1 files changed, 20 insertions, 4 deletions
diff --git a/src/qt/walletmodel.cpp b/src/qt/walletmodel.cpp
index fde136b727..c6f3f5b00c 100644
--- a/src/qt/walletmodel.cpp
+++ b/src/qt/walletmodel.cpp
@@ -67,6 +67,10 @@ WalletModel::~WalletModel()
 
 void WalletModel::startPollBalance()
 {
+    // Update the cached balance right away, so every view can make use of it,
+    // so them don't need to waste resources recalculating it.
+    pollBalanceChanged();
+
     // This timer will be fired repeatedly to update the balance
     // Since the QTimer::timeout is a private signal, it cannot be used
     // in the GUIUtil::ExceptionSafeConnect directly.
@@ -120,12 +124,17 @@ void WalletModel::pollBalanceChanged()
 
 void WalletModel::checkBalanceChanged(const interfaces::WalletBalances& new_balances)
 {
-    if(new_balances.balanceChanged(m_cached_balances)) {
+    if (new_balances.balanceChanged(m_cached_balances)) {
         m_cached_balances = new_balances;
         Q_EMIT balanceChanged(new_balances);
     }
 }
 
+interfaces::WalletBalances WalletModel::getCachedBalance() const
+{
+    return m_cached_balances;
+}
+
 void WalletModel::updateTransaction()
 {
     // Balance and number of transactions might have changed
@@ -194,7 +203,9 @@ WalletModel::SendCoinsReturn WalletModel::prepareTransaction(WalletModelTransact
         return DuplicateAddress;
     }
 
-    CAmount nBalance = m_wallet->getAvailableBalance(coinControl);
+    // If no coin was manually selected, use the cached balance
+    // Future: can merge this call with 'createTransaction'.
+    CAmount nBalance = getAvailableBalance(&coinControl);
 
     if(total > nBalance)
     {
@@ -207,7 +218,7 @@ WalletModel::SendCoinsReturn WalletModel::prepareTransaction(WalletModelTransact
 
         auto& newTx = transaction.getWtx();
         const auto& res = m_wallet->createTransaction(vecSend, coinControl, !wallet().privateKeysDisabled() /* sign */, nChangePosRet, nFeeRequired);
-        newTx = res ? res.GetObj() : nullptr;
+        newTx = res ? *res : nullptr;
         transaction.setTransactionFee(nFeeRequired);
         if (fSubtractFeeFromAmount && newTx)
             transaction.reassignAmounts(nChangePosRet);
@@ -218,7 +229,7 @@ WalletModel::SendCoinsReturn WalletModel::prepareTransaction(WalletModelTransact
             {
                 return SendCoinsReturn(AmountWithFeeExceedsBalance);
             }
-            Q_EMIT message(tr("Send Coins"), QString::fromStdString(res.GetError().translated),
+            Q_EMIT message(tr("Send Coins"), QString::fromStdString(util::ErrorString(res).translated),
                 CClientUIInterface::MSG_ERROR);
             return TransactionCreationFailed;
         }
@@ -602,3 +613,8 @@ uint256 WalletModel::getLastBlockProcessed() const
 {
     return m_client_model ? m_client_model->getBestBlockHash() : uint256{};
 }
+
+CAmount WalletModel::getAvailableBalance(const CCoinControl* control)
+{
+    return control && control->HasSelected() ? wallet().getAvailableBalance(*control) : getCachedBalance().balance;
+}