[Kde-bindings] custom slots

[Thomas Moenicke]

Richard Dale wrote:
> Another way is to override the QObject::metaObject() virtual method in php
> subclasses of the QObject classes, and return a dynamically constructed
> QMetaObject with any slots and signals that were defined in php. Then
> override the qt_metacall() virtual method, and for any php slots marshall
> the args from C++ to php, and call the php method. If the qt_metacall()
> wasn't for a php slot, then call qt_metacall() in the super class, so that
> it will just call an existing C++ slot. Given a list of slot and signal
> type signatures as strings it is reasonably straightforward to construct a
> QMetaObject.

Everything ok, but how to define such a metaobject at runtime? Or more 
precisely how to add slots defined as php methods to a metaobject? Here I 
have the same problem as descibed in my previous mail, or am I wrong with 
that?

> The disadvantage of using proxy methods is that you need to intervene
> everytime a slot or signal is passed to a Qt method, and do something
> different depending on whether the target slot is a C++ on or a php one.
> Whereas if you construct QMetaObjects at runtime from the slots and signals
> declared in php, you only need to override the qt_metacall() method.

Ok. Lets point that out, this is a copy of my experiment:

int Bridge::qt_metacall(QMetaObject::Call _c, int _id, void **_a)
{

    _id = QWidget::qt_metacall(_c, _id, _a);

    if (_id < 0)
        return _id;
    if (_c == QMetaObject::InvokeMetaMethod) {
        switch (_id) {
        case 0: { int _r = check_signal(*reinterpret_cast< int*>(_a[1]));
            if (_a[0]) *reinterpret_cast< int*>(_a[0]) = _r; }  break;
//        case 1: check_slot(*reinterpret_cast< int*>(_a[1])); break;
        case 1: (this->*slot_functions[0])(*reinterpret_cast< int*>(_a[1])); 
break;
        }
        _id -= 2;
    }
    return _id;
}

qt_metacall looks up in any data structure where a pointer to the php function 
is stored. Therefor I need to register the right id for this custom slot.
Well, I can override qt_metacall, but it will only be called if Qt finds a 
name of the slot in their data structures.
Now the question is how to construct metaobjects at runtime, with the names of 
all custom slots inside.

> Given a list of slot and signal
> type signatures as strings it is reasonably straightforward to construct a
> QMetaObject.

Thus, modify this?

static const uint qt_meta_data_Bridge[] = {

 // content:
       1,       // revision
       0,       // classname
       0,    0, // classinfo
       2,   10, // methods
       0,    0, // properties
       0,    0, // enums/sets

 // signals: signature, parameters, type, tag, flags
      21,   12,    8,    7, 0x05,

 // slots: signature, parameters, type, tag, flags
      45,   39,    7,    7, 0x0a,

       0        // eod
};

static const char qt_meta_stringdata_Bridge[] = 
{   "Bridge\0\0int\0newValue\0check_signal(int)\0value\0check_slot(int)\0myownstuff\0"
};


-- 
Thomas