Support for fee rate below 1sat/vb

src/main/java/com/sparrowwallet/sparrow/AppServices.java

@@ -87,8 +87,8 @@ public class AppServices {
     private static final String TOR_DEFAULT_PROXY_CIRCUIT_ID = "default";
 
     public static final List<Integer> TARGET_BLOCKS_RANGE = List.of(1, 2, 3, 4, 5, 10, 25, 50);
-    public static final List<Long> LONG_FEE_RATES_RANGE = List.of(1L, 2L, 4L, 8L, 16L, 32L, 64L, 128L, 256L, 512L, 1024L, 2048L, 4096L, 8192L);
+    public static final List<Double> DOUBLE_FEE_RATES_RANGE = List.of(0.01D, 0.02D, 0.04D, 0.08D, 0.1D, 0.2D, 0.4D, 0.8D, 1D, 2D, 4D, 8D, 16D, 32D, 64D, 128D, 256D, 512D, 1024D, 2048D, 4096D, 8192D);
-    public static final List<Long> FEE_RATES_RANGE = LONG_FEE_RATES_RANGE.subList(0, LONG_FEE_RATES_RANGE.size() - 3);
+    public static final List<Double> FEE_RATES_RANGE = DOUBLE_FEE_RATES_RANGE.subList(0, DOUBLE_FEE_RATES_RANGE.size() - 9);
     public static final double FALLBACK_FEE_RATE = 20000d / 1000;
     public static final double TESTNET_FALLBACK_FEE_RATE = 1000d / 1000;
 

src/main/java/com/sparrowwallet/sparrow/control/FeeRangeSlider.java

@@ -1,17 +1,25 @@
 package com.sparrowwallet.sparrow.control;
 
+import static com.sparrowwallet.sparrow.AppServices.DOUBLE_FEE_RATES_RANGE;
+import static com.sparrowwallet.sparrow.AppServices.FEE_RATES_RANGE;
+import static com.sparrowwallet.sparrow.AppServices.TARGET_BLOCKS_RANGE;
+import static com.sparrowwallet.sparrow.AppServices.getFallbackFeeRate;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
 import com.sparrowwallet.sparrow.AppServices;
 import com.sparrowwallet.sparrow.net.FeeRatesSource;
+
 import javafx.application.Platform;
 import javafx.scene.Node;
 import javafx.scene.control.Slider;
 import javafx.util.StringConverter;
 
-import java.util.*;
-import java.util.stream.Collectors;
-
-import static com.sparrowwallet.sparrow.AppServices.*;
-
 public class FeeRangeSlider extends Slider {
     private static final double FEE_RATE_SCROLL_INCREMENT = 0.01;
 
@@ -27,11 +35,11 @@ public class FeeRangeSlider extends Slider {
         setLabelFormatter(new StringConverter<>() {
             @Override
             public String toString(Double object) {
-                Long feeRate = LONG_FEE_RATES_RANGE.get(object.intValue());
+                Double feeRate = DOUBLE_FEE_RATES_RANGE.get(object.intValue());
-                if(isLongFeeRange() && feeRate >= 1000) {
+                if(isDoubleFeeRange() && feeRate >= 1000) {
                     return feeRate / 1000 + "k";
                 }
-                return Long.toString(feeRate);
+                return feeRate < 1 ? Double.toString(feeRate) : String.format("%.0f", feeRate);
             }
 
             @Override
@@ -51,10 +59,10 @@ public class FeeRangeSlider extends Slider {
         setOnScroll(event -> {
             if(event.getDeltaY() != 0) {
                 double newFeeRate = getFeeRate() + (event.getDeltaY() > 0 ? FEE_RATE_SCROLL_INCREMENT : -FEE_RATE_SCROLL_INCREMENT);
-                if(newFeeRate < LONG_FEE_RATES_RANGE.get(0)) {
+                if(newFeeRate < DOUBLE_FEE_RATES_RANGE.get(0)) {
-                    newFeeRate = LONG_FEE_RATES_RANGE.get(0);
+                    newFeeRate = DOUBLE_FEE_RATES_RANGE.get(0);
-                } else if(newFeeRate > LONG_FEE_RATES_RANGE.get(LONG_FEE_RATES_RANGE.size() - 1)) {
+                } else if(newFeeRate > DOUBLE_FEE_RATES_RANGE.get(DOUBLE_FEE_RATES_RANGE.size() - 1)) {
-                    newFeeRate = LONG_FEE_RATES_RANGE.get(LONG_FEE_RATES_RANGE.size() - 1);
+                    newFeeRate = DOUBLE_FEE_RATES_RANGE.get(DOUBLE_FEE_RATES_RANGE.size() - 1);
                 }
                 setFeeRate(newFeeRate);
             }
@@ -62,7 +70,17 @@ public class FeeRangeSlider extends Slider {
     }
 
     public double getFeeRate() {
-        return Math.pow(2.0, getValue());
+        double value = getValue();
+        // First range: 0.01, 0.02, 0.04, 0.08 and smooth values in between
+        if(value < 3) return 0.01 * Math.pow(2, value);
+        // Transition from 0.08 to 0.1 (smoothly, using factor 1.25)
+        if(value < 4) return 0.08 * Math.pow(1.25, value - 3);
+        // Second binary range: 0.1, 0.2, 0.4, 0.8 and smooth values in between
+        if(value < 7) return 0.1 * Math.pow(2, value - 4);
+        // Transition from 0.8 to 1.0 (smoothly, using factor 1.25)
+        if(value < 8) return 0.8 * Math.pow(1.25, value - 7);
+        // Third binary range: 1, 2, 4, 8, ... and smooth values in between
+        return Math.pow(2, value - 8);
     }
 
     public void setFeeRate(double feeRate) {
@@ -72,16 +90,18 @@ public class FeeRangeSlider extends Slider {
     }
 
     private void updateMaxFeeRange(double value) {
-        if(value >= getMax() && !isLongFeeRange()) {
+        if(value >= getMax() && !isDoubleFeeRange()) {
-            setMax(LONG_FEE_RATES_RANGE.size() - 1);
+            setMin(FEE_RATES_RANGE.size() - 2);
+            setMax(DOUBLE_FEE_RATES_RANGE.size() - 1);
             updateTrackHighlight();
-        } else if(value == getMin() && isLongFeeRange()) {
+        } else if(value == getMin() && isDoubleFeeRange()) {
+            setMin(0);
             setMax(FEE_RATES_RANGE.size() - 1);
             updateTrackHighlight();
         }
     }
 
-    private boolean isLongFeeRange() {
+    private boolean isDoubleFeeRange() {
         return getMax() > FEE_RATES_RANGE.size() - 1;
     }
 
@@ -138,8 +158,8 @@ public class FeeRangeSlider extends Slider {
 
     private int getPercentageOfFeeRange(Double feeRate) {
         double index = Math.log(feeRate) / Math.log(2);
-        if(isLongFeeRange()) {
+        if(isDoubleFeeRange()) {
-            index *= ((double)FEE_RATES_RANGE.size() / (LONG_FEE_RATES_RANGE.size())) * 0.99;
+            index *= ((double)FEE_RATES_RANGE.size() / (DOUBLE_FEE_RATES_RANGE.size())) * 0.99;
         }
         return (int)Math.round(index * 10.0);
     }

src/main/java/com/sparrowwallet/sparrow/transaction/HeadersController.java

@@ -1139,7 +1139,7 @@ public class HeadersController extends TransactionFormController implements Init
 
         if(fee.getValue() > 0) {
             double feeRateAmt = fee.getValue() / headersForm.getTransaction().getVirtualSize();
-            if(feeRateAmt > AppServices.LONG_FEE_RATES_RANGE.get(AppServices.LONG_FEE_RATES_RANGE.size() - 1)) {
+            if(feeRateAmt > AppServices.DOUBLE_FEE_RATES_RANGE.get(AppServices.DOUBLE_FEE_RATES_RANGE.size() - 1)) {
                 Optional<ButtonType> optType = AppServices.showWarningDialog("Very high fee rate!",
                         "This transaction pays a very high fee rate of " + String.format("%.0f", feeRateAmt) + " sats/vB.\n\nBroadcast this transaction?", ButtonType.YES, ButtonType.NO);
                 if(optType.isPresent() && optType.get() == ButtonType.NO) {

src/main/java/com/sparrowwallet/sparrow/wallet/SendController.java

@@ -900,13 +900,13 @@ public class SendController extends WalletFormController implements Initializabl
     }
 
     private void setFeeRatePriority(Double feeRateAmt) {
+        feeRateAmt = Math.round(feeRateAmt * 100.0) / 100.0; // Round to 2 decimal places
         Map<Integer, Double> targetBlocksFeeRates = getTargetBlocksFeeRates();
-        Integer targetBlocks = getTargetBlocks(feeRateAmt);
         if(targetBlocksFeeRates.get(Integer.MAX_VALUE) != null) {
             Double minFeeRate = targetBlocksFeeRates.get(Integer.MAX_VALUE);
-            if(minFeeRate > 1.0 && feeRateAmt < minFeeRate) {
+            if(feeRateAmt > 0.01 && feeRateAmt < minFeeRate) {
                 feeRatePriority.setText("Below Minimum");
-                feeRatePriority.setTooltip(new Tooltip("Transactions at this fee rate are currently being purged from the default sized mempool"));
+                feeRatePriority.setTooltip(new Tooltip("Transactions at this fee rate can be purged from the default sized mempool"));
                 feeRatePriorityGlyph.setStyle("-fx-text-fill: #a0a1a7cc");
                 feeRatePriorityGlyph.setIcon(FontAwesome5.Glyph.EXCLAMATION_CIRCLE);
                 return;
@@ -922,6 +922,7 @@ public class SendController extends WalletFormController implements Initializabl
             }
         }
 
+        Integer targetBlocks = getTargetBlocks(feeRateAmt);
         if(targetBlocks != null) {
             if(targetBlocks < FeeRatesSource.BLOCKS_IN_HALF_HOUR) {
                 Double maxFeeRate = FEE_RATES_RANGE.get(FEE_RATES_RANGE.size() - 1).doubleValue();