feat(pdf): improve page navigation rendering

This commit is contained in:
Lionel DARNIS 2026-07-07 20:35:41 +02:00
parent 42b03acd62
commit a76993f69b

View file

@ -6,7 +6,9 @@
use clap::Parser;
use cosmic::app::{Core, Settings, Task};
use cosmic::iced::{
event, keyboard, mouse, Alignment, ContentFit, Event, Length, Limits, Subscription,
event,
keyboard::{self, key::Named, Key},
mouse, Alignment, ContentFit, Event, Length, Limits, Subscription,
};
use cosmic::{executor, theme, widget, Application, Element};
use std::collections::hash_map::DefaultHasher;
@ -49,6 +51,8 @@ struct Document {
page: usize,
page_count: Option<usize>,
rendered_page: Option<PathBuf>,
rendering_page: Option<usize>,
prefetching_pages: Vec<usize>,
error: Option<String>,
}
@ -64,6 +68,8 @@ impl Document {
page: 0,
page_count,
rendered_page: None,
rendering_page: None,
prefetching_pages: Vec::new(),
error: None,
}
}
@ -93,7 +99,17 @@ enum Message {
ZoomOut,
ResetZoom,
ModifiersChanged(keyboard::Modifiers),
ScrollZoom(f32),
Scroll(f32),
PdfRendered {
path: PathBuf,
page: usize,
result: Result<PathBuf, String>,
},
PdfPrefetched {
path: PathBuf,
page: usize,
result: Result<PathBuf, String>,
},
}
struct NoctuaApp {
@ -167,9 +183,9 @@ impl Application for NoctuaApp {
};
app.refresh_title();
app.ensure_current_rendered();
let task = app.ensure_current_rendered();
(app, Task::none())
(app, task)
}
fn update(&mut self, message: Self::Message) -> Task<Self::Message> {
@ -187,23 +203,10 @@ impl Application for NoctuaApp {
}
}
Message::PreviousPage => {
if let Some(document) = self.current_document_mut() {
if document.kind == DocumentKind::Pdf && document.page > 0 {
document.page -= 1;
document.rendered_page = None;
}
}
self.previous_pdf_page();
}
Message::NextPage => {
if let Some(document) = self.current_document_mut() {
if document.kind == DocumentKind::Pdf {
let page_count = document.page_count.unwrap_or(document.page + 2);
if document.page + 1 < page_count {
document.page += 1;
document.rendered_page = None;
}
}
}
self.next_pdf_page();
}
Message::ZoomIn => {
self.zoom_in();
@ -217,21 +220,66 @@ impl Application for NoctuaApp {
Message::ModifiersChanged(modifiers) => {
self.modifiers = modifiers;
}
Message::ScrollZoom(delta) => {
Message::Scroll(delta) => {
if self.modifiers.control() {
if delta > 0.0 {
self.zoom_in();
} else if delta < 0.0 {
self.zoom_out();
}
} else if delta > 0.0 {
self.previous_pdf_page();
} else if delta < 0.0 {
self.next_pdf_page();
}
}
Message::PdfRendered { path, page, result } => {
if let Some(document) = self
.documents
.iter_mut()
.find(|document| document.path == path)
{
if document.rendering_page == Some(page) {
document.rendering_page = None;
}
if document.page == page {
match result {
Ok(rendered) => {
document.rendered_page = Some(rendered);
document.error = None;
}
Err(err) => {
document.rendered_page = None;
document.error = Some(err);
}
}
}
}
}
Message::PdfPrefetched { path, page, result } => {
if let Some(document) = self
.documents
.iter_mut()
.find(|document| document.path == path)
{
document
.prefetching_pages
.retain(|pending| *pending != page);
if document.page == page && document.rendered_page.is_none() {
if let Ok(rendered) = result {
document.rendered_page = Some(rendered);
document.error = None;
}
}
}
}
}
self.refresh_title();
self.ensure_current_rendered();
Task::none()
self.ensure_current_rendered()
}
fn subscription(&self) -> Subscription<Self::Message> {
@ -239,10 +287,18 @@ impl Application for NoctuaApp {
Event::Keyboard(keyboard::Event::ModifiersChanged(modifiers)) => {
Some(Message::ModifiersChanged(modifiers))
}
Event::Keyboard(keyboard::Event::KeyPressed {
key: Key::Named(Named::PageUp | Named::ArrowUp | Named::ArrowLeft),
..
}) if status == event::Status::Ignored => Some(Message::PreviousPage),
Event::Keyboard(keyboard::Event::KeyPressed {
key: Key::Named(Named::PageDown | Named::ArrowDown | Named::ArrowRight),
..
}) if status == event::Status::Ignored => Some(Message::NextPage),
Event::Mouse(mouse::Event::WheelScrolled { delta })
if status == event::Status::Ignored =>
{
scroll_delta_y(delta).map(Message::ScrollZoom)
scroll_delta_y(delta).map(Message::Scroll)
}
_ => None,
})
@ -333,6 +389,29 @@ impl NoctuaApp {
self.zoom = (self.zoom / 1.2).max(0.2);
}
fn previous_pdf_page(&mut self) {
if let Some(document) = self.current_document_mut() {
if document.kind == DocumentKind::Pdf && document.page > 0 {
document.page -= 1;
document.rendered_page = None;
document.error = None;
}
}
}
fn next_pdf_page(&mut self) {
if let Some(document) = self.current_document_mut() {
if document.kind == DocumentKind::Pdf {
let page_count = document.page_count.unwrap_or(document.page + 2);
if document.page + 1 < page_count {
document.page += 1;
document.rendered_page = None;
document.error = None;
}
}
}
}
fn current_document(&self) -> Option<&Document> {
self.documents.get(self.current)
}
@ -349,25 +428,84 @@ impl NoctuaApp {
self.core.set_header_title(title);
}
fn ensure_current_rendered(&mut self) {
let Some(document) = self.current_document_mut() else {
return;
fn ensure_current_rendered(&mut self) -> Task<Message> {
let render_task = {
let Some(document) = self.current_document_mut() else {
return Task::none();
};
if document.kind != DocumentKind::Pdf {
return Task::none();
}
if document.rendered_page.is_some() {
return self.ensure_adjacent_rendered();
}
if document.rendering_page == Some(document.page) {
return Task::none();
}
if let Some(cached) = cached_pdf_page(&document.path, document.page) {
document.rendered_page = Some(cached);
document.error = None;
document.rendering_page = None;
return self.ensure_adjacent_rendered();
}
document.rendering_page = Some(document.page);
document.error = None;
render_pdf_task(
document.path.clone(),
document.page,
|path, page, result| Message::PdfRendered { path, page, result },
)
};
if document.kind != DocumentKind::Pdf || document.rendered_page.is_some() {
return;
Task::batch([render_task, self.ensure_adjacent_rendered()])
}
fn ensure_adjacent_rendered(&mut self) -> Task<Message> {
let Some(document) = self.current_document_mut() else {
return Task::none();
};
if document.kind != DocumentKind::Pdf || document.rendered_page.is_none() {
return Task::none();
}
match render_pdf_page(&document.path, document.page) {
Ok(rendered) => {
document.rendered_page = Some(rendered);
document.error = None;
}
Err(err) => {
document.rendered_page = None;
document.error = Some(err);
}
let mut pages = Vec::with_capacity(2);
if document
.page_count
.is_none_or(|page_count| document.page + 1 < page_count)
{
pages.push(document.page + 1);
}
if document.page > 0 {
pages.push(document.page - 1);
}
let path = document.path.clone();
let pages = pages
.into_iter()
.filter(|page| document.rendering_page != Some(*page))
.filter(|page| !document.prefetching_pages.contains(page))
.filter(|page| cached_pdf_page(&path, *page).is_none())
.collect::<Vec<_>>();
document.prefetching_pages.extend(pages.iter().copied());
let tasks = pages
.into_iter()
.map(|page| {
render_pdf_task(path.clone(), page, |path, page, result| {
Message::PdfPrefetched { path, page, result }
})
})
.collect::<Vec<_>>();
Task::batch(tasks)
}
fn document_view(&self, document: &Document) -> Element<'_, Message> {
@ -515,13 +653,42 @@ fn pdf_page_count(path: &Path) -> Option<usize> {
})
}
fn render_pdf_task(
path: PathBuf,
page: usize,
on_done: impl FnOnce(PathBuf, usize, Result<PathBuf, String>) -> Message + Send + 'static,
) -> Task<Message> {
Task::perform(
async move {
let result = render_pdf_page(&path, page);
(path, page, result)
},
move |(path, page, result)| cosmic::Action::App(on_done(path, page, result)),
)
}
fn cached_pdf_page(path: &Path, page: usize) -> Option<PathBuf> {
let output = pdf_page_output(path, page);
output.exists().then_some(output)
}
fn pdf_page_output(path: &Path, page: usize) -> PathBuf {
std::env::temp_dir()
.join(format!(
"noctua-pdf-{}-{}",
path_hash(path),
page.saturating_add(1)
))
.with_extension("png")
}
fn render_pdf_page(path: &Path, page: usize) -> Result<PathBuf, String> {
let prefix = std::env::temp_dir().join(format!(
"noctua-pdf-{}-{}",
path_hash(path),
page.saturating_add(1)
));
let output = prefix.with_extension("png");
if let Some(cached) = cached_pdf_page(path, page) {
return Ok(cached);
}
let output = pdf_page_output(path, page);
let prefix = output.with_extension("");
let status = Command::new("pdftocairo")
.arg("-png")
@ -550,6 +717,18 @@ fn render_pdf_page(path: &Path, page: usize) -> Result<PathBuf, String> {
fn path_hash(path: &Path) -> u64 {
let mut hasher = DefaultHasher::new();
path.hash(&mut hasher);
match path.canonicalize() {
Ok(path) => path.hash(&mut hasher),
Err(_) => path.hash(&mut hasher),
}
if let Ok(metadata) = path.metadata() {
metadata.len().hash(&mut hasher);
if let Ok(modified) = metadata.modified() {
modified.hash(&mut hasher);
}
}
hasher.finish()
}