Keep the grid's place when another screen covers it

Opening Settings, Import or People and coming back landed at the top of
the library however deep in it you had been.

The grid is gated on an `if` in the markup, so every route away from it
destroys the subtree and rebuilds it. A Flickable being destroyed passes
its viewport through zero on the way out, and that reaches
`on_library_scrolled` looking exactly like the user having flung the grid
to the top. The handler already guarded against it -- but on
`show-library`, which means "the library rather than develop" and stays
true while any of those four screens replaces the window. So the guard
covered the develop route and none of the other three: `resume_at` was
overwritten with 0 on the way out, and the position was gone before
anything could restore it.

The condition the `if` is actually spelled with is now computed once, in
`app.slint`, and Rust reads that. The two cannot drift apart again
because there is only one of them.

That fixes the overwrite. The second half is that nothing replayed the
position on the way back in: `on_back_to_library` does it by hand, and
Settings, Import, People and the launch screen do not go through it.
Rather than teaching three more modules to call it, `scroll-to` is now
kept current on every scroll. It is read by `seek()`, which runs on a
token change and on `init`, so writing it without bumping the token
cannot move the grid on screen -- and is exactly what the next grid reads
when it is built.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
This commit is contained in:
2026-08-30 20:33:34 +02:00
co-authored by Claude Opus 5
parent 4dc954f01a
commit eed27eb36d
4 changed files with 128 additions and 88 deletions
+30 -7
View File
@@ -2071,7 +2071,7 @@ fn schedule_reload(window: &AppWindow, ctl: &Rc<LibraryController>) {
timer.start(slint::TimerMode::SingleShot, GEOMETRY_SETTLE, move || {
let Some(w) = weak.upgrade() else { return };
let anchor = ctl_cb.pending_anchor.take().unwrap_or(0);
if !w.get_show_library() {
if !w.get_library_visible() {
return;
}
@@ -4131,7 +4131,7 @@ fn start_thumbnail_sweep(window: &AppWindow, ctl: &Rc<LibraryController>) {
// the grid asks the store once per photograph — so
// without this the library the pass just thumbnailed
// stays blank until something else reloads the window.
if w.get_show_library() {
if w.get_library_visible() {
ctl_cb.requested.borrow_mut().clear();
schedule_reload(&w, &ctl_cb);
}
@@ -4159,7 +4159,7 @@ fn start_thumbnail_sweep(window: &AppWindow, ctl: &Rc<LibraryController>) {
let Some(w) = weak_after.upgrade() else {
return;
};
if bursts > 0 && w.get_show_library() {
if bursts > 0 && w.get_library_visible() {
schedule_reload(&w, &ctl_after);
}
},
@@ -5042,7 +5042,7 @@ pub fn wire<F>(
let ctl = ctl.clone();
window.on_library_columns_changed(move || {
if let Some(w) = weak.upgrade() {
if !w.get_show_library() {
if !w.get_library_visible() {
return;
}
@@ -5069,7 +5069,7 @@ pub fn wire<F>(
let ctl = ctl.clone();
window.on_library_viewport_cells(move |on_screen| {
let Some(w) = weak.upgrade() else { return };
if !w.get_show_library() {
if !w.get_library_visible() {
return;
}
let on_screen = (on_screen.max(0) as usize).max(1);
@@ -5099,7 +5099,7 @@ pub fn wire<F>(
// **A report from a grid that is not on screen is not a scroll.**
//
// `show-library` gates an `if`, so opening an image tears the whole
// The grid is gated on an `if`, so leaving it tears the whole
// subtree down — and a Flickable being destroyed passes its viewport
// through zero on the way out, which arrives here indistinguishable
// from the user having flung the grid to the top. Everything below
@@ -5112,9 +5112,19 @@ pub fn wire<F>(
// remote library it also spent a burst of requests on the top of the
// catalog every single time an image was opened.
//
// **`library-visible`, not `show-library`, and the difference is the
// whole bug.** `show-library` says "the library rather than develop"
// and stays true while Settings, Import, People or the launch screen
// replaces the window — all four of which take the grid down just as
// opening an image does. So the teardown's scroll-to-zero passed this
// guard, `resume_at` was set to 0, and coming back from any of those
// four screens landed at the top of the library however deep in it the
// user had been. The property is computed once in `app.slint` beside
// the `if` it is spelled from, so the two cannot drift apart again.
//
// The guard used to cover only `resume_at`, for a narrower version
// of the same reason. It belongs over the whole handler.
if !w.get_show_library() {
if !w.get_library_visible() {
return;
}
@@ -5124,6 +5134,19 @@ pub fn wire<F>(
// is only in the Flickable, which is about to be destroyed.
ctl.resume_at.set(first_visible);
// The same position where a rebuilt grid will look for it.
//
// `scroll-to` is read by `seek()`, which runs on a `scroll-token`
// change and on `init` — so writing it here without bumping the
// token cannot move the grid that is on screen, and *is* what the
// next one reads when it is built. That is every route back to the
// grid at once: Settings, Import, People and the launch screen all
// tear the subtree down and rebuild it, and none of them goes
// through `on_back_to_library` to have the position replayed by
// hand. Without this they each rebuilt against whatever `scroll-to`
// was last *set* to — a stale scrub, or zero — and landed there.
w.set_library_scroll_to(first_visible as i32);
// Move the timeline marker with the view. Scrolling the grid is a
// way of moving through time just as scrubbing is, and a marker
// that only ever moved on a scrub sat still while the photographs