Import existing sources, this is Day 5 with this app

sendmessagehelper.cpp

@@ -0,0 +1,74 @@
+#include "sendmessagehelper.h"
+
+#include <QQmlEngine>
+
+void SendMessageHelper::setDeviceConnection(DeviceConnection *deviceConnection)
+{
+    if (m_deviceConnection == deviceConnection)
+        return;
+
+    if (m_deviceConnection)
+    {
+        disconnect(m_deviceConnection, &DeviceConnection::responseReceived,
+                   this, &SendMessageHelper::responseReceived);
+    }
+
+    emit deviceConnectionChanged(m_deviceConnection = deviceConnection);
+
+    if (m_deviceConnection)
+    {
+        connect(m_deviceConnection, &DeviceConnection::responseReceived,
+                this, &SendMessageHelper::responseReceived);
+    }
+
+    if (!m_requestId.isEmpty())
+    {
+        m_requestId.clear();
+        emit requestIdChanged(m_requestId);
+    }
+
+    if (m_pending)
+        emit pendingChanged(m_pending = false);
+
+    if (!m_response.isNull())
+        emit responseChanged(m_response = {});
+}
+
+void SendMessageHelper::sendMessage(QVariantMap message)
+{
+    if (!m_deviceConnection)
+    {
+        qWarning() << "No device connection set!";
+        qmlEngine(this)->throwError(tr("No device connection set!"));
+    }
+
+    emit requestIdChanged(m_requestId = m_deviceConnection->generateRequestId());
+
+    if (!m_pending)
+        emit pendingChanged(m_pending = true);
+
+    message["requestId"] = m_requestId;
+
+    m_deviceConnection->sendMessage(message);
+}
+
+void SendMessageHelper::responseReceived(const QString &requestId, const QVariantMap &message)
+{
+    if (m_requestId.isEmpty())
+        return;
+
+    if (m_requestId != requestId)
+        return;
+
+    if (!m_requestId.isEmpty())
+    {
+        m_requestId.clear();
+        emit requestIdChanged(m_requestId);
+    }
+
+    if (m_pending)
+        emit pendingChanged(m_pending = false);
+
+    emit responseChanged(m_response = message);
+}
+