qml: Add QRImageProvider

Author: goqusan

src/Makefile.qt.include

@@ -147,6 +147,7 @@ BITCOIN_QT_H = \
   qml/bitcoinamount.h \
   qml/guiconstants.h \
   qml/imageprovider.h \
+  qml/qrimageprovider.h \
   qml/util.h \
   qml/walletqmlcontroller.h \
   qt/addressbookpage.h \
@@ -342,6 +343,7 @@ BITCOIN_QML_BASE_CPP = \
   qml/models/walletqmlmodel.cpp \
   qml/models/walletqmlmodeltransaction.cpp \
   qml/imageprovider.cpp \
+  qml/qrimageprovider.cpp \
   qml/util.cpp \
   qml/walletqmlcontroller.cpp
 

src/qml/bitcoin.cpp

@@ -35,6 +35,7 @@
 #include <qml/models/walletlistmodel.h>
 #include <qml/models/walletqmlmodel.h>
 #include <qml/models/walletqmlmodeltransaction.h>
+#include <qml/qrimageprovider.h>
 #include <qml/util.h>
 #include <qml/walletqmlcontroller.h>
 #include <qt/guiutil.h>
@@ -313,6 +314,7 @@ int QmlGuiMain(int argc, char* argv[])
     QScopedPointer<const NetworkStyle> network_style{NetworkStyle::instantiate(Params().GetChainType())};
     assert(!network_style.isNull());
     engine.addImageProvider(QStringLiteral("images"), new ImageProvider{network_style.data()});
+    engine.addImageProvider(QStringLiteral("qr"), new QRImageProvider);
 
     engine.rootContext()->setContextProperty("networkTrafficTower", &network_traffic_tower);
     engine.rootContext()->setContextProperty("nodeModel", &node_model);

src/qml/qrimageprovider.cpp

@@ -0,0 +1,56 @@
+// Copyright (c) 2025 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <qml/qrimageprovider.h>
+
+#include <QImage>
+#include <QQuickImageProvider>
+#include <QSize>
+#include <QString>
+#include <QUrl>
+#include <QUrlQuery>
+
+#if defined(HAVE_CONFIG_H)
+#include <config/bitcoin-config.h> /* for USE_QRCODE */
+#endif
+
+#ifdef USE_QRCODE
+#include <qrencode.h>
+#endif
+
+QRImageProvider::QRImageProvider()
+    : QQuickImageProvider{QQuickImageProvider::Image}
+{
+}
+
+QImage QRImageProvider::requestImage(const QString& id, QSize* size, const QSize& requested_size)
+{
+#ifdef USE_QRCODE
+    const QUrl url{"image:///" + id};
+    const QUrlQuery query{url};
+    const QString data{url.path().mid(1)};
+    const QColor fg{query.queryItemValue("fg")};
+    const QColor bg{query.queryItemValue("bg")};
+
+    QRcode* code = QRcode_encodeString(data.toUtf8().constData(), 0, QR_ECLEVEL_L, QR_MODE_8, 1);
+
+    if (code) {
+      QImage image{code->width, code->width, QImage::Format_ARGB32};
+      unsigned char* p = code->data;
+      for (int y = 0; y < code->width; ++y) {
+          for (int x = 0; x < code->width; ++x) {
+              image.setPixelColor(x, y, (*p & 1) ? fg : bg);
+              ++p;
+          }
+      }
+      QRcode_free(code);
+      *size = QSize(code->width, code->width);
+      return image;
+    }
+#endif // USE_QRCODE
+    QImage pixel{1, 1, QImage::Format_ARGB32};
+    pixel.setPixelColor(0, 0, QColorConstants::Transparent);
+    *size = QSize(1, 1);
+    return pixel;
+}

src/qml/qrimageprovider.h

@@ -0,0 +1,24 @@
+// Copyright (c) 2025 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_QML_QRIMAGEPROVIDER_H
+#define BITCOIN_QML_QRIMAGEPROVIDER_H
+
+#include <QQuickImageProvider>
+
+QT_BEGIN_NAMESPACE
+class QImage;
+class QSize;
+class QString;
+QT_END_NAMESPACE
+
+class QRImageProvider : public QQuickImageProvider
+{
+public:
+    explicit QRImageProvider();
+
+    QImage requestImage(const QString& id, QSize* size, const QSize& requested_size) override;
+};
+
+#endif // BITCOIN_QML_QRIMAGEPROVIDER_H