Send QVector via socket QString?

Kris Revi

so i have this

    QVector<quint16> RGB565; // quint16 = 16bit 565 | quint32 = 32bit 888
    RGB565.reserve(img2.width() * img2.height());
    for(int y = 0; y < img2.height(); y++) {
        const quint16 *line = reinterpret_cast<const quint16*>(img2.constScanLine(y));
        for(int x = 0; x < img2.width(); x++)
            RGB565 << *(line++);
    }

i need to be able to send this RGB565via socket that is sending with QString

socket.sendCommandStrip(QString("pixArt"), QString(RGB565));

void Socket::sendCommandStrip(const QString &bName, const QString bValue)
{
    m_webSocket.sendTextMessage(QStringLiteral("{ '%0' : '%1' }").arg(bName).arg(bValue));
}

JonB

@Kris-Revi
You have an array of 16-bit values. Don't you want to send them as binary data, or maybe as a hex- or base64-encoded string?

Kris Revi

@JonB well in my python version i sent it as a list (that's what i know worked with the matrix)

    def convertImage(self):
        img = Image.open(self.imagePath)

        # Check if img is RGBA if true convert to RGB
        img = img.convert('RGB')

        # Shift the fucker arround to being RGB565
        self.final = [ (r >> 3) << 11 | (g >> 2) << 5 | (b >> 3) for (r, g, b) in img.getdata() ]

JonB

@Kris-Revi
I don't see why you want to turn the data into a QString to send. It's not text. I don't see any strings in your Python, you have just an array of 16-bit values. Which is presumably what "RGB565" is. Maybe someone else understands what you want.

Not the best of comments in your code... ;-)

Kris Revi

@JonB cause im sending both text and ints so i figured String was the best option! if you know a better way then please tell me!

SGaist

Hi,

Your python code just shows a list creation not how you actually are sending data.

As @JonB already wrote, you have to serialize your vector to string before sending it.

Kris Revi

@SGaist you are actualy right! :P

here (that's how in python)

self.ui.BUTTON_SEND_ESP32.clicked.connect(lambda : self.socket.sendImage('pixArt', self.final))

SGaist

What is self.socket ?

Kris Revi

@SGaist

self.socket = Socket(host="matrix32")
self.socket.Connect()

MySocket.py

from PyQt5 import QtCore, QtWebSockets
from PyQt5.QtCore import QUrl
import json

class Socket:

    def __init__(self, *args, **kwargs):
        self.client = QtWebSockets.QWebSocket('', QtWebSockets.QWebSocketProtocol.Version13, None)
        self.client.error.connect(self.on_error)
        self.hostAdr = kwargs['host']

    def Connect(self):
        self.client.open(QUrl(f"ws://{self.hostAdr}:80"))

    def sendMessage(self, bName, bValue):
        self.client.sendTextMessage('{"' + bName + '": "' + str(bValue) + '"}')

    def sendImage(self, bName, bValue):
        self.client.sendTextMessage(json.dumps({bName: bValue}))

    def on_error(self, error_code):
        print('error code: {}'.format(error_code))
        print(self.client.errorString())

    def close(self):
        self.client.close()

i see here that i actualy json.dumps what is the equal for Qt ?

JonB

@Kris-Revi
const QByteArray QJsonDocument::toJson(QJsonDocument::JsonFormat format)

SGaist

Technically there's no direct equivalent. However you can build a QString with a simple loop for example. Maybe std::transform or QTextStream.

JonB

@SGaist
? Why isn't const QByteArray QJsonDocument::toJson(QJsonDocument::JsonFormat format) the closest to what OP wants for json.dumps?

Kris Revi

@JonB said in Send QVector via socket QString?:

const QByteArray QJsonDocument::toJson(QJsonDocument::JsonFormat format)

how do i use that?

Bonnie

You don't have to use QVector.
To make it easy for json, I would change the code to

QJsonArray RGB565;
for(int y = 0; y < img2.height(); y++) {
    const quint16 *line = reinterpret_cast<const quint16*>(img2.constScanLine(y));
    for(int x = 0; x < img2.width(); x++)
        RGB565 << *(line++);
}

Meanwhile your send command can also be changed to more json-friendly

void Socket::sendCommandStrip(const QString &bName, const QJsonValue bValue)
{
    m_webSocket.sendTextMessage(QJsonDocument(QJsonObject{{bName, bValue}}).toJson(QJsonDocument::Compact));
}

So then you can call the command directly

socket.sendCommandStrip(QString("pixArt"), RGB565);
//you can also pass QString as the value
socket.sendCommandStrip(QString("otherName"), QString("otherValue"));
//or number
socket.sendCommandStrip(QString("anotherName"), 100);

Kris Revi

@Bonnie omg that is sexy! 😅

JonB

@Kris-Revi said in Send QVector via socket QString?:

const QByteArray QJsonDocument::toJson(QJsonDocument::JsonFormat format)

how do i use that?

Note how that is what @Bonnie is using in his example :)

Kris Revi

@JonB yea i see that :) but he also made my sendCommand sexy in the process xD

JonB

@Kris-Revi
LOL. If that's what floats your "sexy" boat, that is good :D The point anyway is that it is via QJsonDocument::toJson() that you can transform your data into something suitable to send.