Verify display restoration and expose outputs

config/dot/quickshell/displays-harness.qml

@@ -16,7 +16,8 @@ ShellRoot {
                 name: monitor ? monitor.name : "",
                 width: monitor ? monitor.width : 0,
                 height: monitor ? monitor.height : 0,
-                refresh: monitor ? Math.round(monitor.refreshRate) : 0,
+                refresh: monitor ? monitor.refreshRate : 0,
+                mode: monitor ? monitor.mode : "",
                 scale: monitor ? monitor.scale : 0,
                 transform: monitor ? monitor.transform : -1,
                 modes: monitor ? monitor.modes.length : 0,
@@ -31,14 +32,14 @@ ShellRoot {
         function applyScale(scale: real): bool {
             const monitor = Displays.monitors[0];
             if (!monitor) return false;
-            const mode = monitor.width + "x" + monitor.height + "@" + Math.round(monitor.refreshRate);
+            const mode = monitor.mode;
             return Displays.apply(monitor.name, mode, scale, monitor.transform);
         }
 
         function applyBad(kind: string): bool {
             const monitor = Displays.monitors[0];
             if (!monitor) return false;
-            const mode = monitor.width + "x" + monitor.height + "@" + Math.round(monitor.refreshRate);
+            const mode = monitor.mode;
             if (kind === "mode") return Displays.apply(monitor.name, "9999x9999@240", monitor.scale, monitor.transform);
             if (kind === "scale") return Displays.apply(monitor.name, mode, 1.37, monitor.transform);
             if (kind === "dirtyScale") {

config/dot/quickshell/modules/settings/DisplaysPage.qml

@@ -20,11 +20,24 @@ SettingsPage {
     title: "Displays"
     lede: SystemSettings.monitorDescription || "Reading the active display…"
 
-    readonly property var monitor: Displays.monitors.length > 0 ? Displays.monitors[0] : null
+    property string selectedOutput: ""
+    readonly property var monitor: Displays.monitorNamed(root.selectedOutput)
+        ?? (Displays.monitors.length > 0 ? Displays.monitors[0] : null)
     readonly property string currentMode: root.monitor
-        ? `${root.monitor.width}x${root.monitor.height}@${Math.round(root.monitor.refreshRate)}`
+        ? root.monitor.mode
         : ""
 
+    function syncSelectedOutput(): void {
+        if (!Displays.monitorNamed(root.selectedOutput))
+            root.selectedOutput = Displays.monitors.length > 0 ? Displays.monitors[0].name : "";
+    }
+
+    Component.onCompleted: root.syncSelectedOutput()
+    Connections {
+        target: Displays
+        function onMonitorsChanged(): void { root.syncSelectedOutput(); }
+    }
+
     // The confirmation sits above everything, because while it is counting down
     // it is the only thing that matters on this page.
     header: Component {
@@ -86,6 +99,25 @@ SettingsPage {
         }
     }
 
+    SettingsCard {
+        visible: Displays.monitors.length > 1
+        title: "Connected display"
+        subtitle: "Choose the output whose resolution, scale, and rotation you want to adjust."
+
+        ChoiceGrid {
+            width: parent.width
+            label: "Display"
+            options: Displays.monitors.map(monitor => ({
+                value: monitor.name,
+                label: monitor.description || monitor.name
+            }))
+            current: root.monitor ? root.monitor.name : ""
+            enabled: !Displays.awaitingConfirmation && !Displays.busy
+            divider: false
+            onPicked: value => root.selectedOutput = value
+        }
+    }
+
     SettingsCard {
         title: root.monitor ? root.monitor.name : (SystemSettings.monitorName || "Active display")
         subtitle: root.monitor

config/dot/quickshell/services/Displays.qml

@@ -36,6 +36,8 @@ Singleton {
     property var pendingRequested: null
     property bool pendingVerified: false
     property bool revertQueued: false
+    property var revertExpected: null
+    property string revertReason: ""
     property int secondsLeft: 0
 
     readonly property bool awaitingConfirmation: root.pendingOutput !== ""
@@ -43,6 +45,7 @@ Singleton {
         && root.pendingVerified
         && !root.busy
     readonly property bool busy: query.running || applyRun.running || revertRun.running
+        || root.revertExpected !== null
 
     readonly property int confirmSeconds: 15
 
@@ -91,9 +94,10 @@ Singleton {
     Process {
         id: revertRun
         onExited: (exitCode, exitStatus) => {
-            if (exitCode !== 0)
+            // Exit status is advisory only. Hyprland's Lua bridge can report
-                root.lastError = "The previous display setting could not be restored automatically.";
+            // success without applying a value, so exact readback decides.
-            root.refresh();
+            revertVerifyTimer.attempts = 0;
+            revertVerifyTimer.restart();
         }
     }
 
@@ -107,22 +111,42 @@ Singleton {
     function parse(text: string): void {
         try {
             const raw = JSON.parse(text);
-            root.monitors = raw.map(monitor => ({
+            root.monitors = raw.map(monitor => {
-                name: monitor.name ?? "",
+                const modes = root.normaliseModes(monitor.availableModes ?? []);
-                description: monitor.description ?? monitor.model ?? "Display",
+                const width = monitor.width ?? 0;
-                width: monitor.width ?? 0,
+                const height = monitor.height ?? 0;
-                height: monitor.height ?? 0,
+                const refreshRate = monitor.refreshRate ?? 0;
-                refreshRate: monitor.refreshRate ?? 0,
+                const current = modes
-                scale: monitor.scale ?? 1,
+                    .filter(mode => mode.width === width && mode.height === height)
-                transform: monitor.transform ?? 0,
+                    .sort((left, right) =>
-                modes: root.normaliseModes(monitor.availableModes ?? [])
+                        Math.abs(left.refresh - refreshRate) - Math.abs(right.refresh - refreshRate))[0];
-            }));
+                return {
+                    name: monitor.name ?? "",
+                    description: monitor.description ?? monitor.model ?? "Display",
+                    width: width,
+                    height: height,
+                    refreshRate: refreshRate,
+                    mode: current?.mode ?? `${width}x${height}@${refreshRate}`,
+                    scale: monitor.scale ?? 1,
+                    transform: monitor.transform ?? 0,
+                    modes: modes
+                };
+            });
             if (root.awaitingConfirmation && root.pendingRequested
                     && root.matchesRequest(root.monitorNamed(root.pendingOutput), root.pendingRequested)) {
                 root.pendingVerified = true;
                 verifyTimer.stop();
                 root.lastError = "";
-            } else if (!root.awaitingConfirmation && (
+            } else if (root.revertExpected
+                    && root.matchesRequest(root.monitorNamed(root.revertExpected.output), root.revertExpected)) {
+                revertVerifyTimer.stop();
+                root.revertExpected = null;
+                if (root.revertReason === "")
+                    root.lastError = "";
+                else
+                    root.lastError = root.revertReason;
+                root.revertReason = "";
+            } else if (!root.awaitingConfirmation && !root.revertExpected && (
                     root.lastError === "Could not read the connected displays."
                     || root.lastError === "The display list could not be read.")) {
                 root.lastError = "";
@@ -133,9 +157,9 @@ Singleton {
     }
 
     // "[email protected]" -> a sortable record. The compositor reports the same
-    // resolution several times at refresh rates that differ only in rounding
+    // resolution at distinct rates such as 60.00 and 59.94. Those identities
-    // (60.00 and 59.94), which as a list of buttons is noise rather than
+    // remain separate because confirmation and recovery must read back the
-    // choice, so equal rounded pairs collapse to one.
+    // exact mode the user chose, even when their rounded labels look similar.
     function normaliseModes(raw: var): var {
         const seen = {};
         const out = [];
@@ -145,15 +169,19 @@ Singleton {
                 continue;
             const width = Number(match[1]);
             const height = Number(match[2]);
-            const refresh = Math.round(Number(match[3]));
+            const refreshText = match[3];
-            const key = `${width}x${height}@${refresh}`;
+            const refresh = Number(refreshText);
+            const roundedRefresh = Math.round(refresh);
+            const key = `${width}x${height}@${refreshText}`;
             if (seen[key])
                 continue;
             seen[key] = true;
             out.push({
                 label: `${width} × ${height}`,
-                refreshLabel: `${refresh} Hz`,
+                refreshLabel: Math.abs(refresh - roundedRefresh) < 0.005
-                mode: key,
+                    ? `${roundedRefresh} Hz`
+                    : `${refresh.toFixed(2)} Hz`,
+                mode: `${width}x${height}@${refreshText}`,
                 width: width,
                 height: height,
                 refresh: refresh
@@ -207,7 +235,7 @@ Singleton {
         return !!parts
             && monitor.width === parts.width
             && monitor.height === parts.height
-            && Math.abs(monitor.refreshRate - parts.refresh) < 0.6
+            && Math.abs(monitor.refreshRate - parts.refresh) < 0.01
             && Math.abs(monitor.scale - requested.scale) < 0.001
             && monitor.transform === requested.transform;
     }
@@ -215,6 +243,10 @@ Singleton {
     // Applies immediately and starts the countdown. Nothing is stored yet: the
     // settings file is only written by confirm().
     function apply(output: string, mode: string, scale: real, transform: int): bool {
+        if (root.busy) {
+            root.lastError = "Wait for the current display operation to finish.";
+            return false;
+        }
         if (root.awaitingConfirmation) {
             root.lastError = "Finish the current display change first.";
             return false;
@@ -239,7 +271,7 @@ Singleton {
 
         root.pendingPrevious = {
             output: output,
-            mode: `${monitor.width}x${monitor.height}@${Math.round(monitor.refreshRate)}`,
+            mode: monitor.mode,
             scale: monitor.scale,
             transform: monitor.transform
         };
@@ -313,6 +345,7 @@ Singleton {
         countdown.stop();
         verifyTimer.stop();
         root.pendingVerified = false;
+        root.revertReason = message;
         if (message !== "")
             root.lastError = message;
         if (applyRun.running) {
@@ -324,6 +357,7 @@ Singleton {
 
     function performRevert(): void {
         const previous = root.pendingPrevious;
+        root.revertExpected = previous;
         root.clearPending();
         if (previous) {
             revertRun.exec(["hyprctl", "eval",
@@ -362,6 +396,24 @@ Singleton {
         }
     }
 
+    Timer {
+        id: revertVerifyTimer
+        property int attempts: 0
+        interval: 120
+        repeat: true
+        onTriggered: {
+            attempts++;
+            if (attempts > 25) {
+                stop();
+                root.revertExpected = null;
+                root.revertReason = "";
+                root.lastError = "The previous display setting could not be verified. Open Displays and restore it manually.";
+                return;
+            }
+            root.refresh();
+        }
+    }
+
     Timer {
         id: countdown
         interval: 1000

tests/quickshell/displays-contract.sh

@@ -36,6 +36,7 @@ fail() {
 # Keep is unavailable until compositor readback exactly matches the request.
 for contract in \
     'property var pendingRequested:' \
+    'property var revertExpected:' \
     'readonly property bool canConfirm:' \
     'function matchesRequest(' \
     'function scalesForMode(' \
@@ -46,6 +47,14 @@ rg -Fq 'enabled: Displays.canConfirm' "$page" \
     || fail 'Keep is enabled before the display change is verified'
 rg -Fq 'options: Displays.scalesForMode(' "$page" \
     || fail 'scale choices are not filtered for the active resolution'
+rg -Fq 'property string selectedOutput:' "$page" \
+    || fail 'connected outputs cannot be selected'
+rg -Fq 'options: Displays.monitors.map(' "$page" \
+    || fail 'the output selector is not populated from connected displays'
+rg -Fq 'id: revertVerifyTimer' "$service" \
+    || fail 'automatic restoration has no bounded readback verification'
+rg -Fq 'if (root.busy)' "$service" \
+    || fail 'the display service accepts a new apply while another operation is busy'
 
 # Stored JSON is untyped at field level, so the Lua startup consumer is the
 # final validation boundary and must support every named output it accepts.
@@ -125,7 +134,7 @@ display_is_restored() {
         --argjson scale "$original_scale" \
         --argjson transform "$original_transform" \
         '.width == $width and .height == $height
-            and ((.refreshRate - $refresh) | fabs) < 0.6
+            and ((.refreshRate - $refresh) | fabs) < 0.01
             and ((.scale - $scale) | fabs) < 0.001
             and .transform == $transform' <<<"$current" >/dev/null
 }
@@ -179,7 +188,7 @@ done
 state="$(status)"
 monitor_name="$(jq -r .name <<<"$state")"
 [[ -n "$monitor_name" ]] || fail "no display was detected: $state"
-original_mode="$(jq -r '"\(.width)x\(.height)@\(.refresh)"' <<<"$state")"
+original_mode="$(jq -r .mode <<<"$state")"
 original_width="$(jq -r .width <<<"$state")"
 original_height="$(jq -r .height <<<"$state")"
 original_refresh="$(jq -r .refresh <<<"$state")"