Add Behavior.targetProperty property

[ChangeLog][Behavior] Behavior now have a targetProperty property to
allow custom logic based on the target property's object or name.

Fixes: QTBUG-70964
Change-Id: I866c10d36c7de181fff48da94c8e16cd73ce49b1
Reviewed-by: Paul Wicking <paul.wicking@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

2 files changed, 38 insertions, 0 deletions

diff --git a/tests/auto/quick/qquickbehaviors/data/targetProperty.qml b/tests/auto/quick/qquickbehaviors/data/targetProperty.qml
new file mode 100644
index 0000000000..18abd46010
--- /dev/null
+++ b/tests/auto/quick/qquickbehaviors/data/targetProperty.qml
@@ -0,0 +1,16 @@
+import QtQuick 2.15
+
+Item {
+    readonly property QtObject xBehaviorObject: xBehavior.targetProperty.object
+    readonly property string xBehaviorName: xBehavior.targetProperty.name
+    readonly property QtObject emptyBehaviorObject: emptyBehavior.targetProperty.object
+    readonly property string emptyBehaviorName: emptyBehavior.targetProperty.name
+    Behavior on x {
+        id: xBehavior
+        objectName: "xBehavior"
+    }
+    Behavior {
+        id: emptyBehavior
+        objectName: "emptyBehavior"
+    }
+}
diff --git a/tests/auto/quick/qquickbehaviors/tst_qquickbehaviors.cpp b/tests/auto/quick/qquickbehaviors/tst_qquickbehaviors.cpp
index 64e32dcdfd..3b46019f64 100644
--- a/tests/auto/quick/qquickbehaviors/tst_qquickbehaviors.cpp
+++ b/tests/auto/quick/qquickbehaviors/tst_qquickbehaviors.cpp
@@ -75,6 +75,7 @@ private slots:
     void innerBehaviorOverwritten();
     void oneWay();
     void safeToDelete();
+    void targetProperty();
 };
 
 void tst_qquickbehaviors::simpleBehavior()
@@ -656,6 +657,27 @@ void tst_qquickbehaviors::safeToDelete()
     QVERIFY(c.create());
 }
 
+Q_DECLARE_METATYPE(QQmlProperty)
+void tst_qquickbehaviors::targetProperty()
+{
+    QQmlEngine engine;
+    QQmlComponent c(&engine, testFileUrl("targetProperty.qml"));
+    QScopedPointer<QQuickItem> item(qobject_cast<QQuickItem*>(c.create()));
+    QVERIFY2(!item.isNull(), qPrintable(c.errorString()));
+
+    QQuickBehavior* xBehavior =
+        qobject_cast<QQuickBehavior*>(item->findChild<QQuickBehavior*>("xBehavior"));
+    QCOMPARE(xBehavior->property("targetProperty").value<QQmlProperty>(), QQmlProperty(item.data(), "x"));
+    QCOMPARE(item->property("xBehaviorObject").value<QObject*>(), item.data());
+    QCOMPARE(item->property("xBehaviorName").toString(), "x");
+
+    QQuickBehavior* emptyBehavior =
+        qobject_cast<QQuickBehavior*>(item->findChild<QQuickBehavior*>("emptyBehavior"));
+    QCOMPARE(emptyBehavior->property("targetProperty").value<QQmlProperty>().isValid(), false);
+    QCOMPARE(item->property("emptyBehaviorObject").value<QObject*>(), nullptr);
+    QCOMPARE(item->property("emptyBehaviorName").toString(), "");
+}
+
 
 
 QTEST_MAIN(tst_qquickbehaviors)