feat(ui): Review & apply greyed out while nothing would change; the Done screen shows why a run stopped

ui/qml/AppState.qml

@@ -18,6 +18,10 @@ Item {
     property var steps: ({})                 // id -> "wait"|"run"|"ok"|"fail"
     property var failed: []
     property bool restartNeeded: false
+    // Review & apply only when something would change; "Re-apply what's on"
+    // is for when nothing did.
+    readonly property bool canApply: computePlan().length > 0
+    onCanApplyChanged: if (!canApply && sel === rows.length) sel = Math.max(0, rows.length - 1)
     property string runError: ""
     property bool wrongPassword: false
     property bool typing: false              // a text field has the keys
@@ -93,7 +97,10 @@ Item {
         if (want.gaming && boot !== bootNow) p.push({ id: "boot", action: boot === "desktop" ? "desktop" : "gaming" });
         return p;
     }
-    function goReview(again) { reapply = again; plan = computePlan(); screen = "review"; }
+    function goReview(again) {
+        if (!again && !canApply) return;
+        reapply = again; plan = computePlan(); screen = "review";
+    }
     function wantedIds() {
         var ids = [];
         for (var i = 0; i < items.length; i++)
@@ -195,7 +202,8 @@ Item {
         if (screen === "menu") {
             if (biosChecking) return;
             if (a === "up") sel = Math.max(0, sel - 1);
-            else if (a === "down") sel = Math.min(rows.length, sel + 1);
+            // The greyed-out Apply button can't be selected.
+            else if (a === "down") sel = Math.min(canApply ? rows.length : rows.length - 1, sel + 1);
             else if (a === "accept") {
                 if (sel === rows.length) { goReview(false); return; }
                 var r = rows[sel];

ui/qml/Btn.qml

@@ -10,11 +10,13 @@ Rectangle {
     signal clicked
     height: 48; radius: 12; width: row.implicitWidth + 36
     color: primary ? Theme.accent : Theme.button
-    border.width: focusRing ? 2 : 0; border.color: Theme.textHi
+    border.width: focusRing && enabled ? 2 : 0; border.color: Theme.textHi
+    // Greyed out while there's nothing to do.
+    opacity: enabled ? 1 : 0.4
     Row { id: row; anchors.centerIn: parent; spacing: 10
         Glyph { k: btn.k; visible: btn.k !== ""; dark: btn.primary; anchors.verticalCenter: parent.verticalCenter }
         Text { text: btn.text; color: btn.primary ? Theme.ink : Theme.text; font.family: Theme.body; font.pixelSize: 15; font.weight: Font.DemiBold
                anchors.verticalCenter: parent.verticalCenter }
     }
-    MouseArea { anchors.fill: parent; cursorShape: Qt.PointingHandCursor; onClicked: btn.clicked() }
+    MouseArea { anchors.fill: parent; enabled: btn.enabled; cursorShape: Qt.PointingHandCursor; onClicked: btn.clicked() }
 }

ui/qml/DoneScreen.qml

@@ -1,5 +1,8 @@
-// The result of a run: all done, a problem, or nothing changed.
+// The result of a run: all done, a problem, or nothing changed. With a
+// problem, the run's output is shown below it (a BIOS check has no progress
+// screen, so this is the only place to read why it stopped).
 import QtQuick
+import QtQuick.Controls.Basic
 
 Item {
     required property AppState app
@@ -20,7 +23,14 @@ Item {
         Text { width: parent.width; horizontalAlignment: Text.AlignHCenter; wrapMode: Text.WordWrap; color: Theme.soft; font.family: Theme.body; font.pixelSize: 17; text: message }
         Rectangle { visible: app.failed.length > 0; anchors.horizontalCenter: parent.horizontalCenter; width: ft.implicitWidth + 32; height: 44; radius: 12; color: Theme.warnBg
             Text { id: ft; anchors.centerIn: parent; color: "#f2c27a"; font.family: Theme.body; font.pixelSize: 14
-                   text: "Had a problem: " + app.failed.map(function (id) { return Texts.label(id); }).join(", ") + ". See the details." } }
+                   text: "Had a problem: " + app.failed.map(function (id) { return Texts.label(id); }).join(", ") + (app.log.count ? ". Details below." : ".") } }
+        Rectangle { visible: app.failed.length > 0 && app.log.count > 0; width: parent.width; height: 190; radius: 14; color: Theme.card
+            ListView { id: details; anchors.fill: parent; anchors.margins: 16; clip: true; model: app.log
+                ScrollBar.vertical: ScrollBar { policy: ScrollBar.AsNeeded }
+                // The end is where it stopped.
+                onCountChanged: positionViewAtEnd()
+                onVisibleChanged: if (visible) positionViewAtEnd()
+                delegate: Text { required property string line; width: details.width - 12; text: line; color: "#aab5c4"; font.family: Theme.mono; font.pixelSize: 13; wrapMode: Text.WrapAnywhere } } }
         Row { anchors.horizontalCenter: parent.horizontalCenter; spacing: 14; topPadding: 8
             Btn { k: Input.g.back; text: "Back to the menu"; height: 52; onClicked: app.act("back") }
             Btn { visible: app.restartNeeded; k: Input.g.ok; text: "Restart now"; primary: true; height: 52; onClicked: app.backend.restart() } }

ui/qml/MenuScreen.qml

@@ -70,7 +70,8 @@ Item {
             Text { readonly property int n: app.computePlan().length
                    text: n === 0 ? "Everything is the way you want it" : n + (n === 1 ? " change" : " changes")
                    color: Theme.faint; font.family: Theme.body; font.pixelSize: 14; anchors.verticalCenter: parent.verticalCenter }
-            Btn { k: screen.g.apply; text: "Review & apply"; primary: true; focusRing: app.sel === app.rows.length; height: 44; onClicked: app.goReview(false) }
+            Btn { k: screen.g.apply; text: "Review & apply"; primary: true; enabled: app.canApply
+                  focusRing: app.sel === app.rows.length; height: 44; onClicked: app.goReview(false) }
         }
     }
 }