wip: bubbling

packages/core/src/events.rs

@@ -76,6 +76,118 @@ impl std::fmt::Debug for SyntheticEvent {
     }
 }
 
+/// Priority of Event Triggers.
+///
+/// Internally, Dioxus will abort work that's taking too long if new, more important, work arrives. Unlike React, Dioxus
+/// won't be afraid to pause work or flush changes to the RealDOM. This is called "cooperative scheduling". Some Renderers
+/// implement this form of scheduling internally, however Dioxus will perform its own scheduling as well.
+///
+/// The ultimate goal of the scheduler is to manage latency of changes, prioritizing "flashier" changes over "subtler" changes.
+///
+/// React has a 5-tier priority system. However, they break things into "Continuous" and "Discrete" priority. For now,
+/// we keep it simple, and just use a 3-tier priority system.
+///
+/// - NoPriority = 0
+/// - LowPriority = 1
+/// - NormalPriority = 2
+/// - UserBlocking = 3
+/// - HighPriority = 4
+/// - ImmediatePriority = 5
+///
+/// We still have a concept of discrete vs continuous though - discrete events won't be batched, but continuous events will.
+/// This means that multiple "scroll" events will be processed in a single frame, but multiple "click" events will be
+/// flushed before proceeding. Multiple discrete events is highly unlikely, though.
+#[derive(Debug, PartialEq, Eq, Clone, Copy, Hash, PartialOrd, Ord)]
+pub enum EventPriority {
+    /// Work that must be completed during the EventHandler phase.
+    ///
+    /// Currently this is reserved for controlled inputs.
+    Immediate = 3,
+
+    /// "High Priority" work will not interrupt other high priority work, but will interrupt medium and low priority work.
+    ///
+    /// This is typically reserved for things like user interaction.
+    ///
+    /// React calls these "discrete" events, but with an extra category of "user-blocking" (Immediate).
+    High = 2,
+
+    /// "Medium priority" work is generated by page events not triggered by the user. These types of events are less important
+    /// than "High Priority" events and will take presedence over low priority events.
+    ///
+    /// This is typically reserved for VirtualEvents that are not related to keyboard or mouse input.
+    ///
+    /// React calls these "continuous" events (e.g. mouse move, mouse wheel, touch move, etc).
+    Medium = 1,
+
+    /// "Low Priority" work will always be pre-empted unless the work is significantly delayed, in which case it will be
+    /// advanced to the front of the work queue until completed.
+    ///
+    /// The primary user of Low Priority work is the asynchronous work system (suspense).
+    ///
+    /// This is considered "idle" work or "background" work.
+    Low = 0,
+}
+
+pub(crate) fn event_meta(event: &UserEvent) -> (bool, EventPriority) {
+    use EventPriority::*;
+
+    match event.name {
+        // clipboard
+        "copy" | "cut" | "paste" => (true, Medium),
+
+        // Composition
+        "compositionend" | "compositionstart" | "compositionupdate" => (true, Low),
+
+        // Keyboard
+        "keydown" | "keypress" | "keyup" => (true, High),
+
+        // Focus
+        "focus" | "blur" => (true, Low),
+
+        // Form
+        "change" | "input" | "invalid" | "reset" | "submit" => (true, Medium),
+
+        // Mouse
+        "click" | "contextmenu" | "doubleclick" | "drag" | "dragend" | "dragenter" | "dragexit"
+        | "dragleave" | "dragover" | "dragstart" | "drop" | "mousedown" | "mouseenter"
+        | "mouseleave" | "mouseout" | "mouseover" | "mouseup" => (true, High),
+
+        "mousemove" => (false, Medium),
+
+        // Pointer
+        "pointerdown" | "pointermove" | "pointerup" | "pointercancel" | "gotpointercapture"
+        | "lostpointercapture" | "pointerenter" | "pointerleave" | "pointerover" | "pointerout" => {
+            (true, Medium)
+        }
+
+        // Selection
+        "select" | "touchcancel" | "touchend" => (true, Medium),
+
+        // Touch
+        "touchmove" | "touchstart" => (true, Medium),
+
+        // Wheel
+        "scroll" | "wheel" => (false, Medium),
+
+        // Media
+        "abort" | "canplay" | "canplaythrough" | "durationchange" | "emptied" | "encrypted"
+        | "ended" | "error" | "loadeddata" | "loadedmetadata" | "loadstart" | "pause" | "play"
+        | "playing" | "progress" | "ratechange" | "seeked" | "seeking" | "stalled" | "suspend"
+        | "timeupdate" | "volumechange" | "waiting" => (true, Medium),
+
+        // Animation
+        "animationstart" | "animationend" | "animationiteration" => (true, Medium),
+
+        // Transition
+        "transitionend" => (true, Medium),
+
+        // Toggle
+        "toggle" => (true, Medium),
+
+        _ => (true, Low),
+    }
+}
+
 pub mod on {
     //! This module defines the synthetic events that all Dioxus apps enable. No matter the platform, every dioxus renderer
     //! will implement the same events and same behavior (bubbling, cancelation, etc).