chore:add qr code support for login

Signed-off-by: Trial97 <alexandru.tripon97@gmail.com>

libraries/qt-qrcodegenerator/qr.cpp

@@ -0,0 +1,29 @@
+
+#include "qr.h"
+#include "qrcodegen.hpp"
+
+void paintQR(QPainter& painter, const QSize sz, const QString& data, QColor fg)
+{
+    // NOTE: At this point you will use the API to get the encoding and format you want, instead of my hardcoded stuff:
+    qrcodegen::QrCode qr = qrcodegen::QrCode::encodeText(data.toUtf8().constData(), qrcodegen::QrCode::Ecc::LOW);
+    const int s = qr.getSize() > 0 ? qr.getSize() : 1;
+    const double w = sz.width();
+    const double h = sz.height();
+    const double aspect = w / h;
+    const double size = ((aspect > 1.0) ? h : w);
+    const double scale = size / (s + 2);
+    // NOTE: For performance reasons my implementation only draws the foreground parts in supplied color.
+    // It expects background to be prepared already (in white or whatever is preferred).
+    painter.setPen(Qt::NoPen);
+    painter.setBrush(fg);
+    for (int y = 0; y < s; y++) {
+        for (int x = 0; x < s; x++) {
+            const int color = qr.getModule(x, y);  // 0 for white, 1 for black
+            if (0 != color) {
+                const double rx1 = (x + 1) * scale, ry1 = (y + 1) * scale;
+                QRectF r(rx1, ry1, scale, scale);
+                painter.drawRects(&r, 1);
+            }
+        }
+    }
+}