fix(shell-gtk): grid drags page from the real pointer and a 10% hint (grid flakes)

crates/shell-gtk/src/overview.rs

@@ -14,6 +14,7 @@ use std::rc::Rc;
 
 use gtk4 as gtk;
 use gtk4::prelude::*;
+use gtk4::subclass::prelude::ObjectSubclassIsExt;
 use gtk4_layer_shell::{Edge, KeyboardMode, Layer, LayerShell};
 use tuna_shell_host::apps::AppEntry;
 
@@ -1171,17 +1172,18 @@ fn grid_hover(widget: &impl IsA<gtk::Widget>, target: String, reflow: Rc<GridRef
     let motion = gtk::DropControllerMotion::new();
     {
         let hover = hover.clone();
-        motion.connect_enter(move |motion, x, _| {
+        motion.connect_enter(move |motion, _, _| {
             hover.generation.set(hover.generation.get() + 1);
             let generation = hover.generation.get();
+            let x = drop_enter_x(motion);
+            let width = motion.widget().map_or(0, |w| w.width());
             if std::env::var_os("TUNA_GRID_TRACE").is_some() {
-                eprintln!(
-                    "tuna-shell-gtk: grid hover entered x={x} width={}",
-                    motion.widget().map_or(0, |w| w.width())
-                );
+                eprintln!("tuna-shell-gtk: grid hover entered x={x:?} width={width}");
             }
-            let edge =
-                crate::logic::drop_edge(x, f64::from(motion.widget().map_or(0, |w| w.width())));
+            // Until the position is known, no edge: motion supplies it.
+            let edge = x.map_or(crate::logic::DropEdge::OnIcon, |x| {
+                crate::logic::drop_edge(x, f64::from(width))
+            });
             hover.motion(edge);
             if let Some(drop) = motion.drop() {
                 let hover = hover.clone();
@@ -1230,41 +1232,96 @@ fn grid_hover(widget: &impl IsA<gtk::Widget>, target: String, reflow: Rc<GridRef
 /// flipped by the wheel, a swipe, PageUp/PageDown, the side arrows or
 /// the indicators; arrows and indicators only with more than one page.
 mod page_hint {
+    use std::cell::RefCell;
+
     use gtk::prelude::*;
     use gtk::subclass::prelude::*;
     use gtk4 as gtk;
 
+    /// Children at explicit positions, like GtkFixed, measured by the
+    /// size request alone. GtkFixed's layout manager measures its
+    /// children's extents and overrides any measure vfunc, so actors
+    /// sliding in from outside the clip widened the 10% hint across the
+    /// grid, where it caught the pointer and turned the page.
     #[derive(Default)]
-    pub struct PageHint;
+    pub struct PageHint {
+        pub(super) children: RefCell<Vec<(gtk::Widget, f64, f64)>>,
+    }
 
     #[glib::object_subclass]
     impl ObjectSubclass for PageHint {
         const NAME: &'static str = "TunaPageHint";
         type Type = super::PageHint;
-        type ParentType = gtk::Fixed;
+        type ParentType = gtk::Widget;
+    }
+    impl ObjectImpl for PageHint {
+        fn dispose(&self) {
+            for (child, _, _) in self.children.take() {
+                child.unparent();
+            }
+        }
     }
-    impl ObjectImpl for PageHint {}
     impl WidgetImpl for PageHint {
-        fn measure(&self, orientation: gtk::Orientation, for_size: i32) -> (i32, i32, i32, i32) {
-            if orientation == gtk::Orientation::Horizontal {
-                // Animated actors begin outside the clip. Their FixedLayout
-                // extents must never enlarge the 10% navigation hint.
-                let width = self.obj().width_request().max(0);
-                (width, width, -1, -1)
-            } else {
-                self.parent_measure(orientation, for_size)
+        fn measure(&self, _: gtk::Orientation, _: i32) -> (i32, i32, i32, i32) {
+            // GTK raises both sizes to the size request.
+            (0, 0, -1, -1)
+        }
+
+        fn size_allocate(&self, _: i32, _: i32, _: i32) {
+            for (child, x, y) in self.children.borrow().iter() {
+                let (_, natural) = child.preferred_size();
+                let at = gtk::graphene::Point::new(*x as f32, *y as f32);
+                child.allocate(
+                    natural.width(),
+                    natural.height(),
+                    -1,
+                    Some(gtk::gsk::Transform::new().translate(&at)),
+                );
             }
         }
     }
-    impl FixedImpl for PageHint {}
 }
 
 glib::wrapper! {
     pub struct PageHint(ObjectSubclass<page_hint::PageHint>)
-        @extends gtk::Fixed, gtk::Widget,
+        @extends gtk::Widget,
         @implements gtk::Accessible, gtk::Buildable, gtk::ConstraintTarget;
 }
 
+impl PageHint {
+    fn put(&self, child: &impl IsA<gtk::Widget>, x: f64, y: f64) {
+        child.set_parent(self);
+        self.imp()
+            .children
+            .borrow_mut()
+            .push((child.clone().upcast(), x, y));
+        self.queue_allocate();
+    }
+
+    fn move_(&self, child: &impl IsA<gtk::Widget>, x: f64, y: f64) {
+        let child = child.upcast_ref::<gtk::Widget>();
+        if let Some(entry) = self
+            .imp()
+            .children
+            .borrow_mut()
+            .iter_mut()
+            .find(|(widget, _, _)| widget == child)
+        {
+            (entry.1, entry.2) = (x, y);
+        }
+        self.queue_allocate();
+    }
+
+    fn remove(&self, child: &impl IsA<gtk::Widget>) {
+        let child = child.upcast_ref::<gtk::Widget>();
+        self.imp()
+            .children
+            .borrow_mut()
+            .retain(|(widget, _, _)| widget != child);
+        child.unparent();
+    }
+}
+
 fn paged_grid(pages: Vec<gtk::FlowBox>, reflow: Rc<GridReflow>) -> gtk::Widget {
     use libadwaita as adw;
     let carousel = adw::Carousel::new();
@@ -1411,10 +1468,14 @@ fn paged_grid(pages: Vec<gtk::FlowBox>, reflow: Rc<GridReflow>) -> gtk::Widget {
     let motion = gtk::DropControllerMotion::new();
     {
         let pager = pager.clone();
-        motion.connect_enter(move |m, x, _| {
+        motion.connect_enter(move |m, _, _| {
             let width = m.widget().map_or(0, |w| w.width());
             pager.begin(width);
-            pager.motion(x, width);
+            // A drag entering at an edge bumps it at once, as a motion
+            // there would; never at the (0, 0) GTK reports for enter.
+            if let Some(x) = drop_enter_x(m) {
+                pager.motion(x, width);
+            }
         });
     }
     {
@@ -1709,6 +1770,23 @@ fn step_page(carousel: &libadwaita::Carousel, step: i32) {
     carousel.scroll_to(&page, true);
 }
 
+/// The pointer's x in the widget of `motion` when a drag enters it.
+/// GDK emits every drag-enter event at (0, 0) (`gdk_drop_emit_enter_event`),
+/// so DropControllerMotion's enter coordinates are not the pointer's;
+/// read the drop device's position, which Wayland's wl_data_device.enter
+/// set. `None` while that position belongs to another surface.
+fn drop_enter_x(motion: &gtk::DropControllerMotion) -> Option<f64> {
+    let widget = motion.widget()?;
+    let native = widget.native()?;
+    let (surface, x, y) = motion.drop()?.device().surface_at_position();
+    if surface? != native.surface()? {
+        return None;
+    }
+    let (dx, dy) = native.surface_transform();
+    let point = gtk::graphene::Point::new((x - dx) as f32, (y - dy) as f32);
+    Some(f64::from(native.compute_point(&widget, &point)?.x()))
+}
+
 /// Make `widget` a drag source of `text`, the widget itself as the
 /// icon (GNOME drags the tile).
 fn drag_source(widget: &impl IsA<gtk::Widget>, text: String) -> gtk::DragSource {

scripts/tuna-gtk-shell-proof

@@ -1509,6 +1509,32 @@ grid_edge() { grid_point "$1" "$2" 4; }
 grid_shown() {
     jq -e --arg name "$2" --argjson ox "$grid_origin_x" --argjson oy "$grid_origin_y" --argjson width "$WIDTH" --argjson height "$HEIGHT" 'any(.[]; .showing and (.role == "push button" or .role == "button") and .name == $name and .bounds[2] > 0 and .bounds[3] > 0 and .bounds[0] + $ox < $width and .bounds[0] + $ox + .bounds[2] > 0 and .bounds[1] + $oy < $height and .bounds[1] + $oy + .bounds[3] > 0)' "$1" >/dev/null
 }
+# A grid drag starts once GTK sees the held pointer pass its threshold,
+# and pages and hints slide on GTK's clock: poll the shell's tree for
+# the state instead of sleeping. a11y_until dumps into $1 until the jq
+# filter $2 holds; a11y_settled until the jq expression $2 is non-empty
+# and unchanged across two dumps in a row. Both give up after ${3:-10} s.
+a11y_until() {
+    a11y_end=$(($(date +%s) + ${3:-10}))
+    until "$PY" "$ROOT/scripts/lib/tuna-a11y-dump.py" tuna-shell-gtk "$1" 20 >/dev/null &&
+        jq -e "$2" "$1" >/dev/null 2>&1; do
+        [ "$(date +%s)" -lt "$a11y_end" ] || return 1
+        sleep 0.1
+    done
+}
+a11y_settled() {
+    a11y_end=$(($(date +%s) + ${3:-10}))
+    a11y_last=""
+    while :; do
+        if "$PY" "$ROOT/scripts/lib/tuna-a11y-dump.py" tuna-shell-gtk "$1" 20 >/dev/null; then
+            a11y_now="$(jq -c "$2" "$1" 2>/dev/null)" || a11y_now=""
+            [ -n "$a11y_now" ] && [ "$a11y_now" = "$a11y_last" ] && return 0
+            a11y_last="$a11y_now"
+        fi
+        [ "$(date +%s)" -lt "$a11y_end" ] || return 1
+        sleep 0.1
+    done
+}
 
 # A local folder source must initialize hints too. Cancel the real drag
 # before dropping and require normal arrows with no preview or stale timer.
@@ -1530,10 +1556,9 @@ for step in $(seq 1 6); do
     xdotool mousemove --window "$WID" $((folder_source_x + step * 10)) "$folder_source_y"
     sleep 0.05
 done
-sleep 0.25
-"$PY" "$ROOT/scripts/lib/tuna-a11y-dump.py" tuna-shell-gtk "$ARTIFACTS/a11y-folder-page-peek.json" 20 || fail G-GRID-DRAG-CANCEL "folder preview dump failed"
+a11y_until "$ARTIFACTS/a11y-folder-page-peek.json" 'any(.[]; .showing and .name == "Next page preview")' ||
+    fail G-GRID-DRAG-CANCEL "real local folder drag has no neighboring-page hint"
 scrot "$ARTIFACTS/11h-folder-page-peek.png" >/dev/null
-showing "$ARTIFACTS/a11y-folder-page-peek.json" "Next page preview" || fail G-GRID-DRAG-CANCEL "real local folder drag has no neighboring-page hint"
 xdotool key Escape
 xdotool mouseup 1
 sleep 1
@@ -1582,11 +1607,17 @@ for step in $(seq 1 6); do
     xdotool mousemove --window "$WID" $((page_source_x + step * 10)) "$page_source_y"
     sleep 0.05
 done
-sleep 0.25
-"$PY" "$ROOT/scripts/lib/tuna-a11y-dump.py" tuna-shell-gtk "$ARTIFACTS/a11y-grid-page-peek.json" 20 || fail G-GRID-PAGE-PEEK "preview dump failed"
+# Wait for the drag's hint, then for its icons to finish sliding in.
+a11y_settled "$ARTIFACTS/a11y-grid-page-peek.json" 'select(any(.[]; .showing and .name == "Next page preview")) | [.[] | select(.showing and .role == "image" and (.name | startswith("Tuna Page App"))) | .bounds] | select(length > 0)' ||
+    fail G-GRID-PAGE-PEEK "next page hint missing or never settled during drag"
 scrot "$ARTIFACTS/11h-grid-page-peek.png" >/dev/null
 showing "$ARTIFACTS/a11y-grid-page-peek.json" "Next page preview" || fail G-GRID-PAGE-PEEK "next page hint missing during drag"
 jq -e 'any(.[]; .showing and .role == "image" and (.name | startswith("Tuna Page App")))' "$ARTIFACTS/a11y-grid-page-peek.json" >/dev/null || fail G-GRID-PAGE-PEEK "neighboring page icons did not enter the hint"
+# GNOME's hint is a tenth of the grid; wider, it covers tiles and turns
+# the page under a pointer that is only crossing them.
+grid_layer_width="$(jq '.layers[] | select(.namespace == "tuna-shell-appgrid") | .rect[2]' "$CSTATE")"
+jq -e --argjson grid "$grid_layer_width" 'all(.[] | select(.showing and (.name | endswith("page preview"))); .bounds[2] > 0 and .bounds[2] <= ($grid / 10 | floor))' "$ARTIFACTS/a11y-grid-page-peek.json" >/dev/null ||
+    fail G-GRID-PAGE-PEEK "the page hint is wider than a tenth of the grid"
 peek_rect="$(jq -r --argjson ox "$grid_origin_x" --argjson oy "$grid_origin_y" '.[] | select(.showing and .name == "Next page preview") | .bounds | "\(.[0] + $ox) \(.[1] + $oy) \(.[2]) \(.[3])"' "$ARTIFACTS/a11y-grid-page-peek.json" | head -1)"
 # shellcheck disable=SC2086
 set -- $peek_rect
@@ -1768,8 +1799,9 @@ printf '[Desktop Entry]\nName=ZZZ Rebuild Probe\nExec=true\nType=Application\n'
 sleep 1.5
 xdotool key super+a
 cstate '.overview_open and .overview_app_grid' "short page setup" || fail G-GRID-SHORT-PAGES "app grid missing"
-sleep 1
-"$PY" "$ROOT/scripts/lib/tuna-a11y-dump.py" tuna-shell-gtk "$ARTIFACTS/a11y-grid-short-before.json" 20 || fail G-GRID-SHORT-PAGES "setup dump failed"
+# The probe in the tree proves the rebuild that read the saved pages.
+a11y_settled "$ARTIFACTS/a11y-grid-short-before.json" 'select(any(.[]; .name == "ZZZ Rebuild Probe")) | [.[] | select(.showing and (.role == "push button" or .role == "button") and .name == "AAA Move Three")][0].bounds | select(. != null)' ||
+    fail G-GRID-SHORT-PAGES "setup grid never settled"
 grid_origin
 grid_shown "$ARTIFACTS/a11y-grid-short-before.json" "AAA Move Three" || fail G-GRID-SHORT-PAGES "source missing from first page"
 if grid_shown "$ARTIFACTS/a11y-grid-short-before.json" "AAA Move Two"; then fail G-GRID-SHORT-PAGES "saved second page was flattened"; fi
@@ -1786,24 +1818,37 @@ for step in $(seq 1 6); do
     xdotool mousemove --window "$WID" $((source_x + step * 10)) "$source_y"
     sleep 0.05
 done
-sleep 0.25
+# The drag starts once GTK sees the held pointer pass its threshold, which
+# a loaded runner can deliver after these steps: bump the edge only then.
+a11y_until "$ARTIFACTS/a11y-grid-short-drag.json" 'any(.[]; .showing and .name == "Next page preview")' ||
+    fail G-GRID-SHORT-PAGES "the drag did not start"
 xdotool mousemove --window "$WID" $((WIDTH - 6)) 330
-sleep 0.6
-"$PY" "$ROOT/scripts/lib/tuna-a11y-dump.py" tuna-shell-gtk "$ARTIFACTS/a11y-grid-short-target.json" 20 || fail G-GRID-SHORT-PAGES "target page dump failed"
+# The bump turns the page: aim once the carousel rests with the target in view.
+a11y_settled "$ARTIFACTS/a11y-grid-short-target.json" "[.[] | select(.showing and (.role == \"push button\" or .role == \"button\") and .name == \"AAA Move Two\" and .bounds[2] > 0 and .bounds[0] + $grid_origin_x >= 0 and .bounds[0] + $grid_origin_x + .bounds[2] <= $WIDTH)][0].bounds | select(. != null)" ||
+    fail G-GRID-SHORT-PAGES "bumping the edge did not turn to the target page"
 grid_coordinates="$(grid_point "$ARTIFACTS/a11y-grid-short-target.json" "AAA Move Two" 4)" || fail G-GRID-SHORT-PAGES "target edge bounds missing"
 read -r target_x target_y <<EOF
 $grid_coordinates
 EOF
 xdotool mousemove --window "$WID" "$target_x" "$target_y"
 sleep 0.35
 xdotool mouseup 1
-sleep 1.5
-"$PY" -c 'from gi.repository import Gio; import json; pages=Gio.Settings.new("org.gnome.shell").get_value("app-picker-layout").unpack(); print(json.dumps([sorted(page, key=lambda key: page[key]["position"]) for page in pages]))' >"$ARTIFACTS/grid-short-pages.json"
-jq -e '.[0] == ["tuna-move-One.desktop"] and .[1][0:2] == ["tuna-move-Three.desktop", "tuna-move-Two.desktop"]' "$ARTIFACTS/grid-short-pages.json" >/dev/null || fail G-GRID-SHORT-PAGES "cross-page move did not leave the source short"
-# Another installed entry forces a complete grid rebuild.
+short_end=$(($(date +%s) + 10))
+until "$PY" -c 'from gi.repository import Gio; import json; pages=Gio.Settings.new("org.gnome.shell").get_value("app-picker-layout").unpack(); print(json.dumps([sorted(page, key=lambda key: page[key]["position"]) for page in pages]))' >"$ARTIFACTS/grid-short-pages.json" &&
+    jq -e '.[0] == ["tuna-move-One.desktop"] and .[1][0:2] == ["tuna-move-Three.desktop", "tuna-move-Two.desktop"]' "$ARTIFACTS/grid-short-pages.json" >/dev/null; do
+    [ "$(date +%s)" -lt "$short_end" ] || fail G-GRID-SHORT-PAGES "cross-page move did not leave the source short"
+    sleep 0.2
+done
+# Another installed entry changes the catalog. The grid lists the catalog
+# as the overview opens, so reopen it and wait for the entry: a rebuild
+# that must keep the saved short page.
 printf '[Desktop Entry]\nName=ZZZ Rebuild Probe Two\nExec=true\nType=Application\n' >"$XDG_DATA_HOME/applications/tuna-grid-rebuild-two.desktop"
-sleep 1.5
-"$PY" "$ROOT/scripts/lib/tuna-a11y-dump.py" tuna-shell-gtk "$ARTIFACTS/a11y-grid-short-rebuilt.json" 20 || fail G-GRID-SHORT-PAGES "rebuild dump failed"
+xdotool key Escape
+cstate '.overview_open | not' "short grid closed for the rebuild" || fail G-GRID-SHORT-PAGES "overview stayed open"
+xdotool key super+a
+cstate '.overview_open and .overview_app_grid' "short grid reopened" || fail G-GRID-SHORT-PAGES "app grid missing after reopening"
+a11y_settled "$ARTIFACTS/a11y-grid-short-rebuilt.json" 'select(any(.[]; .name == "ZZZ Rebuild Probe Two")) | [.[] | select(.showing and (.role == "push button" or .role == "button") and .name == "AAA Move One")][0].bounds | select(. != null)' ||
+    fail G-GRID-SHORT-PAGES "the rebuilt grid never showed the new entry"
 grid_shown "$ARTIFACTS/a11y-grid-short-rebuilt.json" "AAA Move One" || fail G-GRID-SHORT-PAGES "short first page lost its item"
 if grid_shown "$ARTIFACTS/a11y-grid-short-rebuilt.json" "AAA Move Two" || grid_shown "$ARTIFACTS/a11y-grid-short-rebuilt.json" "AAA Move Three"; then fail G-GRID-SHORT-PAGES "rebuilding filled the short first page"; fi
 pass G-GRID-SHORT-PAGES "a cross-page drag leaves its source short and the saved boundary survives a catalog rebuild"