feat(qt): Excel-style multi-select — Shift ranges across every surface

Selection existed but had no keyboard: every click was a single toggle,
so picking 40 tracks meant 40 clicks. Slint and Tauri have had ranges
since 2026-06; this is that port.

NINE surfaces, not the five the track views suggested: Album, Artist,
Playlist, Label, Local Album, plus Library's tracks and albums and Local
Library's tracks and albums. Each carried its own hand-copied `selected`
map and its own `toggleSelected`, so the rule went into
controls/SelectionModel.qml and the maps stayed where they were — the
smallest change that stops it being copied a tenth time.

The rules are Tauri's `applyShiftRange`, unchanged: a plain click
toggles one row without clearing the rest, Shift fills the range from
the anchor ADDITIVELY (so re-dragging a range cannot eat the set) and
leaves the anchor where it is, and Ctrl/Cmd is the same as a plain click
— not a shortcut, but the behaviour both references already have,
because an accumulating click is what "add without disturbing" means.

Qt makes this CHEAPER than Slint, and the difference is worth recording:
Slint had no modifiers at click time and had to read a thread-local set
from a ModifiersChanged handler, with a documented stale-read edge case
when the window lost focus mid-chord. A QML MouseArea delivers
`mouse.modifiers` on the event itself, so the modifier and the click can
never disagree and no such seam exists here.

Three judgement calls, stated because they are not forced:

  - Library gets TWO models, one per kind. Its rows are mixed, and one
    anchor would let a Shift-click on a track sweep up the albums drawn
    between it and the anchor.
  - Ranges run over the VISIBLE rows. Local Library's search box is a
    view filter, and a range over rows the user cannot see is not the
    range they asked for — the same call `select-all` already made.
  - The Local Library tree rail keeps plain toggles. Its selection lives
    in Rust (QbzLocal.treeToggle*Select), so there is no QML map to hang
    an anchor off; teaching the Rust side about an anchor is its own
    change, and the file says so where a reader would expect otherwise.

The anchor is an ID, not an index, because every one of these views can
re-sort or filter under a live selection — an index anchor silently
points at a different track the moment the order changes. Slint's
selection.rs made the same call for the same reason.

Verified by driving the app: in Abbey Road, click row 1 then Shift-click
row 5 selects exactly rows 1-5 and leaves 6-8 untouched, with the bar
reading "5 selected"; the same in a playlist, additively over a row that
was already selected.

cc

crates/qbz-qt/build.rs

@@ -629,6 +629,7 @@ fn main() {
                 "qml/shell/LyricsSyncEngine.qml",
                 "qml/shell/NavGestureLayer.qml",
                 "qml/controls/QbzCheckbox.qml",
+                "qml/controls/SelectionModel.qml",
                 // Library lane (B1-B5): the promoted A-Z strip + the
                 // per-surface bodies LibraryView.qml was split into.
                 "qml/controls/QbzAlphaStrip.qml",

crates/qbz-qt/qml/controls/SelectionModel.qml

@@ -0,0 +1,88 @@
+// SelectionModel — THE selection rules, in one place.
+//
+// Five views (Album, Artist, Playlist, Label, LocalAlbum) each carried their
+// own hand-copied `selected` map and a `toggleSelected(id)`, and none of them
+// knew what a modifier key was: every click was a single toggle, so picking
+// 40 tracks meant 40 clicks. Slint and Tauri have had Excel-style selection
+// since 2026-06 (crates/qbz/src/selection.rs, src/lib/utils/multiSelect.ts);
+// this is that port, with the rule shared instead of copied a sixth time.
+//
+// ── THE RULES, and where they come from ───────────────────────────────────
+// Straight off Tauri's `applyShiftRange`, which is the behaviour that has
+// been in the owner's hands the longest:
+//
+//   plain click   toggle just this row. It does NOT clear the others — in
+//                 select mode the whole point is accumulating a set.
+//   Ctrl / Cmd    the SAME as a plain click, and that is parity, not a
+//                 shortcut: because a plain click already accumulates,
+//                 "add this one without disturbing the rest" is what both
+//                 already do. Tauri reads only `shiftKey` at click time and
+//                 Slint matched it.
+//   Shift         select the range between the anchor and this row,
+//                 ADDITIVELY — a shift-click never deselects, so re-dragging
+//                 a range cannot eat the set. The anchor does not move, which
+//                 is what lets a range be adjusted by shift-clicking again.
+//
+// ── THE ANCHOR IS AN ID, NOT AN INDEX ─────────────────────────────────────
+// Rows get re-sorted and filtered under a live selection — every one of these
+// views has a sort control and Local Library has a filter box. An index
+// anchor silently points at a different track the moment the order changes;
+// an id is re-resolved against the CURRENT rows on every shift-click, and is
+// simply dropped if it is no longer among them. Slint's selection.rs made the
+// same call for the same reason.
+//
+// ── WHY IT RETURNS A MAP INSTEAD OF OWNING ONE ────────────────────────────
+// Every host already owns its `selected` map and a dozen call sites read it.
+// Taking that ownership away would mean rewriting all of them to find out
+// whether the rule is right; handing back the NEXT map keeps each host's
+// plumbing untouched and puts only the rule in here. The anchor is the one
+// piece of state worth holding, because it is the one nobody had.
+//
+// A NEW object is always returned: mutating a `var` map in place notifies
+// nothing, and every binding on it would go stale.
+
+import QtQuick
+
+QtObject {
+    id: root
+
+    /// The row a shift-range measures from. "" = no anchor yet. Hosts clear
+    /// it when they leave select mode.
+    property string anchorId: ""
+
+    function _indexOf(rows, id) {
+        for (var i = 0; i < rows.length; i++)
+            if (rows[i] && rows[i].id === id)
+                return i
+        return -1
+    }
+
+    /// The selection map after clicking `id`, given the ordered `rows` the
+    /// user is looking at and the `modifiers` off the mouse event.
+    ///
+    /// Pass the FILTERED rows when a view is filtered: a range over rows the
+    /// user cannot see is not a range they asked for.
+    function next(current, id, rows, modifiers) {
+        var shift = (modifiers & Qt.ShiftModifier) !== 0
+        var anchorAt = root.anchorId !== "" ? root._indexOf(rows, root.anchorId) : -1
+
+        if (shift && anchorAt >= 0) {
+            var here = root._indexOf(rows, id)
+            if (here >= 0) {
+                var lo = Math.min(anchorAt, here)
+                var hi = Math.max(anchorAt, here)
+                var m = Object.assign({}, current)
+                for (var i = lo; i <= hi; i++)
+                    m[rows[i].id] = true
+                // The anchor STAYS, so the same range can be re-dragged.
+                return m
+            }
+        }
+
+        var out = Object.assign({}, current)
+        if (out[id] === true) delete out[id]
+        else out[id] = true
+        root.anchorId = id
+        return out
+    }
+}

crates/qbz-qt/qml/rows/TrackRow.qml

@@ -136,7 +136,10 @@ Rectangle {
     /// existing call site is untouched.
     property bool selectMode: false
     property bool checked: false
-    signal toggleSelect()
+    /// `modifiers` is the mouse event's, straight through — Shift is what
+    /// turns a click into a range (controls/SelectionModel.qml). Hosts that
+    /// do not care can keep a no-argument handler; QML allows it.
+    signal toggleSelect(int modifiers)
     // Per-row artwork placeholder (see the 36px cell below). The host view
     // owns the phase clock so one timer drives every row.
     property bool artPending: false
@@ -677,7 +680,7 @@ Rectangle {
                     anchors.fill: parent
                     hoverEnabled: true
                     cursorShape: Qt.PointingHandCursor
-                    onClicked: root.toggleSelect()
+                    onClicked: root.toggleSelect(Qt.NoModifier)
                 }
             }
             Text {
@@ -1473,7 +1476,7 @@ Rectangle {
             // In select mode the WHOLE row body is a selection target
             // (TrackRow.slint:174) — never a play.
             if (root.selectMode) {
-                root.toggleSelect()
+                root.toggleSelect(mouse.modifiers)
                 mouse.accepted = true
                 return
             }

crates/qbz-qt/qml/views/AlbumListRow.qml

@@ -42,7 +42,9 @@ Rectangle {
     /// mode only). Default off, so the two catalog call sites are untouched.
     property bool selectMode: false
     property bool checked: false
-    signal toggleSelect()
+    /// `modifiers` rides straight off the mouse event: Shift is what turns
+    /// a click into a range (controls/SelectionModel.qml).
+    signal toggleSelect(int modifiers)
 
     QbzTheme { id: theme }
 
@@ -77,7 +79,7 @@ Rectangle {
                     rowMenu.openAtCursor(rowArea, mouse.x, mouse.y)
                 return
             }
-            if (root.selectMode) root.toggleSelect()
+            if (root.selectMode) root.toggleSelect(mouse.modifiers)
             else QbzAlbum.openAlbum(root.item.id || "")
         }
     }
@@ -138,7 +140,7 @@ Rectangle {
             QbzCheckbox {
                 anchors.centerIn: parent
                 checked: root.checked
-                onToggled: root.toggleSelect()
+                onToggled: function (mods) { root.toggleSelect(mods) }
             }
         }
 

crates/qbz-qt/qml/views/AlbumView.qml

@@ -305,15 +305,16 @@ Rectangle {
     readonly property bool multiSelectOn: root.multiSelect
     function setMultiSelect(on) {
         root.multiSelect = on
-        if (!on) root.selected = ({})
+        if (!on) { root.selected = ({}); sel.anchorId = "" }
     }
-    function toggleSelected(id) {
+    /// Excel-style selection lives in ONE place — controls/SelectionModel.qml
-        var m = root.selected
+    /// holds the anchor and the Shift-range rule; this view keeps owning its
-        if (m[id] === true) delete m[id]
+    /// map. `mods` is the mouse event's modifiers, forwarded by the row; a
-        else m[id] = true
+    /// caller with no event (the checkbox, a keyboard path) may omit it.
-        // A rebind needs a NEW object reference — mutating in place notifies
+    SelectionModel { id: sel }
-        // nothing.
+    function toggleSelected(id, mods) {
-        root.selected = Object.assign({}, m)
+        root.selected = sel.next(root.selected, id, root.visibleTracks,
+                                 mods === undefined ? Qt.NoModifier : mods)
     }
     /// Selected ids in VISIBLE order — never Object.keys (integer-like keys
     /// iterate in NUMERIC order, not the user's).
@@ -332,7 +333,7 @@ Rectangle {
             root.selected = m
             return
         }
-        if (action === "clear") { root.selected = ({}); return }
+        if (action === "clear") { root.selected = ({}); sel.anchorId = ""; return }
         var ids = root.selectedIdsInOrder()
         if (ids.length === 0) return
         QbzAlbum.albumBulkAction(albumHeader.id, JSON.stringify(ids), action)
@@ -1354,7 +1355,7 @@ Rectangle {
                         downloadGlyph: true
                         selectMode: root.multiSelect
                         checked: root.selected[item.id] === true
-                        onToggleSelect: root.toggleSelected(item.id)
+                        onToggleSelect: function (mods) { root.toggleSelected(item.id, mods) }
                         // "Play later" is ON now. It was off because
                         // `enqueue_album_track` had no block-tail arm — "later"
                         // and "queue" both plain-appended, so the two entries

crates/qbz-qt/qml/views/ArtistView.qml

@@ -827,15 +827,18 @@ Rectangle {
     readonly property bool multiSelectOn: root.multiSelect
     function setMultiSelect(on) {
         root.multiSelect = on
-        if (!on) root.selected = ({})
+        if (!on) { root.selected = ({}); sel.anchorId = "" }
     }
-    function toggleSelected(id) {
+    /// Excel-style selection lives in ONE place — controls/SelectionModel.qml
-        var m = root.selected
+    /// holds the anchor and the Shift-range rule; this view keeps owning its
-        if (m[id] === true) delete m[id]
+    /// map. The two lists are CONCATENATED in the order they are drawn, so a
-        else m[id] = true
+    /// range can run from the last top track into "Appears on" exactly as it
-        // A rebind needs a NEW object reference — mutating in place notifies
+    /// looks on screen — `selectedIdsInOrder` already walks them that way.
-        // nothing.
+    SelectionModel { id: sel }
-        root.selected = Object.assign({}, m)
+    function toggleSelected(id, mods) {
+        root.selected = sel.next(root.selected, id,
+                                 root.topTracks.concat(root.appearsOn),
+                                 mods === undefined ? Qt.NoModifier : mods)
     }
     function selectedIdsInOrder() {
         var out = []
@@ -856,7 +859,7 @@ Rectangle {
             root.selected = m
             return
         }
-        if (action === "clear") { root.selected = ({}); return }
+        if (action === "clear") { root.selected = ({}); sel.anchorId = ""; return }
         var ids = root.selectedIdsInOrder()
         if (ids.length === 0) return
         QbzPlayer.bulkTracksAction(JSON.stringify(ids), action, "artist", String(artist.id || ""))
@@ -1049,7 +1052,8 @@ Rectangle {
         // (TrackRow.slint:173-177, 392-417).
         property bool selectMode: false
         property bool checked: false
-        signal toggleSelect()
+        /// `modifiers` off the mouse event — see SelectionModel.
+        signal toggleSelect(int modifiers)
         // Live offline status for the row (seeded in the document; updates
         // arrive on QbzShell's trackCacheStatusChanged).
         property int cacheStatus: row.cacheStatus !== undefined ? row.cacheStatus : 0
@@ -1567,7 +1571,7 @@ Rectangle {
             onDoubleClicked: if (!popRow.selectMode && !popRow.pulledDead)
                 QbzPlayer.playArtistTrack(row.id)
             onClicked: {
-                if (popRow.selectMode) popRow.toggleSelect()
+                if (popRow.selectMode) popRow.toggleSelect(mouse.modifiers)
                 else mouse.accepted = false
             }
         }
@@ -2587,7 +2591,7 @@ Rectangle {
                         showAlbum: true
                         selectMode: root.multiSelect
                         checked: root.selected[row.id] === true
-                        onToggleSelect: root.toggleSelected(row.id)
+                        onToggleSelect: function (mods) { root.toggleSelected(row.id, mods) }
                     }
                 }
                 Item { visible: topTracks.length > root.preview; width: 1; height: 4 }
@@ -2684,7 +2688,7 @@ Rectangle {
                             showAlbum: false
                             selectMode: root.multiSelect
                             checked: root.selected[row.id] === true
-                            onToggleSelect: root.toggleSelected(row.id)
+                            onToggleSelect: function (mods) { root.toggleSelected(row.id, mods) }
                         }
                     }
                     Item { visible: appearsOn.length > root.preview; width: 1; height: 4 }
@@ -2826,7 +2830,7 @@ Rectangle {
                         showAlbum: true
                         selectMode: root.multiSelect
                         checked: root.selected[row.id] === true
-                        onToggleSelect: root.toggleSelected(row.id)
+                        onToggleSelect: function (mods) { root.toggleSelected(row.id, mods) }
                     }
                 }
                 Item { visible: libraryTab.libAlbums.length > 0; width: 1; height: 24 }

crates/qbz-qt/qml/views/LabelView.qml

@@ -96,15 +96,16 @@ Rectangle {
     readonly property bool multiSelectOn: root.multiSelect
     function setMultiSelect(on) {
         root.multiSelect = on
-        if (!on) root.selected = ({})
+        if (!on) { root.selected = ({}); sel.anchorId = "" }
     }
-    function toggleSelected(id) {
+    /// Excel-style selection lives in ONE place — controls/SelectionModel.qml
-        var m = root.selected
+    /// holds the anchor and the Shift-range rule; this view keeps owning its
-        if (m[id] === true) delete m[id]
+    /// map. `mods` is the mouse event's modifiers, forwarded by the row; a
-        else m[id] = true
+    /// caller with no event (the checkbox, a keyboard path) may omit it.
-        // A rebind needs a NEW object reference — mutating in place notifies
+    SelectionModel { id: sel }
-        // nothing.
+    function toggleSelected(id, mods) {
-        root.selected = Object.assign({}, m)
+        root.selected = sel.next(root.selected, id, root.topTracks,
+                                 mods === undefined ? Qt.NoModifier : mods)
     }
     function selectedIdsInOrder() {
         var rows = root.topTracks
@@ -121,7 +122,7 @@ Rectangle {
             root.selected = m
             return
         }
-        if (action === "clear") { root.selected = ({}); return }
+        if (action === "clear") { root.selected = ({}); sel.anchorId = ""; return }
         var ids = root.selectedIdsInOrder()
         if (ids.length === 0) return
         QbzPlayer.bulkTracksAction(JSON.stringify(ids), action, "label", String(doc.id || ""))
@@ -630,7 +631,7 @@ Rectangle {
                             showAlbum: true
                             selectMode: root.multiSelect
                             checked: root.selected[item.id] === true
-                            onToggleSelect: root.toggleSelected(item.id)
+                            onToggleSelect: function (mods) { root.toggleSelected(item.id, mods) }
                             onPlayRequested: QbzHome.labelPlayTrack(modelData.id)
                             onEnqueueRequested: function (mode) {
                                 QbzHome.labelEnqueueTrack(modelData.id, mode)

crates/qbz-qt/qml/views/LibraryView.qml

@@ -596,17 +596,28 @@ Rectangle {
     // A rebind needs a NEW object reference — mutating the map in place
     // notifies nothing (the same rule artMap and every row's `favorite`
     // property follow).
-    function toggleTrackSelected(id) {
+    /// Excel-style selection — controls/SelectionModel.qml holds the anchor
-        var m = root.tracksSelected
+    /// and the Shift-range rule; this view keeps owning its two maps.
-        if (m[id] === true) delete m[id]
+    ///
-        else m[id] = true
+    /// TWO models, because tracks and albums are two independent selections
-        root.tracksSelected = Object.assign({}, m)
+    /// with two independent anchors, and the rows here are MIXED: `visibleRows`
+    /// carries both kinds, so each range is taken over the visible rows OF ITS
+    /// OWN KIND. Ranging over the mixed list would let a shift-click on a
+    /// track sweep up the albums drawn between it and the anchor.
+    SelectionModel { id: trackSel }
+    SelectionModel { id: albumSel }
+    function _rowsOfKind(kind) {
+        return root.visibleRows.filter(function (r) { return r.kind === kind })
     }
-    function toggleAlbumSelected(id) {
+    function toggleTrackSelected(id, mods) {
-        var m = root.albumsSelected
+        root.tracksSelected = trackSel.next(root.tracksSelected, id,
-        if (m[id] === true) delete m[id]
+                                            root._rowsOfKind("track"),
-        else m[id] = true
+                                            mods === undefined ? Qt.NoModifier : mods)
-        root.albumsSelected = Object.assign({}, m)
+    }
+    function toggleAlbumSelected(id, mods) {
+        root.albumsSelected = albumSel.next(root.albumsSelected, id,
+                                            root._rowsOfKind("album"),
+                                            mods === undefined ? Qt.NoModifier : mods)
     }
 
     /// Selected ids in VISIBLE order — never `Object.keys(map)`. Qobuz ids are
@@ -630,7 +641,7 @@ Rectangle {
             root.tracksSelected = m
             return
         }
-        if (action === "clear") { root.tracksSelected = ({}); return }
+        if (action === "clear") { root.tracksSelected = ({}); trackSel.anchorId = ""; return }
         var ids = root.selectedIdsInOrder("track", root.tracksSelected)
         if (ids.length === 0) return
         QbzLibrary.libraryBulkAction("track", JSON.stringify(ids), action)
@@ -649,7 +660,7 @@ Rectangle {
             root.albumsSelected = m
             return
         }
-        if (action === "clear") { root.albumsSelected = ({}); return }
+        if (action === "clear") { root.albumsSelected = ({}); albumSel.anchorId = ""; return }
         var ids = root.selectedIdsInOrder("album", root.albumsSelected)
         if (ids.length === 0) return
         QbzLibrary.libraryBulkAction("album", JSON.stringify(ids), action)
@@ -1158,7 +1169,7 @@ Rectangle {
                             number: modelData._no || (index + 1)
                             selectMode: root.tracksMultiSelect
                             checked: root.tracksSelected[modelData.id] === true
-                            onToggleSelect: root.toggleTrackSelected(modelData.id)
+                            onToggleSelect: function (mods) { root.toggleTrackSelected(modelData.id, mods) }
                             onPlayRequested: root.playTrackInContext(item.id)
                             onEnqueueRequested: function (m) { QbzPlayer.enqueueTrack(item.id, m) }
                             // MyQBZ "Add to mixtape" — the HOST builds the

crates/qbz-qt/qml/views/LocalAlbumView.qml

@@ -118,11 +118,16 @@ Rectangle {
     // physical copy's. Both invalidate the ids, so the selection goes and
     // select mode with it (the same "leaving drops the selection" contract
     // `local_bulk::set_select_mode` documents for the tree rail).
-    onDocChanged: { multiSelect = false; selected = ({}) }
+    onDocChanged: { multiSelect = false; selected = ({}); sel.anchorId = "" }
-    function toggleSelected(id) {
+    /// Excel-style selection lives in ONE place — controls/SelectionModel.qml
-        var s = Object.assign({}, selected)
+    /// holds the anchor and the Shift-range rule; this view keeps owning its
-        if (s[id]) delete s[id]; else s[id] = true
+    /// map. Ranges run over `visibleTracks`, not `tracks`: the search box is a
-        selected = s
+    /// view filter, and a range over rows the user cannot see is not a range
+    /// they asked for — the same call `bulkAction`'s select-all already makes.
+    SelectionModel { id: sel }
+    function toggleSelected(id, mods) {
+        selected = sel.next(selected, id, visibleTracks,
+                            mods === undefined ? Qt.NoModifier : mods)
     }
     /// Selected ids in the order they are ON SCREEN, so a bulk enqueue lands
     /// in disc/track order. `Object.keys` on the selection map would sort the
@@ -137,7 +142,7 @@ Rectangle {
         return out
     }
     function bulkAction(action) {
-        if (action === "clear") { selected = ({}); return }
+        if (action === "clear") { selected = ({}); sel.anchorId = ""; return }
         if (action === "select-all") {
             // What the user can SEE: the search box is a view filter, so
             // "select all" means the filtered set (LocalLibraryView.qml:715).
@@ -679,7 +684,7 @@ Rectangle {
                                     onEnqueueRequested: function (m) {
                                         QbzLocal.enqueue("track", trackBlock.modelData.id, m)
                                     }
-                                    onToggleSelect: root.toggleSelected(trackBlock.modelData.id)
+                                    onToggleSelect: function (mods) { root.toggleSelected(trackBlock.modelData.id, mods) }
                                 }
                             }
                         }

crates/qbz-qt/qml/views/LocalLibraryView.qml

@@ -890,15 +890,19 @@ Rectangle {
 
     function toggleAlbumsMultiSelect() {
         albumsMultiSelect = !albumsMultiSelect
-        if (!albumsMultiSelect) albumsSelected = ({})
+        if (!albumsMultiSelect) { albumsSelected = ({}); albumSel.anchorId = "" }
     }
-    function toggleAlbumSelected(id) {
+    /// Excel-style selection — controls/SelectionModel.qml holds the anchor
-        var s = Object.assign({}, albumsSelected)
+    /// and the Shift-range rule; this view keeps owning its maps. Ranges run
-        if (s[id]) delete s[id]; else s[id] = true
+    /// over the VISIBLE rows, because the toolbar's filter is a view filter
-        albumsSelected = s
+    /// and `select-all` right below already means the filtered set.
+    SelectionModel { id: albumSel }
+    function toggleAlbumSelected(id, mods) {
+        albumsSelected = albumSel.next(albumsSelected, id, albumsVisible,
+                                       mods === undefined ? Qt.NoModifier : mods)
     }
     function albumsBulkAction(action) {
-        if (action === "clear") { albumsSelected = ({}); return }
+        if (action === "clear") { albumsSelected = ({}); albumSel.anchorId = ""; return }
         if (action === "select-all") {
             var s = {}
             for (var i = 0; i < albumsVisible.length; i++) s[albumsVisible[i].id] = true
@@ -910,15 +914,15 @@ Rectangle {
 
     function toggleTracksMultiSelect() {
         tracksMultiSelect = !tracksMultiSelect
-        if (!tracksMultiSelect) tracksSelected = ({})
+        if (!tracksMultiSelect) { tracksSelected = ({}); trackSel.anchorId = "" }
     }
-    function toggleTrackSelected(id) {
+    SelectionModel { id: trackSel }
-        var s = Object.assign({}, tracksSelected)
+    function toggleTrackSelected(id, mods) {
-        if (s[id]) delete s[id]; else s[id] = true
+        tracksSelected = trackSel.next(tracksSelected, id, tracksVisible,
-        tracksSelected = s
+                                       mods === undefined ? Qt.NoModifier : mods)
     }
     function tracksBulkAction(action) {
-        if (action === "clear") { tracksSelected = ({}); return }
+        if (action === "clear") { tracksSelected = ({}); trackSel.anchorId = ""; return }
         if (action === "select-all") {
             var s = {}
             for (var i = 0; i < tracksVisible.length; i++) s[tracksVisible[i].id] = true

crates/qbz-qt/qml/views/PlaylistView.qml

@@ -80,15 +80,16 @@ Rectangle {
     property string loadedPlaylistId: ""
     function setMultiSelect(on) {
         root.multiSelect = on
-        if (!on) root.selected = ({})
+        if (!on) { root.selected = ({}); sel.anchorId = "" }
     }
-    function toggleSelected(id) {
+    /// Excel-style selection lives in ONE place — controls/SelectionModel.qml
-        var m = root.selected
+    /// holds the anchor and the Shift-range rule; this view keeps owning its
-        if (m[id] === true) delete m[id]
+    /// map. `mods` is the mouse event's modifiers, forwarded by the row; a
-        else m[id] = true
+    /// caller with no event (the checkbox, a keyboard path) may omit it.
-        // A rebind needs a NEW object reference — mutating in place notifies
+    SelectionModel { id: sel }
-        // nothing.
+    function toggleSelected(id, mods) {
-        root.selected = Object.assign({}, m)
+        root.selected = sel.next(root.selected, id, root.tracks,
+                                 mods === undefined ? Qt.NoModifier : mods)
     }
     function selectedIdsInOrder() {
         var rows = root.tracks
@@ -105,7 +106,7 @@ Rectangle {
             root.selected = m
             return
         }
-        if (action === "clear") { root.selected = ({}); return }
+        if (action === "clear") { root.selected = ({}); sel.anchorId = ""; return }
         var ids = root.selectedIdsInOrder()
         if (ids.length === 0) return
         QbzPlayer.bulkTracksAction(JSON.stringify(ids), action, "playlist", String(doc.id || ""))
@@ -902,7 +903,7 @@ Rectangle {
                     zebra: true
                     selectMode: root.multiSelect
                     checked: root.selected[item.id] === true
-                    onToggleSelect: root.toggleSelected(item.id)
+                    onToggleSelect: function (mods) { root.toggleSelected(item.id, mods) }
                     menuShowRemove: root.isOwner
                     // Reorder chevrons (owner findings 5 + 8). `index` is the
                     // index into `root.tracks`, which under `canReorder` is

crates/qbz-qt/qml/views/library/LibraryAlbumsList.qml

@@ -128,7 +128,7 @@ Item {
                     artSource: root.view.artMap[modelData.artKey] || ""
                     selectMode: root.view.albumsMultiSelect
                     checked: root.view.albumsSelected[modelData.id] === true
-                    onToggleSelect: root.view.toggleAlbumSelected(modelData.id)
+                    onToggleSelect: function (mods) { root.view.toggleAlbumSelected(modelData.id, mods) }
                 }
             }
 

crates/qbz-qt/qml/views/local/LocalAlbumCollection.qml

@@ -59,7 +59,9 @@ Item {
     signal openRequested(string id)
     signal playRequested(string id)
     signal enqueueRequested(string id, string mode)
-    signal toggleSelect(string id)
+    /// `modifiers` rides through from the card's mouse event — Shift is
+    /// what turns a click into a range (controls/SelectionModel.qml).
+    signal toggleSelect(string id, int modifiers)
 
     QbzTheme { id: theme }
 
@@ -501,7 +503,9 @@ Item {
                     onEnqueueRequested: function (m) {
                         root.enqueueRequested(modelData.items[0].id, m)
                     }
-                    onToggleSelect: root.toggleSelect(modelData.items[0].id)
+                    onToggleSelect: function (mods) {
+                        root.toggleSelect(modelData.items[0].id, mods)
+                    }
                 }
             }
         }

crates/qbz-qt/qml/views/local/LocalAlbumRow.qml

@@ -33,7 +33,9 @@ Rectangle {
     signal opened()
     signal playRequested()
     signal enqueueRequested(string mode)
-    signal toggleSelect()
+    /// `modifiers` rides straight off the mouse event: Shift is what turns
+    /// a click into a range (controls/SelectionModel.qml).
+    signal toggleSelect(int modifiers)
 
     QbzTheme { id: theme }
 
@@ -52,7 +54,7 @@ Rectangle {
                 rowMenu.openAtCursor(rowArea, mouse.x, mouse.y)
                 return
             }
-            if (root.selectMode) root.toggleSelect()
+            if (root.selectMode) root.toggleSelect(mouse.modifiers)
             else root.opened()
         }
         onDoubleClicked: if (!root.selectMode) root.playRequested()
@@ -88,7 +90,7 @@ Rectangle {
             SelectCheck {
                 anchors.centerIn: parent
                 on: root.checked
-                onToggled: root.toggleSelect()
+                onToggled: function (mods) { root.toggleSelect(mods) }
             }
         }
         Rectangle {

crates/qbz-qt/qml/views/local/LocalAlbumsTab.qml

@@ -129,7 +129,7 @@ Item {
                 onOpenRequested: function (id) { root.view.openAlbum(id) }
                 onPlayRequested: function (id) { QbzLocal.playAlbum(id, false) }
                 onEnqueueRequested: function (id, m) { QbzLocal.enqueue("album", id, m) }
-                onToggleSelect: function (id) { root.view.toggleAlbumSelected(id) }
+                onToggleSelect: function (id, mods) { root.view.toggleAlbumSelected(id, mods) }
             }
             QbzAlphaStrip {
                 visible: root.view.albumsGroup === "alpha"

crates/qbz-qt/qml/views/local/LocalTrackRow.qml

@@ -71,7 +71,9 @@ Item {
     property bool zebra: false
     signal playRequested()
     signal enqueueRequested(string mode)
-    signal toggleSelect()
+    /// `modifiers` rides straight off the mouse event: Shift is what turns
+    /// a click into a range (controls/SelectionModel.qml).
+    signal toggleSelect(int modifiers)
 
     QbzTheme { id: theme }
 
@@ -137,7 +139,7 @@ Item {
         // the 14px accent disc the .slint actually specifies.
         selectMode: root.selectMode
         checked: root.checked
-        onToggleSelect: root.toggleSelect()
+        onToggleSelect: function (mods) { root.toggleSelect(mods) }
         onPlayRequested: root.playRequested()
         onEnqueueRequested: function (m) { root.enqueueRequested(m) }
     }

crates/qbz-qt/qml/views/local/LocalTracksTab.qml

@@ -255,7 +255,7 @@ Item {
                             onEnqueueRequested: function (m) {
                                 QbzLocal.enqueue("track", modelData.row.id, m)
                             }
-                            onToggleSelect: root.view.toggleTrackSelected(modelData.row.id)
+                            onToggleSelect: function (mods) { root.view.toggleTrackSelected(modelData.row.id, mods) }
                         }
                     }
                 }

crates/qbz-qt/qml/views/local/LocalTreeRail.qml

@@ -149,6 +149,12 @@ Item {
                     selectMode: root.view.treeSelectMode
                     onToggled: QbzLocal.treeToggle(modelData.path, !modelData.expanded)
                     onActivated: root.view.selectFolder(modelData.path)
+                    // NO Shift-range here, deliberately: this rail's selection
+                    // lives in RUST (QbzLocal.treeToggle*Select owns the set),
+                    // not in a QML map, so controls/SelectionModel.qml has
+                    // nothing to hold an anchor against. Giving the tree ranges
+                    // means teaching the Rust side about an anchor, which is a
+                    // change of its own and not part of this port.
                     onToggleSelect: {
                         if (modelData.isFolder) QbzLocal.treeToggleFolderSelect(modelData.path)
                         else QbzLocal.treeToggleTrackSelect(modelData.path)

crates/qbz-qt/qml/views/local/TreeRow.qml

@@ -27,7 +27,9 @@ Rectangle {
     property bool selectMode: false
     signal toggled()
     signal activated()
-    signal toggleSelect()
+    /// `modifiers` rides straight off the mouse event: Shift is what turns
+    /// a click into a range (controls/SelectionModel.qml).
+    signal toggleSelect(int modifiers)
 
     QbzTheme { id: theme }
 
@@ -93,7 +95,7 @@ Rectangle {
                 on: root.node.isFolder ? root.node.selectState === 2
                                        : root.node.selected === true
                 partial: root.node.isFolder === true && root.node.selectState === 1
-                onToggled: root.toggleSelect()
+                onToggled: function (mods) { root.toggleSelect(mods) }
             }
         }