settings: one snackbar for every page's messages

Save, apply and upload results went to the page header, one line capped
at 420px and cut with an ellipsis. They now go to a snackbar at the foot
of the settings window, wrapped in full: green fades after 6s, yellow and
red stay until dismissed or replaced, and changing page clears it.

Snack.qml is the singleton pages call (ok, wait, error); Snackbar.qml
draws it once in Settings.qml. SaveBar forwards its notice and error, so
the 24 pages using it change nothing; the header keeps only the draft's
state. The boot logo page calls Snack directly.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 71 insertions, 0 deletions

diff --git a/desktop/Snackbar.qml b/desktop/Snackbar.qml
new file mode 100644
index 0000000..467ac73
--- /dev/null
+++ b/desktop/Snackbar.qml
@@ -0,0 +1,71 @@
+// Copyright (C) 2026 Danilo M. <danix@danix.xyz>
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License version 2 as
+// published by the Free Software Foundation.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+import QtQuick
+
+// Snack's message at the foot of the settings window: wrapped in full, a
+// stripe in its colour, a cross to dismiss. Place it once per window.
+Rectangle {
+    id: bar
+
+    readonly property bool shown: Snack.text !== ""
+
+    implicitHeight: Math.max(msg.implicitHeight, 20) + 20
+    radius: 10
+    color: Theme.surface
+    border.width: 1
+    border.color: Qt.alpha(Snack.color, 0.6)
+    opacity: shown ? 1 : 0
+    visible: opacity > 0
+    Behavior on opacity { NumberAnimation { duration: 160 } }
+
+    Timer {
+        id: fade
+        interval: 6000
+        onTriggered: Snack.clear()
+    }
+    Connections {
+        target: Snack
+        function onSerialChanged() { if (Snack.sticky) fade.stop(); else fade.restart(); }
+    }
+
+    Rectangle {
+        anchors { left: parent.left; top: parent.top; bottom: parent.bottom; margins: 6 }
+        width: 4
+        radius: 2
+        color: Snack.color
+    }
+
+    Text {
+        id: msg
+        anchors { left: parent.left; leftMargin: 20; right: close.left; rightMargin: 12; verticalCenter: parent.verticalCenter }
+        wrapMode: Text.Wrap
+        textFormat: Text.PlainText
+        text: Snack.text
+        font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 3 }
+        color: Theme.text
+    }
+
+    Text {
+        id: close
+        anchors { right: parent.right; rightMargin: 12; verticalCenter: parent.verticalCenter }
+        text: ""  // nf-fa-xmark
+        font { family: Theme.iconFamily; pixelSize: Theme.fontSize - 2 }
+        color: hit.containsMouse ? Theme.text : Theme.subtext
+        MouseArea {
+            id: hit
+            anchors { fill: parent; margins: -6 }
+            hoverEnabled: true
+            cursorShape: Qt.PointingHandCursor
+            onClicked: Snack.clear()
+        }
+    }
+}