Add "Shield to sapling" menu item on balances table.

src/mainwindow.cpp

@@ -691,7 +691,7 @@ void MainWindow::setupBalancesTab() {
     ui->unconfirmedWarning->setVisible(false);
 
     // Double click on balances table
-    auto fnDoSendFrom = [=](const QString& addr) {
+    auto fnDoSendFrom = [=](const QString& addr, const QString& to = QString(), bool sendMax = false) {
         // Find the inputs combo
         for (int i = 0; i < ui->inputsCombo->count(); i++) {
             if (ui->inputsCombo->itemText(i).startsWith(addr)) {
@@ -700,6 +700,18 @@ void MainWindow::setupBalancesTab() {
             }
         }
 
+        // If there's a to address, add that as well
+        if (!to.isEmpty()) {
+            // Remember to clear any existing address fields, because we are creating a new transaction.
+            this->removeExtraAddresses();
+            ui->Address1->setText(to);
+        }
+
+        // See if max button has to be checked
+        if (sendMax) {
+            ui->Max1->setChecked(true);
+        }
+
         // And switch to the send tab.
         ui->tabWidget->setCurrentIndex(1);
     };
@@ -757,6 +769,13 @@ void MainWindow::setupBalancesTab() {
         });
 
         if (addr.startsWith("t")) {
+            auto defaultSapling = rpc->getDefaultSaplingAddress();
+            if (!defaultSapling.isEmpty()) {
+                menu.addAction("Shield balance to Sapling", [=] () {
+                    fnDoSendFrom(addr, defaultSapling, true);
+                });
+            }
+
             menu.addAction("View on block explorer", [=] () {
                 QString url;
                 if (Settings::getInstance()->isTestnet()) {

src/rpc.cpp

@@ -1009,3 +1009,15 @@ void RPC::getZboardTopics(std::function<void(QMap<QString, QString>)> cb) {
         }
     });
 }
+
+/** 
+ * Get a Sapling address from the user's wallet
+ */ 
+QString RPC::getDefaultSaplingAddress() {
+    for (QString addr: *zaddresses) {
+        if (Settings::getInstance()->isSaplingAddress(addr))
+            return addr;
+    }
+
+    return QString();
+}

src/rpc.h

@@ -62,6 +62,8 @@ public:
     void shutdownZcashd();
     void noConnection();
 
+    QString getDefaultSaplingAddress();
+
     void getAllPrivKeys(const std::function<void(QList<QPair<QString, QString>>)>);
 
     Turnstile*  getTurnstile()  { return turnstile; }