) { self.platform().write_to_clipboard(item) } + /// Reads data from the platform clipboard. pub fn read_from_clipboard(&self) -> Option { self.platform().read_from_clipboard() } + /// Writes credentials to the platform keychain. pub fn write_credentials(&self, url: &str, username: &str, password: &[u8]) -> Result<()> { self.platform().write_credentials(url, username, password) } + /// Reads credentials from the platform keychain. pub fn read_credentials(&self, url: &str) -> Result)>> { self.platform().read_credentials(url) } + /// Deletes credentials from the platform keychain. pub fn delete_credentials(&self, url: &str) -> Result<()> { self.platform().delete_credentials(url) } + /// Directs the platform's default browser to open the given URL. pub fn open_url(&self, url: &str) { self.platform().open_url(url); } @@ -744,6 +812,9 @@ impl MainThread { }) } + /// Opens a new window with the given option and the root view returned by the given function. + /// The function is invoked with a `WindowContext`, which can be used to interact with window-specific + /// functionality. pub fn open_window( &mut self, options: crate::WindowOptions, @@ -760,6 +831,8 @@ impl MainThread { }) } + /// Update the global of the given type with a closure. Unlike `global_mut`, this method provides + /// your closure with mutable access to the `MainThread` and the global simultaneously. pub fn update_global( &mut self, update: impl FnOnce(&mut G, &mut MainThread) -> R, @@ -771,6 +844,7 @@ impl MainThread { } } +/// These effects are processed at the end of each application update cycle. pub(crate) enum Effect { Notify { emitter: EntityId, @@ -792,6 +866,7 @@ pub(crate) enum Effect { }, } +/// Wraps a global variable value during `update_global` while the value has been moved to the stack. pub(crate) struct GlobalLease { global: AnyBox, global_type: PhantomData, @@ -820,6 +895,8 @@ impl DerefMut for GlobalLease { } } +/// Contains state associated with an active drag operation, started by dragging an element +/// within the window or by dragging into the app from the underlying platform. pub(crate) struct AnyDrag { pub drag_handle_view: Option, pub cursor_offset: Point, diff --git a/crates/gpui2/src/window.rs b/crates/gpui2/src/window.rs index cf15082d31..fd5aba6057 100644 --- a/crates/gpui2/src/window.rs +++ b/crates/gpui2/src/window.rs @@ -30,16 +30,22 @@ use std::{ }; use util::ResultExt; +/// A global stacking order, which is created by stacking successive z-index values. +/// Each z-index will always be interpreted in the context of its parent z-index. #[derive(Deref, DerefMut, Ord, PartialOrd, Eq, PartialEq, Clone, Default)] -pub struct StackingOrder(pub(crate) SmallVec<[u32; 16]>); +pub(crate) struct StackingOrder(pub(crate) SmallVec<[u32; 16]>); +/// Represents the two different phases when dispatching events. #[derive(Default, Copy, Clone, Debug, Eq, PartialEq)] pub enum DispatchPhase { - /// After the capture phase comes the bubble phase, in which event handlers are - /// invoked front to back. This is the phase you'll usually want to use for event handlers. + /// After the capture phase comes the bubble phase, in which mouse event listeners are + /// invoked front to back and keyboard event listeners are invoked from the focused element + /// to the root of the element tree. This is the phase you'll most commonly want to use when + /// registering event listeners. #[default] Bubble, - /// During the initial capture phase, event handlers are invoked back to front. This phase + /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard + /// listeners are invoked from the root of the tree downward toward the focused element. This phase /// is used for special purposes such as clearing the "pressed" state for click events. If /// you stop event propagation during this phase, you need to know what you're doing. Handlers /// outside of the immediate region may rely on detecting non-local events during this phase. @@ -61,6 +67,7 @@ type AnyFocusListener = Box>>, @@ -92,20 +99,26 @@ impl FocusHandle { } } + /// Obtains whether the element associated with this handle is currently focused. pub fn is_focused(&self, cx: &WindowContext) -> bool { cx.window.focus == Some(self.id) } + /// Obtains whether the element associated with this handle contains the focused + /// element or is itself focused. pub fn contains_focused(&self, cx: &WindowContext) -> bool { cx.focused() .map_or(false, |focused| self.contains(&focused, cx)) } + /// Obtains whether the element associated with this handle is contained within the + /// focused element or is itself focused. pub fn within_focused(&self, cx: &WindowContext) -> bool { let focused = cx.focused(); focused.map_or(false, |focused| focused.contains(self, cx)) } + /// Obtains whether this handle contains the given handle in the most recently rendered frame. pub(crate) fn contains(&self, other: &Self, cx: &WindowContext) -> bool { let mut ancestor = Some(other.id); while let Some(ancestor_id) = ancestor { @@ -143,6 +156,7 @@ impl Drop for FocusHandle { } } +// Holds the state for a specific window. pub struct Window { handle: AnyWindowHandle, platform_window: MainThreadOnly>, @@ -253,6 +267,9 @@ impl Window { } } +/// When constructing the element tree, we maintain a stack of key dispatch frames until we +/// find the focused element. We interleave key listeners with dispatch contexts so we can use the +/// contexts when matching key events against the keymap. enum KeyDispatchStackFrame { Listener { event_type: TypeId, @@ -261,6 +278,9 @@ enum KeyDispatchStackFrame { Context(DispatchContext), } +/// Indicates which region of the window is visible. Content falling outside of this mask will not be +/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type +/// to leave room to support more complex shapes in the future. #[derive(Clone, Debug, Default, PartialEq, Eq)] #[repr(C)] pub struct ContentMask { @@ -268,18 +288,23 @@ pub struct ContentMask { } impl ContentMask { + /// Scale the content mask's pixel units by the given scaling factor. pub fn scale(&self, factor: f32) -> ContentMask { ContentMask { bounds: self.bounds.scale(factor), } } + /// Intersect the content mask with the given content mask. pub fn intersect(&self, other: &Self) -> Self { let bounds = self.bounds.intersect(&other.bounds); ContentMask { bounds } } } +/// Provides access to application state in the context of a single window. Derefs +/// to an `AppContext`, so you can also pass a `WindowContext` to any method that takes +/// an `AppContext` and call any `AppContext` methods. pub struct WindowContext<'a, 'w> { pub(crate) app: Reference<'a, AppContext>, pub(crate) window: Reference<'w, Window>, @@ -300,24 +325,30 @@ impl<'a, 'w> WindowContext<'a, 'w> { } } + /// Obtain a handle to the window that belongs to this context. pub fn window_handle(&self) -> AnyWindowHandle { self.window.handle } + /// Mark the window as dirty, scheduling it to be redrawn on the next frame. pub fn notify(&mut self) { self.window.dirty = true; } + /// Obtain a new `FocusHandle`, which allows you to track and manipulate the keyboard focus + /// for elements rendered within this window. pub fn focus_handle(&mut self) -> FocusHandle { FocusHandle::new(&self.window.focus_handles) } + /// Obtain the currently focused `FocusHandle`. If no elements are focused, returns `None`. pub fn focused(&self) -> Option { self.window .focus .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles)) } + /// Move focus to the element associated with the given `FocusHandle`. pub fn focus(&mut self, handle: &FocusHandle) { if self.window.last_blur.is_none() { self.window.last_blur = Some(self.window.focus); @@ -332,6 +363,7 @@ impl<'a, 'w> WindowContext<'a, 'w> { self.notify(); } + /// Remove focus from all elements within this context's window. pub fn blur(&mut self) { if self.window.last_blur.is_none() { self.window.last_blur = Some(self.window.focus); @@ -346,6 +378,9 @@ impl<'a, 'w> WindowContext<'a, 'w> { self.notify(); } + /// Schedule the given closure to be run on the main thread. It will be invoked with + /// a `MainThread`, which provides access to platform-specific functionality + /// of the window. pub fn run_on_main( &mut self, f: impl FnOnce(&mut MainThread>) -> R + Send + 'static, @@ -363,10 +398,13 @@ impl<'a, 'w> WindowContext<'a, 'w> { } } + /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across + /// await points in async code. pub fn to_async(&self) -> AsyncWindowContext { AsyncWindowContext::new(self.app.to_async(), self.window.handle) } + /// Schedule the given closure to be run directly after the current frame is rendered. pub fn on_next_frame(&mut self, f: impl FnOnce(&mut WindowContext) + Send + 'static) { let f = Box::new(f); let display_id = self.window.display_id; @@ -410,6 +448,9 @@ impl<'a, 'w> WindowContext<'a, 'w> { .detach(); } + /// Spawn the future returned by the given closure on the application thread pool. + /// The closure is provided a handle to the current window and an `AsyncWindowContext` for + /// use within your future. pub fn spawn( &mut self, f: impl FnOnce(AnyWindowHandle, AsyncWindowContext) -> Fut + Send + 'static, @@ -426,6 +467,8 @@ impl<'a, 'w> WindowContext<'a, 'w> { }) } + /// Update the global of the given type. The given closure is given simultaneous mutable + /// access both to the global and the context. pub fn update_global(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R where G: 'static, @@ -436,6 +479,9 @@ impl<'a, 'w> WindowContext<'a, 'w> { result } + /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which + /// layout is being requested, along with the layout ids of any children. This method is called during + /// calls to the `Element::layout` trait method and enables any element to participate in layout. pub fn request_layout( &mut self, style: &Style, @@ -450,6 +496,12 @@ impl<'a, 'w> WindowContext<'a, 'w> { .request_layout(style, rem_size, &self.app.layout_id_buffer) } + /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children, + /// this variant takes a function that is invoked during layout so you can use arbitrary logic to + /// determine the element's size. One place this is used internally is when measuring text. + /// + /// The given closure is invoked at layout time with the known dimensions and available space and + /// returns a `Size`. pub fn request_measured_layout< F: Fn(Size>, Size) -> Size + Send + Sync + 'static, >( @@ -463,6 +515,9 @@ impl<'a, 'w> WindowContext<'a, 'w> { .request_measured_layout(style, rem_size, measure) } + /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not + /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically + /// in order to pass your element its `Bounds` automatically. pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds { let mut bounds = self .window @@ -473,14 +528,20 @@ impl<'a, 'w> WindowContext<'a, 'w> { bounds } + /// The scale factor of the display associated with the window. For example, it could + /// return 2.0 for a "retina" display, indicating that each logical pixel should actually + /// be rendered as two pixels on screen. pub fn scale_factor(&self) -> f32 { self.window.scale_factor } + /// The size of an em for the base font of the application. Adjusting this value allows the + /// UI to scale, just like zooming a web page. pub fn rem_size(&self) -> Pixels { self.window.rem_size } + /// The line height associated with the current text style. pub fn line_height(&self) -> Pixels { let rem_size = self.rem_size(); let text_style = self.text_style(); @@ -489,14 +550,23 @@ impl<'a, 'w> WindowContext<'a, 'w> { .to_pixels(text_style.font_size.into(), rem_size) } + /// Call to prevent the default action of an event. Currently only used to prevent + /// parent elements from becoming focused on mouse down. pub fn prevent_default(&mut self) { self.window.default_prevented = true; } + /// Obtain whether default has been prevented for the event currently being dispatched. pub fn default_prevented(&self) -> bool { self.window.default_prevented } + /// Register a mouse event listener on the window for the current frame. The type of event + /// is determined by the first parameter of the given listener. When the next frame is rendered + /// the listener will be cleared. + /// + /// This is a fairly low-level method, so prefer using event handlers on elements unless you have + /// a specific need to register a global listener. pub fn on_mouse_event( &mut self, handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + Send + 'static, @@ -514,17 +584,21 @@ impl<'a, 'w> WindowContext<'a, 'w> { )) } + /// The position of the mouse relative to the window. pub fn mouse_position(&self) -> Point { self.window.mouse_position } - pub fn stack(&mut self, order: u32, f: impl FnOnce(&mut Self) -> R) -> R { - self.window.z_index_stack.push(order); + /// Called during painting to invoke the given closure in a new stacking context. The given + /// z-index is interpreted relative to the previous call to `stack`. + pub fn stack(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R { + self.window.z_index_stack.push(z_index); let result = f(self); self.window.z_index_stack.pop(); result } + /// Paint one or more drop shadows into the scene for the current frame at the current z-index. pub fn paint_shadows( &mut self, bounds: Bounds, @@ -552,6 +626,8 @@ impl<'a, 'w> WindowContext<'a, 'w> { } } + /// Paint one or more quads into the scene for the current frame at the current stacking context. + /// Quads are colored rectangular regions with an optional background, border, and corner radius. pub fn paint_quad( &mut self, bounds: Bounds, @@ -578,6 +654,7 @@ impl<'a, 'w> WindowContext<'a, 'w> { ); } + /// Paint the given `Path` into the scene for the current frame at the current z-index. pub fn paint_path(&mut self, mut path: Path, color: impl Into) { let scale_factor = self.scale_factor(); let content_mask = self.content_mask(); @@ -589,6 +666,7 @@ impl<'a, 'w> WindowContext<'a, 'w> { .insert(&window.z_index_stack, path.scale(scale_factor)); } + /// Paint an underline into the scene for the current frame at the current z-index. pub fn paint_underline( &mut self, origin: Point, @@ -621,6 +699,7 @@ impl<'a, 'w> WindowContext<'a, 'w> { Ok(()) } + /// Paint a monochrome (non-emoji) glyph into the scene for the current frame at the current z-index. pub fn paint_glyph( &mut self, origin: Point, @@ -673,6 +752,7 @@ impl<'a, 'w> WindowContext<'a, 'w> { Ok(()) } + /// Paint an emoji glyph into the scene for the current frame at the current z-index. pub fn paint_emoji( &mut self, origin: Point, @@ -723,6 +803,7 @@ impl<'a, 'w> WindowContext<'a, 'w> { Ok(()) } + /// Paint a monochrome SVG into the scene for the current frame at the current stacking context. pub fn paint_svg( &mut self, bounds: Bounds, @@ -763,6 +844,7 @@ impl<'a, 'w> WindowContext<'a, 'w> { Ok(()) } + /// Paint an image into the scene for the current frame at the current z-index. pub fn paint_image( &mut self, bounds: Bounds, @@ -798,6 +880,7 @@ impl<'a, 'w> WindowContext<'a, 'w> { Ok(()) } + /// Draw pixels to the display for this window based on the contents of its scene. pub(crate) fn draw(&mut self) { let root_view = self.window.root_view.take().unwrap(); @@ -870,12 +953,17 @@ impl<'a, 'w> WindowContext<'a, 'w> { window.freeze_key_dispatch_stack = false; } + /// Dispatch a mouse or keyboard event on the window. fn dispatch_event(&mut self, event: InputEvent) -> bool { let event = match event { + // Track the mouse position with our own state, since accessing the platform + // API for the mouse position can only occur on the main thread. InputEvent::MouseMove(mouse_move) => { self.window.mouse_position = mouse_move.position; InputEvent::MouseMove(mouse_move) } + // Translate dragging and dropping of external files from the operating system + // to internal drag and drop events. InputEvent::FileDrop(file_drop) => match file_drop { FileDropEvent::Entered { position, files } => { self.window.mouse_position = position; @@ -1036,6 +1124,7 @@ impl<'a, 'w> WindowContext<'a, 'w> { true } + /// Attempt to map a keystroke to an action based on the keymap. pub fn match_keystroke( &mut self, element_id: &GlobalElementId, @@ -1058,6 +1147,8 @@ impl<'a, 'w> WindowContext<'a, 'w> { key_match } + /// Register the given handler to be invoked whenever the global of the given type + /// is updated. pub fn observe_global( &mut self, f: impl Fn(&mut WindowContext<'_, '_>) + Send + 'static, @@ -1182,6 +1273,10 @@ impl Context for WindowContext<'_, '_> { impl VisualContext for WindowContext<'_, '_> { type ViewContext<'a, 'w, V> = ViewContext<'a, 'w, V>; + /// Builds a new view in the current window. The first argument is a function that builds + /// an entity representing the view's state. It is invoked with a `ViewContext` that provides + /// entity-specific access to the window and application state during construction. The second + /// argument is a render function that returns a component based on the view's state. fn build_view( &mut self, build_view_state: impl FnOnce(&mut Self::ViewContext<'_, '_, V>) -> V, @@ -1199,6 +1294,7 @@ impl VisualContext for WindowContext<'_, '_> { view } + /// Update the given view. Prefer calling `View::update` instead, which calls this method. fn update_view( &mut self, view: &View, @@ -1251,6 +1347,10 @@ pub trait BorrowWindow: BorrowMut + BorrowMut { self.borrow_mut() } + /// Pushes the given element id onto the global stack and invokes the given closure + /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor + /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is + /// used to associate state with identified elements across separate frames. fn with_element_id( &mut self, id: impl Into, @@ -1277,6 +1377,8 @@ pub trait BorrowWindow: BorrowMut + BorrowMut { result } + /// Invoke the given function with the given content mask after intersecting it + /// with the current mask. fn with_content_mask( &mut self, mask: ContentMask, @@ -1289,6 +1391,8 @@ pub trait BorrowWindow: BorrowMut + BorrowMut { result } + /// Update the global element offset based on the given offset. This is used to implement + /// scrolling and position drag handles. fn with_element_offset( &mut self, offset: Option>, @@ -1305,6 +1409,7 @@ pub trait BorrowWindow: BorrowMut + BorrowMut { result } + /// Obtain the current element offset. fn element_offset(&self) -> Point { self.window() .element_offset_stack @@ -1313,6 +1418,10 @@ pub trait BorrowWindow: BorrowMut + BorrowMut { .unwrap_or_default() } + /// Update or intialize state for an element with the given id that lives across multiple + /// frames. If an element with this id existed in the previous frame, its state will be passed + /// to the given closure. The state returned by the closure will be stored so it can be referenced + /// when drawing the next frame. fn with_element_state( &mut self, id: ElementId, @@ -1349,6 +1458,8 @@ pub trait BorrowWindow: BorrowMut + BorrowMut { }) } + /// Like `with_element_state`, but for situations where the element_id is optional. If the + /// id is `None`, no state will be retrieved or stored. fn with_optional_element_state( &mut self, element_id: Option, @@ -1364,6 +1475,7 @@ pub trait BorrowWindow: BorrowMut + BorrowMut { } } + /// Obtain the current content mask. fn content_mask(&self) -> ContentMask { self.window() .content_mask_stack @@ -1377,6 +1489,8 @@ pub trait BorrowWindow: BorrowMut + BorrowMut { }) } + /// The size of an em for the base font of the application. Adjusting this value allows the + /// UI to scale, just like zooming a web page. fn rem_size(&self) -> Pixels { self.window().rem_size }