freya_components/
image_viewer.rs

1use std::{
2    cell::RefCell,
3    fs,
4    hash::{
5        Hash,
6        Hasher,
7    },
8    path::PathBuf,
9    rc::Rc,
10};
11
12use anyhow::Context;
13use bytes::Bytes;
14use freya_core::{
15    elements::image::*,
16    prelude::*,
17};
18use freya_engine::prelude::{
19    SkData,
20    SkImage,
21};
22#[cfg(feature = "remote-asset")]
23use ureq::http::Uri;
24
25use crate::{
26    cache::*,
27    loader::CircularLoader,
28};
29
30/// ### URI
31///
32/// Good to load remote images.
33///
34/// > Needs the `remote-asset` feature enabled.
35///
36/// ```rust
37/// # use freya::prelude::*;
38/// let source: ImageSource =
39///     "https://upload.wikimedia.org/wikipedia/commons/8/8a/Gecarcinus_quadratus_%28Nosara%29.jpg"
40///         .into();
41/// ```
42///
43/// ### Path
44///
45/// Good for dynamic loading.
46///
47/// ```rust
48/// # use freya::prelude::*;
49/// # use std::path::PathBuf;
50/// let source: ImageSource = PathBuf::from("./examples/rust_logo.png").into();
51/// ```
52/// ### Raw bytes
53///
54/// Good for embedded images.
55///
56/// ```rust
57/// # use freya::prelude::*;
58/// let source: ImageSource = (
59///     "rust-logo",
60///     include_bytes!("../../../examples/rust_logo.png"),
61/// )
62///     .into();
63/// ```
64#[derive(PartialEq, Clone)]
65pub enum ImageSource {
66    #[cfg(feature = "remote-asset")]
67    Uri(Uri),
68
69    Path(PathBuf),
70
71    Bytes(&'static str, Bytes),
72}
73
74impl From<(&'static str, Bytes)> for ImageSource {
75    fn from((id, bytes): (&'static str, Bytes)) -> Self {
76        Self::Bytes(id, bytes)
77    }
78}
79
80impl From<(&'static str, &'static [u8])> for ImageSource {
81    fn from((id, bytes): (&'static str, &'static [u8])) -> Self {
82        Self::Bytes(id, Bytes::from_static(bytes))
83    }
84}
85
86impl<const N: usize> From<(&'static str, &'static [u8; N])> for ImageSource {
87    fn from((id, bytes): (&'static str, &'static [u8; N])) -> Self {
88        Self::Bytes(id, Bytes::from_static(bytes))
89    }
90}
91
92#[cfg(feature = "remote-asset")]
93impl From<Uri> for ImageSource {
94    fn from(uri: Uri) -> Self {
95        Self::Uri(uri)
96    }
97}
98
99#[cfg(feature = "remote-asset")]
100impl From<&'static str> for ImageSource {
101    fn from(src: &'static str) -> Self {
102        Self::Uri(Uri::from_static(src))
103    }
104}
105
106impl From<PathBuf> for ImageSource {
107    fn from(path: PathBuf) -> Self {
108        Self::Path(path)
109    }
110}
111
112impl Hash for ImageSource {
113    fn hash<H: Hasher>(&self, state: &mut H) {
114        match self {
115            #[cfg(feature = "remote-asset")]
116            Self::Uri(uri) => uri.hash(state),
117            Self::Path(path) => path.hash(state),
118            Self::Bytes(id, _) => id.hash(state),
119        }
120    }
121}
122
123impl ImageSource {
124    pub async fn bytes(&self) -> anyhow::Result<(SkImage, Bytes)> {
125        let source = self.clone();
126        blocking::unblock(move || {
127            let bytes = match source {
128                #[cfg(feature = "remote-asset")]
129                Self::Uri(uri) => ureq::get(uri)
130                    .call()?
131                    .body_mut()
132                    .read_to_vec()
133                    .map(Bytes::from)?,
134                Self::Path(path) => fs::read(path).map(Bytes::from)?,
135                Self::Bytes(_, bytes) => bytes.clone(),
136            };
137            let image = SkImage::from_encoded(unsafe { SkData::new_bytes(&bytes) })
138                .context("Failed to decode Image.")?;
139            Ok((image, bytes))
140        })
141        .await
142    }
143}
144
145/// Image viewer component.
146///
147/// # Example
148///
149/// ```rust
150/// # use freya::prelude::*;
151/// fn app() -> impl IntoElement {
152///     let source: ImageSource =
153///         "https://upload.wikimedia.org/wikipedia/commons/8/8a/Gecarcinus_quadratus_%28Nosara%29.jpg"
154///             .into();
155///
156///     ImageViewer::new(source)
157/// }
158///
159/// # use freya_testing::prelude::*;
160/// # use std::path::PathBuf;
161/// # launch_doc(|| {
162/// #   rect().center().expanded().child(ImageViewer::new(("rust-logo", include_bytes!("../../../examples/rust_logo.png"))))
163/// # }, "./images/gallery_image_viewer.png").with_hook(|t| { t.poll(std::time::Duration::from_millis(1), std::time::Duration::from_millis(50)); t.sync_and_update(); }).with_scale_factor(1.).render();
164/// ```
165///
166/// # Preview
167/// ![ImageViewer Preview][image_viewer]
168#[cfg_attr(feature = "docs",
169    doc = embed_doc_image::embed_image!("image_viewer", "images/gallery_image_viewer.png")
170)]
171#[derive(PartialEq)]
172pub struct ImageViewer {
173    source: ImageSource,
174
175    layout: LayoutData,
176    image_data: ImageData,
177    accessibility: AccessibilityData,
178
179    children: Vec<Element>,
180
181    key: DiffKey,
182}
183
184impl ImageViewer {
185    pub fn new(source: impl Into<ImageSource>) -> Self {
186        ImageViewer {
187            source: source.into(),
188            layout: LayoutData::default(),
189            image_data: ImageData::default(),
190            accessibility: AccessibilityData::default(),
191            children: Vec::new(),
192            key: DiffKey::None,
193        }
194    }
195}
196
197impl KeyExt for ImageViewer {
198    fn write_key(&mut self) -> &mut DiffKey {
199        &mut self.key
200    }
201}
202
203impl LayoutExt for ImageViewer {
204    fn get_layout(&mut self) -> &mut LayoutData {
205        &mut self.layout
206    }
207}
208
209impl ContainerWithContentExt for ImageViewer {}
210
211impl ImageExt for ImageViewer {
212    fn get_image_data(&mut self) -> &mut ImageData {
213        &mut self.image_data
214    }
215}
216
217impl AccessibilityExt for ImageViewer {
218    fn get_accessibility_data(&mut self) -> &mut AccessibilityData {
219        &mut self.accessibility
220    }
221}
222
223impl ChildrenExt for ImageViewer {
224    fn get_children(&mut self) -> &mut Vec<Element> {
225        &mut self.children
226    }
227}
228
229impl Render for ImageViewer {
230    fn render(&self) -> impl IntoElement {
231        let asset_config = AssetConfiguration::new(&self.source, AssetAge::default());
232        let asset = use_asset(&asset_config);
233        let mut asset_cacher = use_hook(AssetCacher::get);
234        let mut assets_tasks = use_state::<Vec<TaskHandle>>(Vec::new);
235
236        use_side_effect_with_deps(&self.source, move |source| {
237            let source = source.clone();
238
239            // Cancel previous asset fetching requests
240            for asset_task in assets_tasks.write().drain(..) {
241                asset_task.cancel();
242            }
243
244            // Fetch asset if still pending or errored
245            if matches!(
246                asset_cacher.read_asset(&asset_config),
247                Some(Asset::Pending) | Some(Asset::Error(_))
248            ) {
249                // Mark asset as loading
250                asset_cacher.update_asset(asset_config.clone(), Asset::Loading);
251
252                let asset_config = asset_config.clone();
253                let asset_task = spawn(async move {
254                    match source.bytes().await {
255                        Ok((image, bytes)) => {
256                            // Image loaded
257                            let image_holder = ImageHolder {
258                                bytes,
259                                image: Rc::new(RefCell::new(image)),
260                            };
261                            asset_cacher.update_asset(
262                                asset_config.clone(),
263                                Asset::Cached(Rc::new(image_holder)),
264                            );
265                        }
266                        Err(err) => {
267                            // Image errored asset_cacher
268                            asset_cacher.update_asset(asset_config, Asset::Error(err.to_string()));
269                        }
270                    }
271                });
272
273                assets_tasks.write().push(asset_task);
274            }
275        });
276
277        match asset {
278            Asset::Cached(asset) => {
279                let asset = asset.downcast_ref::<ImageHolder>().unwrap().clone();
280                image(asset)
281                    .accessibility(self.accessibility.clone())
282                    .a11y_role(AccessibilityRole::Image)
283                    .a11y_focusable(true)
284                    .layout(self.layout.clone())
285                    .image_data(self.image_data.clone())
286                    .children(self.children.clone())
287                    .into_element()
288            }
289            Asset::Pending | Asset::Loading => rect()
290                .layout(self.layout.clone())
291                .center()
292                .child(CircularLoader::new())
293                .into(),
294            Asset::Error(err) => err.into(),
295        }
296    }
297
298    fn render_key(&self) -> DiffKey {
299        self.key.clone().or(self.default_key())
300    }
301}
freya_components/image_viewer.rs

freya_components/
image_viewer.rs
