Merge pull request #110 from cake-tech/CAKE-296-remove-xmr-to-xrp-and-xmr-to-xlm-exchange-pairs

Cake 296 remove xmr to xrp and xmr to xlm exchange pairs

lib/src/screens/exchange/exchange_page.dart

@@ -248,7 +248,8 @@ class ExchangePage extends BasePage {
                                   exchangeViewModel
                                       .isReceiveAddressEnabled,
                                   isAmountEstimated: true,
-                                  currencies: CryptoCurrency.all,
+                                  currencies:
+                                    exchangeViewModel.receiveCurrencies,
                                   onCurrencySelected: (currency) =>
                                       exchangeViewModel
                                           .changeReceiveCurrency(

lib/view_model/exchange/exchange_view_model.dart

@@ -57,6 +57,9 @@ abstract class ExchangeViewModelBase with Store {
         _onPairChange();
       }
     });
+    receiveCurrencies = CryptoCurrency.all.where((cryptoCurrency) =>
+      (cryptoCurrency != CryptoCurrency.xlm)&&
+      (cryptoCurrency != CryptoCurrency.xrp)).toList();
     _defineIsReceiveAmountEditable();
     isFixedRateMode = false;
     isReceiveAmountEntered = false;
@@ -123,6 +126,8 @@ abstract class ExchangeViewModelBase with Store {
   bool get hasAllAmount =>
       wallet.type == WalletType.bitcoin && depositCurrency == wallet.currency;
 
+  List<CryptoCurrency> receiveCurrencies;
+
   Limits limits;
 
   NumberFormat _cryptoNumberFormat;
@@ -369,19 +374,17 @@ abstract class ExchangeViewModelBase with Store {
             pair.from == depositCurrency && pair.to == receiveCurrency)
         .isNotEmpty;
 
-    if (!isPairExist) {
+    if (isPairExist) {
       final provider =
           _providerForPair(from: depositCurrency, to: receiveCurrency);
 
       if (provider != null) {
         changeProvider(provider: provider);
       }
+    } else {
+      depositAmount = '';
+      receiveAmount = '';
     }
-
-    _defineIsReceiveAmountEditable();
-    depositAmount = '';
-    receiveAmount = '';
-    loadLimits();
   }
 
   ExchangeProvider _providerForPair({CryptoCurrency from, CryptoCurrency to}) {