Fix possible jump in animation timer.

If both a stop and start happen within an event loop, ensure they are
processed in order.

Based on a patch from Charles Yin.

Task-number: QTBUG-22865
Change-Id: I6131bd43a6ba5ad4fa37c863a9f4598bf2ac0e01
Reviewed-by: Leonardo Sobral Cunha <leo.cunha@nokia.com>
Reviewed-by: Martin Jones <martin.jones@nokia.com>

1 files changed, 45 insertions, 1 deletions

diff --git a/tests/auto/corelib/animation/qabstractanimation/tst_qabstractanimation.cpp b/tests/auto/corelib/animation/qabstractanimation/tst_qabstractanimation.cpp
index 8fd5237606..083324bdd8 100644
--- a/tests/auto/corelib/animation/qabstractanimation/tst_qabstractanimation.cpp
+++ b/tests/auto/corelib/animation/qabstractanimation/tst_qabstractanimation.cpp
@@ -58,6 +58,8 @@ private slots:
     void loopCount();
     void state();
     void totalDuration();
+    void avoidJumpAtStart();
+    void avoidJumpAtStartWithStop();
 };
 
 class TestableQAbstractAnimation : public QAbstractAnimation
@@ -65,10 +67,15 @@ class TestableQAbstractAnimation : public QAbstractAnimation
     Q_OBJECT
 
 public:
+    TestableQAbstractAnimation() : m_duration(10) {}
     virtual ~TestableQAbstractAnimation() {};
 
-    int duration() const { return 10; }
+    int duration() const { return m_duration; }
     virtual void updateCurrentTime(int) {}
+
+    void setDuration(int duration) { m_duration = duration; }
+private:
+    int m_duration;
 };
 
 class DummyQAnimationGroup : public QAnimationGroup
@@ -150,6 +157,43 @@ void tst_QAbstractAnimation::totalDuration()
     QCOMPARE(anim.totalDuration(), 50);
 }
 
+void tst_QAbstractAnimation::avoidJumpAtStart()
+{
+    TestableQAbstractAnimation anim;
+    anim.setDuration(1000);
+
+    /*
+        the timer shouldn't actually start until we hit the event loop,
+        so the sleep should have no effect
+    */
+    anim.start();
+    QTest::qSleep(300);
+    QCoreApplication::processEvents();
+    QVERIFY(anim.currentTime() < 50);
+}
+
+void tst_QAbstractAnimation::avoidJumpAtStartWithStop()
+{
+    TestableQAbstractAnimation anim;
+    anim.setDuration(1000);
+
+    TestableQAbstractAnimation anim2;
+    anim2.setDuration(1000);
+
+    anim.start();
+    QTest::qWait(300);
+    anim.stop();
+
+    /*
+        same test as avoidJumpAtStart, but after there is a
+        running animation that is stopped
+    */
+    anim2.start();
+    QTest::qSleep(300);
+    QCoreApplication::processEvents();
+    QVERIFY(anim2.currentTime() < 50);
+}
+
 QTEST_MAIN(tst_QAbstractAnimation)
 
 #include "tst_qabstractanimation.moc"