Transfer: disable Send button if the payment id is invalid

pages/Transfer.qml

@@ -251,7 +251,7 @@ Rectangle {
         shadowPressedColor: "#B32D00"
         releasedColor: "#FF6C3C"
         pressedColor: "#FF4304"
-        enabled : addressLine.text.length > 0 && amountLine.text.length > 0
+        enabled : addressLine.text.length > 0 && amountLine.text.length > 0 && (paymentIdLine.text.trim() === "" || walletManager.paymentIdValid(paymentIdLine.text.trim()))
         onClicked: {
             console.log("Transfer: paymentClicked")
             var priority = priorityModel.get(priorityDropdown.currentIndex).priority

src/libwalletqt/WalletManager.cpp

@@ -149,6 +149,11 @@ quint64 WalletManager::amountFromDouble(double amount) const
     return Bitmonero::Wallet::amountFromDouble(amount);
 }
 
+bool WalletManager::paymentIdValid(const QString &payment_id) const
+{
+    return Bitmonero::Wallet::paymentIdValid(payment_id.toStdString());
+}
+
 void WalletManager::setLogLevel(int logLevel)
 {
     Bitmonero::WalletManagerFactory::setLogLevel(logLevel);

src/libwalletqt/WalletManager.h

@@ -89,6 +89,8 @@ public:
     // QML JS engine doesn't support unsigned integers
     Q_INVOKABLE QString maximumAllowedAmountAsSting() const;
 
+    Q_INVOKABLE bool paymentIdValid(const QString &payment_id) const;
+
     // QML missing such functionality, implementing these helpers here
     Q_INVOKABLE QString urlToLocalPath(const QUrl &url) const;
     Q_INVOKABLE QUrl localPathToUrl(const QString &path) const;