[Interest] QML introspection and dynamic component creation

[Bo Thorsen]

Sorry, Harri, but that's not the problem here.

The problem was to look at the list of ParameterPanel children and 
create the objects based on the introspection. The problem is how to 
figure out which objects to create, not how to create them. Dynamic 
creation itself is easy enough.

There are some things that can be done with the children[i], but I don't 
think it's enough. Not unless you do evil hacks like encode stuff in the 
objectName. Maybe some other parameter stuff could be used as a sort of 
homegrown introspection.

Bo.

Den 17-12-2011 11:04, Harri Pasanen skrev:
> On 12/17/2011 10:15 AM, Bo Thorsen wrote:
>>
>>> When the user selects Wobble from the list of effects, a Loader is used
>>> to create a WobbleEffect item, and the id of this item is assigned to
>>> the effect property of the ParameterPanel. What I then want to happen is
>>> for sliders to be created and connected [...]
>> As you say, this is pretty easy to do with C++ introspection. So why not
>> use that? Export a C++ function to QML that does this.
>>
>> I don't know of a way to do this in QML, but I'd be happy to know. So
>> anyone with this knowledge, please step up and describe it.
>
> You can probably do it trough javascript as well.
>
> For instance, I have a Piece.qml that acts  as kind of "class header" to
> create instances of Piece qml objects.
>
>   From javascript I the do:
>
>    var component = Qt.createComponent("Piece.qml");
>
> pieces.push(component.createObject(gameBoard, {"x": xpos, "y": ypos,
> "width": pw, "height": pw}
>
> to setup a gaming board.
>
> To connect the signals, at the end of Piece.qml I have something like:
>
>       Component.onCompleted: {
>         mouse.swipe.connect(Ui.movePlayer)
>
> Where mouse.swipe is a signal I created for MouseArea {id: mouse ...} and
> where Ui is my javascript, movePlayer being a function in there.
>
> Then to clear the board and remove the objects from screen I do:
>
>       for (var i in pieces)
>           pieces[i].destroy()
>
>
> So to lookup in docs is Qt.createComponent, createObject, connect, destroy.
>
> quickhit example is QtSDK is a full example to play around with.
>
> Hope this helps a bit,
>
> Harri
>
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Bo Thorsen,
Fionia Software.

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