rxdbcomb.pas

rxlib2.75控件包

{*******************************************************}
{                                                       }
{         Delphi VCL Extensions (RX)                    }
{                                                       }
{         Copyright (c) 1997 Master-Bank                }
{                                                       }
{*******************************************************}

unit RxDBComb;

{$I RX.INC}

interface

uses Windows, DbCtrls, VDBConsts,
  Messages, Menus, Graphics, Classes, Controls, DB, 
  {$IFNDEF RX_D3} DBTables, {$ENDIF} StdCtrls, DBConsts;

type

{ TCustomDBComboBox }

  TCustomDBComboBox = class(TCustomComboBox)
  private
    FDataLink: TFieldDataLink;
{$IFDEF WIN32}
    FPaintControl: TPaintControl;
{$ENDIF}
    procedure DataChange(Sender: TObject);
    procedure EditingChange(Sender: TObject);
    function GetDataField: string;
    function GetDataSource: TDataSource;
    function GetField: TField;
    function GetReadOnly: Boolean;
    procedure SetDataField(const Value: string);
    procedure SetDataSource(Value: TDataSource);
    procedure SetEditReadOnly;
    procedure SetReadOnly(Value: Boolean);
    procedure UpdateData(Sender: TObject);
    function GetComboText: string; virtual;
    procedure SetComboText(const Value: string); virtual;
    procedure CMExit(var Message: TCMExit); message CM_EXIT;
{$IFDEF WIN32}
    procedure CMGetDataLink(var Message: TMessage); message CM_GETDATALINK;
    procedure WMPaint(var Message: TWMPaint); message WM_PAINT;
{$ELSE}
    function GetStyle: TComboBoxStyle;
{$ENDIF}
  protected
    procedure SetItems(const Value: TStrings); override;
    procedure Change; override;
    procedure Click; override;
    procedure ComboWndProc(var Message: TMessage; ComboWnd: HWnd;
      ComboProc: Pointer); override;
    procedure CreateWnd; override;
    procedure DropDown; override;
    function GetPaintText: string; virtual;
    procedure KeyDown(var Key: Word; Shift: TShiftState); override;
    procedure KeyPress(var Key: Char); override;
    procedure Loaded; override;
    procedure Notification(AComponent: TComponent;
      Operation: TOperation); override;
    procedure SetStyle(Value: TComboBoxStyle); {$IFDEF WIN32} override {$ELSE} virtual {$ENDIF};
    procedure WndProc(var Message: TMessage); override;
    property ComboText: string read GetComboText write SetComboText;
{$IFNDEF WIN32}
    property Style: TComboBoxStyle read GetStyle write SetStyle default csDropDown;
{$ENDIF WIN32}
    property DataField: string read GetDataField write SetDataField;
    property DataSource: TDataSource read GetDataSource write SetDataSource;
    property ReadOnly: Boolean read GetReadOnly write SetReadOnly default False;
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
{$IFDEF RX_D4}
    function ExecuteAction(Action: TBasicAction): Boolean; override;
    function UpdateAction(Action: TBasicAction): Boolean; override;
    function UseRightToLeftAlignment: Boolean; override;
{$ENDIF}
    property Field: TField read GetField;
    property Items write SetItems;
    property Text;
  end;

{ TRxDBComboBox }

  TRxDBComboBox = class(TCustomDBComboBox)
  private
    FValues: TStrings;
    FEnableValues: Boolean;
    procedure SetEnableValues(Value: Boolean);
    procedure SetValues(Value: TStrings);
    procedure ValuesChanged(Sender: TObject);
  protected
    procedure SetStyle(Value: TComboBoxStyle); override;
    function GetComboText: string; override;
    function GetPaintText: string; override;
    procedure SetComboText(const Value: string); override;
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
  published
    property Style; { must be published before Items }
    property Color;
    property Ctl3D;
    property DataField;
    property DataSource;
    property DragMode;
    property DragCursor;
    property DropDownCount;
    property Enabled;
    property EnableValues: Boolean read FEnableValues write SetEnableValues;
    property Font;
{$IFDEF RX_D4}
    property Anchors;
    property BiDiMode;
    property Constraints;
    property DragKind;
    property ParentBiDiMode;
{$ENDIF}
{$IFDEF WIN32}
  {$IFNDEF VER90}
    property ImeMode;
    property ImeName;
  {$ENDIF}
{$ENDIF}
    property ItemHeight;
    property Items;
    property ParentColor;
    property ParentCtl3D;
    property ParentFont;
    property ParentShowHint;
    property PopupMenu;
    property ReadOnly;
    property ShowHint;
    property Sorted;
    property TabOrder;
    property TabStop;
    property Values: TStrings read FValues write SetValues;
    property Visible;
    property OnChange;
    property OnClick;
    property OnDblClick;
    property OnDragDrop;
    property OnDragOver;
    property OnDrawItem;
    property OnDropDown;
    property OnEndDrag;
    property OnEnter;
    property OnExit;
    property OnKeyDown;
    property OnKeyPress;
    property OnKeyUp;
    property OnMeasureItem;
{$IFDEF WIN32}
    property OnStartDrag;
{$ENDIF}
{$IFDEF RX_D5}
    property OnContextPopup;
{$ENDIF}
{$IFDEF RX_D4}
    property OnEndDock;
    property OnStartDock;
{$ENDIF}
  end;

implementation

uses DBUtils;

{ TCustomDBComboBox }

constructor TCustomDBComboBox.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
{$IFDEF WIN32}
  ControlStyle := ControlStyle + [csReplicatable];
{$ENDIF}
  FDataLink := TFieldDataLink.Create;
  FDataLink.Control := Self;
  FDataLink.OnDataChange := DataChange;
  FDataLink.OnUpdateData := UpdateData;
  FDataLink.OnEditingChange := EditingChange;
{$IFDEF WIN32}
  FPaintControl := TPaintControl.Create(Self, 'COMBOBOX');
{$ENDIF}
end;

destructor TCustomDBComboBox.Destroy;
begin
{$IFDEF WIN32}
  FPaintControl.Free;
{$ENDIF}
  FDataLink.OnDataChange := nil;
  FDataLink.OnUpdateData := nil;
  FDataLink.Free;
  FDataLink := nil;
  inherited Destroy;
end;

procedure TCustomDBComboBox.Loaded;
begin
  inherited Loaded;
  if (csDesigning in ComponentState) then DataChange(Self);
end;

procedure TCustomDBComboBox.Notification(AComponent: TComponent;
  Operation: TOperation);
begin
  inherited Notification(AComponent, Operation);
  if (Operation = opRemove) and (FDataLink <> nil) and
    (AComponent = DataSource) then DataSource := nil;
end;

procedure TCustomDBComboBox.CreateWnd;
begin
  inherited CreateWnd;
  SetEditReadOnly;
end;

procedure TCustomDBComboBox.DataChange(Sender: TObject);
begin
  if DroppedDown then Exit;
  if FDataLink.Field <> nil then ComboText := FDataLink.Field.Text
  else if csDesigning in ComponentState then ComboText := Name
  else ComboText := '';
end;

procedure TCustomDBComboBox.UpdateData(Sender: TObject);
begin
  FDataLink.Field.Text := ComboText;
end;

procedure TCustomDBComboBox.SetComboText(const Value: string);
var
  I: Integer;
  Redraw: Boolean;
begin
  if Value <> ComboText then begin
    if Style <> csDropDown then begin
      Redraw := (Style <> csSimple) and HandleAllocated;
      if Redraw then SendMessage(Handle, WM_SETREDRAW, 0, 0);
      try
        if Value = '' then I := -1 else I := Items.IndexOf(Value);
        ItemIndex := I;
      finally
        if Redraw then begin
          SendMessage(Handle, WM_SETREDRAW, 1, 0);
          Invalidate;
        end;
      end;
      if I >= 0 then Exit;
    end;
    if Style in [csDropDown, csSimple] then Text := Value;
  end;
end;

function TCustomDBComboBox.GetComboText: string;
var
  I: Integer;
begin
  if Style in [csDropDown, csSimple] then Result := Text
  else begin
    I := ItemIndex;
    if I < 0 then Result := '' else Result := Items[I];
  end;
end;

procedure TCustomDBComboBox.Change;
begin
  FDataLink.Edit;
  inherited Change;
  FDataLink.Modified;
end;

procedure TCustomDBComboBox.Click;
begin
  FDataLink.Edit;
  inherited Click;
  FDataLink.Modified;
end;

procedure TCustomDBComboBox.DropDown;
begin
{$IFNDEF WIN32}
  FDataLink.Edit;
{$ENDIF}
  inherited DropDown;
end;

function TCustomDBComboBox.GetDataSource: TDataSource;
begin
  Result := FDataLink.DataSource;
end;

procedure TCustomDBComboBox.SetDataSource(Value: TDataSource);
begin
{$IFDEF RX_D4}
  if not (FDataLink.DataSourceFixed and (csLoading in ComponentState)) then
{$ENDIF}
    FDataLink.DataSource := Value;
{$IFDEF WIN32}
  if Value <> nil then Value.FreeNotification(Self);
{$ENDIF}
end;

function TCustomDBComboBox.GetDataField: string;
begin
  Result := FDataLink.FieldName;
end;

procedure TCustomDBComboBox.SetDataField(const Value: string);