cosmic_files/
load_image.rs

1use cosmic::iced::{core as iced_core, widget as iced_widget};
2use iced_core::event::Event;
3use iced_core::widget::{Operation, Tree};
4use iced_core::{
5    Clipboard, Element, Layout, Length, Rectangle, Shell, Vector, Widget, layout, mouse, overlay,
6    renderer,
7};
8
9pub fn loaded_image<'a, Message: 'static, Theme>(
10    handle: <cosmic::Renderer as iced_core::image::Renderer>::Handle,
11) -> LoadedImage<'a, Message, Theme, cosmic::Renderer>
12where
13    Theme: iced_widget::container::Catalog,
14    <Theme as iced_widget::container::Catalog>::Class<'a>: From<cosmic::theme::Container<'a>>,
15{
16    LoadedImage::new(handle)
17}
18
19/// Forces the wrapped image to be loaded before drawing.
20///
21/// May cause a dropped frame if the image is not already in the cache.
22/// This is useful when you want to ensure an image is loaded before it is drawn, for example when swapping out a placeholder.
23/// Otherwise, the image may be blank until the next redraw.
24#[allow(missing_debug_implementations)]
25pub struct LoadedImage<'a, Message, Theme, Renderer>
26where
27    Renderer: iced_core::Renderer + iced_core::image::Renderer,
28{
29    handle: <Renderer as iced_core::image::Renderer>::Handle,
30    content: cosmic::iced::Element<'a, Message, Theme, Renderer>,
31}
32
33impl<'a, Message, Theme, Renderer> LoadedImage<'a, Message, Theme, Renderer>
34where
35    Renderer: iced_core::Renderer + iced_core::image::Renderer,
36    <Renderer as iced_core::image::Renderer>::Handle: 'a,
37{
38    /// Creates an empty [`LoadedImage`].
39    pub(crate) fn new(handle: <Renderer as iced_core::image::Renderer>::Handle) -> Self {
40        LoadedImage {
41            handle: handle.clone(),
42            content: cosmic::widget::Image::new(handle).into(),
43        }
44    }
45}
46
47impl<Message, Theme, Renderer> Widget<Message, Theme, Renderer>
48    for LoadedImage<'_, Message, Theme, Renderer>
49where
50    Renderer: iced_core::Renderer + iced_core::image::Renderer,
51{
52    fn children(&self) -> Vec<Tree> {
53        vec![Tree::new(&self.content)]
54    }
55
56    fn diff(&mut self, tree: &mut Tree) {
57        tree.diff_children(std::slice::from_mut(&mut self.content));
58    }
59
60    fn size(&self) -> iced_core::Size<Length> {
61        self.content.as_widget().size()
62    }
63
64    fn layout(
65        &mut self,
66        tree: &mut Tree,
67        renderer: &Renderer,
68        limits: &layout::Limits,
69    ) -> layout::Node {
70        let node = self
71            .content
72            .as_widget_mut()
73            .layout(&mut tree.children[0], renderer, limits);
74        let size = node.size();
75        layout::Node::with_children(size, vec![node])
76    }
77
78    fn operate(
79        &mut self,
80        tree: &mut Tree,
81        layout: Layout<'_>,
82        renderer: &Renderer,
83        operation: &mut dyn Operation,
84    ) {
85        operation.container(None, layout.bounds());
86        operation.traverse(&mut |operation| {
87            self.content.as_widget_mut().operate(
88                &mut tree.children[0],
89                layout
90                    .children()
91                    .next()
92                    .unwrap()
93                    .with_virtual_offset(layout.virtual_offset()),
94                renderer,
95                operation,
96            );
97        });
98    }
99
100    fn update(
101        &mut self,
102        tree: &mut Tree,
103        event: &Event,
104        layout: Layout<'_>,
105        cursor_position: mouse::Cursor,
106        renderer: &Renderer,
107        clipboard: &mut dyn Clipboard,
108        shell: &mut Shell<'_, Message>,
109        viewport: &Rectangle,
110    ) {
111        self.content.as_widget_mut().update(
112            &mut tree.children[0],
113            event,
114            layout
115                .children()
116                .next()
117                .unwrap()
118                .with_virtual_offset(layout.virtual_offset()),
119            cursor_position,
120            renderer,
121            clipboard,
122            shell,
123            viewport,
124        );
125    }
126
127    fn mouse_interaction(
128        &self,
129        tree: &Tree,
130        layout: Layout<'_>,
131        cursor_position: mouse::Cursor,
132        viewport: &Rectangle,
133        renderer: &Renderer,
134    ) -> mouse::Interaction {
135        let content_layout = layout.children().next().unwrap();
136        self.content.as_widget().mouse_interaction(
137            &tree.children[0],
138            content_layout.with_virtual_offset(layout.virtual_offset()),
139            cursor_position,
140            viewport,
141            renderer,
142        )
143    }
144
145    fn draw(
146        &self,
147        tree: &Tree,
148        renderer: &mut Renderer,
149        theme: &Theme,
150        renderer_style: &renderer::Style,
151        layout: Layout<'_>,
152        cursor_position: mouse::Cursor,
153        viewport: &Rectangle,
154    ) {
155        let content_layout = layout.children().next().unwrap();
156
157        // forces image to be loaded before drawing
158        _ = renderer.load_image(&self.handle);
159        self.content.as_widget().draw(
160            &tree.children[0],
161            renderer,
162            theme,
163            renderer_style,
164            content_layout.with_virtual_offset(layout.virtual_offset()),
165            cursor_position,
166            viewport,
167        );
168    }
169
170    fn overlay<'b>(
171        &'b mut self,
172        tree: &'b mut Tree,
173        layout: Layout<'b>,
174        renderer: &Renderer,
175        viewport: &Rectangle,
176        translation: Vector,
177    ) -> Option<overlay::Element<'b, Message, Theme, Renderer>> {
178        self.content.as_widget_mut().overlay(
179            &mut tree.children[0],
180            layout
181                .children()
182                .next()
183                .unwrap()
184                .with_virtual_offset(layout.virtual_offset()),
185            renderer,
186            viewport,
187            translation,
188        )
189    }
190
191    fn drag_destinations(
192        &self,
193        state: &Tree,
194        layout: Layout<'_>,
195        renderer: &Renderer,
196        dnd_rectangles: &mut iced_core::clipboard::DndDestinationRectangles,
197    ) {
198        let content_layout = layout.children().next().unwrap();
199        self.content.as_widget().drag_destinations(
200            &state.children[0],
201            content_layout.with_virtual_offset(layout.virtual_offset()),
202            renderer,
203            dnd_rectangles,
204        );
205    }
206}
207
208impl<'a, Message, Theme, Renderer> From<LoadedImage<'a, Message, Theme, Renderer>>
209    for Element<'a, Message, Theme, Renderer>
210where
211    Message: 'a,
212    Renderer: 'a + iced_core::Renderer + iced_core::image::Renderer,
213    Theme: 'a,
214{
215    fn from(c: LoadedImage<'a, Message, Theme, Renderer>) -> Element<'a, Message, Theme, Renderer> {
216        Element::new(c)
217    }
218}
cosmic_files/load_image.rs

cosmic_files/
load_image.rs
