Skip to content

Commit

Permalink
Fix ordering of hovered widgets inter-layer
Browse files Browse the repository at this point in the history
  • Loading branch information
@emilk
emilk committed Dec 13, 2024
1 parent e152980 commit 87a4f5d
Show file tree
Hide file tree
Showing 3 changed files with 56 additions and 56 deletions.
1 change: 1 addition & 0 deletions crates/egui/src/context.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2272,6 +2272,7 @@ impl Context {
if self.style().debug.show_widget_hits {
let hits = self.write(|ctx| ctx.viewport().hits.clone());
let WidgetHits {
close: _,
contains_pointer,
click,
drag,
Expand Down
107 changes: 53 additions & 54 deletions crates/egui/src/hit_test.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -12,11 +12,18 @@ use crate::{ahash, emath, LayerId, Pos2, Rect, WidgetRect, WidgetRects};
/// or if we're currently already dragging something.
#[derive(Clone, Debug, Default)]
pub struct WidgetHits {
/// All widgets close to the pointer, back-to-front.
///
/// This is a superset of all other widgets in this struct.
pub close: Vec<WidgetRect>,

/// All widgets that contains the pointer, back-to-front.
///
/// i.e. both a Window and the button in it can contain the pointer.
/// i.e. both a Window and the Button in it can contain the pointer.
///
/// Some of these may be widgets in a layer below the top-most layer.
///
/// This will be used for hovering.
pub contains_pointer: Vec<WidgetRect>,

/// If the user would start a clicking now, this is what would be clicked.
Expand Down Expand Up @@ -128,37 +135,36 @@ pub fn hit_test(

let mut hits = hit_test_on_close(&close, pos);

// Transform back to local coordinates:
for wr in &mut hits.contains_pointer {
*wr = wr.transform(
layer_to_global
.get(&wr.layer_id)
.copied()
.unwrap_or_default()
.inverse(),
);
}
if let Some(wr) = &mut hits.drag {
debug_assert!(wr.sense.drag);

*wr = wr.transform(
layer_to_global
.get(&wr.layer_id)
.copied()
.unwrap_or_default()
.inverse(),
);
}
if let Some(wr) = &mut hits.click {
debug_assert!(wr.sense.click);

*wr = wr.transform(
layer_to_global
.get(&wr.layer_id)
.copied()
.unwrap_or_default()
.inverse(),
);
hits.contains_pointer = close
.iter()
.filter(|widget| widget.interact_rect.contains(pos))
.copied()
.collect();

hits.close = close;

{
// Undo the to_global-transform we applied earlier,
// go back to local layer-coordinates:

let restore_widget_rect = |w: &mut WidgetRect| {
*w = widgets.get(w.id).copied().unwrap_or(*w);
};

for wr in &mut hits.close {
restore_widget_rect(wr);
}
for wr in &mut hits.contains_pointer {
restore_widget_rect(wr);
}
if let Some(wr) = &mut hits.drag {
debug_assert!(wr.sense.drag);
restore_widget_rect(wr);
}
if let Some(wr) = &mut hits.click {
debug_assert!(wr.sense.click);
restore_widget_rect(wr);
}
}

hits
Expand All @@ -176,13 +182,6 @@ fn hit_test_on_close(close: &[WidgetRect], pos: Pos2) -> WidgetHits {
let hit_click = find_closest_within(close.iter().copied().filter(|w| w.sense.click), pos, 0.0);
let hit_drag = find_closest_within(close.iter().copied().filter(|w| w.sense.drag), pos, 0.0);

// Only those widgets directly under the `pos` (will be used for hovering).
let hits: Vec<WidgetRect> = close
.iter()
.filter(|widget| widget.interact_rect.contains(pos))
.copied()
.collect();

match (hit_click, hit_drag) {
(None, None) => {
// No direct hit on anything. Find the closest interactive widget.
Expand All @@ -197,16 +196,16 @@ fn hit_test_on_close(close: &[WidgetRect], pos: Pos2) -> WidgetHits {

if let Some(closest) = closest {
WidgetHits {
contains_pointer: hits,
click: closest.sense.click.then_some(closest),
drag: closest.sense.drag.then_some(closest),
..Default::default()
}
} else {
// Found nothing
WidgetHits {
contains_pointer: hits,
click: None,
drag: None,
..Default::default()
}
}
}
Expand All @@ -231,17 +230,17 @@ fn hit_test_on_close(close: &[WidgetRect], pos: Pos2) -> WidgetHits {
// This is a smaller thing on a big background - help the user hit it,
// and ignore the big drag background.
WidgetHits {
contains_pointer: hits,
click: Some(closest_click),
drag: Some(closest_click),
..Default::default()
}
} else {
// The drag-widget is separate from the click-widget,
// so return only the drag-widget
WidgetHits {
contains_pointer: hits,
click: None,
drag: Some(hit_drag),
..Default::default()
}
}
} else {
Expand All @@ -255,17 +254,17 @@ fn hit_test_on_close(close: &[WidgetRect], pos: Pos2) -> WidgetHits {
// The drag widget is a big background thing (scroll area),
// so returning a separate click widget should not be confusing
WidgetHits {
contains_pointer: hits,
click: Some(closest_click),
drag: Some(hit_drag),
..Default::default()
}
} else {
// The two widgets are just two normal small widgets close to each other.
// Highlighting both would be very confusing.
WidgetHits {
contains_pointer: hits,
click: None,
drag: Some(hit_drag),
..Default::default()
}
}
}
Expand All @@ -290,17 +289,17 @@ fn hit_test_on_close(close: &[WidgetRect], pos: Pos2) -> WidgetHits {
// `hit_drag` is a big background thing and `closest_drag` is something small on top of it.
// Be helpful and return the small things:
return WidgetHits {
contains_pointer: hits,
click: None,
drag: Some(closest_drag),
..Default::default()
};
}
}

WidgetHits {
contains_pointer: hits,
click: None,
drag: Some(hit_drag),
..Default::default()
}
}
}
Expand All @@ -319,52 +318,52 @@ fn hit_test_on_close(close: &[WidgetRect], pos: Pos2) -> WidgetHits {
// a drag-only widget would click something _behind_ it.

WidgetHits {
contains_pointer: hits,
click: Some(hit_click),
drag: None,
..Default::default()
}
}

(Some(hit_click), Some(hit_drag)) => {
// We have a perfect hit on both click and drag. Which is the topmost?
let click_idx = hits.iter().position(|w| *w == hit_click).unwrap();
let drag_idx = hits.iter().position(|w| *w == hit_drag).unwrap();
let click_idx = close.iter().position(|w| *w == hit_click).unwrap();
let drag_idx = close.iter().position(|w| *w == hit_drag).unwrap();

let click_is_on_top_of_drag = drag_idx < click_idx;
if click_is_on_top_of_drag {
if hit_click.sense.drag {
// The top thing senses both clicks and drags.
WidgetHits {
contains_pointer: hits,
click: Some(hit_click),
drag: Some(hit_click),
..Default::default()
}
} else {
// They are interested in different things,
// and click is on top. Report both hits,
// e.g. the top Button and the ScrollArea behind it.
WidgetHits {
contains_pointer: hits,
click: Some(hit_click),
drag: Some(hit_drag),
..Default::default()
}
}
} else {
if hit_drag.sense.click {
// The top thing senses both clicks and drags.
WidgetHits {
contains_pointer: hits,
click: Some(hit_drag),
drag: Some(hit_drag),
..Default::default()
}
} else {
// The top things senses only drags,
// so we ignore the click-widget, because it would be confusing
// if clicking a drag-widget would actually click something else below it.
WidgetHits {
contains_pointer: hits,
click: None,
drag: Some(hit_drag),
..Default::default()
}
}
}
Expand Down
4 changes: 2 additions & 2 deletions crates/egui/src/interaction.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -264,9 +264,9 @@ pub(crate) fn interact(
// but none below it (an interactive widget stops the hover search).
//
// To know when to stop we need to first know the order of the widgets,
// which luckily we have in the `WidgetRects`.
// which luckily we already have in `hits.close`.

let order = |id| widgets.order(id).map(|(_layer, order)| order); // we ignore the layer, since all widgets at this point is in the same layer
let order = |id| hits.close.iter().position(|w| w.id == id);

let click_order = hits.click.and_then(|w| order(w.id)).unwrap_or(0);
let drag_order = hits.drag.and_then(|w| order(w.id)).unwrap_or(0);
Expand Down

0 comments on commit 87a4f5d

Please sign in to comment.