Thanks! This is exactly the Qt documentation page I had been looking
for. My prior experimentation appears to support what the documentation
says.
There is one remaining issue: Since int * as an argument does not appear
working, what if I need to get more than one output integers from the
Q_INVOKABLE function?
That is, since the following may not work:
// !!! This Q_INVOKABLE function does not work:
void MyClass::myFunc4(int * myOutputInt1, int * myOutputInt2)
{
*myOutputInt1 = 11111;
*myOutputInt2 = 22222;
}
one solution is to package the 2 output integers into an object of a Qt
class that is recognizable by QML, for example, QVariant, as illustrated
below:
// This Q_INVOKABLE function appears working:
QVariant MyClass::myFunc5()
{
int myOutputInt1 = 11111;
int myOutputInt2 = 22222;
QScriptEngine engine;
QScriptValue value = engine.newObject();
value.setProperty("myOutputInt1", myOutputInt1);
value.setProperty("myOutputInt2", myOutputInt2);
return value.toVariant();
}
And in my QML code, I'll do something like this:
var myVariant = myClassObject.myFunc5();
var myInt1 = myVariant.myOutputInt1;
var myInt2 = myVariant.myOutputInt2;
This, although it works, does not look simple and straightforward. Is
there a better way?
On 10/11/2011 11:02 AM, Girish Ramakrishnan wrote:
> Hi Jonathan,
>
> On Tue, Oct 11, 2011 at 10:36 PM, Jonathan Zhong
> <jonathan.zh...@panasonic.aero> wrote:
>> Hi,
>>
>> What are the valid argument types of an invokable member function of a
>> QML extension C++ class? I have noticed that these work:
>>
>> Q_INVOKABLE void myFunc1(int myInputInt);
>> Q_INVOKABLE void myFunc2(int& myInputInt); // but myInputInt cannot
>> be modified.
>>
>> while this does not work:
>>
>> Q_INVOKABLE void myFunc3(int * myOutputInt); // This will cause a
>> runtime error when running qmlviewer.
>>
>> It appears that:
>> 1. The argument can be an object of (or reference to) a basic C/C++ data
>> type (int, int&, double, double&, ...).
>> 2. The argument can be an object or (or reference to) a Qt class which
>> relates to a basic QML type (QString, QString&, QVariant, QVariant&, ..).
>> 3. The argument can be a pointer to QObject or its derived classes
>> (QObject *, QWidget *, ...).
>> ...
>>
>> Is there a Qt documentation page on this subject?
>>
>> Perhaps this is a related question: What are the valid return types of
>> an invokable member function?
>>
> See http://doc.qt.nokia.com/main-snapshot/qtbinding.html#supported-data-types
>
> Girish
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