QuickControls: Add vertical and horizontal header view delegates

Implement QQuickHeaderViewDelegate as the base class for header view
delegates, introducing 'headerView' and 'orientation' properties.
Separate previous delegate settings into HorizontalHeaderViewDelegate
and VerticalHeaderViewDelegate components for Basic, Fusion, and Imagine
styles.

This change improves the modularity and reusability of header view
delegates across different styles. It also allows for more consistent
behavior and easier customization of header views.

A test suite has been added to verify default property settings and
ensure the new components work without warnings.

[ChangeLog][QtQuickControls][HeaderView] Add dedicated delegate
components for vertical and horizontal header views.

Task-number: QTBUG-70326
Change-Id: I8831e77f6909bdae13c3a7262145ab156f63a59a
Reviewed-by: Mitch Curtis <[email protected]>

1 files changed, 33 insertions, 0 deletions

diff --git a/src/quickcontrols/universal/HorizontalHeaderViewDelegate.qml b/src/quickcontrols/universal/HorizontalHeaderViewDelegate.qml
new file mode 100644
index 0000000000..fcfbdd6deb
--- /dev/null
+++ b/src/quickcontrols/universal/HorizontalHeaderViewDelegate.qml
@@ -0,0 +1,33 @@
+// Copyright (C) 2025 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+import QtQuick
+import QtQuick.Controls.impl as ControlsImpl
+import QtQuick.Controls.Universal
+import QtQuick.Templates as T
+
+T.HeaderViewDelegate {
+    id: control
+
+    // same as AbstractButton.qml
+    implicitWidth: Math.max(implicitBackgroundWidth + leftInset + rightInset,
+                            implicitContentWidth + leftPadding + rightPadding)
+    implicitHeight: Math.max(implicitBackgroundHeight + topInset + bottomInset,
+                             implicitContentHeight + topPadding + bottomPadding)
+
+    padding: 8
+
+    highlighted: selected
+
+    background: Rectangle {
+        color: control.Universal.background
+    }
+
+    contentItem: Label {
+        horizontalAlignment: Text.AlignHCenter
+        verticalAlignment: Text.AlignVCenter
+        color: ControlsImpl.Color.transparent(control.Universal.foreground,
+                                 enabled ? 1.0 : 0.2)
+        text: control.model[control.headerView.textRole]
+    }
+}