Expose the target value in Behaviors

So that nested animation can use it.

Change-Id: Ief40cda1dfe1ad9a38cf0d18fbf34456dc36e2ee
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

8 files changed, 98 insertions, 5 deletions

diff --git a/src/quick/util/qquickbehavior.cpp b/src/quick/util/qquickbehavior.cpp
index d024c0099b..76d464e7f8 100644
--- a/src/quick/util/qquickbehavior.cpp
+++ b/src/quick/util/qquickbehavior.cpp
@@ -171,9 +171,28 @@ void QQuickBehavior::setEnabled(bool enabled)
     emit enabledChanged();
 }
 
+/*!
+    \qmlproperty Variant QtQuick::Behavior::targetValue
+
+    This property holds the target value of the property being controlled by the Behavior.
+    This value is set by the Behavior before the animation is started.
+
+    \since QtQuick 2.13
+*/
+QVariant QQuickBehavior::targetValue() const
+{
+    Q_D(const QQuickBehavior);
+    return d->targetValue;
+}
+
 void QQuickBehavior::write(const QVariant &value)
 {
     Q_D(QQuickBehavior);
+    const bool targetValueHasChanged = d->targetValue != value;
+    if (targetValueHasChanged) {
+        d->targetValue = value;
+        emit targetValueChanged(); // emitting the signal here should allow
+    }                              // d->enabled to change if scripted by the user.
     bool bypass = !d->enabled || !d->finalized || QQmlEnginePrivate::designerMode();
     if (!bypass)
         qmlExecuteDeferred(this);
@@ -181,16 +200,13 @@ void QQuickBehavior::write(const QVariant &value)
         if (d->animationInstance)
             d->animationInstance->stop();
         QQmlPropertyPrivate::write(d->property, value, QQmlPropertyData::BypassInterceptor | QQmlPropertyData::DontRemoveBinding);
-        d->targetValue = value;
         return;
     }
 
     bool behaviorActive = d->animation->isRunning();
-    if (behaviorActive && value == d->targetValue)
+    if (behaviorActive && !targetValueHasChanged)
         return;
 
-    d->targetValue = value;
-
     if (d->animationInstance
             && (d->animationInstance->duration() != -1
                 || d->animationInstance->isRenderThreadProxy())
diff --git a/src/quick/util/qquickbehavior_p.h b/src/quick/util/qquickbehavior_p.h
index f939597d15..80a51d77af 100644
--- a/src/quick/util/qquickbehavior_p.h
+++ b/src/quick/util/qquickbehavior_p.h
@@ -69,6 +69,7 @@ class Q_QUICK_PRIVATE_EXPORT QQuickBehavior : public QObject, public QQmlPropert
     Q_CLASSINFO("DefaultProperty", "animation")
     Q_PROPERTY(QQuickAbstractAnimation *animation READ animation WRITE setAnimation)
     Q_PROPERTY(bool enabled READ enabled WRITE setEnabled NOTIFY enabledChanged)
+    Q_PROPERTY(QVariant targetValue READ targetValue NOTIFY targetValueChanged REVISION 13)
     Q_CLASSINFO("DeferredPropertyNames", "animation")
 
 public:
@@ -84,8 +85,11 @@ public:
     bool enabled() const;
     void setEnabled(bool enabled);
 
+    QVariant targetValue() const;
+
 Q_SIGNALS:
     void enabledChanged();
+    void targetValueChanged();
 
 private Q_SLOTS:
     void componentFinalized();
diff --git a/src/quick/util/qquickutilmodule.cpp b/src/quick/util/qquickutilmodule.cpp
index 31d4d4c437..5147ebc6f6 100644
--- a/src/quick/util/qquickutilmodule.cpp
+++ b/src/quick/util/qquickutilmodule.cpp
@@ -135,4 +135,6 @@ void QQuickUtilModule::defineModule()
 
     qmlRegisterUncreatableType<QQuickAbstractAnimation, 12>("QtQuick", 2, 12, "Animation",
         QQuickAbstractAnimation::tr("Animation is an abstract class"));
+    // 5.13
+    qmlRegisterType<QQuickBehavior, 13>("QtQuick", 2, 13, "Behavior");
 }
diff --git a/tests/auto/quick/qquickbehaviors/data/ItemWithInnerBehavior.qml b/tests/auto/quick/qquickbehaviors/data/ItemWithInnerBehavior.qml
index 09983645ef..0ac7f87c42 100644
--- a/tests/auto/quick/qquickbehaviors/data/ItemWithInnerBehavior.qml
+++ b/tests/auto/quick/qquickbehaviors/data/ItemWithInnerBehavior.qml
@@ -5,6 +5,7 @@ Item {
 
     property bool someValue
     Behavior on someValue {
+        objectName: "behavior"
         ScriptAction { script: { parent.behaviorTriggered = true }}
     }
 }
diff --git a/tests/auto/quick/qquickbehaviors/data/aliased.qml b/tests/auto/quick/qquickbehaviors/data/aliased.qml
index e65e035d83..1840cdd22e 100644
--- a/tests/auto/quick/qquickbehaviors/data/aliased.qml
+++ b/tests/auto/quick/qquickbehaviors/data/aliased.qml
@@ -17,6 +17,7 @@ Rectangle {
         anchors.fill: parent
         value: accelerating ? 400 : 0
         Behavior on value {
+            objectName: "behavior"
             NumberAnimation {
                 duration: 500
             }
diff --git a/tests/auto/quick/qquickbehaviors/data/oneway.qml b/tests/auto/quick/qquickbehaviors/data/oneway.qml
new file mode 100644
index 0000000000..0b438b80f6
--- /dev/null
+++ b/tests/auto/quick/qquickbehaviors/data/oneway.qml
@@ -0,0 +1,20 @@
+import QtQuick 2.0
+Rectangle {
+    width: 400
+    height: 400
+    Rectangle {
+        id: rect
+        objectName: "MyRectOneWay"
+        width: 100; height: 100; color: "green"
+        Behavior on x {
+            id: behavior
+            objectName: "MyBehaviorOneWay";
+            enabled: (behavior.targetValue === 0)
+            NumberAnimation {
+                id: ani
+                objectName: "MyAnimationOneWay";
+                duration: 200;
+            }
+        }
+    }
+}
diff --git a/tests/auto/quick/qquickbehaviors/qquickbehaviors.pro b/tests/auto/quick/qquickbehaviors/qquickbehaviors.pro
index 51bc42c390..fd64eb1d40 100644
--- a/tests/auto/quick/qquickbehaviors/qquickbehaviors.pro
+++ b/tests/auto/quick/qquickbehaviors/qquickbehaviors.pro
@@ -7,5 +7,5 @@ include (../../shared/util.pri)
 macx:CONFIG -= app_bundle
 
 TESTDATA = data/*
-
+DISTFILES = $$files(data/*)
 QT += core-private gui-private  qml-private quick-private testlib
diff --git a/tests/auto/quick/qquickbehaviors/tst_qquickbehaviors.cpp b/tests/auto/quick/qquickbehaviors/tst_qquickbehaviors.cpp
index fa9eba095d..6367f327da 100644
--- a/tests/auto/quick/qquickbehaviors/tst_qquickbehaviors.cpp
+++ b/tests/auto/quick/qquickbehaviors/tst_qquickbehaviors.cpp
@@ -73,6 +73,7 @@ private slots:
     void disabledWriteWhileRunning();
     void aliasedProperty();
     void innerBehaviorOverwritten();
+    void oneWay();
 };
 
 void tst_qquickbehaviors::simpleBehavior()
@@ -516,6 +517,7 @@ void tst_qquickbehaviors::disabledWriteWhileRunning()
         myRect->setProperty("x", 200);
         QCOMPARE(myAnimation->isRunning(), true);
         QTRY_VERIFY(myRect->x() != qreal(0) && myRect->x() != qreal(200));
+        QCOMPARE(myBehavior->targetValue(), 200); // grabbed before starting the animation
 
         // set disabled while animation is in progress
         myBehavior->setProperty("enabled", false);
@@ -526,6 +528,7 @@ void tst_qquickbehaviors::disabledWriteWhileRunning()
         myRect->setProperty("x", 100);
         QCOMPARE(myAnimation->isRunning(), false);
         QCOMPARE(myRect->x(), qreal(100));
+        QCOMPARE(myBehavior->targetValue(), 100);
         QTest::qWait(200);
         QCOMPARE(myRect->x(), qreal(100));
     }
@@ -546,17 +549,20 @@ void tst_qquickbehaviors::disabledWriteWhileRunning()
 
         // initial values
         QCOMPARE(myBehavior->enabled(), true);
+        QCOMPARE(myBehavior->targetValue(), QVariant());
         QCOMPARE(myAnimation->isRunning(), false);
         QCOMPARE(myRect->x(), qreal(0));
 
         // start animation
         myRect->setProperty("x", 200);
         QCOMPARE(myAnimation->isRunning(), true);
+        QCOMPARE(myBehavior->targetValue(), 200);
         QTRY_VERIFY(myRect->x() != qreal(0) && myRect->x() != qreal(200));
 
         //set second value
         myRect->setProperty("x", 300);
         QCOMPARE(myAnimation->isRunning(), true);
+        QCOMPARE(myBehavior->targetValue(), 300);
         QTRY_VERIFY(myRect->x() != qreal(0) && myRect->x() != qreal(200));
 
         // set disabled while animation is in progress
@@ -568,6 +574,7 @@ void tst_qquickbehaviors::disabledWriteWhileRunning()
         myRect->setProperty("x", 100);
         QCOMPARE(myAnimation->isRunning(), false);
         QCOMPARE(myRect->x(), qreal(100));
+        QCOMPARE(myBehavior->targetValue(), 100);
         QTest::qWait(200);
         QCOMPARE(myRect->x(), qreal(100));
     }
@@ -580,7 +587,12 @@ void tst_qquickbehaviors::aliasedProperty()
     QScopedPointer<QQuickRectangle> rect(qobject_cast<QQuickRectangle*>(c.create()));
     QVERIFY2(!rect.isNull(), qPrintable(c.errorString()));
 
+    QQuickBehavior* behavior =
+        qobject_cast<QQuickBehavior*>(rect->findChild<QQuickBehavior*>("behavior"));
+    QSignalSpy targetValueSpy(behavior, SIGNAL(targetValueChanged()));
     QQuickItemPrivate::get(rect.data())->setState("moved");
+    QCOMPARE(behavior->targetValue(), 400);
+    QCOMPARE(targetValueSpy.count(), 1);
     QScopedPointer<QQuickRectangle> acc(qobject_cast<QQuickRectangle*>(rect->findChild<QQuickRectangle*>("acc")));
     QScopedPointer<QQuickRectangle> range(qobject_cast<QQuickRectangle*>(acc->findChild<QQuickRectangle*>("range")));
     QTRY_VERIFY(acc->property("value").toDouble() > 0);
@@ -595,7 +607,44 @@ void tst_qquickbehaviors::innerBehaviorOverwritten()
     QQmlEngine engine;
     QQmlComponent c(&engine, testFileUrl("overwrittenbehavior.qml"));
     QScopedPointer<QQuickItem> item(qobject_cast<QQuickItem*>(c.create()));
+    QQuickBehavior* behavior =
+        qobject_cast<QQuickBehavior*>(item->findChild<QQuickBehavior*>("behavior"));
     QVERIFY(item->property("behaviorTriggered").toBool());
+    QCOMPARE(behavior->targetValue(), true);
+}
+
+void tst_qquickbehaviors::oneWay()
+{
+    QQmlEngine engine;
+    QQmlComponent c(&engine, testFileUrl("oneway.qml"));
+    QScopedPointer<QQuickRectangle> rect(qobject_cast<QQuickRectangle*>(c.create()));;
+    QVERIFY2(!rect.isNull(), qPrintable(c.errorString()));
+    QQuickBehavior* behavior =
+        qobject_cast<QQuickBehavior*>(rect->findChild<QQuickBehavior*>("MyBehaviorOneWay"));
+    QCOMPARE(behavior->enabled(), false);
+    QCOMPARE(behavior->targetValue(), QVariant());
+
+    QSignalSpy targetValueSpy(behavior, SIGNAL(targetValueChanged()));
+    QQuickRectangle *myRect = qobject_cast<QQuickRectangle*>(rect->findChild<QQuickRectangle*>("MyRectOneWay"));
+    myRect->setProperty("x", 100);
+    QCOMPARE(behavior->targetValue(), 100);
+    QCOMPARE(targetValueSpy.count(), 1);
+    QCOMPARE(behavior->enabled(), false);
+    qreal x = myRect->x();
+    QCOMPARE(x, qreal(100));    //should change immediately
+    QQuickNumberAnimation *myAnimation =
+        qobject_cast<QQuickNumberAnimation*>(behavior->findChild<QQuickNumberAnimation*>("MyAnimationOneWay"));
+    QCOMPARE(myAnimation->isRunning(), false);
+
+    myRect->setProperty("x", 0);
+    QCOMPARE(behavior->targetValue(), 0);
+    QCOMPARE(targetValueSpy.count(), 2);
+    QCOMPARE(behavior->enabled(), true);
+    QCOMPARE(myAnimation->isRunning(), true);
+    QVERIFY(myRect->x() > 0.0);
+    QTRY_VERIFY(myRect->x() < 100.0);
+    QTRY_COMPARE(myRect->x(), qreal(0));
+    QCOMPARE(myAnimation->isRunning(), false);
 }
 
 QTEST_MAIN(tst_qquickbehaviors)