make send coins dialog more user friendly (better checking)

gui/src/addressbookdialog.cpp

@@ -127,6 +127,12 @@ void AddressBookDialog::on_buttonBox_accepted()
         QVariant address = table->model()->data(index);
         returnValue = address.toString();
     }
-
-    accept();
+    if(!returnValue.isEmpty())
+    {
+        accept();
+    }
+    else
+    {
+        reject();
+    }
 }

gui/src/bitcoingui.cpp

@@ -211,7 +211,12 @@ void BitcoinGUI::addressbookClicked()
     qDebug() << "Address book clicked";
     AddressBookDialog dlg;
     dlg.setTab(AddressBookDialog::SendingTab);
-    dlg.exec();
+    /* if an address accepted, do a 'send' to specified address */
+    if(dlg.exec())
+    {
+        SendCoinsDialog send(0, dlg.getReturnValue());
+        send.exec();
+    }
 }
 
 void BitcoinGUI::receivingAddressesClicked()

gui/src/sendcoinsdialog.cpp

@@ -6,17 +6,31 @@
 
 #include <QApplication>
 #include <QClipboard>
+#include <QMessageBox>
+#include <QLocale>
 
 #include "base58.h"
 
-SendCoinsDialog::SendCoinsDialog(QWidget *parent) :
+SendCoinsDialog::SendCoinsDialog(QWidget *parent, const QString &address) :
     QDialog(parent),
     ui(new Ui::SendCoinsDialog)
 {
     ui->setupUi(this);
+
+    /* Set up validators */
     ui->payTo->setMaxLength(BitcoinAddressValidator::MaxAddressLength);
     ui->payTo->setValidator(new BitcoinAddressValidator(this));
-    ui->payAmount->setValidator(new QDoubleValidator(this));
+    QDoubleValidator *amountValidator = new QDoubleValidator(this);
+    amountValidator->setDecimals(8);
+    amountValidator->setBottom(0.0);
+    ui->payAmount->setValidator(amountValidator);
+
+    /* Set initial address if provided */
+    if(!address.isEmpty())
+    {
+        ui->payTo->setText(address);
+        ui->payAmount->setFocus();
+    }
 }
 
 SendCoinsDialog::~SendCoinsDialog()
@@ -28,14 +42,31 @@ void SendCoinsDialog::on_sendButton_clicked()
 {
     QByteArray payTo = ui->payTo->text().toUtf8();
     uint160 payToHash = 0;
-    if(AddressToHash160(payTo.constData(), payToHash))
-    {
-        accept();
-    }
-    else
-    {
+    double payAmount = 0.0;
+    bool valid = false;
 
+    if(!AddressToHash160(payTo.constData(), payToHash))
+    {
+        QMessageBox::warning(this, tr("Warning"),
+                                       tr("The recepient address is not valid, please recheck."),
+                                       QMessageBox::Ok,
+                                       QMessageBox::Ok);
+        ui->payTo->setFocus();
+        return;
     }
+    payAmount = QLocale::system().toDouble(ui->payAmount->text(), &valid);
+    if(!valid || payAmount <= 0.0)
+    {
+        QMessageBox::warning(this, tr("Warning"),
+                                       tr("The amount to pay must be a valid number larger than 0."),
+                                       QMessageBox::Ok,
+                                       QMessageBox::Ok);
+        ui->payAmount->setFocus();
+        return;
+    }
+
+    /* TODO: send command to core, once this succeeds do accept() */
+    accept();
 }
 
 void SendCoinsDialog::on_pasteButton_clicked()