dblookupeh.pas

自己做的用delphi开发的学生成绩管理系统。

{*******************************************************}
{                                                       }
{                       EhLib v3.0                      }
{             TDBLookupComboboxEh component             }
{                                                       }
{      Copyright (c) 2001-2003 by Dmitry V. Bolshakov   }
{                                                       }
{*******************************************************}

{$I EhLib.Inc}

{$IFDEF EH_LIB_VCL}
unit DBLookupEh;
{$ELSE}
unit QDBLookupEh;
{$ENDIF}

interface

{$IFDEF EH_LIB_VCL}
uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
{$IFDEF EH_LIB_6}Variants, {$ENDIF}
  StdCtrls, Mask, Db, DBCtrls, Buttons, DBCtrlsEh, ToolCtrlsEh, Menus,
  DBLookupGridsEh, DBGridEh;
{$ELSE}
uses
  SysUtils, Classes, Variants, Db, DBCtrls, QGraphics, QControls,
  QForms, QDialogs, QStdCtrls, QMask, QButtons, QDBCtrlsEh, QToolCtrlsEh,
  QMenus, QDBLookupGridsEh, QDBGridEh;
{$ENDIF}

type

  TCustomDBLookupComboboxEh = class;

  TLookupComboboxDropDownBoxEh = class(TColumnDropDownBoxEh)
  published
    property Align;
    property AutoDrop;
    property Rows;
    property ShowTitles;
    property Sizable;
    property SpecRow;
    property Width;
  end;

{ TDataSourceLinkEh }

  TDataSourceLinkEh = class(TFieldDataLinkEh)
  private
    FDataIndependentValueAsText: Boolean;
    FDBLookupControl: TCustomDBLookupComboboxEh;
  protected
    constructor Create;
    procedure LayoutChanged; override;
  end;

{ TListSourceLinkEh }

  TListSourceLinkEh = class(TDataLink)
  private
    FDBLookupControl: TCustomDBLookupComboboxEh;
  protected
    procedure ActiveChanged; override;
    procedure DataSetChanged; override;
    procedure LayoutChanged; override;
  public
    constructor Create;
  end;

{ TDBLookupComboboxEh }

  TDBLookupComboboxEhStyle = (csDropDownListEh, csDropDownEh);

  TCustomDBLookupComboboxEh = class(TCustomDBEditEh, ILookupGridOwner)
  private
    FDataFields: TFieldsArrEh;
    FDataFieldName: String;
    FDataFieldsUpdating: Boolean;
    FDataList: TPopupDataGridEh;
    FDropDownBox: TLookupComboboxDropDownBoxEh;
    FInternalTextSetting: Boolean;
    FKeyFields: TFieldsArrEh;
    FKeyFieldName: String;
    FKeyTextIndependent: Boolean;
    FKeyValue: Variant;
    FListActive: Boolean;
    FListColumnMothed: Boolean;
    FListField: TField;
    FListFieldIndex: Integer;
    FListFieldName: String;
    FListFields: TList;
    FListLink: TListSourceLinkEh;
    FListSource: TDataSource;
    FListVisible: Boolean;
    FLockUpdateKeyTextIndependent: Boolean;
    FLookupMode: Boolean;
    FLookupSource: TDataSource;
    FMasterFields: TFieldsArrEh;
    FMasterFieldNames: String;
    FOnCloseUp: TCloseUpEventEh;
    FOnDropDown: TNotifyEvent;
    FOnKeyValueChanged: TNotifyEvent;
    FOnNotInList: TNotInListEventEh;
    FStyle: TDBLookupComboboxEhStyle;
    FTextBeenChanged: Boolean;
    function GetDataLink: TDataSourceLinkEh;
    function GetKeyFieldName: String;
    function GetListSource: TDataSource;
    function GetOnButtonClick: TButtonClickEventEh;
    function GetOnButtonDown: TButtonDownEventEh;
    function GetOnDropDownBoxCheckButton: TCheckTitleEhBtnEvent;
    function GetOnDropDownBoxDrawColumnCell: TDrawColumnEhCellEvent;
    function GetOnDropDownBoxGetCellParams: TGetCellEhParamsEvent;
    function GetOnDropDownBoxSortMarkingChanged: TNotifyEvent;
    function GetOnDropDownBoxTitleBtnClick: TTitleEhClickEvent;
    procedure CheckNotCircular;
    procedure CheckNotLookup;
    procedure CMCancelMode(var Message: TCMCancelMode); message CM_CANCELMODE;
    procedure CMMouseWheel(var Message: TCMMouseWheel); message CM_MOUSEWHEEL;
    procedure CMWantSpecialKey(var Message: TCMWantSpecialKey); message CM_WANTSPECIALKEY;
    procedure DataListKeyValueChanged(Sender: TObject);
    procedure EMReplacesel(var Message: TMessage); message EM_REPLACESEL;
//    procedure ListMouseUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
    procedure ListMouseCloseUp(Sender: TObject; Accept: Boolean);
    procedure ListColumnMoved(Sender: TObject; FromIndex, ToIndex: Longint);
    procedure SetDataFieldName(const Value: String);
    procedure SetDropDownBox(const Value: TLookupComboboxDropDownBoxEh);
    procedure SetKeyFieldName(const Value: String);
    procedure SetKeyValue(const Value: Variant);
    procedure SetListFieldName(const Value: String);
    procedure SetListSource(Value: TDataSource);
    procedure SetLookupMode(Value: Boolean);
    procedure SetOnButtonClick(const Value: TButtonClickEventEh);
    procedure SetOnButtonDown(const Value: TButtonDownEventEh);
    procedure SetOnDropDownBoxCheckButton(const Value: TCheckTitleEhBtnEvent);
    procedure SetOnDropDownBoxDrawColumnCell(const Value: TDrawColumnEhCellEvent);
    procedure SetOnDropDownBoxGetCellParams(const Value: TGetCellEhParamsEvent);
    procedure SetOnDropDownBoxSortMarkingChanged(const Value: TNotifyEvent);
    procedure SetOnDropDownBoxTitleBtnClick(const Value: TTitleEhClickEvent);
    procedure SetStyle(const Value: TDBLookupComboboxEhStyle);
    procedure UpdateKeyTextIndependent;
    procedure UpdateReadOnly;
    procedure WMChar(var Message: TWMChar); message WM_CHAR;
    procedure WMCut(var Message: TMessage); message WM_CUT;
    procedure WMKeyDown(var Message: TWMKeyDown); message WM_KEYDOWN;
    procedure WMKillFocus(var Message: TWMKillFocus); message WM_KILLFOCUS;
    procedure WMPaste(var Message: TMessage); message WM_PASTE;
    procedure WMSetCursor(var Message: TWMSetCursor); message WM_SETCURSOR;
  protected
    function ButtonEnabled: Boolean; override;
    function CanModify(TryEdit: Boolean): Boolean; virtual;
    function CreateDataLink: TFieldDataLinkEh; override;
    function CreateEditButton: TEditButtonEh; override;
    function CompatibleVarValue(AFieldsArr: TFieldsArrEh; AVlaue: Variant): Boolean; virtual;
    function DefaultAlignment: TAlignment; override;
    function DoMouseWheelDown(Shift: TShiftState; MousePos: TPoint): Boolean; override;
    function DoMouseWheelUp(Shift: TShiftState; MousePos: TPoint): Boolean; override;
    function GetDataField: TField; reintroduce;
    function GetDisplayTextForPaintCopy: String; override;
    function GetListFieldsWidth: Integer; virtual;
    function GetVariantValue: Variant; override;
    function IsValidChar(InputChar: Char): Boolean; override;
    function LocateStr(Str: String; PartialKey: Boolean): Boolean; virtual;
    function TraceMouseMoveForPopupListbox(Sender: TObject; Shift: TShiftState; X, Y: Integer): Boolean;
    function UsedListSource: TDataSource;
    procedure ActiveChanged; override;
    procedure ButtonDown(IsDownButton: Boolean); override;
    procedure Click; override;
    procedure DataChanged; override;
    procedure EditButtonMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer); override;
    procedure InternalSetText(AText: String); override;
    procedure InternalSetValue(AValue: Variant); override;
    procedure HookOnChangeEvent(Sender: TObject);
    procedure KeyDown(var Key: Word; Shift: TShiftState); override;
    procedure KeyPress(var Key: Char); override;
    procedure KeyValueChanged; virtual;
    procedure KeyUp(var Key: Word; Shift: TShiftState); override;
    procedure ListLinkDataChanged; virtual;
    procedure Loaded; override;
    procedure MouseDown(Button: TMouseButton; Shift: TShiftState; X, Y: Integer); override;
    procedure MouseMove(Shift: TShiftState; X, Y: Integer); override;
    procedure Notification(AComponent: TComponent; Operation: TOperation); override;
    procedure ProcessSearchStr(Str: String); virtual;
    procedure SelectKeyValue(const Value: Variant); virtual;
    procedure SetEditText(Value: String);
    procedure SetFocused(Value: Boolean); override;
    procedure SpecRowChanged(Sender: TObject); virtual;
    procedure UpdateDataFields; virtual;
    procedure UpdateListFields; virtual;
    procedure UpdateListLinkDataSource; virtual;
    property DataLink: TDataSourceLinkEh read GetDataLink;
    property ListActive: Boolean read FListActive;
    property ListFields: TList read FListFields;
    property ListLink: TListSourceLinkEh read FListLink;
    property OnButtonClick: TButtonClickEventEh read GetOnButtonClick write SetOnButtonClick;
    property OnButtonDown: TButtonDownEventEh read GetOnButtonDown write SetOnButtonDown;
  protected
    { ILookupGridOwner }
    function GetLookupGrid: TCustomDBGridEh;
    function GetOptions: TDBLookupGridEhOptions;
    procedure SetOptions(Value: TDBLookupGridEhOptions);
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    function LocateKey: Boolean; virtual;
    procedure ClearDataProps;
    procedure CloseUp(Accept: Boolean); override;
    procedure DefaultHandler(var Message); override;
    procedure DropDown; override;
    procedure SelectAll; virtual;
    procedure SelectNextValue(IsPrior: Boolean);
    procedure UpdateData; override;
    property DataField: String read FDataFieldName write SetDataFieldName;
    property DataList: TPopupDataGridEh read FDataList;
    //property DataSource: TDataSource read GetDataSource write SetDataSource; //Internal error: E4983
    property DropDownBox: TLookupComboboxDropDownBoxEh read FDropDownBox write SetDropDownBox;
    property Field: TField read GetDataField;
    property KeyField: String read GetKeyFieldName write SetKeyFieldName;
    property KeyValue: Variant read FKeyValue write SelectKeyValue;
    property ListField: String read FListFieldName write SetListFieldName;
    property ListFieldIndex: Integer read FListFieldIndex write FListFieldIndex default 0;
    property ListSource: TDataSource read GetListSource write SetListSource;
    property ListVisible: Boolean read FListVisible;
    property Style: TDBLookupComboboxEhStyle read FStyle write SetStyle default csDropDownListEh;
    property Text;
    property OnCloseUp: TCloseUpEventEh read FOnCloseUp write FOnCloseUp;
    property OnDropDown: TNotifyEvent read FOnDropDown write FOnDropDown;
    property OnKeyValueChanged: TNotifyEvent read FOnKeyValueChanged write FOnKeyValueChanged;
    property OnNotInList: TNotInListEventEh read FOnNotInList write FOnNotInList;
    property OnDropDownBoxCheckButton: TCheckTitleEhBtnEvent
      read GetOnDropDownBoxCheckButton write SetOnDropDownBoxCheckButton;
    property OnDropDownBoxDrawColumnCell: TDrawColumnEhCellEvent
      read GetOnDropDownBoxDrawColumnCell write SetOnDropDownBoxDrawColumnCell;
    property OnDropDownBoxGetCellParams: TGetCellEhParamsEvent
      read GetOnDropDownBoxGetCellParams write SetOnDropDownBoxGetCellParams;
    property OnDropDownBoxSortMarkingChanged: TNotifyEvent
      read GetOnDropDownBoxSortMarkingChanged write SetOnDropDownBoxSortMarkingChanged;
    property OnDropDownBoxTitleBtnClick: TTitleEhClickEvent
      read GetOnDropDownBoxTitleBtnClick write SetOnDropDownBoxTitleBtnClick;
  end;

  TDBLookupComboboxEh = class(TCustomDBLookupComboboxEh)
  published
    property Alignment;
    property AlwaysShowBorder;
    property AutoSelect;
    property AutoSize;
    property BorderStyle;
    property Anchors;
    property BiDiMode;
    property Constraints;
    property DragKind;
    property ParentBiDiMode;
    property OnEndDock;
    property OnStartDock;
{$IFDEF EH_LIB_5}
    property OnContextPopup;
{$ENDIF}
    property Color;
    property Ctl3D;
    property DataField;
    property DataSource;
    property DragCursor;
    property DragMode;
    property DropDownBox;
    property Enabled;
    property EditButton;
    property EditButtons;
    property Font;
    property Flat;
    property ImeMode;
    property ImeName;
    property KeyField;
    property ListField;
    property ListFieldIndex;
    property ListSource;
    property ParentColor;
    property ParentCtl3D;
    property ParentFont;
    property ParentShowHint;
    property PopupMenu;
    property ReadOnly;
    property ShowHint;
    property Style;
    property TabOrder;
    property TabStop;
    property Visible;
    property WordWrap;
    property OnButtonClick;
    property OnButtonDown;
    property OnChange;
    property OnClick;
    property OnCloseUp;
    property OnDragDrop;
    property OnDragOver;
    property OnDropDown;
    property OnDropDownBoxCheckButton;
    property OnDropDownBoxDrawColumnCell;
    property OnDropDownBoxGetCellParams;
    property OnDropDownBoxSortMarkingChanged;
    property OnDropDownBoxTitleBtnClick;
    property OnEndDrag;
    property OnEnter;
    property OnExit;
    property OnKeyDown;
    property OnKeyPress;
    property OnKeyUp;
    property OnKeyValueChanged;
    property OnMouseDown;
    property OnMouseMove;
    property OnMouseUp;
    property OnNotInList;
    property OnUpdateData;
    property OnStartDrag;
  end;

implementation

uses DbConsts, DBGrids, Clipbrd{$IFDEF EH_LIB_6}, VDBConsts{$ENDIF};

function VarEquals(const V1, V2: Variant): Boolean;
var i: Integer;
begin
  Result := not (VarIsArray(V1) xor VarIsArray(V2));
  if not Result then Exit;
  Result := False;
  try
    if VarIsArray(V1) and VarIsArray(V2) and
      (VarArrayDimCount(V1) = VarArrayDimCount(V2)) and
      (VarArrayLowBound(V1, 1) = VarArrayLowBound(V2, 1)) and
      (VarArrayHighBound(V1, 1) = VarArrayHighBound(V2, 1))
      then
      for i := VarArrayLowBound(V1, 1) to VarArrayHighBound(V1, 1) do
      begin
        Result := V1[i] = V2[i];
        if not Result then Exit;
      end
    else
      Result := V1 = V2;
  except
  end;
end;

{ TDataSourceLinkEh }

constructor TDataSourceLinkEh.Create;
begin
  inherited Create;
  MultiFields := True;
end;

procedure TDataSourceLinkEh.LayoutChanged;
begin
  if FDBLookupControl <> nil then FDBLookupControl.UpdateDataFields;
end;

{ TListSourceLinkEh }

constructor TListSourceLinkEh.Create;
begin
  inherited Create;
  VisualControl := True;
end;

procedure TListSourceLinkEh.ActiveChanged;
begin
  if FDBLookupControl <> nil then FDBLookupControl.UpdateListFields;
end;

procedure TListSourceLinkEh.DataSetChanged;
begin
  if FDBLookupControl <> nil then FDBLookupControl.ListLinkDataChanged;
end;

procedure TListSourceLinkEh.LayoutChanged;
begin
  if FDBLookupControl <> nil then FDBLookupControl.UpdateListFields;
end;

{ TCustomDBLookupComboboxEh }

constructor TCustomDBLookupComboboxEh.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);

  FLookupSource := TDataSource.Create(Self);
  FListLink := TListSourceLinkEh.Create;
  FListLink.FDBLookupControl := Self;
  FListFields := TList.Create;
  FKeyValue := Null;

  FDataList := TPopupDataGridEh.Create(Self);
  FDataList.Parent := Self;
  FDataList.Visible := False;
  FDataList.Ctl3D := True;
  FDataList.ParentCtl3D := False;
  //FDataList.OnMouseUp := ListMouseUp;
  FDataList.OnMouseCloseUp := ListMouseCloseUp;
  FDataList.OnUserKeyValueChange := DataListKeyValueChanged;


  FDropDownBox := TLookupComboboxDropDownBoxEh.Create(Self);
  FDropDownBox.Rows := 7;
  FDropDownBox.SpecRow.OnChanged := SpecRowChanged;
  FKeyTextIndependent := True;
end;

destructor TCustomDBLookupComboboxEh.Destroy;
begin
  FListFields.Free;
  FListFields := nil;
  FListLink.FDBLookupControl := nil;
  FListLink.Free;
  FListLink := nil;
  FDropDownBox.Free;
  FDropDownBox := nil;
  inherited Destroy;