pax_runtime_api/

events.rs

//! Event payloads and cancellation wrappers passed to Pax event handlers.

use super::*;

// Unified events

/// One settled viewport-proximity sample in logical window coordinates.
///
/// Bounds are transformed layout AABBs, not padded paint coverage. Rectangular
/// clips are intersected; curved/rotated clips use their bounding envelopes.
/// Opacity, alpha coverage, sibling occlusion and external windows are ignored.
#[derive(Clone, Copy, Debug, PartialEq)]
pub struct ViewportProximitySnapshot {
    /// Whether the target intersects the proximity region with positive area.
    pub in_proximity: bool,
    /// Presented layout bounds relative to the global visual viewport's origin.
    pub bounds: kurbo::Rect,
    /// Positive-area intersection with the global viewport and ancestor clips.
    pub viewport_intersection: Option<kurbo::Rect>,
}

impl ViewportProximitySnapshot {
    /// Whether any positive-area viewport intersection exists.
    pub fn is_in_viewport(&self) -> bool {
        self.viewport_intersection.is_some()
    }

    /// Fraction of the layout AABB inside the effective viewport, from zero to one.
    pub fn intersection_ratio(&self) -> f64 {
        let area = self.bounds.area();
        if area.is_finite() && area > 0.0 {
            self.viewport_intersection
                .map_or(0.0, |r| (r.area() / area).clamp(0.0, 1.0))
        } else {
            0.0
        }
    }
}

/// Entry into global viewport proximity, including initially nearby targets.
/// Delivered before the initial change event. This local event does not bubble.
#[derive(Clone, Debug)]
pub struct ViewportProximityEnter {
    /// Frozen sample shared with the initial change notification.
    pub current: ViewportProximitySnapshot,
}

/// A settled geometry change during a continuous proximity visit.
///
/// First admission/re-entry has no previous sample. Departure sends one final
/// change outside proximity before exit. Unchanged frames emit nothing.
#[derive(Clone, Debug)]
pub struct ViewportProximityChange {
    /// Last delivered sample in this visit; `None` on admission/re-entry.
    pub previous: Option<ViewportProximitySnapshot>,
    /// Current frozen geometry, including the terminal outside sample.
    pub current: ViewportProximitySnapshot,
}

/// Departure from global viewport proximity, after the terminal change event.
/// Unmount cancels observation without synthesizing a geometric exit.
#[derive(Clone, Debug)]
pub struct ViewportProximityExit {
    /// Last sample inside proximity.
    pub previous: ViewportProximitySnapshot,
    /// Terminal outside sample shared with the final change notification.
    pub current: ViewportProximitySnapshot,
}

/// Event wrapper passed to Pax event handlers.
///
/// `Event<T>` carries the typed event payload and shared cancellation state,
/// allowing handlers to call `prevent_default` where the active chassis supports it.
#[derive(Clone)]
pub struct Event<T> {
    /// The event-specific payload, for example `Click` or `KeyDown`.
    pub args: T,
    // Shared cancellation state, so cloned event wrappers preserve `prevent_default`.
    cancelled: Rc<Cell<bool>>,
}

impl<T: Clone + 'static> ImplToFromPaxAny for Event<T> {}

impl<T> Event<T> {
    /// Constructs an event wrapper around a raw payload.
    pub fn new(args: T) -> Self {
        Self {
            args,
            cancelled: Default::default(),
        }
    }

    /// Cancels the platform default for this event, when the chassis supports cancellation.
    pub fn prevent_default(&self) {
        self.cancelled.set(true);
    }

    // Whether `prevent_default` has been called.
    pub fn cancelled(&self) -> bool {
        self.cancelled.get()
    }
}

impl<T> Deref for Event<T> {
    type Target = T;

    fn deref(&self) -> &Self::Target {
        &self.args
    }
}

/// Scroll is the shared delta-based path for wheel scrolling, touch swipe gestures, and
/// read-only native scroller position changes.
/// Use `Wheel` or `TouchMove` when you need platform-specific details instead of the normalized
/// delta stream.
#[derive(Clone)]
pub struct Scroll {
    /// Horizontal scroll delta.
    pub delta_x: f64,
    /// Vertical scroll delta.
    pub delta_y: f64,
}

// Touch Events

/// Represents a single touch event.
#[derive(Clone)]
pub struct Touch {
    /// The window-space x-coordinate of this touch point.
    /// Use `NodeContext::local_point` to convert it into coordinates relative to a handler's node.
    pub x: f64,
    /// The window-space y-coordinate of this touch point.
    /// Use `NodeContext::local_point` to convert it into coordinates relative to a handler's node.
    pub y: f64,
    /// Stable identifier for this touch across a touch sequence.
    pub identifier: i64,
    /// Horizontal delta since the previous touch update.
    pub delta_x: f64,
    /// Vertical delta since the previous touch update.
    pub delta_y: f64,
}

impl From<&TouchMessage> for Touch {
    fn from(value: &TouchMessage) -> Self {
        Touch {
            x: value.x,
            y: value.y,
            identifier: value.identifier,
            delta_x: value.delta_x,
            delta_y: value.delta_y,
        }
    }
}

/// A TouchStart occurs when the user touches an element.
/// The contained `touches` represent a list of touch points. The hit node is captured for the
/// touch identifier so subsequent move and end events keep routing to the same subtree.
#[derive(Clone)]
pub struct TouchStart {
    /// Active touch points at the start of this touch sequence.
    pub touches: Vec<Touch>,
}

/// A TouchMove occurs when the user moves while touching an element.
/// The contained `touches` represent a list of touch points and the event targets the node captured
/// at touch start, even when the point has moved outside its bounds.
#[derive(Clone)]
pub struct TouchMove {
    /// Active touch points after this touch movement.
    pub touches: Vec<Touch>,
}

/// A TouchEnd occurs when the user stops touching an element.
/// The contained `touches` represent a list of touch points and the event targets, then releases,
/// the node captured at touch start.
#[derive(Clone)]
pub struct TouchEnd {
    /// Touch points that ended.
    pub touches: Vec<Touch>,
}

/// A TouchCancel occurs when the platform aborts an active touch sequence before normal release,
/// such as during a system interruption or host-level gesture cancellation.
///
/// The contained `touches` represent the cancelled touch points and the event targets, then
/// releases, the node captured at touch start. Cancelled touches must not produce activation.
/// A native Scroller that can observe its pan simultaneously with child touches keeps delivering
/// move events and finishes the child sequence with `TouchEnd`; winning scroll arbitration alone
/// does not cancel the touch.
#[derive(Clone)]
pub struct TouchCancel {
    /// Touch points whose active sequence was cancelled.
    pub touches: Vec<Touch>,
}

// Keyboard Events

/// Common properties in keyboard events.
#[derive(Clone)]
pub struct KeyboardEventArgs {
    /// Platform-normalized key string.
    pub key: String,
    /// Modifier keys active during the event.
    pub modifiers: Vec<ModifierKey>,
    /// Whether this event was generated by key-repeat.
    pub is_repeat: bool,
}

/// User is pressing a key.
#[derive(Clone)]
pub struct KeyDown {
    /// Common keyboard event data.
    pub keyboard: KeyboardEventArgs,
}

/// A native text selection is beginning.
#[derive(Clone)]
pub struct SelectStart {}

/// User has released a key.
#[derive(Clone)]
pub struct KeyUp {
    /// Common keyboard event data.
    pub keyboard: KeyboardEventArgs,
}

/// User presses a key that displays a character (alphanumeric or symbol).
#[derive(Clone)]
pub struct KeyPress {
    /// Common keyboard event data.
    pub keyboard: KeyboardEventArgs,
}

/// Window or component focused.
#[derive(Clone)]
pub struct Focus {}

// Mouse Events

/// Common properties in mouse-backed events and normalized activation events.
#[derive(Clone)]
pub struct MouseEventArgs {
    /// The window-space x-coordinate of the event.
    /// Use `NodeContext::local_point` to convert it into coordinates relative to a handler's node.
    pub x: f64,
    /// The window-space y-coordinate of the event.
    /// Use `NodeContext::local_point` to convert it into coordinates relative to a handler's node.
    pub y: f64,
    /// Mouse button associated with the event.
    pub button: MouseButton,
    /// Modifier keys active during the event.
    pub modifiers: Vec<ModifierKey>,
}

/// The variants of mouse buttons available on mouse-supporting platforms.
#[derive(Clone, PartialEq)]
pub enum MouseButton {
    /// Primary mouse button.
    Left,
    /// Secondary mouse button.
    Right,
    /// Middle mouse button.
    Middle,
    /// Button not identified by the chassis.
    Unknown,
}

impl From<MouseButtonMessage> for MouseButton {
    fn from(value: MouseButtonMessage) -> Self {
        match value {
            MouseButtonMessage::Left => MouseButton::Left,
            MouseButtonMessage::Right => MouseButton::Right,
            MouseButtonMessage::Middle => MouseButton::Middle,
            MouseButtonMessage::Unknown => MouseButton::Unknown,
        }
    }
}

/// The variants of modifier keys available on keyboard-supporting platforms.
#[derive(Clone)]
pub enum ModifierKey {
    /// Shift key.
    Shift,
    /// Control key.
    Control,
    /// Alt or Option key.
    Alt,
    /// Command, Meta, or Windows key.
    Command,
}

impl From<&ModifierKeyMessage> for ModifierKey {
    fn from(value: &ModifierKeyMessage) -> Self {
        match value {
            ModifierKeyMessage::Shift => ModifierKey::Shift,
            ModifierKeyMessage::Control => ModifierKey::Control,
            ModifierKeyMessage::Alt => ModifierKey::Alt,
            ModifierKeyMessage::Command => ModifierKey::Command,
        }
    }
}

/// User activates an element with a mouse click or single-touch tap.
///
/// `@click` and `@tap` handlers both receive `Event<Click>`. A touch tap is
/// emitted after touch end and normalized with `button` set to
/// `MouseButton::Left` and no modifiers.
#[derive(Clone)]
pub struct Click {
    /// Common mouse event data.
    pub mouse: MouseEventArgs,
}

/// User drops a file-like payload over an element.
#[derive(Clone)]
pub struct Drop {
    /// The x-coordinate of the drop in the receiving node's local coordinate space.
    pub x: f64,
    /// The y-coordinate of the drop in the receiving node's local coordinate space.
    pub y: f64,
    /// File or payload name supplied by the platform.
    pub name: String,
    /// MIME type supplied by the platform.
    pub mime_type: String,
    /// Raw dropped payload bytes.
    pub data: Vec<u8>,
}

/// User double-clicks a mouse button over an element.
#[derive(Clone)]
pub struct DoubleClick {
    /// Common mouse event data.
    pub mouse: MouseEventArgs,
}

/// User moves the mouse while it is over an element.
#[derive(Clone)]
pub struct MouseMove {
    /// Common mouse event data.
    pub mouse: MouseEventArgs,
}

/// User scrolls the mouse wheel over an element.
#[derive(Clone)]
pub struct Wheel {
    /// The x-coordinate of the wheel event in the receiving node's local coordinate space.
    pub x: f64,
    /// The y-coordinate of the wheel event in the receiving node's local coordinate space.
    pub y: f64,
    /// Horizontal wheel delta.
    pub delta_x: f64,
    /// Vertical wheel delta.
    pub delta_y: f64,
    /// Modifier keys active during the event.
    pub modifiers: Vec<ModifierKey>,
}

/// User checks or unchecks a checkbox.
#[derive(Clone)]
pub struct CheckboxChange {
    /// The new checked state.
    pub checked: bool,
}

/// User changes a slider's value.
#[derive(Clone)]
pub struct SliderChange {
    /// The new slider value.
    pub value: f64,
}

/// User types into a text input field.
#[derive(Clone)]
pub struct TextInput {
    /// Text committed by the input event.
    pub text: String,
}

/// User changes the text in a text input field.
#[derive(Clone)]
pub struct TextboxChange {
    /// Current text after the change.
    pub text: String,
}

/// Text input reported while the user edits a textbox.
///
/// On web, this follows the DOM `input` event. `TextboxChange` follows the
/// DOM `change` event instead; commit timing depends on the platform control.
#[derive(Clone)]
pub struct TextboxInput {
    /// Current text reported by the input event.
    pub text: String,
}

/// User activates a native button by click or tap.
#[derive(Clone)]
pub struct ButtonClick {}

/// Completion status for a native photo picker request.
#[derive(Clone, PartialEq)]
pub enum PhotoPickerStatus {
    /// One or more photos were selected.
    Selected,
    /// The platform picker was dismissed without a selection.
    Cancelled,
    /// Camera or picker permission was denied or restricted.
    PermissionDenied,
    /// The requested source is not available on this platform/device.
    Unavailable,
    /// One or more candidate photos exceeded the configured byte limit.
    SizeLimitExceeded,
    /// The platform picker failed for another reason.
    Failed,
}

impl From<&str> for PhotoPickerStatus {
    fn from(value: &str) -> Self {
        match value {
            "selected" => Self::Selected,
            "cancelled" => Self::Cancelled,
            "permission_denied" => Self::PermissionDenied,
            "unavailable" => Self::Unavailable,
            "size_limit_exceeded" => Self::SizeLimitExceeded,
            _ => Self::Failed,
        }
    }
}

/// Platform source used to produce a selected photo.
#[derive(Clone, PartialEq)]
pub enum PhotoPickerSourceKind {
    /// Existing image from a photo library.
    Library,
    /// Existing image from the filesystem.
    File,
    /// Newly captured camera image.
    Camera,
    /// Source not recognized by this runtime version.
    Other(String),
}

impl From<&str> for PhotoPickerSourceKind {
    fn from(value: &str) -> Self {
        match value {
            "library" => Self::Library,
            "file" => Self::File,
            "camera" => Self::Camera,
            other => Self::Other(other.to_string()),
        }
    }
}

/// One selected image returned by a native photo picker.
#[derive(Clone)]
pub struct PhotoPickerPhoto {
    /// Stable temporary identifier for this selection.
    pub temp_id: String,
    /// File name supplied by the platform, when available.
    pub file_name: Option<String>,
    /// MIME type supplied or inferred by the platform.
    pub mime_type: String,
    /// Byte size of the selected asset.
    pub byte_size: u64,
    /// Image width in pixels, when available.
    pub width: Option<u32>,
    /// Image height in pixels, when available.
    pub height: Option<u32>,
    /// Source used for this image.
    pub source_kind: PhotoPickerSourceKind,
    /// Platform preview/read handle, such as an object URL or file URL.
    pub handle: Option<String>,
    /// Copied asset bytes when the chassis can provide them within configured limits.
    pub data: Option<Vec<u8>>,
}

impl From<&PhotoPickerAssetArgs> for PhotoPickerPhoto {
    fn from(value: &PhotoPickerAssetArgs) -> Self {
        Self {
            temp_id: value.temp_id.clone(),
            file_name: value.file_name.clone(),
            mime_type: value.mime_type.clone(),
            byte_size: value.byte_size,
            width: value.width,
            height: value.height,
            source_kind: PhotoPickerSourceKind::from(value.source_kind.as_str()),
            handle: value.handle.clone(),
            data: if value.data.is_empty() {
                None
            } else {
                Some(value.data.clone())
            },
        }
    }
}

/// Native photo picker completion event.
#[derive(Clone)]
pub struct PhotoPickerChange {
    /// Picker node id that produced the result.
    pub id: u32,
    /// App-controlled request id, usually copied from the picker trigger value.
    pub request_id: u64,
    /// Completion status.
    pub status: PhotoPickerStatus,
    /// Human-readable platform message for errors or partial results.
    pub message: Option<String>,
    /// Selected photos, empty for cancellation, permission denial, or unavailable sources.
    pub photos: Vec<PhotoPickerPhoto>,
}

impl From<&PhotoPickerInterruptArgs> for PhotoPickerChange {
    fn from(value: &PhotoPickerInterruptArgs) -> Self {
        Self {
            id: value.id,
            request_id: value.request_id,
            status: PhotoPickerStatus::from(value.status.as_str()),
            message: value.message.clone(),
            photos: value.photos.iter().map(PhotoPickerPhoto::from).collect(),
        }
    }
}

/// User presses a mouse button over an element.
#[derive(Clone)]
pub struct MouseDown {
    /// Common mouse event data.
    pub mouse: MouseEventArgs,
}

/// User releases a mouse button over an element.
#[derive(Clone)]
pub struct MouseUp {
    /// Common mouse event data.
    pub mouse: MouseEventArgs,
}

/// User moves the mouse onto an element.
#[derive(Clone)]
pub struct MouseOver {}

/// User moves the mouse away from an element.
#[derive(Clone)]
pub struct MouseOut {}

/// User right-clicks an element to open the context menu.
#[derive(Clone)]
pub struct ContextMenu {
    /// Common mouse event data.
    pub mouse: MouseEventArgs,
}