jvcllaz: Add new component TDBLookupTreeView with demo.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@6870 8e941d3f-bd1b-0410-a28a-d453659cc2b4
2019-04-27 17:15:09 +00:00
parent 0d39fd7dfd
commit 0bd361c6e9
20 changed files with 2228 additions and 16 deletions
--- a/components/jvcllaz/design/JvDB/JvDBReg.pas
+++ b/components/jvcllaz/design/JvDB/JvDBReg.pas
@ -16,13 +16,13 @@ implementation

 uses
  Classes, JvDsgnConsts, //JvDBSearchCombobox,
-  JvDBSearchEdit, JvDBTreeView, JvDBControls, JvDBHTLabel, JvDBLookup;
+  JvDBSearchEdit, JvDBTreeView, JvDBControls, JvDBHTLabel, JvDBLookup, JvDBLookupTreeView;

 procedure Register;
 const
 //  cDataField = 'DataField';
-//  cKeyField = 'KeyField';
-//  cListField = 'ListField';
+  cKeyField = 'KeyField';
+  cListField = 'ListField';
 //  cDisplayField = 'DisplayField';
 //  cListKeyField = 'ListKeyField';
  cMasterField = 'MasterField';
@ -43,13 +43,19 @@ begin
 //    TJvDBSearchCombobox,
    TJvDBTreeView,
    TJvDBHTLabel,
-    TJvDBLookupList, TJvDBLookupCombo
+    TJvDBLookupList, TJvDBLookupCombo, TJvDBLookupTreeView
  ]);
                
-  RegisterPropertyEditor(TypeInfo(string), TJvDBTreeView, cItemField, TFieldProperty); //TJvDataFieldProperty);
-  RegisterPropertyEditor(TypeInfo(string), TJvDBTreeView, cMasterField, TFieldProperty); //TJvDataFieldProperty);
-  RegisterPropertyEditor(TypeInfo(string), TJvDBTreeView, cDetailField, TFieldProperty); //TJvDataFieldProperty);
-  RegisterPropertyEditor(TypeInfo(string), TJvDBTreeView, cIconField, TFieldProperty); //TJvDataFieldProperty);
+  RegisterPropertyEditor(TypeInfo(string), TJvDBTreeView, cItemField, TFieldProperty); 
+  RegisterPropertyEditor(TypeInfo(string), TJvDBTreeView, cMasterField, TFieldProperty);
+  RegisterPropertyEditor(TypeInfo(string), TJvDBTreeView, cDetailField, TFieldProperty);
+  RegisterPropertyEditor(TypeInfo(string), TJvDBTreeView, cIconField, TFieldProperty);
+
+  RegisterPropertyEditor(TypeInfo(string), TJvDBLookupTreeView, cKeyField, TLookupFieldProperty);
+  RegisterPropertyEditor(TypeInfo(string), TJvDBLookupTreeView, cListField, TLookupFieldProperty);
+  RegisterPropertyEditor(TypeInfo(string), TJvDBLookupTreeView, cMasterField, TLookupFieldProperty);
+  RegisterPropertyEditor(TypeInfo(string), TJvDBLookupTreeView, cDetailField, TLookupFieldProperty);
+  RegisterPropertyEditor(TypeInfo(string), TJvDBLookupTreeView, cIconField, TLookupFieldProperty);
 end;

 end.
--- a/components/jvcllaz/design/JvDB/images/images.txt
+++ b/components/jvcllaz/design/JvDB/images/images.txt
@ -3,3 +3,6 @@ tjvdbhtlabel.bmp
 tjvdbsearchcombobox.bmp
 tjvdbsearchedit.bmp
 tjvdbtreeview.bmp
+tjvdblookuptreeview.bmp
+tjvdblookuplist.bmp
+tjvdblookupcombo.bmp
--- a/components/jvcllaz/design/JvDB/images/tjvdblookupcombo.bmp
+++ b/components/jvcllaz/design/JvDB/images/tjvdblookupcombo.bmp
--- a/components/jvcllaz/design/JvDB/images/tjvdblookuplist.bmp
+++ b/components/jvcllaz/design/JvDB/images/tjvdblookuplist.bmp
--- a/components/jvcllaz/design/JvDB/images/tjvdblookuptreeview.bmp
+++ b/components/jvcllaz/design/JvDB/images/tjvdblookuptreeview.bmp
--- a/components/jvcllaz/examples/JvDBLookupTreeView/JvDBLookupTreeViewDemo.lpi
+++ b/components/jvcllaz/examples/JvDBLookupTreeView/JvDBLookupTreeViewDemo.lpi
@ -0,0 +1,73 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<CONFIG>
+  <ProjectOptions>
+    <Version Value="12"/>
+    <PathDelim Value="\"/>
+    <General>
+      <Flags>
+        <CompatibilityMode Value="True"/>
+      </Flags>
+      <SessionStorage Value="InProjectDir"/>
+      <Title Value="JvDBLookupTreeViewDemo"/>
+      <Scaled Value="True"/>
+      <ResourceType Value="res"/>
+      <UseXPManifest Value="True"/>
+      <XPManifest>
+        <DpiAware Value="True"/>
+      </XPManifest>
+      <Icon Value="0"/>
+    </General>
+    <BuildModes Count="1">
+      <Item1 Name="Default" Default="True"/>
+    </BuildModes>
+    <PublishOptions>
+      <Version Value="2"/>
+    </PublishOptions>
+    <RunParams>
+      <FormatVersion Value="2"/>
+      <Modes Count="0"/>
+    </RunParams>
+    <RequiredPackages Count="3">
+      <Item1>
+        <PackageName Value="JvDBLazR"/>
+      </Item1>
+      <Item2>
+        <PackageName Value="FCL"/>
+      </Item2>
+      <Item3>
+        <PackageName Value="LCL"/>
+      </Item3>
+    </RequiredPackages>
+    <Units Count="2">
+      <Unit0>
+        <Filename Value="JvDBLookupTreeViewDemo.lpr"/>
+        <IsPartOfProject Value="True"/>
+      </Unit0>
+      <Unit1>
+        <Filename Value="main.pas"/>
+        <IsPartOfProject Value="True"/>
+        <ComponentName Value="Form1"/>
+        <HasResources Value="True"/>
+        <ResourceBaseClass Value="Form"/>
+      </Unit1>
+    </Units>
+  </ProjectOptions>
+  <CompilerOptions>
+    <Version Value="11"/>
+    <PathDelim Value="\"/>
+    <Target>
+      <Filename Value="..\..\bin\JvDBLookupTreeViewDemo"/>
+    </Target>
+    <SearchPaths>
+      <IncludeFiles Value="$(ProjOutDir)"/>
+      <UnitOutputDirectory Value="lib\$(TargetCPU)-$(TargetOS)"/>
+    </SearchPaths>
+    <Linking>
+      <Options>
+        <Win32>
+          <GraphicApplication Value="True"/>
+        </Win32>
+      </Options>
+    </Linking>
+  </CompilerOptions>
+</CONFIG>
--- a/components/jvcllaz/examples/JvDBLookupTreeView/JvDBLookupTreeViewDemo.lpr
+++ b/components/jvcllaz/examples/JvDBLookupTreeView/JvDBLookupTreeViewDemo.lpr
@ -0,0 +1,22 @@
+program JvDBLookupTreeViewDemo;
+
+{$mode objfpc}{$H+}
+
+uses
+  {$IFDEF UNIX}{$IFDEF UseCThreads}
+  cthreads,
+  {$ENDIF}{$ENDIF}
+  Interfaces, // this includes the LCL widgetset
+  Forms, main
+  { you can add units after this };
+
+{$R *.res}
+
+begin
+  RequireDerivedFormResource := True;
+  Application.Scaled := True;
+  Application.Initialize;
+  Application.CreateForm(TForm1, Form1);
+  Application.Run;
+end.
+
--- a/components/jvcllaz/examples/JvDBLookupTreeView/main.lfm
+++ b/components/jvcllaz/examples/JvDBLookupTreeView/main.lfm
@ -0,0 +1,176 @@
+object Form1: TForm1
+  Left = 374
+  Height = 477
+  Top = 164
+  Width = 594
+  Caption = 'JvDBLookup controls'
+  ClientHeight = 477
+  ClientWidth = 594
+  OnShow = FormShow
+  LCLVersion = '2.1.0.0'
+  object JvDBLookupTreeView1: TJvDBLookupTreeView
+    AnchorSideLeft.Control = Bevel1
+    AnchorSideLeft.Side = asrBottom
+    AnchorSideRight.Control = Owner
+    AnchorSideRight.Side = asrBottom
+    AnchorSideBottom.Control = Owner
+    AnchorSideBottom.Side = asrBottom
+    Left = 307
+    Height = 349
+    Top = 112
+    Width = 271
+    BorderSpacing.Right = 16
+    BorderSpacing.Bottom = 16
+    DataField = 'ID'
+    DataSource = DSPersons
+    KeyField = 'RelID'
+    ListField = 'RelName'
+    ListSource = DSRelationships
+    TabOrder = 0
+    Anchors = [akTop, akLeft, akRight, akBottom]
+    MasterField = 'RelID'
+    DetailField = 'RelParentID'
+    StartMasterValue = '0'
+    Indent = 15
+  end
+  object Label2: TLabel
+    AnchorSideTop.Control = DBNavigator1
+    AnchorSideTop.Side = asrBottom
+    Left = 16
+    Height = 15
+    Top = 92
+    Width = 39
+    BorderSpacing.Top = 16
+    Caption = 'Person:'
+    ParentColor = False
+  end
+  object DBNavigator1: TDBNavigator
+    AnchorSideLeft.Control = Owner
+    AnchorSideTop.Control = Panel1
+    AnchorSideTop.Side = asrBottom
+    Left = 16
+    Height = 26
+    Top = 50
+    Width = 241
+    BevelOuter = bvNone
+    BorderSpacing.Left = 16
+    BorderSpacing.Top = 16
+    ChildSizing.EnlargeHorizontal = crsScaleChilds
+    ChildSizing.EnlargeVertical = crsScaleChilds
+    ChildSizing.ShrinkHorizontal = crsScaleChilds
+    ChildSizing.ShrinkVertical = crsScaleChilds
+    ChildSizing.Layout = cclLeftToRightThenTopToBottom
+    ChildSizing.ControlsPerLine = 100
+    ClientHeight = 26
+    ClientWidth = 241
+    DataSource = DSPersons
+    Options = []
+    TabOrder = 1
+  end
+  object Label3: TLabel
+    AnchorSideLeft.Control = Bevel1
+    AnchorSideLeft.Side = asrBottom
+    AnchorSideTop.Control = Label2
+    Left = 307
+    Height = 15
+    Top = 92
+    Width = 146
+    Caption = 'Relationship to protagonist:'
+    ParentColor = False
+  end
+  object Panel1: TPanel
+    Left = 0
+    Height = 34
+    Top = 0
+    Width = 594
+    Align = alTop
+    Caption = '(Some) persons in the novel "The Grapes of Wrath" by John Steinbeck'
+    Color = clBackground
+    Font.Color = clHighlightText
+    Font.Height = -16
+    Font.Style = [fsBold]
+    ParentColor = False
+    ParentFont = False
+    TabOrder = 2
+  end
+  object DBGrid1: TDBGrid
+    AnchorSideLeft.Control = DBNavigator1
+    AnchorSideTop.Control = Label2
+    AnchorSideTop.Side = asrBottom
+    AnchorSideRight.Control = Bevel1
+    AnchorSideBottom.Control = Owner
+    AnchorSideBottom.Side = asrBottom
+    Left = 16
+    Height = 350
+    Top = 111
+    Width = 271
+    Anchors = [akTop, akLeft, akRight, akBottom]
+    AutoFillColumns = True
+    BorderSpacing.Top = 4
+    BorderSpacing.Bottom = 16
+    Color = clWindow
+    Columns = <    
+      item
+        Title.Caption = 'Name'
+        Width = 238
+        FieldName = 'Name'
+      end>
+    DataSource = DSPersons
+    TabOrder = 3
+    OnPrepareCanvas = DBGrid1PrepareCanvas
+  end
+  object Bevel1: TBevel
+    AnchorSideLeft.Control = Owner
+    AnchorSideLeft.Side = asrCenter
+    Left = 287
+    Height = 50
+    Top = 78
+    Width = 20
+    Shape = bsSpacer
+  end
+  object Persons: TBufDataset
+    FieldDefs = <    
+      item
+        Name = 'ID'
+        DataType = ftInteger
+      end    
+      item
+        Name = 'Name'
+        DataType = ftString
+        Size = 30
+      end>
+    left = 80
+    top = 160
+  end
+  object Relationships: TBufDataset
+    FieldDefs = <    
+      item
+        Name = 'RelID'
+        DataType = ftInteger
+      end    
+      item
+        Name = 'RelName'
+        DataType = ftString
+        Size = 30
+      end    
+      item
+        Name = 'RelParentID'
+        DataType = ftString
+        Size = 16
+      end>
+    left = 424
+    top = 160
+  end
+  object DSPersons: TDataSource
+    AutoEdit = False
+    DataSet = Persons
+    left = 80
+    top = 224
+  end
+  object DSRelationships: TDataSource
+    AutoEdit = False
+    DataSet = Relationships
+    left = 424
+    top = 224
+  end
+end
--- a/components/jvcllaz/examples/JvDBLookupTreeView/main.pas
+++ b/components/jvcllaz/examples/JvDBLookupTreeView/main.pas
@ -0,0 +1,111 @@
+unit main;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, BufDataset, DB, Forms, Controls, Graphics, Dialogs,
+  DBGrids, JvDBLookup, JvDBLookupTreeView, JvDBTreeView, ExtCtrls, DBCtrls,
+  StdCtrls, Grids;
+
+type
+
+  { TForm1 }
+
+  TForm1 = class(TForm)
+    Bevel1: TBevel;
+    DBGrid1: TDBGrid;
+    DBNavigator1: TDBNavigator;
+    Label2: TLabel;
+    Label3: TLabel;
+    Panel1: TPanel;
+    JvDBLookupTreeView1: TJvDBLookupTreeView;
+    Persons: TBufDataset;
+    Relationships: TBufDataset;
+    DSPersons: TDataSource;
+    DSRelationships: TDataSource;
+    procedure DBGrid1PrepareCanvas(sender: TObject; DataCol: Integer;
+      Column: TColumn; AState: TGridDrawState);
+    procedure FormShow(Sender: TObject);
+  private
+
+  public
+    Image: TImage;
+  end;
+
+var
+  Form1: TForm1;
+
+implementation
+
+{$R *.lfm}
+
+{ TForm1 }
+
+{ Assignment of table fields to lookup tree
+
+   Table "Persons" --> Master table
+   Table "Relationships" --> Lookup table
+
+   Establish the tree for lookup table:
+      DSRelationships      --> LookupTreeView.ListSource
+      Field "RelID"        --> LookuptreeView.MasterField
+      Field "RelParentID"  --> LookupTreeView.DetailField
+      Field "RelName"      --> LookupTreeView.ListField         // Node text
+
+  Establish lookup connection:
+      DSPersons           --> LookupTreeView.Datasource
+      Field "ID"          --> LookupTreeView.DataField
+      Field "RelID"       --> LookupTreeView.KeyField
+}
+procedure TForm1.FormShow(Sender: TObject);
+begin
+  Relationships.CreateDataset;
+  Relationships.Open;
+  Relationships.AppendRecord([ 1, 'Grandparents',    0]);
+  Relationships.AppendRecord([10, 'Parents',         1]);
+  Relationships.AppendRecord([11, 'Uncle',           1]);
+  Relationships.AppendRecord([12, 'Aunt',            1]);
+  Relationships.AppendRecord([20, 'Protagonist',    10]);
+  Relationships.AppendRecord([21, 'Brother',        10]);
+  Relationships.AppendRecord([22, 'Sister',         10]);
+  Relationships.AppendRecord([23, 'Brother-in-law', 21]);
+  Relationships.AppendRecord([24, 'Brother-in-law', 22]);
+  Relationships.AppendRecord([25, 'Sister-in-law',  21]);
+  Relationships.AppendRecord([26, 'Sister-in-law',  22]);
+  Relationships.AppendRecord([30, 'Son',            20]);
+  Relationships.AppendRecord([31, 'Daughter',       20]);
+  Relationships.AppendRecord([90, 'Friend',          0]);
+  Relationships.AppendRecord([91, 'Neighbor',        0]);
+
+  // data from: https://en.wikipedia.org/wiki/The_Grapes_of_Wrath
+  Persons.CreateDataset;
+  Persons.Open;
+  Persons.AppendRecord([20, 'Tom Joad']);         // Protagonist
+  Persons.AppendRecord([11, 'Uncle John Joad']);
+  Persons.Appendrecord([10, 'Ma Joad']);          // name not mentioned
+  Persons.AppendRecord([10, 'Tom Joad']);         // Pa Joad
+  Persons.AppendRecord([21, 'Al Joad']);
+  Persons.AppendRecord([21, 'Noah Joad']);
+  Persons.AppendRecord([22, 'Ruthie Joad']);
+  Persons.AppendRecord([22, 'Winfield Joad']);
+  Persons.AppendRecord([22, 'Rose of Sharon Joad Rivers']);
+  Persons.AppendRecord([ 1, 'William James Joad']);
+  Persons.AppendRecord([ 1, 'Granma Joad']);      // name not mentioned
+  Persons.AppendRecord([90, 'Jim Casy']);
+  Persons.AppendRecord([91, 'Muley Graves']);
+  Persons.AppendRecord([24, 'Connie Rivers']);
+  Persons.IndexFieldNames := 'Name';
+  Persons.First;
+end;
+
+procedure TForm1.DBGrid1PrepareCanvas(sender: TObject; DataCol: Integer;
+  Column: TColumn; AState: TGridDrawState);
+begin
+  if Persons.FieldByName('ID').AsInteger = 20 then    // Protagonist
+    DBGrid1.Canvas.Font.Style := [fsBold];
+end;
+
+end.
+
--- a/components/jvcllaz/examples/JvDBTreeView/main.lfm
+++ b/components/jvcllaz/examples/JvDBTreeView/main.lfm
@ -7,7 +7,7 @@ object Form1: TForm1
  ClientHeight = 509
  ClientWidth = 758
  OnCreate = FormCreate
-  LCLVersion = '1.9.0.0'
+  LCLVersion = '2.1.0.0'
  object DBGrid1: TDBGrid
    AnchorSideLeft.Control = Owner
    AnchorSideTop.Control = Owner
--- a/components/jvcllaz/examples/JvDBTreeView/main.pas
+++ b/components/jvcllaz/examples/JvDBTreeView/main.pas
@ -67,6 +67,14 @@ begin
  JvDBTreeView1.FullCollapse;
 end;

+{ Assignment of table fields to tree
+
+   Table                 Tree
+   ID         -->    Tree.MasterField
+   ParentID   -->    Tree.DetailField
+   Name       -->    Tree.itemField
+   Icon       -->    Tree.IconField
+}
 procedure TForm1.FormCreate(Sender: TObject);

  procedure AddRecord(ID, ParentID: Integer; AName: String; AIcon: Integer = -1);
--- a/components/jvcllaz/packages/JvDBLazR.lpk
+++ b/components/jvcllaz/packages/JvDBLazR.lpk
@ -19,7 +19,7 @@
 "/>
    <License Value="The JVCL is released in accordance with the MPL 1.1 license. To get your own copy or read it, go to http://www.mozilla.org/MPL/MPL-1.1.html. "/>
    <Version Major="1" Release="4"/>
-    <Files Count="6">
+    <Files Count="8">
      <Item1>
        <Filename Value="..\run\JvDB\JvDBHTLabel.pas"/>
        <UnitName Value="JvDBHTLabel"/>
@ -44,6 +44,14 @@
        <Filename Value="..\run\JvDB\jvdbutils.pas"/>
        <UnitName Value="JvDBUtils"/>
      </Item6>
+      <Item7>
+        <Filename Value="..\run\JvDB\jvdblookuptreeview.pas"/>
+        <UnitName Value="JvDBLookupTreeView"/>
+      </Item7>
+      <Item8>
+        <Filename Value="..\run\JvDB\jvdbconst.pas"/>
+        <UnitName Value="jvdbconst"/>
+      </Item8>
    </Files>
    <RequiredPkgs Count="4">
      <Item1>
--- a/components/jvcllaz/packages/jvmmlazr.lpk
+++ b/components/jvcllaz/packages/jvmmlazr.lpk
@ -39,7 +39,7 @@
      </Item5>
      <Item6>
        <Filename Value="..\run\JvMM\jvid3v2base.pas"/>
-        <UnitName Value="JvID3v2Base"/>
+        <UnitName Value="JvId3v2Base"/>
      </Item6>
      <Item7>
        <Filename Value="..\run\JvMM\jvid3v2.pas"/>
--- a/components/jvcllaz/resource/jvdbreg.res
+++ b/components/jvcllaz/resource/jvdbreg.res
--- a/components/jvcllaz/run/JvCore/JvJCLUtils.pas
+++ b/components/jvcllaz/run/JvCore/JvJCLUtils.pas
@ -336,6 +336,11 @@ function StrToBool(const S: string): Boolean;
 function Var2Type(V: Variant; const DestVarType: Integer): Variant;
 function VarToInt(V: Variant): Integer;
 function VarToFloat(V: Variant): Double;
+*************)
+
+function VarIsNullEmpty(const V: Variant): Boolean;
+
+(****************************** NOT CONVERTED ****

 { following functions are not documented
  because they do not work properly sometimes, so do not use them }
@ -1255,7 +1260,7 @@ function FindUnusedFileName(FileName: string; const FileExt: string; NumberPrefi
 implementation

 uses
-  Math, LazFileUtils, LclStrConsts,
+  Math, Variants, LazFileUtils, LclStrConsts,
  JvConsts;

 (******************** NOT CONVERTED
@ -2959,6 +2964,14 @@ function VarToFloat(V: Variant): Double;
 begin
  Result := Var2Type(V, varDouble);
 end;
+*********)
+
+function VarIsNullEmpty(const V: Variant): Boolean;
+begin
+  Result := VarIsNull(V) or VarIsEmpty(V);
+end;
+
+(************************** NOT CONVERTED ***

 function CopyDir(const SourceDir, DestDir: TFileName): Boolean;
 var
--- a/components/jvcllaz/run/JvCore/JvTypes.pas
+++ b/components/jvcllaz/run/JvCore/JvTypes.pas
@ -307,6 +307,7 @@ type
    ckID: TJvFourCC;
    ckSize: Longint;
  end;
+****************************)

  TJvAniHeader = packed record
    dwSizeof: Longint;
@ -322,7 +323,6 @@ type

  TJvChangeColorEvent = procedure(Sender: TObject; Foreground, Background: TColor) of object;

-***********)
  TJvLayout = (lTop, lCenter, lBottom);
  TJvBevelStyle = (bsShape, bsLowered, bsRaised);

--- a/components/jvcllaz/run/JvDB/JvDBTreeView.pas
+++ b/components/jvcllaz/run/JvDB/JvDBTreeView.pas
@ -48,6 +48,19 @@ Usage:
  - The text to be displayed as node text is taken from field "ItemField"
  - Optionally, there can ba an "IconField" from which the icon index into the
    ImageList is taken.
+
+From http://wiki.delphi-jedi.org/wiki/JVCL_Help:TJvDBTreeView:
+  - MasterField: is equivalent to the absoluteIndex of the TreeView, a unique
+                 ID for each TreeNode or record in the table.
+  - DetailField: is the hierachical link to the parent item, a foreing key
+                 to the master filed in a self relation table
+  - ItemField:   is the field that contain the display name or the caption of
+                 a treeNode.
+  - IconField:   is a integer field that point to a image index on a TImageList
+                 object that contains the icons for the treeView.
+  - StartMasterValue: is the begining level to start build the TreeView,
+                 0 = start from the root itens, 1 = start from the second level,
+                 and so on.
 -----------------------------------------------------------------------------}
 // $Id$

@ -201,9 +214,6 @@ type
    property MasterValue: Variant read FMasterValue;
  end;

-  {$IFDEF RTL230_UP}
-  [ComponentPlatformsAttribute(pidWin32 or pidWin64)]
-  {$ENDIF RTL230_UP}
  TJvDBTreeView = class(TJvCustomDBTreeView)
  published
    property DataSource;
--- a/components/jvcllaz/run/JvDB/jvdbconst.pas
+++ b/components/jvcllaz/run/JvDB/jvdbconst.pas
@ -0,0 +1,17 @@
+unit JvDBConst;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils;
+
+resourcestring
+  SPropDefByLookup = 'Property already defined by lookup field.';
+  SDataSourceFixed = 'Operation is not allowed with DataSource.';
+
+implementation
+
+end.
+
--- a/components/jvcllaz/run/JvDB/jvdblookuptreeview.pas
+++ b/components/jvcllaz/run/JvDB/jvdblookuptreeview.pas
--- a/components/jvcllaz/run/JvDB/jvdbutils.pas
+++ b/components/jvcllaz/run/JvDB/jvdbutils.pas
@ -132,6 +132,9 @@ procedure CheckRequiredField(Field: TField);
 procedure CheckRequiredFields(const Fields: array of TField);
 procedure GotoBookmarkEx(DataSet: TDataSet; const Bookmark: TBookmark; Mode: TResyncMode = [rmExact, rmCenter]; ForceScrollEvents: Boolean = False);

+function GetFieldProperty(ADataSet: TDataSet; AControl: TComponent;
+  const AFieldName: string): TField;
+
 { SQL expressions }

 function DateToSQL(Value: TDateTime): string;
@ -264,6 +267,15 @@ begin
  end;
 end;

+function GetFieldProperty(ADataSet: TDataSet; AControl: TComponent;
+  const AFieldName: string): TField;
+begin
+  Result := ADataSet.FindField(AFieldName);
+  if Result = nil then
+    DatabaseErrorFmt(SFieldNotFound, [AFieldName], AControl);
+end;
+
+
 { Refresh Query procedure }

 procedure RefreshQuery(Query: TDataSet);