Optimalisation Qt QML

Damian7546

Hi,
I exchange data between Qt and QML by Q_PROPERTY.
Please someone tell me how can I optimize exchange bool data? I am currently doing the following:

Qt:

    Q_PROPERTY(bool rs0State READ rs0State WRITE setRs0State NOTIFY rs0StateChanged)
    Q_PROPERTY(bool rs1State READ rs1State WRITE setRs1State NOTIFY rs1StateChanged)
    Q_PROPERTY(bool rs2State READ rs2State WRITE setRs2State NOTIFY rs2StateChanged)
    Q_PROPERTY(bool rs3State READ rs3State WRITE setRs3State NOTIFY rs3StateChanged)

QML:

active: if (systemController.rs0State === true)
                        return true
                    else
                        return false

The QBitArray doesnt't work in QML,

JoeCFD

@Damian7546 https://doc.qt.io/qt-5/qtqml-cppintegration-data.html#sequence-type-to-javascript-array
you can use vector<bool>, QList<bool>, qvector<bool>
remember QML works with Java Script. C++ code can not be added to qml simply.

sierdzio

@Damian7546 said in Optimalisation Qt QML:

QML:

active: if (systemController.rs0State === true)
                        return true
                    else
                        return false

This part is an overkill. Do this instead:

active: systemController.rs0State

dheerendra

Apart from @sierdzio suggestion what is the other optimization are you looking for ?
Can add more details to your question.

Damian7546

@sierdzio thanks for suggestion .

@dheerendra
I would like to instead four Q_PROPERTY use only one. I tried with QBitArray but it not possible refer to an item array from QML.

sierdzio

Then perhaps you can try with an enum set up to be a Q_FLAG.
Getting it to work on QML side will be a bit tricky but should be possible.

Damian7546

And it is possible send Struct data to QML by Q_PROPERTY ?

sierdzio

@Damian7546 said in Optimalisation Qt QML:

And it is possible send Struct data to QML by Q_PROPERTY ?

Yes, look into Q_GADGET.

But if you do that, you will most likely end up using more memory than 4 * bool (so 4 * int).

JoeCFD

@Damian7546 https://doc.qt.io/qt-5/qtqml-cppintegration-data.html#sequence-type-to-javascript-array
you can use vector<bool>, QList<bool>, qvector<bool>
remember QML works with Java Script. C++ code can not be added to qml simply.