Support required properties in model delegates

If a delegates declares a required property of a given name, and that
name exists as a role in the model, we set the property accordingly.
The same holds true for the special properties that come from the
QQmlDelegateModel like "index" and "model".

All roles are still injected into scope and thus accessible;
changing this in Qt5 would be tedious or even impossible while still
maintaining backwardscompatibility with delegates that do not use
required properties.

Change-Id: I4f388ba549c42f1ff9822bdb3b8357c4d45e4b66
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

3 files changed, 63 insertions, 1 deletions

diff --git a/tests/auto/quick/qquickrepeater/data/objlist_required.qml b/tests/auto/quick/qquickrepeater/data/objlist_required.qml
new file mode 100644
index 0000000000..cc9dd9566c
--- /dev/null
+++ b/tests/auto/quick/qquickrepeater/data/objlist_required.qml
@@ -0,0 +1,23 @@
+import QtQuick 2.0
+
+Rectangle {
+    id: container
+    objectName: "container"
+    width: 240
+    height: 320
+    color: "white"
+    Repeater {
+        id: repeater
+        objectName: "repeater"
+        model: testData
+        property int errors: 0
+        property int instantiated: 0
+        Component {
+            Item{
+                required property int index
+                required property int idx
+                Component.onCompleted: {if (index != idx) repeater.errors += 1; repeater.instantiated++}
+            }
+        }
+    }
+}
diff --git a/tests/auto/quick/qquickrepeater/data/requiredProperty.qml b/tests/auto/quick/qquickrepeater/data/requiredProperty.qml
new file mode 100644
index 0000000000..80eb3c28ee
--- /dev/null
+++ b/tests/auto/quick/qquickrepeater/data/requiredProperty.qml
@@ -0,0 +1,16 @@
+import QtQuick 2.14
+
+Item {
+    Column {
+        Repeater {
+            model: ["apples", "oranges", "pears"]
+            Text {
+                id: txt
+                required property string modelData
+                required property int index
+                text: modelData + index
+                Component.onCompleted: () => {console.info(txt.text)}
+            }
+        }
+    }
+}
diff --git a/tests/auto/quick/qquickrepeater/tst_qquickrepeater.cpp b/tests/auto/quick/qquickrepeater/tst_qquickrepeater.cpp
index 65e7d29595..ccfef63902 100644
--- a/tests/auto/quick/qquickrepeater/tst_qquickrepeater.cpp
+++ b/tests/auto/quick/qquickrepeater/tst_qquickrepeater.cpp
@@ -55,6 +55,7 @@ public:
 
 private slots:
     void numberModel();
+    void objectList_data();
     void objectList();
     void stringList();
     void dataModel_adding();
@@ -79,6 +80,7 @@ private slots:
     void QTBUG54859_asynchronousMove();
     void package();
     void ownership();
+    void requiredProperties();
 };
 
 class TestObject : public QObject
@@ -143,6 +145,14 @@ void tst_QQuickRepeater::numberModel()
     delete window;
 }
 
+void tst_QQuickRepeater::objectList_data()
+{
+    QTest::addColumn<QUrl>("filename");
+
+    QTest::newRow("normal") << testFileUrl("objlist.qml");
+    QTest::newRow("required") << testFileUrl("objlist_required.qml");
+}
+
 class MyObject : public QObject
 {
     Q_OBJECT
@@ -157,6 +167,7 @@ public:
 
 void tst_QQuickRepeater::objectList()
 {
+    QFETCH(QUrl, filename);
     QQuickView *window = createView();
     QObjectList data;
     for (int i=0; i<100; i++)
@@ -165,7 +176,7 @@ void tst_QQuickRepeater::objectList()
     QQmlContext *ctxt = window->rootContext();
     ctxt->setContextProperty("testData", QVariant::fromValue(data));
 
-    window->setSource(testFileUrl("objlist.qml"));
+    window->setSource(filename);
     qApp->processEvents();
 
     QQuickRepeater *repeater = findItem<QQuickRepeater>(window->rootObject(), "repeater");
@@ -1108,6 +1119,18 @@ void tst_QQuickRepeater::ownership()
     QVERIFY(!modelGuard);
 }
 
+void tst_QQuickRepeater::requiredProperties()
+{
+    QTest::ignoreMessage(QtMsgType::QtInfoMsg, "apples0");
+    QTest::ignoreMessage(QtMsgType::QtInfoMsg, "oranges1");
+    QTest::ignoreMessage(QtMsgType::QtInfoMsg, "pears2");
+    QQmlEngine engine;
+
+    QQmlComponent component(&engine, testFileUrl("requiredProperty.qml"));
+    QScopedPointer<QObject> o {component.create()};
+    QVERIFY(o);
+}
+
 QTEST_MAIN(tst_QQuickRepeater)
 
 #include "tst_qquickrepeater.moc"