GUI: improved wallet refresh stability

src/core.utils/UDataSources.pas

@@ -6,7 +6,9 @@ unit UDataSources;
 interface
 
 uses
-  Classes, SysUtils, UAccounts, UNode, UBlockchain, UCommon, UMemory, UConst, UCommon.Data, UCommon.Collections, Generics.Collections, Generics.Defaults, syncobjs;
+  Classes, SysUtils, UAccounts, UNode, UBlockchain, UCoreObjects,
+  UCommon, UMemory, UConst, UCommon.Data,
+  UCommon.Collections, Generics.Collections, Generics.Defaults, syncobjs;
 
 type
 
@@ -22,27 +24,28 @@ type
   { TAccountsDataSource }
 
   TAccountsDataSource = class(TAccountsDataSourceBase)
-    public type
-      TOverview = record
-        TotalPASC : UInt64;
-        TotalPASA : Cardinal;
-      end;
-    private
-      FLastKnownUserAccounts : TArray<TAccount>;
-      FKeys : TSortedHashSet<TAccountKey>;
     protected
-      FLastOverview : TOverview;
+      FKeys : TSortedHashSet<TAccountKey>;
       function GetFilterKeys : TArray<TAccountKey>;
       procedure SetFilterKeys (const AKeys : TArray<TAccountKey>);
     public
-      property Overview : TOverview read FLastOverview;
-      property LastFetchResult : TArray<TAccount> read FLastKnownUserAccounts;
       property FilterKeys : TArray<TAccountKey> read GetFilterKeys write SetFilterKeys;
       constructor Create(AOwner: TComponent); override;
       destructor Destroy; override;
       procedure FetchAll(const AContainer : TList<TAccount>); override;
   end;
 
+  { TFastAccountsDataSource }
+
+  TFastAccountsDataSource = class(TAccountsDataSource)
+    private
+      FPSummary : PUserSummary;
+    public
+      property Summary : PUserSummary read FPSummary write FPSummary;
+      constructor Create(AOwner: TComponent; APSummary : PUserSummary); overload;
+      procedure FetchAll(const AContainer : TList<TAccount>); override;
+  end;
+
   { TOperationsDataSourceBase }
 
   TOperationsDataSourceBase = class(TCustomDataSource<TOperationResume>)
@@ -91,7 +94,7 @@ type
 implementation
 
 uses
-  math, UCoreUtils, UWallet, UUserInterface, UTime;
+  math, UCoreUtils, UWallet, UTime;
 
 { TAccountsDataSourceBase }
 
@@ -169,44 +172,43 @@ end;
 
 procedure TAccountsDataSource.FetchAll(const AContainer : TList<TAccount>);
 var
-  i,j : integer;
+  i : integer;
   acc : TAccount;
   safeBox : TPCSafeBox;
-  GC : TDisposables;
-  left,right:TAccountKey;
 begin
-  FLastOverview.TotalPASC := 0;
-  FLastOverview.TotalPASA := 0;
-  safeBox := TUserInterface.Node.Bank.SafeBox;
+  safeBox := TNode.Node.Bank.SafeBox;
   safeBox.StartThreadSafe;
   try
    if FKeys.Count = 0 then
-     for i := 0 to safeBox.AccountsCount - 1 do begin
-       // Load all accounts
-       AContainer.Add(safeBox.Account(i));
-       FLastOverview.TotalPASC := FLastOverview.TotalPASC + acc.Balance;
-       inc(FLastOverview.TotalPASA);
-     end
-   else begin
-     // load key-matching accounts
-     for i := 0 to safeBox.AccountsCount - 1 do begin
+     for i := 0 to safeBox.AccountsCount - 1 do
+       AContainer.Add(safeBox.Account(i)) // Load all accounts
+   else
+     for i := 0 to safeBox.AccountsCount - 1 do begin // Load key-matching accounts
        acc := safeBox.Account(i);
-       if FKeys.Contains(acc.accountInfo.accountKey) then begin
-         AContainer.Add(acc);
-         FLastOverview.TotalPASC := FLastOverview.TotalPASC + acc.Balance;
-         inc(FLastOverview.TotalPASA);
-       end else begin
-         for left in FKeys do begin
-           right := acc.accountInfo.accountKey;
-
-         end;
-       end;
+       if FKeys.Contains(acc.accountInfo.accountKey) then
+         AContainer.Add(acc)
      end;
-   end;
   finally
    safeBox.EndThreadSave;
   end;
-  FLastKnownUserAccounts := AContainer.ToArray;
+end;
+
+{ TFastAccountsDataSource }
+
+constructor TFastAccountsDataSource.Create(AOwner: TComponent; APSummary : PUserSummary);
+begin
+  inherited Create(AOwner);
+  FPSummary := APSummary;
+end;
+
+procedure TFastAccountsDataSource.FetchAll(const AContainer : TList<TAccount>);
+var
+  i : integer;
+begin
+  if NOT Assigned(FPSummary) then exit;
+  for i := Low(FPSummary^.Accounts) to High(FPSummary^.Accounts) do
+    if FKeys.Contains(FPSummary^.Accounts[i].accountInfo.accountKey) then
+      AContainer.Add(FPSummary^.Accounts[i]);
 end;
 
 { TOperationsDataSourceBase }
@@ -283,7 +285,7 @@ begin
   else if ABindingName = 'BlockLocation' then
     Result := IIF(AItem.OpType <> CT_PseudoOp_Reward, Inttostr(AItem.Block) + '/' + Inttostr(AItem.NOpInsideBlock+1), Inttostr(AItem.Block))
   else if ABindingName = 'BlockLocationSortable' then
-    Result := UInt64(AItem.Block) * 4294967296 + UInt32(AItem.NOpInsideBlock)   // number pattern = [block][opindex]
+    Result := IIF(AItem.OpType <> CT_PseudoOp_Reward, UInt64(AItem.Block) * 4294967296 + UInt32(AItem.NOpInsideBlock), 0)  // number pattern = [block][opindex]
   else if ABindingName = 'Account' then
     Result := TAccountComp.AccountNumberToAccountTxtNumber(AItem.AffectedAccount)
   else if ABindingName = 'AccountNumber' then
@@ -352,7 +354,7 @@ begin
   node := TNode.Node;
   if Not Assigned(Node)
     then exit;
-  TUserInterface.Node.Bank.SafeBox.StartThreadSafe;
+  TNode.Node.Bank.SafeBox.StartThreadSafe;
   try
     accountBlockOps := GC.AddObject(TOperationsResumeList.Create ) as TOperationsResumeList;
     list := GC.AddObject( Classes.TList.Create ) as Classes.TList;
@@ -378,7 +380,7 @@ begin
         AContainer.Add(accountBlockOps[i]);
     end;
   finally
-   TUserInterface.Node.Bank.SafeBox.EndThreadSave;
+   TNode.Node.Bank.SafeBox.EndThreadSave;
   end;
 end;
 

src/gui/UCTRLWallet.pas

@@ -9,7 +9,7 @@ interface
 uses
   Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs, StdCtrls, Menus,
   ExtCtrls, PairSplitter, Buttons, UVisualGrid, UCommon.UI, Generics.Collections,
-  UAccounts, UDataSources, UNode, UWIZSendPASC, UWIZChangeKey;
+  UAccounts, UDataSources, UNode, UWIZSendPASC, UWIZChangeKey, UCoreObjects, UCoreUtils;
 
 type
 
@@ -17,7 +17,7 @@ type
 
   TCTRLWalletAccountsMode = (wamMyAccounts, wamFirstAccount);
   TCTRLWalletOperationsMode = (womSelectedAccounts, womAllAccounts);
-  TCTRLWalletOperationsHistory = (woh30Days, wohFullHistory);
+  TCTRLWalletOperationsHistory = (woh7Days, woh30Days, wohFullHistory);
 
   TCTRLWallet = class(TApplicationForm)
     cbAccounts: TComboBox;
@@ -65,20 +65,23 @@ type
     FOperationsHistory: TCTRLWalletOperationsHistory;
     FAccountsGrid: TVisualGrid;
     FOperationsGrid: TVisualGrid;
-    FAccountsDataSource: TAccountsDataSource;
+    FUserData : TUserSummary;
+    FAccountsDataSource: TFastAccountsDataSource;
     FOperationsDataSource: TAccountsOperationsDataSource;
     procedure SetAccountsMode(AMode: TCTRLWalletAccountsMode);
     procedure SetOperationsMode(AMode: TCTRLWalletOperationsMode);
     procedure SetOperationsHistory(AHistory: TCTRLWalletOperationsHistory);
+    procedure FetchUserData;
     procedure RefreshMyAccountsCombo;
-    function GetAccNoWithoutChecksum(constref ARow: variant): cardinal; inline;
+    procedure RefreshTotals;
     function GetAccounts(const AccountNumbers: TArray<cardinal>): TArray<TAccount>;
   protected
     procedure ActivateFirstTime; override;
+    function HasUserDataChanged : boolean; overload;
+    function HasUserDataChanged(out AChangedAccounts : TArray<TAccount>) : boolean; overload;
     procedure OnPrivateKeysChanged(Sender: TObject);
     procedure OnNodeBlocksChanged(Sender: TObject);
     procedure OnNodeNewOperation(Sender: TObject);
-    procedure OnAccountsUpdated(Sender: TObject);
     procedure OnAccountsSelected(Sender: TObject; constref ASelection: TVisualGridSelection);
     procedure OnOperationSelected(Sender: TObject; constref ASelection: TVisualGridSelection);
     procedure OnPrepareAccountPopupMenu(Sender: TObject; constref ASelection: TVisualGridSelection; out APopupMenu: TPopupMenu);
@@ -92,7 +95,7 @@ type
 implementation
 
 uses
-  UUserInterface, UCellRenderers, UBlockChain, UWallet, UCrypto, UCoreUtils,
+  UUserInterface, UCellRenderers, UBlockChain, UWallet, UCrypto,
   UCommon, UMemory, Generics.Defaults, UCommon.Data, UCommon.Collections, UWIZModels;
 
 {$R *.lfm}
@@ -109,19 +112,21 @@ begin
   FNodeNotifyEvents.OnOperationsChanged := OnNodeNewOperation;
   TWallet.Keys.OnChanged.Add(OnPrivateKeysChanged);
 
-
   // fields
-  FAccountsDataSource := TAccountsDataSource.Create(Self);
-  FAccountsDataSource.FilterKeys := TWallet.Keys.AccountsKeyList.ToArray;
+  FAccountsDataSource := TFastAccountsDataSource.Create(Self);
+  FAccountsDataSource.Summary:= @FUserData;
   FOperationsDataSource := TAccountsOperationsDataSource.Create(Self);
+  FOperationsHistory := woh7Days;
+  FOperationsMode:= womAllAccounts;
+  FAccountsMode := wamMyAccounts;
 
   // grids
   FAccountsGrid := TVisualGrid.Create(Self);
   FAccountsGrid.SortMode := smMultiColumn;
-  FAccountsGrid.FetchDataInThread := True;
+  FAccountsGrid.FetchDataInThread := true;
   FAccountsGrid.AutoPageSize := True;
-  FAccountsGrid.SelectionType := stMultiRow;
   FAccountsGrid.DeselectionType := dtDefault;
+  FAccountsGrid.SelectionType := stMultiRow;
   FAccountsGrid.Options := [vgoColAutoFill, vgoColSizing, vgoSortDirectionAllowNone, vgoAutoHidePaging, vgoAutoHideSearchPanel];
   with FAccountsGrid.AddColumn('Account') do
   begin
@@ -152,15 +157,14 @@ begin
   end;
 
   FAccountsGrid.OnSelection := OnAccountsSelected;
-  FAccountsGrid.OnFinishedUpdating := OnAccountsUpdated;
   FAccountsGrid.OnPreparePopupMenu := OnPrepareAccountPopupMenu;
 
   FOperationsGrid := TVisualGrid.Create(Self);
   FOperationsGrid.SortMode := smMultiColumn;
   FOperationsGrid.FetchDataInThread := True;
   FOperationsGrid.AutoPageSize := True;
-  FOperationsGrid.SelectionType := stRow;
   FOperationsGrid.DeselectionType := dtDefault;
+  FOperationsGrid.SelectionType := stRow;
   FOperationsGrid.Options := [vgoColAutoFill, vgoColSizing, vgoSortDirectionAllowNone, vgoAutoHidePaging, vgoAutoHideSearchPanel];
   with FOperationsGrid.AddColumn('Time') do
   begin
@@ -253,6 +257,7 @@ begin
   cmbDuration.ReadOnly := True;
   cmbDuration.Items.BeginUpdate;
   try
+    cmbDuration.AddItem('7 Days', TObject(woh7Days));
     cmbDuration.AddItem('30 Days', TObject(woh30Days));
     cmbDuration.AddItem('Maximum', TObject(wohFullHistory));
   finally
@@ -262,6 +267,13 @@ begin
   cmbDuration.OnChange := cmbDurationChange;
   FOperationsGrid.WidgetControl := cmbDuration;
 
+  // Add datasources to grid
+  FAccountsGrid.DataSource := FAccountsDataSource;
+  FOperationsGrid.DataSource := FOperationsDataSource;
+
+  // Add grid to panels
+  paAccounts.AddControlDockCenter(FAccountsGrid);
+  paOperations.AddControlDockCenter(FOperationsGrid);
 end;
 
 procedure TCTRLWallet.FormDestroy(Sender: TObject);
@@ -277,14 +289,42 @@ end;
 
 procedure TCTRLWallet.ActivateFirstTime;
 begin
-  // Configure grid states
-  AccountsMode := wamMyAccounts;
-  OperationsMode := womAllAccounts;
-  OperationsHistory := woh30Days;
-
-  // Load up selected for some reasons
-  FAccountsGrid.InternalDrawGrid.ClearSelections;
-  FOperationsGrid.InternalDrawGrid.ClearSelections;
+  FetchUserData;
+  RefreshTotals;
+  FAccountsGrid.RefreshGrid;
+  FOperationsGrid.RefreshGrid;
+end;
+
+procedure TCTRLWallet.FetchUserData;
+var
+  GC : TDisposables;
+
+  function GetAccNo(constref AAccount: TAccount): cardinal; overload;
+  begin
+    Result := AAccount.account;
+  end;
+
+begin
+  FUserData := TUserInterface.Node.Bank.SafeBox.GetUserSummary(TWallet.Keys.AccountsKeyList.ToArray, true);
+  FOperationsDataSource.Accounts := TListTool<TAccount, cardinal>.Transform(FUserData.Accounts, GetAccNo);
+end;
+
+function TCTRLWallet.HasUserDataChanged : boolean;
+var LArr : TArray<TAccount>;
+begin
+  Result := HasUserDataChanged(LArr);
+end;
+
+function TCTRLWallet.HasUserDataChanged(out AChangedAccounts : TArray<TAccount>) : boolean;
+begin
+  AChangedAccounts := TUserInterface.Node.Bank.SafeBox.GetModifiedAccounts(FUserData.Accounts);
+  Result := Length (AChangedAccounts) > 0;
+end;
+
+procedure TCTRLWallet.RefreshTotals;
+begin
+  lblTotalPASC.Caption := TAccountComp.FormatMoney(FUserData.TotalPASC);
+  lblTotalPASA.Caption := Format('%d', [FUserData.TotalPASA]);
 end;
 
 procedure TCTRLWallet.RefreshMyAccountsCombo;
@@ -384,27 +424,31 @@ begin
 end;
 
 procedure TCTRLWallet.SetAccountsMode(AMode: TCTRLWalletAccountsMode);
-var
-  sel1: TVisualGridSelection;
-  sel2: TRect;
 begin
-  FAccountsMode := AMode;
-  paAccounts.RemoveAllControls(False);
-  case AMode of
-    wamMyAccounts:
-    begin
-      FOperationsGrid.DataSource := FOperationsDataSource;
-      FAccountsGrid.DataSource := FAccountsDataSource;
-      FAccountsGrid.Caption.Text := 'My Accounts';
-      paAccounts.RemoveAllControls(False);
-      sel1 := FAccountsGrid.Selection;
-      sel2 := FAccountsGrid.InternalDrawGrid.Selection;
-      paAccounts.RemoveAllControls(False);
-      paAccounts.AddControlDockCenter(FAccountsGrid);
-      paOperations.RemoveAllControls(False);
-      paOperations.AddControlDockCenter(FOperationsGrid);
+  FUILock.Acquire;
+  try
+    FAccountsMode := AMode;
+    paAccounts.RemoveAllControls(False);
+    case AMode of
+      wamMyAccounts:
+      begin
+        // reset account combo
+        cbAccounts.OnChange := nil; // disable event
+        cbAccounts.ItemIndex :=0;
+        cbAccounts.OnChange := cbAccountsChange; // re-enable event
+
+        // reset accounts grid/datasource
+        FAccountsGrid.DataSource := FAccountsDataSource;
+        FAccountsGrid.Caption.Text := 'My Accounts';
+        if FAccountsGrid.Parent <> paAccounts then begin
+          paAccounts.RemoveAllControls(False);
+          paAccounts.AddControlDockCenter(FAccountsGrid);
+        end;
+      end;
+      wamFirstAccount: raise Exception.Create('Not implemented');
     end;
-    wamFirstAccount: raise Exception.Create('Not implemented');
+  finally
+    FUILock.Release;
   end;
 end;
 
@@ -421,32 +465,34 @@ procedure TCTRLWallet.SetOperationsMode(AMode: TCTRLWalletOperationsMode);
   end;
 
 begin
-  case AMode of
-    womAllAccounts:
-    begin
-      FOperationsGrid.Caption.Text := '';
-      FOperationsDataSource.Accounts :=
-        TListTool<TAccount, cardinal>.Transform(
-        FAccountsDataSource.LastFetchResult, GetAccNo);
+  if AMode = FOperationsMode then
+    exit;
+  FUILock.Acquire;
+  try
+    FOperationsMode := AMode;
+    case AMode of
+      womAllAccounts: begin
+        FOperationsGrid.Caption.Text := '';
+        FOperationsDataSource.Accounts := TListTool<TAccount, cardinal>.Transform(FUserData.Accounts, GetAccNo);
+      end;
+      womSelectedAccounts:
+      begin
+        FOperationsGrid.Caption.Text := 'Selected Accounts';
+        FOperationsDataSource.Accounts := TListTool<variant, cardinal>.Transform(FAccountsGrid.SelectedRows, GetAccNo);
+      end else
+        raise ENotSupportedException.Create(Format('AMode %d not supported', [integer(AMode)]));
     end;
-    womSelectedAccounts:
-    begin
-      FOperationsGrid.Caption.Text := 'Selected Accounts';
-      FOperationsDataSource.Accounts :=
-        TListTool<variant, cardinal>.Transform(FAccountsGrid.SelectedRows, GetAccNo);
-    end
-    else
-      raise ENotSupportedException.Create(Format('AMode %d not supported',
-        [integer(AMode)]));
+    FOperationsGrid.RefreshGrid;
+  finally
+    FUILock.Release;
   end;
-  FOperationsGrid.RefreshGrid;
-  FOperationsMode := AMode;
 end;
 
 procedure TCTRLWallet.SetOperationsHistory(AHistory: TCTRLWalletOperationsHistory);
 begin
   FOperationsHistory := AHistory;
   case FOperationsHistory of
+    woh7Days: FOperationsDataSource.TimeSpan := TTimeSpan.FromDays(7);
     woh30Days: FOperationsDataSource.TimeSpan := TTimeSpan.FromDays(30);
     wohFullHistory: FOperationsDataSource.TimeSpan := TTimeSpan.FromDays(10 * 365);
   end;
@@ -459,23 +505,28 @@ begin
 end;
 
 procedure TCTRLWallet.OnNodeBlocksChanged(Sender: TObject);
+var changed : TArray<TAccount>;
 begin
+  if NOT TUserInterface.Node.HasBestKnownBlockchainTip then
+    exit; // node syncing
+
+  FetchUserData;
+  RefreshTotals;
   FAccountsGrid.RefreshGrid;
   FOperationsGrid.RefreshGrid;
 end;
 
 procedure TCTRLWallet.OnNodeNewOperation(Sender: TObject);
 begin
+  if (NOT TUserInterface.Node.HasBestKnownBlockchainTip) OR (NOT HasUserDataChanged) then
+    exit; // node syncing
+
+  FetchUserData;
+  RefreshTotals;
   FAccountsGrid.RefreshGrid;
   FOperationsGrid.RefreshGrid;
 end;
 
-procedure TCTRLWallet.OnAccountsUpdated(Sender: TObject);
-begin
-  lblTotalPASC.Caption := TAccountComp.FormatMoney(FAccountsDataSource.Overview.TotalPASC);
-  lblTotalPASA.Caption := Format('%d', [FAccountsDataSource.Overview.TotalPASA]);
-end;
-
 procedure TCTRLWallet.OnAccountsSelected(Sender: TObject; constref ASelection: TVisualGridSelection);
 var
   row: longint;
@@ -507,8 +558,10 @@ begin
   if (row >= 0) and (row < FOperationsGrid.RowCount) then begin
     v := FOperationsGrid.Rows[row];
     ophash := FOperationsGrid.Rows[row].OPHASH;
-    if TPCOperation.IsValidOperationHash(ophash) then
+    if TPCOperation.IsValidOperationHash(ophash) then begin
       TUserInterface.ShowOperationInfoDialog(self, ophash);
+      FOperationsGrid.ClearSelection;
+    end;
   end;
 end;
 
@@ -543,8 +596,9 @@ begin
     exit;
 
   case cmbDuration.ItemIndex of
-    0: OperationsHistory := woh30Days;
-    1: OperationsHistory := wohFullHistory;
+    0: OperationsHistory := woh7Days;
+    1: OperationsHistory := woh30Days;
+    2: OperationsHistory := wohFullHistory;
   end;
 end;
 
@@ -581,6 +635,12 @@ var
   wiz: TWIZSendPASCWizard;
   model: TWIZOperationsModel;
   AccountNumbersWithoutChecksum: TArray<cardinal>;
+
+  function GetAccNoWithoutChecksum(constref ARow: variant): cardinal;
+  begin
+    Result := ARow.__KEY;
+  end;
+
 begin
   wiz := Scoped.AddObject(TWIZSendPASCWizard.Create(nil)) as TWIZSendPASCWizard;
   model := TWIZOperationsModel.Create(wiz, omtSendPasc);
@@ -595,6 +655,12 @@ var
   wiz: TWIZChangeKeyWizard;
   model: TWIZOperationsModel;
   AccountNumbersWithoutChecksum: TArray<cardinal>;
+
+  function GetAccNoWithoutChecksum(constref ARow: variant): cardinal;
+  begin
+    Result := ARow.__KEY;
+  end;
+
 begin
   wiz := Scoped.AddObject(TWIZChangeKeyWizard.Create(nil)) as TWIZChangeKeyWizard;
   model := TWIZOperationsModel.Create(wiz, omtChangeKey);
@@ -637,11 +703,4 @@ begin
   TUserInterface.ShowOperationInfoDialog(Self, FOperationsGrid.SelectedRows[0].__KEY);
 end;
 
-// Aux
-
-function TCTRLWallet.GetAccNoWithoutChecksum(constref ARow: variant): cardinal;
-begin
-  Result := ARow.__KEY;
-end;
-
 end.

src/gui/UCellRenderers.pas

@@ -175,6 +175,10 @@ begin
     end;
     CT_Op_ChangeKeySigned: result :=  'Change Key';
     CT_Op_ChangeAccountInfo: result := 'Change Info';
+    CT_Op_MultiOperation: case OpSubType of
+      CT_OpSubtype_MultiOperation_Global: Result := 'Mixed-Transfer';
+      CT_OpSubtype_MultiOperation_AccountInfo: Result := 'Mixed-Change';
+    end;
     else result := 'Unknown';
   end;
 end;

src/pascalcoin_wallet.lpi

@@ -33,7 +33,7 @@
         <PackageName Value="LCL"/>
       </Item1>
     </RequiredPackages>
-    <Units Count="97">
+    <Units Count="98">
       <Unit0>
         <Filename Value="pascalcoin_wallet.dpr"/>
         <IsPartOfProject Value="True"/>
@@ -346,7 +346,7 @@
         <IsPartOfProject Value="True"/>
       </Unit62>
       <Unit63>
-        <Filename Value="core.utils\UCoreUtils.pas"/>
+        <Filename Value="core.utils\UCoreObjects.pas"/>
         <IsPartOfProject Value="True"/>
       </Unit63>
       <Unit64>
@@ -549,6 +549,10 @@
         <Filename Value="gui-classic\UGridUtils.pas"/>
         <IsPartOfProject Value="True"/>
       </Unit96>
+      <Unit97>
+        <Filename Value="core.utils\UCoreUtils.pas"/>
+        <IsPartOfProject Value="True"/>
+      </Unit97>
     </Units>
   </ProjectOptions>
   <CompilerOptions>