Implement a more effective solution for hiding and unhiding columns in ListColumns.

Pros:
- ShowDBProperties doesn't reset column layout
- Sort direction is remembered automatically
- Reading columnlist from registry is done once in a TMDIChild, not on each ShowDBProperties
- Hiding/unhiding columns doesn't call ShowDBProperties
- No more hassling with what is called a "default column" or not. popupDBGrid is usable like in Windows Explorer.
- Column layout is stored global, not per session.
Cons:
- Column layout from old settings logic needed to be discarded

Side effect:
- Fixes a potential AV in FormatNumber(str) with empty strings.
- Created an overloaded FormatByteNumber() which can take a string as input

source/childwin.dfm

@@ -361,14 +361,14 @@ object MDIChild: TMDIChild
             Height = 203
             Align = alClient
             EditDelay = 500
-            Header.AutoSizeIndex = 6
+            Header.AutoSizeIndex = -1
             Header.Font.Charset = DEFAULT_CHARSET
             Header.Font.Color = clWindowText
             Header.Font.Height = -11
             Header.Font.Name = 'Tahoma'
             Header.Font.Style = []
             Header.Height = 20
-            Header.Options = [hoAutoResize, hoColumnResize, hoDblClickResize, hoHotTrack, hoShowSortGlyphs, hoVisible]
+            Header.Options = [hoColumnResize, hoDblClickResize, hoHotTrack, hoShowSortGlyphs, hoVisible]
             Header.PopupMenu = popupDbGridHeader
             Header.SortColumn = 0
             Images = MainForm.ImageList1
@@ -432,8 +432,78 @@ object MDIChild: TMDIChild
               item
                 Options = [coAllowClick, coEnabled, coParentBidiMode, coParentColor, coResizable, coShowDropMark, coVisible]
                 Position = 6
-                Width = 10
+                Width = 100
                 WideText = 'Comment'
+              end
+              item
+                Options = [coAllowClick, coEnabled, coParentBidiMode, coParentColor, coResizable, coShowDropMark, coVisible]
+                Position = 7
+                WideText = 'Version'
+              end
+              item
+                Options = [coAllowClick, coEnabled, coParentBidiMode, coParentColor, coResizable, coShowDropMark, coVisible]
+                Position = 8
+                Width = 70
+                WideText = 'Row format'
+              end
+              item
+                Alignment = taRightJustify
+                Options = [coAllowClick, coEnabled, coParentBidiMode, coParentColor, coResizable, coShowDropMark, coVisible]
+                Position = 9
+                Width = 70
+                WideText = 'Avg row length'
+              end
+              item
+                Alignment = taRightJustify
+                Options = [coAllowClick, coEnabled, coParentBidiMode, coParentColor, coResizable, coShowDropMark, coVisible]
+                Position = 10
+                Width = 70
+                WideText = 'Max data length'
+              end
+              item
+                Alignment = taRightJustify
+                Options = [coAllowClick, coEnabled, coParentBidiMode, coParentColor, coResizable, coShowDropMark, coVisible]
+                Position = 11
+                Width = 70
+                WideText = 'Index length'
+              end
+              item
+                Alignment = taRightJustify
+                Options = [coAllowClick, coEnabled, coParentBidiMode, coParentColor, coResizable, coShowDropMark, coVisible]
+                Position = 12
+                Width = 70
+                WideText = 'Data free'
+              end
+              item
+                Alignment = taRightJustify
+                Options = [coAllowClick, coEnabled, coParentBidiMode, coParentColor, coResizable, coShowDropMark, coVisible]
+                Position = 13
+                Width = 90
+                WideText = 'Auto increment'
+              end
+              item
+                Options = [coAllowClick, coEnabled, coParentBidiMode, coParentColor, coResizable, coShowDropMark, coVisible]
+                Position = 14
+                Width = 120
+                WideText = 'Check time'
+              end
+              item
+                Options = [coAllowClick, coEnabled, coParentBidiMode, coParentColor, coResizable, coShowDropMark, coVisible]
+                Position = 15
+                Width = 70
+                WideText = 'Collation'
+              end
+              item
+                Options = [coAllowClick, coEnabled, coParentBidiMode, coParentColor, coResizable, coShowDropMark, coVisible]
+                Position = 16
+                Width = 70
+                WideText = 'Checksum'
+              end
+              item
+                Options = [coAllowClick, coEnabled, coParentBidiMode, coParentColor, coResizable, coShowDropMark, coVisible]
+                Position = 17
+                Width = 70
+                WideText = 'Create options'
               end>
           end
           object pnlDatabaseToolbar: TPanel
@@ -2189,7 +2259,6 @@ object MDIChild: TMDIChild
   object popupDbGridHeader: TPopupMenu
     AutoHotkeys = maManual
     AutoLineReduction = maManual
-    Images = MainForm.ImageList1
     Left = 72
     Top = 80
     object DefaultColumnLayout1: TMenuItem

source/childwin.pas

@@ -523,6 +523,7 @@ type
       UserQueryFired             : Boolean;
       CachedTableLists           : TStringList;
       QueryHelpersSelectedItems  : Array[0..3] of Integer;
+      ListTablesColumnNames      : TStringList;
 
       function GetQueryRunning: Boolean;
       procedure SetQueryRunning(running: Boolean);
@@ -533,6 +534,7 @@ type
       function RunThreadedQuery(AQuery : String) : TMysqlQuery;
       procedure DisplayRowCountStats(ds: TDataSet);
       procedure insertFunction(Sender: TObject);
+      procedure SetupListTablesHeader;
 
     public
       ActualDatabase             : String;
@@ -1951,14 +1953,10 @@ end;
 { Show tables and their properties on the tabsheet "Database" }
 procedure TMDIChild.ShowDBProperties(Sender: TObject);
 var
-  i,j,k           : Integer;
+  i               : Integer;
   bytes           : Extended;
-  menuitem        : TMenuItem;
-  TablelistColumns: TStringList;
-  column          : TVirtualTreeColumn;
   ds              : TDataSet;
-  OldSortColumn   : Integer;
+  ListCaptions    : TStringList;
-  OldSortDirection: TSortDirection;
 begin
   // DB-Properties
   Screen.Cursor := crHourGlass;
@@ -1974,146 +1972,107 @@ begin
 
     ds := FetchActiveDbTableList;
 
-    // Generate items for popupDbGridHeader
-    for i:=popupDbGridHeader.Items.Count-1 downto 2 do
-      popupDbGridHeader.Items.Delete( i );
-    with TRegistry.Create do
-    begin
-      openkey( REGPATH + '\Servers\' + FConn.Description, true );
-      if ValueExists( 'TablelistDefaultColumns' ) then
-        popupDbGridHeader.Items[0].Checked := ReadBool( 'TablelistDefaultColumns' );
-      if ValueExists( 'TablelistColumns' ) then
-        TablelistColumns := Explode( ',', ReadString( 'TablelistColumns' ) )
-      else
-        TablelistColumns := TStringList.Create;
-      free;
-    end;
-    for i:=0 to ds.FieldCount-1 do
-    begin
-      menuitem := TMenuItem.Create( self );
-      menuitem.Caption := ds.Fields[i].Fieldname;
-      menuitem.Tag := 2;
-      menuitem.OnClick := MenuTablelistColumnsClick;
-      if i=0 then
-      begin
-        menuitem.Enabled := false; // tablename should always be kept
-        menuitem.Checked := true;
-      end
-      else if TablelistColumns.Count > 0 then
-      begin
-        menuitem.Checked := TablelistColumns.IndexOf( menuitem.Caption ) > -1;
-      end;
-      popupDbGridHeader.Items.Add( menuitem );
-    end;
-
-    // Remember sorting options and restore them later
-    OldSortColumn := ListTables.Header.SortColumn;
-    OldSortDirection := ListTables.Header.SortDirection;
-
     ListTables.BeginUpdate;
     ListTables.Clear;
-    ListTables.Header.Columns.BeginUpdate;
-    ListTables.Header.Columns.Clear;
-    column := ListTables.Header.Columns.Add;
-    column.Text := 'Table';
-    column.Width := 120;
-    if popupDbGridHeader.Items[0].Checked then
-    begin // Default columns - initialize column headers
-      column := ListTables.Header.Columns.Add;
-      column.Text := 'Records';
-      column.Alignment := taRightJustify;
-      column.Width := 80;
 
-      column := ListTables.Header.Columns.Add;
+    // (Un)hides (un)selected column names in list
-      column.Text := 'Size';
+    SetupListTablesHeader;
-      column.Alignment := taRightJustify;
-      column.Width := 70;
-
-      column := ListTables.Header.Columns.Add;
-      column.Text := 'Created';
-      column.Width := 120;
-
-      column := ListTables.Header.Columns.Add;
-      column.Text := 'Updated';
-      column.Width := 120;
-
-      column := ListTables.Header.Columns.Add;
-      column.Text := 'Engine';
-      column.Width := 70;
-
-      column := ListTables.Header.Columns.Add;
-      column.Text := 'Comment';
-      column.Width := 50;
-    end;
-    for i:=0 to TablelistColumns.Count-1 do
-    begin
-      column := ListTables.Header.Columns.Add;
-      column.Text := TablelistColumns[i];
-      column.Width := 50;
-      column.MinWidth := 50;
-    end;
-    // Ensure AutoResize does not cause an AV
-    ListTables.Header.SortColumn := OldSortColumn;
-    ListTables.Header.SortDirection := OldSortDirection;
-    ListTables.Header.Columns.EndUpdate;
 
     SetLength(VTRowDataListTables, ds.RecordCount);
     for i := 1 to ds.RecordCount do
     begin
-      VTRowDataListTables[i-1].Captions := TStringList.Create;
+      listcaptions := TStringList.Create;
-      VTRowDataListTables[i-1].ImageIndex := 39;
       // Table
-      VTRowDataListTables[i-1].Captions.Add( ds.Fields[0].AsString );
+      ListCaptions.Add( ds.Fields[0].AsString );
-      if (mysql_version >= 32300) and popupDbGridHeader.Items[0].Checked then
+      if mysql_version >= 32300 then
       begin // Default columns
         // Records
-        VTRowDataListTables[i-1].Captions.Add( FormatNumber( ds.FieldByName('Rows').AsFloat ) );
+        ListCaptions.Add( FormatNumber( ds.FieldByName('Rows').AsFloat ) );
         // Size: Data_length + Index_length
         bytes := ds.FieldByName('Data_length').AsFloat + ds.FieldByName('Index_length').AsFloat;
-        VTRowDataListTables[i-1].Captions.Add( FormatNumber( bytes / 1024 + 1 ) + ' KB');
+        ListCaptions.Add( FormatNumber( bytes / 1024 + 1 ) + ' KB');
         // Created:
         if not ds.FieldByName('Create_time').IsNull then
-          VTRowDataListTables[i-1].Captions.Add( ds.FieldByName('Create_time').AsString )
+          ListCaptions.Add( ds.FieldByName('Create_time').AsString )
         else
-          VTRowDataListTables[i-1].Captions.Add('N/A');
+          ListCaptions.Add('N/A');
 
         // Updated:
         if not ds.FieldByName('Update_time').IsNull then
-          VTRowDataListTables[i-1].Captions.Add( ds.FieldByName('Update_time').AsString )
+          ListCaptions.Add( ds.FieldByName('Update_time').AsString )
         else
-          VTRowDataListTables[i-1].Captions.Add('N/A');
+          ListCaptions.Add('N/A');
 
         // Type
         if ds.FindField('Type')<>nil then
-          VTRowDataListTables[i-1].Captions.Add( ds.FieldByName('Type').AsString )
+          ListCaptions.Add( ds.FieldByName('Type').AsString )
         else if ds.FindField('Engine')<>nil then
-          VTRowDataListTables[i-1].Captions.Add( ds.FieldByName('Engine').AsString )
+          ListCaptions.Add( ds.FieldByName('Engine').AsString )
         else
-          VTRowDataListTables[i-1].Captions.Add('');
+          ListCaptions.Add('');
 
         // Comment
-        VTRowDataListTables[i-1].Captions.Add( ds.FieldByName('Comment').AsString );
+        ListCaptions.Add( ds.FieldByName('Comment').AsString );
-      end;
+
-      for j:=0 to TablelistColumns.Count-1 do
+        // Add content from other columns which are not visible in ListTables by default
-      begin
+
-        for k:=0 to ds.FieldCount-1 do
+        if ds.FindField('Version')<>nil then
-        begin
+          ListCaptions.Add( ds.FieldByName('Version').AsString )
-          if TablelistColumns[j] = ds.Fields[k].FieldName then
+        else
-          begin
+          ListCaptions.Add('');
-            if ds.Fields[k].DataType in [ftInteger, ftSmallint, ftWord, ftFloat, ftWord ] then
+
-            begin
+        if ds.FindField('Row_format')<>nil then
-              // Number
+          ListCaptions.Add( ds.FieldByName('Row_format').AsString )
-              // TODO: doesn't match any column
+        else
-              ListTables.Header.Columns[ListTables.Header.Columns.Count-1].Alignment := taRightJustify;
+          ListCaptions.Add('');
-              VTRowDataListTables[i-1].Captions.Add( FormatNumber( ds.Fields[k].AsFloat ) );
+
-            end
+        if ds.FindField('Avg_row_length')<>nil then
-            else
+          ListCaptions.Add( FormatByteNumber(ds.FieldByName('Avg_row_length').AsString) )
-              // String
+        else
-              VTRowDataListTables[i-1].Captions.Add( ds.Fields[k].AsString );
+          ListCaptions.Add('');
-            break;
+
-          end;
+        if ds.FindField('Max_data_length')<>nil then
-        end;
+          ListCaptions.Add( FormatByteNumber(ds.FieldByName('Max_data_length').AsString) )
+        else
+          ListCaptions.Add('');
+
+        if ds.FindField('Index_length')<>nil then
+          ListCaptions.Add( FormatByteNumber(ds.FieldByName('Index_length').AsString) )
+        else
+          ListCaptions.Add('');
+
+        if ds.FindField('Data_free')<>nil then
+          ListCaptions.Add( FormatByteNumber(ds.FieldByName('Data_free').AsString) )
+        else
+          ListCaptions.Add('');
+
+        if ds.FindField('Auto_increment')<>nil then
+          ListCaptions.Add( FormatNumber(ds.FieldByName('Auto_increment').AsString) )
+        else
+          ListCaptions.Add('');
+
+        if ds.FindField('Check_time')<>nil then
+          ListCaptions.Add( ds.FieldByName('Check_time').AsString )
+        else
+          ListCaptions.Add('');
+
+        if ds.FindField('Collation')<>nil then
+          ListCaptions.Add( ds.FieldByName('Collation').AsString )
+        else
+          ListCaptions.Add('');
+
+        if ds.FindField('Checksum')<>nil then
+          ListCaptions.Add( ds.FieldByName('Checksum').AsString )
+        else
+          ListCaptions.Add('');
+
+        if ds.FindField('Create_options')<>nil then
+          ListCaptions.Add( ds.FieldByName('Create_options').AsString )
+        else
+          ListCaptions.Add('');
       end;
+      VTRowDataListTables[i-1].ImageIndex := 39;
+      VTRowDataListTables[i-1].Captions := ListCaptions;
       ds.Next;
     end;
     mainform.showstatus(ActualDatabase + ': ' + IntToStr(ds.RecordCount) +' table(s)');
@@ -5509,44 +5468,6 @@ end;
 
 
 
-// Click on first menu-item in context-menu of tablelist-columns
-procedure TMDIChild.MenuTablelistColumnsClick(Sender: TObject);
-var
-  menuitem : TMenuItem;
-  TablelistColumnsList : TStringList;
-begin
-  menuitem := (Sender as TMenuItem);
-  with TRegistry.Create do
-  try
-    openkey( REGPATH + '\Servers\' + FConn.Description, true );
-    case menuitem.Tag of
-      1 : // Toggle default-columns
-        WriteBool( 'TablelistDefaultColumns', not menuitem.Checked );
-      2 :
-        begin
-          if ValueExists( 'TablelistColumns' ) then
-            TablelistColumnsList := Explode( ',', ReadString( 'TablelistColumns' ) )
-          else
-            TablelistColumnsList := TStringList.Create;
-          if TablelistColumnsList.IndexOf( menuitem.Caption ) > -1 then
-            TablelistColumnsList.Delete( TablelistColumnsList.IndexOf( menuitem.Caption ) )
-          else
-            TablelistColumnsList.Add( menuitem.Caption );
-          WriteString( 'TablelistColumns', implodestr( ',', TablelistColumnsList ) );
-        end;
-     end;
-    free;
-  except
-    free;
-    MessageDlg( 'Error while writing to registry.', mtError, [mbOK], 0 );
-    exit;
-  end;
-  menuitem.Checked := not menuitem.Checked;
-  ShowDBProperties( self );
-end;
-
-
-
 function TMDIChild.mask(str: String) : String;
 begin
   result := maskSql(mysql_version, str);
@@ -6136,6 +6057,85 @@ begin
 end;
 
 
+{**
+  Click on popupDBGridHeader
+}
+procedure TMDIChild.MenuTablelistColumnsClick(Sender: TObject);
+var
+  menuitem : TMenuItem;
+  reg : TRegistry;
+begin
+  menuitem := (Sender as TMenuItem);
+  reg := TRegistry.Create;
+  reg.OpenKey( REGPATH, true );
+  if ListTablesColumnNames.IndexOf( menuitem.Caption ) > -1 then
+    ListTablesColumnNames.Delete( ListTablesColumnNames.IndexOf( menuitem.Caption ) )
+  else
+    ListTablesColumnNames.Add( menuitem.Caption );
+  // Store list of columns in registry
+  reg.WriteString( REGNAME_LISTTABLESCOLUMNNAMES, ListTablesColumnNames.DelimitedText );
+  SetupListTablesHeader;
+end;
+
+
+{**
+  (Un)hides (un)selected columns in ListTables
+}
+procedure TMDIChild.SetupListTablesHeader;
+var
+  reg : TRegistry;
+  i : Integer;
+  menuitem : TMenuItem;
+begin
+  if ListTablesColumnNames = nil then
+  begin
+    // First time we read the columns list from registry into this global variable
+    ListTablesColumnNames := TStringList.Create;
+
+    reg := TRegistry.Create;
+    reg.openkey( REGPATH, true );
+    if reg.ValueExists( REGNAME_LISTTABLESCOLUMNNAMES ) then
+    begin
+      ListTablesColumnNames.DelimitedText := reg.ReadString( REGNAME_LISTTABLESCOLUMNNAMES );
+      // Ensure first column (Table) is always visible
+      if ListTablesColumnNames.IndexOf(ListTables.Header.Columns[0].Text) = -1 then
+        ListTablesColumnNames.Add( ListTables.Header.Columns[0].Text );
+    end
+    else begin
+      // If not set, by default make the first 7 columns visible
+      for i:=0 to ListTables.Header.Columns.Count-1 do
+      begin
+        ListTablesColumnNames.Add(ListTables.Header.Columns[i].Text);
+        if i >= 6 then
+          break;
+      end;
+    end;
+    reg.Free;
+  end;
+
+  // All columns in ListTables are created at designtime. Only (un)hide them here
+  // Plus generate menuitems for popupDBgridColumns
+  popupDBGridHeader.Items.Clear;
+  for i:=0 to ListTables.Header.Columns.Count-1 do
+  begin
+    menuitem := TMenuItem.Create( popupDBGridHeader );
+    menuitem.Caption := ListTables.Header.Columns[i].Text;
+    menuitem.OnClick := MenuTablelistColumnsClick;
+    // Disable hiding first column
+    menuitem.Enabled := i>0;
+    popupDbGridHeader.Items.Add( menuitem );
+    if (i=0) or (ListTablesColumnNames.IndexOf( ListTables.Header.Columns[i].Text ) > -1) then
+    begin
+      ListTables.Header.Columns[i].Options := ListTables.Header.Columns[i].Options + [coVisible];
+      menuitem.Checked := True;
+    end
+    else begin
+      ListTables.Header.Columns[i].Options := ListTables.Header.Columns[i].Options - [coVisible];
+      menuitem.Checked := False;
+    end;
+  end;
+end;
+
 
 end.
 

source/const.inc

@@ -38,6 +38,7 @@ const
   // Registry name for storing list of displayed columns
   REGNAME_DISPLAYEDCOLUMNS = 'DisplayedColumns';
   REGNAME_SORTDISPLAYEDCOLUMNS = 'DisplayedColumnsSorted';
+  REGNAME_LISTTABLESCOLUMNNAMES = 'ListTablesColumnNames';
 
   // how much memory we're aiming to use for the
   // data grid and it's automatic limit function

source/helpers.pas

@@ -81,7 +81,8 @@ type
   function GetFieldValue( Field: TField ): String;
   function LastPos( substr: WideString; str: WideString): Integer;
   function ConvertServerVersion( Version: Integer ): String;
-  function FormatByteNumber( Bytes: Int64; Decimals: Byte = 1 ): String;
+  function FormatByteNumber( Bytes: Int64; Decimals: Byte = 1 ): String; Overload;
+  function FormatByteNumber( Bytes: String; Decimals: Byte = 1 ): String; Overload;
   function FormatTimeNumber( Seconds: Cardinal ): String;
   function TColorToHex( Color : TColor ): string;
   function GetVTCaptions( VT: TVirtualStringTree; OnlySelected: Boolean = False; Column: Integer = 0 ): TStringList;
@@ -1587,7 +1588,10 @@ end;
 }
 function FormatNumber( str: String ): String; Overload;
 begin
-  result := FormatNumber( StrToFloat( str ) );
+  if str <> '' then
+    result := FormatNumber( StrToFloat( str ) )
+  else
+    result := FormatNumber( 0 );
 end;
 
 
@@ -1950,7 +1954,7 @@ end;
   @param Int64 Number of Bytes
   @param Byte Decimals to display when bytes is bigger than 1M
 }
-function FormatByteNumber( Bytes: Int64; Decimals: Byte = 1 ): String;
+function FormatByteNumber( Bytes: Int64; Decimals: Byte = 1 ): String; Overload;
 const
   KB = 1024;
 begin
@@ -1965,6 +1969,16 @@ begin
 end;
 
 
+{**
+  An overloaded function of the previous one which can
+  take a string as input
+}
+function FormatByteNumber( Bytes: String; Decimals: Byte = 1 ): String; Overload;
+begin
+  Result := FormatByteNumber( MakeInt(Bytes), Decimals );
+end;
+
+
 {**
   Format a number of seconds to a human readable time format
   @param Cardinal Number of seconds