problem with chained signal/slot connections

django.Reinhard

Hi,

I'm working on condition classes and this time I have trouble with 'AndCondition', which uses other conditionals.

Each conditional works together with ValueModels, which is similar to Qt properties, i.e. a valueModel has a name and a value and issues an event in case of value changes.

A stripped down testunit is available.

Testcase looks like this:

void TestEngine::testAndCondition() {
  ValueModel v0("left", 13);
  ValueModel v1("right", 3);
  GreaterCondition gc(&v0, 20);
  NotCondition     nc(&v1, 3);
  AndCondition     ac(gc, nc);

  connect(&ac, &AbstractCondition::conditionChanged, this, &TestEngine::updateCondition);

  QCOMPARE(result = ac.result(), false);

  qDebug() << "set v0 to 32";
  v0.setValue(32);

  QCOMPARE(result, false);

  qDebug() << "set v1 to 5";
  v1.setValue(5);

  QCOMPARE(result, true);
  disconnect(&ac, &AbstractCondition::conditionChanged, this, &TestEngine::updateCondition);
  }

TestEngine class is declared like this:

class TestEngine : public QObject
{
  Q_OBJECT
public slots:
  void updateCondition(bool result) {
    qDebug() << "TEST --- updateCondition to " << (result ? "true" : "false");
    this->result = result;
    };

private slots:
  void testAndCondition();

  void init() { result = true; }

private:
  volatile bool result;
  };

Debug logs look like:

QDEBUG : TestEngine::testAndCondition() AbstractCondition::update() ...
QDEBUG : TestEngine::testAndCondition() GreaterCondition::eval() ...
QDEBUG : TestEngine::testAndCondition() compare signed integers (>):  13 	value:  20
QDEBUG : TestEngine::testAndCondition() 	eval returned:  false
QDEBUG : TestEngine::testAndCondition() 	gonna fire condition changed event ...
QDEBUG : TestEngine::testAndCondition() AbstractCondition::update() ...
QDEBUG : TestEngine::testAndCondition() NotCondition::eval() ...
QDEBUG : TestEngine::testAndCondition() model type matches value type QVariant(int, 3) <> QVariant(int, 3)
QDEBUG : TestEngine::testAndCondition() 	eval returned:  false
QDEBUG : TestEngine::testAndCondition() 	gonna fire condition changed event ...
QDEBUG : TestEngine::testAndCondition() set v0 to 32
QDEBUG : TestEngine::testAndCondition() AbstractCondition::update() ...
QDEBUG : TestEngine::testAndCondition() GreaterCondition::eval() ...
QDEBUG : TestEngine::testAndCondition() compare signed integers (>):  32 	value:  20
QDEBUG : TestEngine::testAndCondition() 	eval returned:  true
QDEBUG : TestEngine::testAndCondition() 	gonna fire condition changed event ...
QDEBUG : TestEngine::testAndCondition() AndCondition::eval() ... true <> false
QDEBUG : TestEngine::testAndCondition() set v1 to 5
QDEBUG : TestEngine::testAndCondition() AbstractCondition::update() ...
QDEBUG : TestEngine::testAndCondition() NotCondition::eval() ...
QDEBUG : TestEngine::testAndCondition() model type matches value type QVariant(int, 5) <> QVariant(int, 3)
QDEBUG : TestEngine::testAndCondition() 	eval returned:  true
QDEBUG : TestEngine::testAndCondition() 	gonna fire condition changed event ...
QDEBUG : TestEngine::testAndCondition() AndCondition::eval() ... true <> true
FAIL!  : TestEngine::testAndCondition() Compared values are not the same

which means, that signal/slot connections work between ValueModel and conditionals, but not on a conditional, that depends on other conditionals?!?

When I debug this test, value that should be published by emit signal is changed and code runs into emit call - but slot from TestEngine is not called.

Christian Ehrlicher

@django-Reinhard said in problem with chained signal/slot connections:

QCOMPARE(result, false);

qDebug() << "set v1 to 5";
v1.setValue(5);

QCOMPARE(result, true);

How should result change between the first and the second test?

django.Reinhard

Hi Christian,

thank you very much for your attention and your question!

I just wanted to explain, why result should change between second and third test and not between first and second test.
... when I discovered my error!

I connected the wrong function to signals.
Fixed that and now the tests pass :)

Thanks!