Port QSequentialAnimationGroup to new property system

There is only one property in QSequentialAnimationGroup,
currentAnimation.
This patch ports this property to the new property system

Task-number: QTBUG-85520
Change-Id: Id528d30f551e88a6165bbb6a3c09d44e89257de5
Reviewed-by: Sona Kurazyan <sona.kurazyan@qt.io>
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

src/corelib/animation/qsequentialanimationgroup.cpp

@@ -301,6 +301,11 @@ QAbstractAnimation *QSequentialAnimationGroup::currentAnimation() const
     return d->currentAnimation;
 }
 
+QBindable<QAbstractAnimation *> QSequentialAnimationGroup::bindableCurrentAnimation() const
+{
+    return &d_func()->currentAnimation;
+}
+
 /*!
     \reimp
 */
@@ -424,6 +429,8 @@ bool QSequentialAnimationGroup::event(QEvent *event)
 void QSequentialAnimationGroupPrivate::setCurrentAnimation(int index, bool intermediate)
 {
     Q_Q(QSequentialAnimationGroup);
+    // currentAnimation.removeBindingUnlessInWrapper()
+    // is not necessary here, since it is read only
 
     index = qMin(index, animations.count() - 1);
 
@@ -443,8 +450,8 @@ void QSequentialAnimationGroupPrivate::setCurrentAnimation(int index, bool inter
     if (currentAnimation)
         currentAnimation->stop();
 
-    currentAnimation = animations.at(index);
     currentAnimationIndex = index;
+    currentAnimation = animations.at(index);
 
     emit q->currentAnimationChanged(currentAnimation);
 

src/corelib/animation/qsequentialanimationgroup.h

@@ -52,7 +52,8 @@ class QSequentialAnimationGroupPrivate;
 class Q_CORE_EXPORT QSequentialAnimationGroup : public QAnimationGroup
 {
     Q_OBJECT
-    Q_PROPERTY(QAbstractAnimation* currentAnimation READ currentAnimation NOTIFY currentAnimationChanged)
+    Q_PROPERTY(QAbstractAnimation *currentAnimation READ currentAnimation NOTIFY
+                       currentAnimationChanged BINDABLE bindableCurrentAnimation)
 
 public:
     QSequentialAnimationGroup(QObject *parent = nullptr);
@@ -62,10 +63,11 @@ public:
     QPauseAnimation *insertPause(int index, int msecs);
 
     QAbstractAnimation *currentAnimation() const;
+    QBindable<QAbstractAnimation *> bindableCurrentAnimation() const;
     int duration() const override;
 
 Q_SIGNALS:
-    void currentAnimationChanged(QAbstractAnimation *current);
+    void currentAnimationChanged(QAbstractAnimation *current) const;
 
 protected:
     QSequentialAnimationGroup(QSequentialAnimationGroupPrivate &dd, QObject *parent);

src/corelib/animation/qsequentialanimationgroup_p.h

@@ -53,6 +53,7 @@
 
 #include "qsequentialanimationgroup.h"
 #include "private/qanimationgroup_p.h"
+#include "private/qproperty_p.h"
 
 QT_REQUIRE_CONFIG(animation);
 
@@ -62,10 +63,7 @@ class QSequentialAnimationGroupPrivate : public QAnimationGroupPrivate
 {
     Q_DECLARE_PUBLIC(QSequentialAnimationGroup)
 public:
-    QSequentialAnimationGroupPrivate()
-        : currentAnimation(nullptr), currentAnimationIndex(-1), lastLoop(0)
-    { }
-
+    QSequentialAnimationGroupPrivate() : currentAnimationIndex(-1), lastLoop(0) { }
 
     struct AnimationIndex
     {
@@ -87,7 +85,10 @@ public:
 
     bool atEnd() const;
 
-    QAbstractAnimation *currentAnimation;
+    Q_OBJECT_BINDABLE_PROPERTY_WITH_ARGS(QSequentialAnimationGroupPrivate, QAbstractAnimation *,
+                                         currentAnimation,
+                                         nullptr // initial value
+    )
     int currentAnimationIndex;
 
     // this is the actual duration of uncontrolled animations

tests/auto/corelib/animation/qsequentialanimationgroup/tst_qsequentialanimationgroup.cpp

@@ -71,6 +71,7 @@ private slots:
     void insertAnimation();
     void clear();
     void pauseResume();
+    void bindings();
 };
 
 void tst_QSequentialAnimationGroup::initTestCase()
@@ -1667,5 +1668,48 @@ void tst_QSequentialAnimationGroup::pauseResume()
     QCOMPARE(spy.count(), 1);
 }
 
+void tst_QSequentialAnimationGroup::bindings()
+{
+    // create a group consisting of three animations
+    QSequentialAnimationGroup group;
+    QPointer<QAbstractAnimation> anim1 = new DummyPropertyAnimation(&group);
+    QCOMPARE(group.animationCount(), 1);
+    QPointer<QAbstractAnimation> anim2 = new DummyPropertyAnimation(&group);
+    QCOMPARE(group.animationCount(), 2);
+    QPointer<QAbstractAnimation> anim3 = new DummyPropertyAnimation(&group);
+    QCOMPARE(group.animationCount(), 3);
+
+    // bind a QProperty to group.currentAnimation
+    QProperty<QAbstractAnimation *> currentAnim;
+    currentAnim.setBinding([&]() { return group.currentAnimation(); });
+
+    // check that everything behaves as expected
+    QSignalSpy spy(&group, &QSequentialAnimationGroup::currentAnimationChanged);
+    QVERIFY(spy.isValid());
+
+    int totalDuration = group.duration();
+
+    group.setCurrentTime(int(totalDuration * 0.5 / 3));
+    QCOMPARE(currentAnim.value(), anim1.get());
+    QCOMPARE(spy.count(), 0);
+
+    group.setCurrentTime(int(totalDuration * 1.5 / 3));
+    QCOMPARE(currentAnim.value(), anim2.get());
+    QCOMPARE(spy.count(), 1);
+
+    // change to other style of formulating a binding to test both
+    currentAnim.setBinding(group.bindableCurrentAnimation().makeBinding());
+
+    group.setCurrentTime(int(totalDuration * 2.5 / 3));
+    QCOMPARE(currentAnim.value(), anim3.get());
+    QCOMPARE(spy.count(), 2);
+
+    // currentAnimation is read-only. Binding it to something should have no effect
+    QProperty<QAbstractAnimation *> leader;
+    group.bindableCurrentAnimation().setBinding([&]() { return leader.value(); });
+
+    QCOMPARE(group.currentAnimation(), anim3.get());
+}
+
 QTEST_MAIN(tst_QSequentialAnimationGroup)
 #include "tst_qsequentialanimationgroup.moc"