diff --git a/crates/ui-egui/src/canvas/navigation.rs b/crates/ui-egui/src/canvas/navigation.rs index 731b2c2586..98be96a72a 100644 --- a/crates/ui-egui/src/canvas/navigation.rs +++ b/crates/ui-egui/src/canvas/navigation.rs @@ -268,7 +268,11 @@ impl DocView { let Some(forward) = self.wheel.feed(unit, dy, phase, now, can_turn) else { return false }; let before = self.current; self.step_page(forward); - self.current != before + if self.current == before { + self.wheel.unturn(); + return false; + } + true } /// One wheel event in a non-continuous view whose page is taller than the window, where the @@ -288,6 +292,7 @@ impl DocView { let before = self.current; self.step_page(forward); if self.current == before { + self.wheel.unturn(); return false; } if !forward { diff --git a/crates/ui-egui/src/canvas/wheel_pager.rs b/crates/ui-egui/src/canvas/wheel_pager.rs index d12c445a8a..adabb8bee1 100644 --- a/crates/ui-egui/src/canvas/wheel_pager.rs +++ b/crates/ui-egui/src/canvas/wheel_pager.rs @@ -73,6 +73,11 @@ impl WheelPager { self.accum = 0.0; } + /// Reset any turned state when a turn did not happen (e.g. at document boundary). + pub(crate) fn unturn(&mut self) { + self.turned = None; + } + /// Whether the current gesture already turned a page: the rest of it must not pan the page /// just shown away from its top (or bottom). pub(crate) fn gesture_turned(&self) -> bool { diff --git a/crates/ui-egui/tests/it/view.rs b/crates/ui-egui/tests/it/view.rs index 7f444bee0f..584cb064cb 100644 --- a/crates/ui-egui/tests/it/view.rs +++ b/crates/ui-egui/tests/it/view.rs @@ -520,6 +520,48 @@ fn single_page_swipe_that_reaches_the_edge_does_not_turn_but_a_fresh_one_does() ); } +#[test] +fn single_page_wheel_at_last_page_bottom_edge_can_scroll_back_up() { + let mut h = harness_stepping(1.0 / 60.0, &[("layout", "single"), ("zoom", "200")]); + h.state_mut().views[0].go_to_page(2); // Go to last page of PAGES (3 pages) + h.run_steps(20); + let at = h.state().views[0].viewport_rect().center(); + h.hover_at(at); + h.run_steps(4); + + // Scroll to the bottom edge of page 3 + let mut notches = 0; + let mut last = rect(&h, 2).expect("page 3 on screen").min.y; + let mut at_bottom = false; + while notches < 80 { + h.event(wheel(MouseWheelUnit::Line, -1.0, TouchPhase::Move)); + h.run_steps(12); + notches += 1; + if let Some(r) = rect(&h, 2) { + if (r.min.y - last).abs() < 0.01 { + at_bottom = true; + break; + } + last = r.min.y; + } + } + assert!(at_bottom, "reached bottom edge of last page"); + assert_eq!(h.state().views[0].current, 2, "remains on page 3"); + + // Push the wheel further against the bottom edge (cannot turn because it's the last page) + for _ in 0..5 { + h.event(wheel(MouseWheelUnit::Line, -1.0, TouchPhase::Move)); + h.run_steps(12); + } + let bottom_y = rect(&h, 2).expect("page 3 on screen").min.y; + + // Roll the wheel back up: the page must move away from the bottom edge (#5713) + h.event(wheel(MouseWheelUnit::Line, 1.0, TouchPhase::Move)); + h.run_steps(12); + let after_up_y = rect(&h, 2).expect("page 3 on screen").min.y; + assert!(after_up_y > bottom_y, "scrolling up moves the page away from the bottom edge: {after_up_y} > {bottom_y}"); +} + #[test] fn stepping_past_either_end_leaves_the_view_alone() { // Paging on past the first or last page must not jump the page back to its top.