doc: Clarify usage of palette; testable snippets

- color groups are better shown with copyable monospace syntax rather
  than capitalized
- clarify that using palette grouped-property syntax does not imply
  that you must define every color
- Window has a palette property, inited from SystemPalette: it's
  not only ApplicationWindow
- testable snippets
- reuse part of the windowPalette snippet for the Window.active
  property (switching colors might be the main use case)
- make more links

Pick-to: 6.2 6.5
Change-Id: I5974351ba66fc9aeec34cb6a4aba1eb85289f536
Reviewed-by: Oliver Eftevaag <oliver.eftevaag@qt.io>

1 files changed, 38 insertions, 0 deletions

diff --git a/src/quick/doc/snippets/qml/windowPalette.qml b/src/quick/doc/snippets/qml/windowPalette.qml
new file mode 100644
index 0000000000..0638213c57
--- /dev/null
+++ b/src/quick/doc/snippets/qml/windowPalette.qml
@@ -0,0 +1,38 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+//![entire]
+import QtQuick
+import QtQuick.Controls
+
+//![declaration-and-color]
+Window {
+    visible: true
+
+    // here we use the Window.active and Window.palette ordinary properties
+    color: active ? palette.active.window : palette.inactive.window
+//![declaration-and-color]
+
+    // colors that are not customized here come from SystemPalette
+    palette.active.window: "peachpuff"
+    palette.windowText: "brown"
+
+    Text {
+        anchors.centerIn: parent
+        // here we use the Window.active attached property and the Item.palette property
+        color: Window.active ? palette.active.windowText : palette.inactive.windowText
+        text: Window.active ? "active" : "inactive"
+    }
+
+    Button {
+        text: "Button"
+        anchors {
+            bottom: parent.bottom
+            bottomMargin: 6
+            horizontalCenter: parent.horizontalCenter
+        }
+    }
+//![closing-brace]
+}
+//![closing-brace]
+//![entire]