update QRCodeDialog

- remove unused #include <QDebug> and lblBTC label
- update Bitcoin input field to a BitcoinAmountField to allow Bitcoin unit selection
- use BitcoinUnits::format for the resulting amount parameter in the generated URI (always use BTC as per BIP21)
- move MAX_URI_LENGTH and EXPORT_IMAGE_SIZE to guiconstants.h
- add OptionsModel in AddressBookPage and use it in on_showQRCode_clicked() to pass it to QRCodeDialog
- add OptionsModel in QRCodeDialog to enable display unit updates
- add updateDisplayUnit() slot to be able to imediately update currently set bitcoin unit
- make all labels in the UI-file plain text
- resize dialog to match for an updated layout (fields are now stacked and new field)
- remove unused parameters from private slots
- only enable save button, when QR Code was generated
- show message when entered amound is invalid
- add read-only QPlainTextEdit field to output generated URI

7 files changed, 215 insertions, 152 deletions

diff --git a/src/qt/addressbookpage.cpp b/src/qt/addressbookpage.cpp
index 5849f5b23d..663ff68669 100644
--- a/src/qt/addressbookpage.cpp
+++ b/src/qt/addressbookpage.cpp
@@ -2,6 +2,7 @@
 #include "ui_addressbookpage.h"
 
 #include "addresstablemodel.h"
+#include "optionsmodel.h"
 #include "bitcoingui.h"
 #include "editaddressdialog.h"
 #include "csvmodelwriter.h"
@@ -20,6 +21,7 @@ AddressBookPage::AddressBookPage(Mode mode, Tabs tab, QWidget *parent) :
     QDialog(parent),
     ui(new Ui::AddressBookPage),
     model(0),
+    optionsModel(0),
     mode(mode),
     tab(tab)
 {
@@ -139,6 +141,11 @@ void AddressBookPage::setModel(AddressTableModel *model)
     selectionChanged();
 }
 
+void AddressBookPage::setOptionsModel(OptionsModel *optionsModel)
+{
+    this->optionsModel = optionsModel;
+}
+
 void AddressBookPage::on_copyToClipboard_clicked()
 {
     GUIUtil::copyEntryData(ui->tableView, AddressTableModel::Address);
@@ -314,6 +321,8 @@ void AddressBookPage::on_showQRCode_clicked()
         QString address = index.data().toString(), label = index.sibling(index.row(), 0).data(Qt::EditRole).toString();
 
         QRCodeDialog *dialog = new QRCodeDialog(address, label, tab == ReceivingTab, this);
+        if(optionsModel)
+            dialog->setModel(optionsModel);
         dialog->setAttribute(Qt::WA_DeleteOnClose);
         dialog->show();
     }
diff --git a/src/qt/addressbookpage.h b/src/qt/addressbookpage.h
index b2e91c7cb2..e94c556131 100644
--- a/src/qt/addressbookpage.h
+++ b/src/qt/addressbookpage.h
@@ -7,6 +7,7 @@ namespace Ui {
     class AddressBookPage;
 }
 class AddressTableModel;
+class OptionsModel;
 
 QT_BEGIN_NAMESPACE
 class QTableView;
@@ -37,6 +38,7 @@ public:
     ~AddressBookPage();
 
     void setModel(AddressTableModel *model);
+    void setOptionsModel(OptionsModel *optionsModel);
     const QString &getReturnValue() const { return returnValue; }
 
 public slots:
@@ -46,6 +48,7 @@ public slots:
 private:
     Ui::AddressBookPage *ui;
     AddressTableModel *model;
+    OptionsModel *optionsModel;
     Mode mode;
     Tabs tab;
     QString returnValue;
diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
index c642f4aa0b..3ef03c437e 100644
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -357,6 +357,8 @@ void BitcoinGUI::setClientModel(ClientModel *clientModel)
         connect(clientModel, SIGNAL(error(QString,QString,bool)), this, SLOT(error(QString,QString,bool)));
 
         rpcConsole->setClientModel(clientModel);
+        addressBookPage->setOptionsModel(clientModel->getOptionsModel());
+        receiveCoinsPage->setOptionsModel(clientModel->getOptionsModel());
     }
 }
 
diff --git a/src/qt/forms/qrcodedialog.ui b/src/qt/forms/qrcodedialog.ui
index 6199b68749..52e9db3762 100644
--- a/src/qt/forms/qrcodedialog.ui
+++ b/src/qt/forms/qrcodedialog.ui
@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>334</width>
-    <height>425</height>
+    <width>340</width>
+    <height>530</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -28,8 +28,8 @@
        <height>300</height>
       </size>
      </property>
-     <property name="text">
-      <string>QR Code</string>
+     <property name="textFormat">
+      <enum>Qt::PlainText</enum>
      </property>
      <property name="alignment">
       <set>Qt::AlignCenter</set>
@@ -40,133 +40,122 @@
     </widget>
    </item>
    <item>
+    <widget class="QPlainTextEdit" name="outUri">
+     <property name="sizePolicy">
+      <sizepolicy hsizetype="Expanding" vsizetype="Minimum">
+       <horstretch>0</horstretch>
+       <verstretch>0</verstretch>
+      </sizepolicy>
+     </property>
+     <property name="minimumSize">
+      <size>
+       <width>0</width>
+       <height>50</height>
+      </size>
+     </property>
+     <property name="tabChangesFocus">
+      <bool>true</bool>
+     </property>
+     <property name="textInteractionFlags">
+      <set>Qt::TextSelectableByKeyboard|Qt::TextSelectableByMouse</set>
+     </property>
+    </widget>
+   </item>
+   <item>
     <widget class="QWidget" name="widget" native="true">
      <layout class="QVBoxLayout" name="verticalLayout_2">
       <item>
-       <layout class="QHBoxLayout" name="horizontalLayout_2">
-        <item>
-         <layout class="QVBoxLayout" name="verticalLayout">
-          <item>
-           <widget class="QCheckBox" name="chkReqPayment">
-            <property name="enabled">
-             <bool>true</bool>
-            </property>
-            <property name="text">
-             <string>Request Payment</string>
-            </property>
-           </widget>
-          </item>
-          <item>
-           <layout class="QHBoxLayout" name="horizontalLayout">
-            <item>
-             <widget class="QLabel" name="lblAmount">
-              <property name="sizePolicy">
-               <sizepolicy hsizetype="Preferred" vsizetype="Maximum">
-                <horstretch>0</horstretch>
-                <verstretch>0</verstretch>
-               </sizepolicy>
-              </property>
-              <property name="text">
-               <string>Amount:</string>
-              </property>
-              <property name="alignment">
-               <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
-              </property>
-              <property name="buddy">
-               <cstring>lnReqAmount</cstring>
-              </property>
-             </widget>
-            </item>
-            <item>
-             <widget class="QLineEdit" name="lnReqAmount">
-              <property name="enabled">
-               <bool>false</bool>
-              </property>
-              <property name="minimumSize">
-               <size>
-                <width>60</width>
-                <height>0</height>
-               </size>
-              </property>
-              <property name="alignment">
-               <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
-              </property>
-             </widget>
-            </item>
-            <item>
-             <widget class="QLabel" name="lblBTC">
-              <property name="sizePolicy">
-               <sizepolicy hsizetype="Preferred" vsizetype="Maximum">
-                <horstretch>0</horstretch>
-                <verstretch>0</verstretch>
-               </sizepolicy>
-              </property>
-              <property name="text">
-               <string>BTC</string>
-              </property>
-              <property name="buddy">
-               <cstring>lnReqAmount</cstring>
-              </property>
-             </widget>
-            </item>
-           </layout>
-          </item>
-         </layout>
+       <widget class="QCheckBox" name="chkReqPayment">
+        <property name="enabled">
+         <bool>true</bool>
+        </property>
+        <property name="text">
+         <string>Request Payment</string>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <layout class="QFormLayout" name="formLayout">
+        <property name="fieldGrowthPolicy">
+         <enum>QFormLayout::AllNonFixedFieldsGrow</enum>
+        </property>
+        <item row="1" column="0">
+         <widget class="QLabel" name="lblLabel">
+          <property name="text">
+           <string>Label:</string>
+          </property>
+          <property name="textFormat">
+           <enum>Qt::PlainText</enum>
+          </property>
+          <property name="alignment">
+           <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+          </property>
+          <property name="buddy">
+           <cstring>lnLabel</cstring>
+          </property>
+         </widget>
         </item>
-        <item>
-         <layout class="QGridLayout" name="gridLayout">
-          <item row="0" column="0">
-           <widget class="QLabel" name="lblLabel">
-            <property name="text">
-             <string>Label:</string>
-            </property>
-            <property name="alignment">
-             <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
-            </property>
-            <property name="buddy">
-             <cstring>lnLabel</cstring>
-            </property>
-           </widget>
-          </item>
-          <item row="0" column="1">
-           <widget class="QLineEdit" name="lnLabel">
-            <property name="minimumSize">
-             <size>
-              <width>100</width>
-              <height>0</height>
-             </size>
-            </property>
-           </widget>
-          </item>
-          <item row="1" column="0">
-           <widget class="QLabel" name="lblMessage">
-            <property name="text">
-             <string>Message:</string>
-            </property>
-            <property name="alignment">
-             <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
-            </property>
-            <property name="buddy">
-             <cstring>lnMessage</cstring>
-            </property>
-           </widget>
-          </item>
-          <item row="1" column="1">
-           <widget class="QLineEdit" name="lnMessage">
-            <property name="minimumSize">
-             <size>
-              <width>100</width>
-              <height>0</height>
-             </size>
-            </property>
-           </widget>
-          </item>
-         </layout>
+        <item row="1" column="1">
+         <widget class="QLineEdit" name="lnLabel"/>
+        </item>
+        <item row="2" column="0">
+         <widget class="QLabel" name="lblMessage">
+          <property name="text">
+           <string>Message:</string>
+          </property>
+          <property name="textFormat">
+           <enum>Qt::PlainText</enum>
+          </property>
+          <property name="alignment">
+           <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+          </property>
+          <property name="buddy">
+           <cstring>lnMessage</cstring>
+          </property>
+         </widget>
+        </item>
+        <item row="2" column="1">
+         <widget class="QLineEdit" name="lnMessage"/>
+        </item>
+        <item row="0" column="0">
+         <widget class="QLabel" name="lblAmount">
+          <property name="sizePolicy">
+           <sizepolicy hsizetype="Preferred" vsizetype="Maximum">
+            <horstretch>0</horstretch>
+            <verstretch>0</verstretch>
+           </sizepolicy>
+          </property>
+          <property name="text">
+           <string>Amount:</string>
+          </property>
+          <property name="textFormat">
+           <enum>Qt::PlainText</enum>
+          </property>
+          <property name="alignment">
+           <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+          </property>
+          <property name="buddy">
+           <cstring>lnReqAmount</cstring>
+          </property>
+         </widget>
+        </item>
+        <item row="0" column="1">
+         <widget class="BitcoinAmountField" name="lnReqAmount">
+          <property name="enabled">
+           <bool>false</bool>
+          </property>
+          <property name="minimumSize">
+           <size>
+            <width>80</width>
+            <height>0</height>
+           </size>
+          </property>
+         </widget>
         </item>
        </layout>
       </item>
       <item>
-       <layout class="QHBoxLayout" name="horizontalLayout_3">
+       <layout class="QHBoxLayout" name="horizontalLayout">
         <item>
          <spacer name="horizontalSpacer">
           <property name="orientation">
@@ -194,6 +183,13 @@
    </item>
   </layout>
  </widget>
+ <customwidgets>
+  <customwidget>
+   <class>BitcoinAmountField</class>
+   <extends>QSpinBox</extends>
+   <header>bitcoinamountfield.h</header>
+  </customwidget>
+ </customwidgets>
  <resources/>
  <connections>
   <connection>
diff --git a/src/qt/guiconstants.h b/src/qt/guiconstants.h
index 54e9d644fe..6f6fa7f261 100644
--- a/src/qt/guiconstants.h
+++ b/src/qt/guiconstants.h
@@ -25,4 +25,10 @@ static const int STATUSBAR_ICONSIZE = 16;
  */
 static const int TOOLTIP_WRAP_THRESHOLD = 80;
 
+/* Maximum allowed URI length */
+static const int MAX_URI_LENGTH = 255;
+
+/* QRCodeDialog -- size of exported QR Code image */
+#define EXPORT_IMAGE_SIZE 256
+
 #endif // GUICONSTANTS_H
diff --git a/src/qt/qrcodedialog.cpp b/src/qt/qrcodedialog.cpp
index 32e5462cee..ca94975128 100644
--- a/src/qt/qrcodedialog.cpp
+++ b/src/qt/qrcodedialog.cpp
@@ -1,28 +1,34 @@
 #include "qrcodedialog.h"
 #include "ui_qrcodedialog.h"
+
+#include "bitcoinunits.h"
+#include "guiconstants.h"
 #include "guiutil.h"
+#include "optionsmodel.h"
 
 #include <QPixmap>
 #include <QUrl>
-#include <QDebug>
 
 #include <qrencode.h>
 
-#define EXPORT_IMAGE_SIZE 256
-
 QRCodeDialog::QRCodeDialog(const QString &addr, const QString &label, bool enableReq, QWidget *parent) :
-    QDialog(parent), ui(new Ui::QRCodeDialog), address(addr)
+    QDialog(parent),
+    ui(new Ui::QRCodeDialog),
+    model(0),
+    address(addr)
 {
     ui->setupUi(this);
+
     setWindowTitle(QString("%1").arg(address));
 
     ui->chkReqPayment->setVisible(enableReq);
-    ui->lnReqAmount->setVisible(enableReq);
     ui->lblAmount->setVisible(enableReq);
-    ui->lblBTC->setVisible(enableReq);
+    ui->lnReqAmount->setVisible(enableReq);
 
     ui->lnLabel->setText(label);
 
+    ui->btnSaveAs->setEnabled(false);
+
     genCode();
 }
 
@@ -31,6 +37,17 @@ QRCodeDialog::~QRCodeDialog()
     delete ui;
 }
 
+void QRCodeDialog::setModel(OptionsModel *model)
+{
+    this->model = model;
+
+    if (model)
+        connect(model, SIGNAL(displayUnitChanged(int)), this, SLOT(updateDisplayUnit()));
+
+    // update the display unit, to not use the default ("BTC")
+    updateDisplayUnit();
+}
+
 void QRCodeDialog::genCode()
 {
     QString uri = getURI();
@@ -57,26 +74,34 @@ void QRCodeDialog::genCode()
             }
         }
         QRcode_free(code);
+
         ui->lblQRCode->setPixmap(QPixmap::fromImage(myImage).scaled(300, 300));
+
+        ui->outUri->setPlainText(uri);
     }
-    else
-        ui->lblQRCode->setText(tr("Resulting URI too long, try to reduce the text for label / message."));
 }
 
 QString QRCodeDialog::getURI()
 {
     QString ret = QString("bitcoin:%1").arg(address);
-
     int paramCount = 0;
-    if (ui->chkReqPayment->isChecked() && !ui->lnReqAmount->text().isEmpty())
+
+    ui->outUri->clear();
+
+    if (ui->chkReqPayment->isChecked())
     {
-        bool ok = false;
-        ui->lnReqAmount->text().toDouble(&ok);
-        if (ok)
+        if (ui->lnReqAmount->validate())
         {
-            ret += QString("?amount=%1").arg(ui->lnReqAmount->text());
+            // even if we allow a non BTC unit input in lnReqAmount, we generate the URI with BTC as unit (as defined in BIP21)
+            ret += QString("?amount=%1").arg(BitcoinUnits::format(BitcoinUnits::BTC, ui->lnReqAmount->value()));
             paramCount++;
         }
+        else
+        {
+            ui->btnSaveAs->setEnabled(false);
+            ui->lblQRCode->setText(tr("The entered amount is invalid, please check."));
+            return QString("");
+        }
     }
 
     if (!ui->lnLabel->text().isEmpty())
@@ -93,24 +118,29 @@ QString QRCodeDialog::getURI()
         paramCount++;
     }
 
-    // limit URI length to 255 chars, to prevent a DoS against the QR-Code dialog
-    if (ret.length() < 256)
-        return ret;
-    else
+    // limit URI length to prevent a DoS against the QR-Code dialog
+    if (ret.length() > MAX_URI_LENGTH)
+    {
+        ui->btnSaveAs->setEnabled(false);
+        ui->lblQRCode->setText(tr("Resulting URI too long, try to reduce the text for label / message."));
         return QString("");
+    }
+
+    ui->btnSaveAs->setEnabled(true);
+    return ret;
 }
 
-void QRCodeDialog::on_lnReqAmount_textChanged(const QString &arg1)
+void QRCodeDialog::on_lnReqAmount_textChanged()
 {
     genCode();
 }
 
-void QRCodeDialog::on_lnLabel_textChanged(const QString &arg1)
+void QRCodeDialog::on_lnLabel_textChanged()
 {
     genCode();
 }
 
-void QRCodeDialog::on_lnMessage_textChanged(const QString &arg1)
+void QRCodeDialog::on_lnMessage_textChanged()
 {
     genCode();
 }
@@ -122,7 +152,20 @@ void QRCodeDialog::on_btnSaveAs_clicked()
         myImage.scaled(EXPORT_IMAGE_SIZE, EXPORT_IMAGE_SIZE).save(fn);
 }
 
-void QRCodeDialog::on_chkReqPayment_toggled(bool)
+void QRCodeDialog::on_chkReqPayment_toggled(bool fChecked)
 {
+    if (!fChecked)
+        // if chkReqPayment is not active, don't display lnReqAmount as invalid
+        ui->lnReqAmount->setValid(true);
+
     genCode();
 }
+
+void QRCodeDialog::updateDisplayUnit()
+{
+    if (model)
+    {
+        // Update lnReqAmount with the current unit
+        ui->lnReqAmount->setDisplayUnit(model->getDisplayUnit());
+    }
+}
diff --git a/src/qt/qrcodedialog.h b/src/qt/qrcodedialog.h
index ad0611605b..c55c34bce6 100644
--- a/src/qt/qrcodedialog.h
+++ b/src/qt/qrcodedialog.h
@@ -7,6 +7,7 @@
 namespace Ui {
     class QRCodeDialog;
 }
+class OptionsModel;
 
 class QRCodeDialog : public QDialog
 {
@@ -16,22 +17,25 @@ public:
     explicit QRCodeDialog(const QString &addr, const QString &label, bool enableReq, QWidget *parent = 0);
     ~QRCodeDialog();
 
+    void setModel(OptionsModel *model);
+
 private slots:
-    void on_lnReqAmount_textChanged(const QString &arg1);
-    void on_lnLabel_textChanged(const QString &arg1);
-    void on_lnMessage_textChanged(const QString &arg1);
+    void on_lnReqAmount_textChanged();
+    void on_lnLabel_textChanged();
+    void on_lnMessage_textChanged();
     void on_btnSaveAs_clicked();
+    void on_chkReqPayment_toggled(bool fChecked);
 
-    void on_chkReqPayment_toggled(bool checked);
+    void updateDisplayUnit();
 
 private:
     Ui::QRCodeDialog *ui;
-    QImage myImage;
-
-    QString getURI();
+    OptionsModel *model;
     QString address;
+    QImage myImage;
 
     void genCode();
+    QString getURI();
 };
 
 #endif // QRCODEDIALOG_H