QQuickTableView: add layoutChanged() signal

Add a new signal to TableView that tells when the
layout has changed. This signal can be used to
reposition any overlay on the content item, including
e.g SelectionHandles.

[ChangeLog][Quick][TableView] Added new signal 'layoutChanged()'

Change-Id: I5b89a064521c2831279accbc889deb768d9b1a1b
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

1 files changed, 46 insertions, 0 deletions

diff --git a/src/quick/doc/snippets/qml/tableview/overlay.qml b/src/quick/doc/snippets/qml/tableview/overlay.qml
new file mode 100644
index 0000000000..b79e457f81
--- /dev/null
+++ b/src/quick/doc/snippets/qml/tableview/overlay.qml
@@ -0,0 +1,46 @@
+// Copyright (C) 2022 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+import QtQuick
+import QtQuick.Window
+
+Window {
+    width: 480
+    height: 640
+    visible: true
+    visibility: Window.AutomaticVisibility
+
+    TableView {
+        id: tableView
+        anchors.fill: parent
+        clip: true
+    }
+
+    //![0]
+    Rectangle {
+        id: overlay
+        width: 20
+        height: 20
+        radius: 10
+        color: "blue"
+
+        z: 10
+        parent: tableView.contentItem
+
+        Connections {
+            target: tableView
+            function onLayoutChanged() {
+                let item = tableView.itemAtCell(5, 5)
+                let insideViewport = item !== null
+
+                overlay.visible = insideViewport
+                if (insideViewport) {
+                    overlay.x = item.x
+                    overlay.y = item.y
+                }
+            }
+        }
+    }
+    //![0]
+
+}