Refactor & simplify fee service.

core/src/main/java/bisq/core/api/CoreApi.java

@@ -413,17 +413,12 @@ public boolean verifyBsqSentToAddress(String address, String amount) {
         return walletsService.verifyBsqSentToAddress(address, amount);
     }
 
-    public void getTxFeeRate(ResultHandler resultHandler) {
-        walletsService.getTxFeeRate(resultHandler);
+    public void setTxFeeRatePreference(long txFeeRate   ) {
+        walletsService.setTxFeeRatePreference(txFeeRate);
     }
 
-    public void setTxFeeRatePreference(long txFeeRate,
-                                       ResultHandler resultHandler) {
-        walletsService.setTxFeeRatePreference(txFeeRate, resultHandler);
-    }
-
-    public void unsetTxFeeRatePreference(ResultHandler resultHandler) {
-        walletsService.unsetTxFeeRatePreference(resultHandler);
+    public void unsetTxFeeRatePreference() {
+        walletsService.unsetTxFeeRatePreference();
     }
 
     public TxFeeRateInfo getMostRecentTxFeeRateInfo() {

core/src/main/java/bisq/core/api/CoreWalletsService.java

@@ -362,33 +362,7 @@ boolean verifyBsqSentToAddress(String address, String amount) {
         return numMatches > 0;
     }
 
-    void getTxFeeRate(ResultHandler resultHandler) {
-        try {
-            @SuppressWarnings({"unchecked", "Convert2MethodRef"})
-            ListenableFuture<Void> future =
-                    (ListenableFuture<Void>) executor.submit(() -> feeService.requestFees());
-            //noinspection NullableProblems
-            Futures.addCallback(future, new FutureCallback<>() {
-                @Override
-                public void onSuccess(@Nullable Void ignored) {
-                    resultHandler.handleResult();
-                }
-
-                @Override
-                public void onFailure(Throwable t) {
-                    log.error("", t);
-                    throw new IllegalStateException("could not request fees from fee service", t);
-                }
-            }, MoreExecutors.directExecutor());
-
-        } catch (Exception ex) {
-            log.error(ex.toString());
-            throw new IllegalStateException("could not request fees from fee service", ex);
-        }
-    }
-
-    void setTxFeeRatePreference(long txFeeRate,
-                                ResultHandler resultHandler) {
+    void setTxFeeRatePreference(long txFeeRate) {
         long minFeePerVbyte = feeService.getMinFeePerVByte();
         if (txFeeRate < minFeePerVbyte)
             throw new IllegalArgumentException(
@@ -397,12 +371,10 @@ void setTxFeeRatePreference(long txFeeRate,
         preferences.setUseCustomWithdrawalTxFee(true);
         Coin satsPerByte = Coin.valueOf(txFeeRate);
         preferences.setWithdrawalTxFeeInVbytes(satsPerByte.value);
-        getTxFeeRate(resultHandler);
     }
 
-    void unsetTxFeeRatePreference(ResultHandler resultHandler) {
+    void unsetTxFeeRatePreference() {
         preferences.setUseCustomWithdrawalTxFee(false);
-        getTxFeeRate(resultHandler);
     }
 
     TxFeeRateInfo getMostRecentTxFeeRateInfo() {

core/src/main/java/bisq/core/btc/BitcoinModule.java

@@ -27,7 +27,6 @@
 import bisq.core.btc.wallet.NonBsqCoinSelector;
 import bisq.core.btc.wallet.TradeWalletService;
 import bisq.core.provider.ProvidersRepository;
-import bisq.core.provider.fee.FeeProvider;
 import bisq.core.provider.fee.FeeService;
 import bisq.core.provider.price.PriceFeedService;
 
@@ -95,7 +94,6 @@ protected void configure() {
         bind(Balances.class).in(Singleton.class);
 
         bind(ProvidersRepository.class).in(Singleton.class);
-        bind(FeeProvider.class).in(Singleton.class);
         bind(PriceFeedService.class).in(Singleton.class);
         bind(FeeService.class).in(Singleton.class);
         bind(TxFeeEstimationService.class).in(Singleton.class);

core/src/main/java/bisq/core/offer/bisq_v1/TakeOfferModel.java

@@ -165,13 +165,7 @@ private void calculateTxFees() {
     }
 
     private Coin getTxFeePerVbyte() {
-        try {
-            CompletableFuture<Void> feeRequestFuture = CompletableFuture.runAsync(feeService::requestFees);
-            feeRequestFuture.get();  // Block until async fee request is complete.
-            return feeService.getTxFeePerVbyte();
-        } catch (InterruptedException | ExecutionException e) {
-            throw new IllegalStateException("Could not request fees from fee service.", e);
-        }
+        return feeService.getTxFeePerVbyte();
     }
 
     private void calculateTotalToPay() {

core/src/main/java/bisq/core/offer/bsq_swap/BsqSwapOfferModel.java

@@ -395,11 +395,9 @@ private void applyTxFeePerVbyte() {
         // We only set the txFeePerVbyte at start, otherwise we might get diff. required amounts while user has view open
         txFeePerVbyte = feeService.getTxFeePerVbyte().getValue();
         resetTxFeeAndMissingFunds();
-        feeService.requestFees(() -> {
-            txFeePerVbyte = feeService.getTxFeePerVbyte().getValue();
-            calculateInputAndPayout();
-            resetTxFeeAndMissingFunds();
-        });
+        txFeePerVbyte = feeService.getTxFeePerVbyte().getValue();
+        calculateInputAndPayout();
+        resetTxFeeAndMissingFunds();
     }
 
     private void resetTxFeeAndMissingFunds() {