iced_widget/shader/
program.rs

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1use crate::core::Rectangle;
2use crate::core::mouse;
3use crate::renderer::wgpu::Primitive;
4use crate::shader::{self, Action};
5
6/// The state and logic of a [`Shader`] widget.
7///
8/// A [`Program`] can mutate the internal state of a [`Shader`] widget
9/// and produce messages for an application.
10///
11/// [`Shader`]: crate::Shader
12pub trait Program<Message> {
13    /// The internal state of the [`Program`].
14    type State: Default + 'static;
15
16    /// The type of primitive this [`Program`] can draw.
17    type Primitive: Primitive + 'static;
18
19    /// Update the internal [`State`] of the [`Program`]. This can be used to reflect state changes
20    /// based on mouse & other events. You can return an [`Action`] to publish a message, request a
21    /// redraw, or capture the event.
22    ///
23    /// By default, this method returns `None`.
24    ///
25    /// [`State`]: Self::State
26    fn update(
27        &self,
28        _state: &mut Self::State,
29        _event: &shader::Event,
30        _bounds: Rectangle,
31        _cursor: mouse::Cursor,
32    ) -> Option<Action<Message>> {
33        None
34    }
35
36    /// Draws the [`Primitive`].
37    ///
38    /// [`Primitive`]: Self::Primitive
39    fn draw(
40        &self,
41        state: &Self::State,
42        cursor: mouse::Cursor,
43        bounds: Rectangle,
44    ) -> Self::Primitive;
45
46    /// Returns the current mouse interaction of the [`Program`].
47    ///
48    /// The interaction returned will be in effect even if the cursor position is out of
49    /// bounds of the [`Shader`]'s program.
50    ///
51    /// [`Shader`]: crate::Shader
52    fn mouse_interaction(
53        &self,
54        _state: &Self::State,
55        _bounds: Rectangle,
56        _cursor: mouse::Cursor,
57    ) -> mouse::Interaction {
58        mouse::Interaction::default()
59    }
60}
iced_widget/shader/program.rs

iced_widget/shader/
program.rs
