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

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());
+    }
+}