[Qt] overhaul smart-fee slider, adjust default confirmation target

src/qt/forms/sendcoinsdialog.ui

@@ -1031,7 +1031,7 @@
                    <item>
                     <widget class="QLabel" name="labelSmartFee3">
                      <property name="text">
-                      <string>Confirmation time:</string>
+                      <string>Confirmation time target:</string>
                      </property>
                      <property name="margin">
                       <number>2</number>
@@ -1095,6 +1095,26 @@
                        </property>
                       </widget>
                      </item>
+                     <item>
+                      <spacer name="horizontalSpacer_7">
+                       <property name="orientation">
+                        <enum>Qt::Horizontal</enum>
+                       </property>
+                       <property name="sizeHint" stdset="0">
+                        <size>
+                         <width>40</width>
+                         <height>20</height>
+                        </size>
+                       </property>
+                      </spacer>
+                     </item>
+                     <item>
+                      <widget class="QLabel" name="confirmationTargetLabel">
+                       <property name="text">
+                        <string>(count)</string>
+                       </property>
+                      </widget>
+                     </item>
                      <item>
                       <spacer name="horizontalSpacer_3">
                        <property name="orientation">

src/qt/sendcoinsdialog.cpp

@@ -110,7 +110,6 @@ SendCoinsDialog::SendCoinsDialog(const PlatformStyle *_platformStyle, QWidget *p
     ui->groupCustomFee->setId(ui->radioCustomPerKilobyte, 0);
     ui->groupCustomFee->setId(ui->radioCustomAtLeast, 1);
     ui->groupCustomFee->button((int)std::max(0, std::min(1, settings.value("nCustomFeeRadio").toInt())))->setChecked(true);
-    ui->sliderSmartFee->setValue(settings.value("nSmartFeeSliderPosition").toInt());
     ui->customFee->setValue(settings.value("nTransactionFee").toLongLong());
     ui->checkBoxMinimumFee->setChecked(settings.value("fPayOnlyMinFee").toBool());
     minimizeFeeSection(settings.value("fFeeSectionMinimized").toBool());
@@ -172,6 +171,13 @@ void SendCoinsDialog::setModel(WalletModel *_model)
         updateMinFeeLabel();
         updateSmartFeeLabel();
         updateGlobalFeeVariables();
+
+        // set the smartfee-sliders default value (wallets default conf.target or last stored value)
+        QSettings settings;
+        if (settings.value("nSmartFeeSliderPosition").toInt() == 0)
+            ui->sliderSmartFee->setValue(ui->sliderSmartFee->maximum() - model->getDefaultConfirmTarget() + 1);
+        else
+            ui->sliderSmartFee->setValue(settings.value("nSmartFeeSliderPosition").toInt());
     }
 }
 
@@ -229,10 +235,17 @@ void SendCoinsDialog::on_sendButton_clicked()
     // prepare transaction for getting txFee earlier
     WalletModelTransaction currentTransaction(recipients);
     WalletModel::SendCoinsReturn prepareStatus;
-    if (model->getOptionsModel()->getCoinControlFeatures()) // coin control enabled
-        prepareStatus = model->prepareTransaction(currentTransaction, CoinControlDialog::coinControl);
+
+    // Always use a CCoinControl instance, use the CoinControlDialog instance if CoinControl has been enabled
+    CCoinControl ctrl;
+    if (model->getOptionsModel()->getCoinControlFeatures())
+        ctrl = *CoinControlDialog::coinControl;
+    if (ui->radioSmartFee->isChecked())
+        ctrl.nConfirmTarget = ui->sliderSmartFee->maximum() - ui->sliderSmartFee->value() + 1;
     else
-        prepareStatus = model->prepareTransaction(currentTransaction);
+        ctrl.nConfirmTarget = 0;
+
+    prepareStatus = model->prepareTransaction(currentTransaction, &ctrl);
 
     // process prepareStatus and on error generate message shown to user
     processSendCoinsReturn(prepareStatus,
@@ -576,6 +589,7 @@ void SendCoinsDialog::updateFeeSectionControls()
     ui->labelFeeEstimation      ->setEnabled(ui->radioSmartFee->isChecked());
     ui->labelSmartFeeNormal     ->setEnabled(ui->radioSmartFee->isChecked());
     ui->labelSmartFeeFast       ->setEnabled(ui->radioSmartFee->isChecked());
+    ui->confirmationTargetLabel ->setEnabled(ui->radioSmartFee->isChecked());
     ui->checkBoxMinimumFee      ->setEnabled(ui->radioCustomFee->isChecked());
     ui->labelMinFeeWarning      ->setEnabled(ui->radioCustomFee->isChecked());
     ui->radioCustomPerKilobyte  ->setEnabled(ui->radioCustomFee->isChecked() && !ui->checkBoxMinimumFee->isChecked());
@@ -587,15 +601,17 @@ void SendCoinsDialog::updateGlobalFeeVariables()
 {
     if (ui->radioSmartFee->isChecked())
     {
-        nTxConfirmTarget = defaultConfirmTarget - ui->sliderSmartFee->value();
+        int nConfirmTarget = ui->sliderSmartFee->maximum() - ui->sliderSmartFee->value() + 1;
         payTxFee = CFeeRate(0);
 
         // set nMinimumTotalFee to 0 to not accidentally pay a custom fee
         CoinControlDialog::coinControl->nMinimumTotalFee = 0;
+
+        // show the estimated reuquired time for confirmation
+        ui->confirmationTargetLabel->setText(GUIUtil::formatDurationStr(nConfirmTarget*600)+" / "+tr("%n block(s)", "", nConfirmTarget));
     }
     else
     {
-        nTxConfirmTarget = defaultConfirmTarget;
         payTxFee = CFeeRate(ui->customFee->value());
 
         // if user has selected to set a minimum absolute fee, pass the value to coincontrol
@@ -630,7 +646,7 @@ void SendCoinsDialog::updateSmartFeeLabel()
     if(!model || !model->getOptionsModel())
         return;
 
-    int nBlocksToConfirm = defaultConfirmTarget - ui->sliderSmartFee->value();
+    int nBlocksToConfirm = ui->sliderSmartFee->maximum() - ui->sliderSmartFee->value() + 1;
     int estimateFoundAtBlocks = nBlocksToConfirm;
     CFeeRate feeRate = mempool.estimateSmartFee(nBlocksToConfirm, &estimateFoundAtBlocks);
     if (feeRate <= CFeeRate(0)) // not enough data => minfee
@@ -701,6 +717,8 @@ void SendCoinsDialog::coinControlFeatureChanged(bool checked)
     if (!checked && model) // coin control features disabled
         CoinControlDialog::coinControl->SetNull();
 
+    // make sure we set back the confirmation target
+    updateGlobalFeeVariables();
     coinControlUpdateLabels();
 }
 

src/qt/sendcoinsdialog.h

@@ -26,8 +26,6 @@ QT_BEGIN_NAMESPACE
 class QUrl;
 QT_END_NAMESPACE
 
-const int defaultConfirmTarget = 25;
-
 /** Dialog for sending bitcoins */
 class SendCoinsDialog : public QDialog
 {