fix(@desktop/wallet): fixing crash on switching testnet model from on to off

src/app/modules/main/wallet_section/all_tokens/flat_tokens_model.nim

@@ -128,12 +128,9 @@ QtObject:
       of ModelRole.MarketDetailsLoading:
         result = newQVariant(self.delegate.getTokensMarketValuesLoading())
 
-
-  proc modelsAboutToUpdate*(self: FlatTokensModel) =
-    self.tokenMarketDetails = @[]
-    self.beginResetModel()
-
   proc modelsUpdated*(self: FlatTokensModel) =
+    self.beginResetModel()
+    self.tokenMarketDetails = @[]
     for token in self.delegate.getFlatTokensList():
       let symbol = if token.communityId.isEmptyOrWhitespace: token.symbol
                    else: ""

src/app/modules/main/wallet_section/all_tokens/module.nim

@@ -49,8 +49,6 @@ method load*(self: Module) =
     self.controller.rebuildMarketData()
 
   # Passing on the events for changes in model to abstract model
-  self.events.on(SIGNAL_TOKENS_LIST_ABOUT_TO_BE_UPDATED) do(e: Args):
-    self.view.modelsAboutToUpdate()
   self.events.on(SIGNAL_TOKENS_LIST_UPDATED) do(e: Args):
     self.view.modelsUpdated()
     self.view.setTokenListUpdatedAt(self.controller.getTokenListUpdatedAt())

src/app/modules/main/wallet_section/all_tokens/sources_of_tokens_model.nim

@@ -69,8 +69,6 @@ QtObject:
       of ModelRole.TokensCount:
         result = newQVariant(item.tokensCount)
 
-  proc modelsAboutToUpdate*(self: SourcesOfTokensModel) =
-      self.beginResetModel()
-
   proc modelsUpdated*(self: SourcesOfTokensModel) =
+      self.beginResetModel()
       self.endResetModel()

src/app/modules/main/wallet_section/all_tokens/token_by_symbol_model.nim

@@ -128,12 +128,10 @@ QtObject:
       of ModelRole.MarketDetailsLoading:
         result = newQVariant(self.delegate.getTokensMarketValuesLoading())
 
-  proc modelsAboutToUpdate*(self: TokensBySymbolModel) =
+  proc modelsUpdated*(self: TokensBySymbolModel) =
+    self.beginResetModel()
     self.tokenMarketDetails = @[]
     self.addressPerChainModel = @[]
-    self.beginResetModel()
-
-  proc modelsUpdated*(self: TokensBySymbolModel) =
     let tokensList = self.delegate.getTokenBySymbolList()
     for index in countup(0, tokensList.len-1):
       self.addressPerChainModel.add(newAddressPerChainModel(self.delegate, index))

src/app/modules/main/wallet_section/all_tokens/view.nim

@@ -116,11 +116,6 @@ QtObject:
     read = getTokensBySymbolModel
     notify = tokensBySymbolModelChanged
 
-  proc modelsAboutToUpdate*(self: View) =
-    self.sourcesOfTokensModel.modelsAboutToUpdate()
-    self.flatTokensModel.modelsAboutToUpdate()
-    self.tokensBySymbolModel.modelsAboutToUpdate()
-
   proc modelsUpdated*(self: View) =
     self.sourcesOfTokensModel.modelsUpdated()
     self.flatTokensModel.modelsUpdated()

src/app/modules/main/wallet_section/assets/grouped_account_assets_model.nim

@@ -58,17 +58,18 @@ QtObject:
     of ModelRole.Balances:
       result = newQVariant(self.balancesPerChain[index.row])
 
-  proc modelsAboutToUpdate*(self: Model) =
-    self.beginResetModel()
-
   proc modelsUpdated*(self: Model) =
+    self.beginResetModel()
     let lengthOfGroupedAssets = self.delegate.getGroupedAccountsAssetsList().len
     let balancesPerChainLen = self.balancesPerChain.len
     let diff = abs(lengthOfGroupedAssets - balancesPerChainLen)
+    # Please note that in case more tokens are added either due to refresh or adding of new accounts
+    # new entries to fetch balances data are created.
+    # On the other hand we are not deleting in case the assets disappear either on refresh
+    # as there is no balance or accounts were deleted because it causes a crash on UI.
+    # Also this will automatically be removed on the next time app is restarted
     if lengthOfGroupedAssets > balancesPerChainLen:
       for i in countup(0, diff-1):
         self.balancesPerChain.add(newBalancesModel(self.delegate, balancesPerChainLen+i))
-    elif lengthOfGroupedAssets <  balancesPerChainLen:
-      self.balancesPerChain.delete(balancesPerChainLen - diff, balancesPerChainLen-1)
     self.endResetModel()
     self.countChanged()

src/app/modules/main/wallet_section/assets/module.nim

@@ -44,9 +44,6 @@ method delete*(self: Module) =
 method load*(self: Module) =
   singletonInstance.engine.setRootContextProperty("walletSectionAssets", newQVariant(self.view))
 
-  self.events.on(SIGNAL_WALLET_ACCOUNT_TOKENS_BEING_FETCHED) do(e:Args):
-    self.view.modelsAboutToUpdate()
-
   self.events.on(SIGNAL_WALLET_ACCOUNT_TOKENS_REBUILT) do(e:Args):
     self.view.modelsUpdated()
     self.view.setHasBalanceCache(self.controller.getHasBalanceCache())

src/app/modules/main/wallet_section/assets/view.nim

@@ -56,8 +56,5 @@ QtObject:
     self.hasMarketValuesCache = hasMarketValuesCache
     self.hasMarketValuesCacheChanged()
 
-  proc modelsAboutToUpdate*(self: View) =
-    self.groupedAccountAssetsModel.modelsAboutToUpdate()
-
   proc modelsUpdated*(self: View) =
     self.groupedAccountAssetsModel.modelsUpdated()

src/app_service/service/token/service.nim

@@ -33,7 +33,6 @@ const CRYPTO_SUB_UNITS_TO_FACTOR = {
 const SIGNAL_TOKEN_HISTORICAL_DATA_LOADED* = "tokenHistoricalDataLoaded"
 const SIGNAL_BALANCE_HISTORY_DATA_READY* = "tokenBalanceHistoryDataReady"
 const SIGNAL_TOKENS_LIST_UPDATED* = "tokensListUpdated"
-const SIGNAL_TOKENS_LIST_ABOUT_TO_BE_UPDATED* = "tokensListAboutToBeUpdated"
 const SIGNAL_TOKENS_DETAILS_ABOUT_TO_BE_UPDATED* = "tokensDetailsAboutToBeUpdated"
 const SIGNAL_TOKENS_DETAILS_UPDATED* = "tokensDetailsUpdated"
 const SIGNAL_TOKENS_MARKET_VALUES_ABOUT_TO_BE_UPDATED* = "tokensMarketValuesAboutToBeUpdated"
@@ -342,8 +341,6 @@ QtObject:
       error "error: ", errDesription
 
   proc getSupportedTokensList*(self: Service) =
-    # this is emited so that the models can know that an update is about to happen
-    self.events.emit(SIGNAL_TOKENS_LIST_ABOUT_TO_BE_UPDATED, Args())
     let arg = QObjectTaskArg(
       tptr: cast[ByteAddress](getSupportedTokenList),
       vptr: cast[ByteAddress](self.vptr),

src/app_service/service/wallet_account/service_token.nim

@@ -80,9 +80,6 @@ proc buildAllTokens*(self: Service, accounts: seq[string], store: bool) =
   for waddress in accounts:
     self.updateAssetsLoadingState(waddress, true)
 
-  # this is emited so that the models can know that an update is about to happen
-  self.events.emit(SIGNAL_WALLET_ACCOUNT_TOKENS_BEING_FETCHED, Args())
-
   let arg = BuildTokensTaskArg(
     tptr: cast[ByteAddress](prepareTokensTask),
     vptr: cast[ByteAddress](self.vptr),

src/app_service/service/wallet_account/signals_and_payloads.nim

@@ -13,7 +13,6 @@ const SIGNAL_WALLET_ACCOUNT_DELETED* = "walletAccount/accountDeleted"
 const SIGNAL_WALLET_ACCOUNT_UPDATED* = "walletAccount/walletAccountUpdated"
 const SIGNAL_WALLET_ACCOUNT_NETWORK_ENABLED_UPDATED* = "walletAccount/networkEnabledUpdated"
 const SIGNAL_WALLET_ACCOUNT_TOKENS_REBUILT* = "walletAccount/tokensRebuilt"
-const SIGNAL_WALLET_ACCOUNT_TOKENS_BEING_FETCHED* = "walletAccount/tokenFetching"
 const SIGNAL_WALLET_ACCOUNT_DERIVED_ADDRESSES_FETCHED* = "walletAccount/derivedAddressesFetched"
 const SIGNAL_WALLET_ACCOUNT_DERIVED_ADDRESSES_FROM_MNEMONIC_FETCHED* = "walletAccount/derivedAddressesFromMnemonicFetched"
 const SIGNAL_WALLET_ACCOUNT_ADDRESS_DETAILS_FETCHED* = "walletAccount/addressDetailsFetched"