cbf_compositor/model/
composition.rs

1use crate::model::{geometry::Rect, ids::CompositionItemId, target::SurfaceTarget};
2
3/// Background drawing policy for a scene item.
4#[derive(Debug, Clone, Copy, PartialEq, Eq)]
5pub enum BackgroundPolicy {
6    /// The item should use a non-transparent background.
7    Opaque,
8    /// The item should clear its background to transparent.
9    Transparent,
10}
11
12impl From<BackgroundPolicy> for cbf::data::background::BackgroundPolicy {
13    fn from(value: BackgroundPolicy) -> Self {
14        match value {
15            BackgroundPolicy::Opaque => Self::Opaque,
16            BackgroundPolicy::Transparent => Self::Transparent,
17        }
18    }
19}
20
21/// Hit-test behavior for one scene item.
22#[derive(Debug, Clone, Copy, PartialEq, Eq)]
23pub enum HitTestPolicy {
24    /// The item never receives pointer hit-tests.
25    Passthrough,
26    /// The item's full bounds participate in hit-testing.
27    Bounds,
28    /// Only the latest pushed hit-test snapshot participates in hit-testing.
29    RegionSnapshot,
30}
31
32/// How a hit-test snapshot interprets its listed regions.
33#[derive(Debug, Clone, Copy, PartialEq, Eq)]
34pub enum HitTestRegionMode {
35    /// Listed regions consume pointer input and all other bounds pass through.
36    ConsumeListedRegions,
37    /// Listed regions pass pointer input through and all other bounds consume it.
38    PassthroughListedRegions,
39}
40
41/// Coordinate space used by pushed hit-test regions.
42#[derive(Debug, Clone, Copy, PartialEq, Eq)]
43pub enum HitTestCoordinateSpace {
44    /// Item-local CSS pixel coordinates with an origin at the item's top-left.
45    ItemLocalCssPx,
46}
47
48/// Axis-aligned rectangle used by hit-test snapshots.
49#[derive(Debug, Clone, Copy, PartialEq)]
50pub struct HitTestRegion {
51    /// Left edge in the chosen coordinate space.
52    pub x: f32,
53    /// Top edge in the chosen coordinate space.
54    pub y: f32,
55    /// Rectangle width.
56    pub width: f32,
57    /// Rectangle height.
58    pub height: f32,
59}
60
61impl HitTestRegion {
62    /// Create a new hit-test region rectangle.
63    pub const fn new(x: f32, y: f32, width: f32, height: f32) -> Self {
64        Self {
65            x,
66            y,
67            width,
68            height,
69        }
70    }
71}
72
73/// Cached hit-test snapshot for one scene item.
74#[derive(Debug, Clone, PartialEq)]
75pub struct HitTestRegionSnapshot {
76    /// Monotonic identifier used to discard stale async updates.
77    pub snapshot_id: u64,
78    /// Coordinate space for every region in this snapshot.
79    pub coordinate_space: HitTestCoordinateSpace,
80    /// Interpretation mode for the listed regions.
81    pub mode: HitTestRegionMode,
82    /// Regions interpreted according to [`Self::mode`].
83    pub regions: Vec<HitTestRegion>,
84}
85
86/// Declarative description of one scene item inside a compositor window.
87#[derive(Debug, Clone, PartialEq)]
88pub struct CompositionItemSpec {
89    /// Stable identifier for this scene item.
90    pub item_id: CompositionItemId,
91    /// Browser-managed surface shown by this item.
92    pub target: SurfaceTarget,
93    /// Item bounds in compositor-window coordinates.
94    pub bounds: Rect,
95    /// Whether the item should currently be visible.
96    pub visible: bool,
97    /// Hit-test behavior for the item.
98    pub hit_test: HitTestPolicy,
99    /// Background drawing policy for the item.
100    pub background: BackgroundPolicy,
101}
102
103/// Full scene description for one compositor-managed window.
104#[derive(Debug, Clone, Default, PartialEq)]
105pub struct WindowCompositionSpec {
106    /// Scene items to show in the window, ordered from front to back.
107    pub items: Vec<CompositionItemSpec>,
108}
cbf_compositor/model/composition.rs

cbf_compositor/model/
composition.rs
