oldschooldbnavigator.pas

地址档案管理系统

{*******************************************************}
{                                                       }
{       Borland Delphi Visual Component Library         }
{                                                       }
{       Copyright (c) 1995,99 Inprise Corporation       }
{                                                       }
{*******************************************************}
{$G+} 

unit OldSchoolDBNavigator;

{$R-,H+,X+}


interface

uses Variants, Windows, SysUtils, Messages, Controls, Forms, Classes, 
     Graphics, Menus, StdCtrls, ExtCtrls, Mask, Buttons, ComCtrls, DB, DBCtrls;

type

{ TOldSchoolDBNavigator }
  TOSDataLink = class;
  TOSButton = class;
  TOSButtonStyle = set of (nsAllowTimer, nsFocusRect);

  TOldSchoolDBNavigator = class (TCustomPanel)
  private
    FDataLink: TOSDataLink;
    FVisibleButtons: TButtonSet;
    FHints: TStrings;
    FDefHints: TStrings;
    ButtonWidth: Integer;
    MinBtnSize: TPoint;
    FOnNavClick: ENavClick;
    FBeforeAction: ENavClick;
    FocusedButton: TNavigateBtn;
    FConfirmDelete: Boolean;
    FFlat: Boolean;
    procedure BtnMouseDown (Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure ClickHandler(Sender: TObject);
    function GetDataSource: TDataSource;
    function GetHints: TStrings;
    procedure HintsChanged(Sender: TObject);
    procedure InitButtons;
    procedure InitHints;
    procedure SetDataSource(Value: TDataSource);
    procedure SetFlat(Value: Boolean);
    procedure SetHints(Value: TStrings);
    procedure SetSize(var W: Integer; var H: Integer);
    procedure SetVisible(Value: TButtonSet);
    procedure WMSize(var Message: TWMSize);  message WM_SIZE;
    procedure WMSetFocus(var Message: TWMSetFocus); message WM_SETFOCUS;
    procedure WMKillFocus(var Message: TWMKillFocus); message WM_KILLFOCUS;
    procedure WMGetDlgCode(var Message: TWMGetDlgCode); message WM_GETDLGCODE;
    procedure CMEnabledChanged(var Message: TMessage); message CM_ENABLEDCHANGED;
    procedure WMWindowPosChanging(var Message: TWMWindowPosChanging); message WM_WINDOWPOSCHANGING;
  protected
    Buttons: array[TNavigateBtn] of TOSButton;
    procedure DataChanged;
    procedure EditingChanged;
    procedure ActiveChanged;
    procedure Loaded; override;
    procedure KeyDown(var Key: Word; Shift: TShiftState); override;
    procedure Notification(AComponent: TComponent;
      Operation: TOperation); override;
    procedure GetChildren(Proc: TGetChildProc; Root: TComponent); override;
    procedure CalcMinSize(var W, H: Integer);
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    procedure SetBounds(ALeft, ATop, AWidth, AHeight: Integer); override;
    procedure BtnClick(Index: TNavigateBtn); virtual;
  published
    property DataSource: TDataSource read GetDataSource write SetDataSource;
    property VisibleButtons: TButtonSet read FVisibleButtons write SetVisible
      default [nbFirst, nbPrior, nbNext, nbLast, nbInsert, nbDelete,
        nbEdit, nbPost, nbCancel, nbRefresh];
    property Align;
    property Anchors;
    property Constraints;
    property DragCursor;
    property DragKind;
    property DragMode;
    property Enabled;
    property Flat: Boolean read FFlat write SetFlat default False;
    property Ctl3D;
    property Hints: TStrings read GetHints write SetHints;
    property ParentCtl3D;
    property ParentShowHint;
    property PopupMenu;
    property ConfirmDelete: Boolean read FConfirmDelete write FConfirmDelete default True;
    property ShowHint;
    property TabOrder;
    property TabStop;
    property Visible;
    property BeforeAction: ENavClick read FBeforeAction write FBeforeAction;
    property OnClick: ENavClick read FOnNavClick write FOnNavClick;
    property OnContextPopup;
    property OnDblClick;
    property OnDragDrop;
    property OnDragOver;
    property OnEndDock;
    property OnEndDrag;
    property OnEnter;
    property OnExit;
    property OnResize;
    property OnStartDock;
    property OnStartDrag;
  end;

{ TOSButton }

  TOSButton = class(TSpeedButton)
  private
    FIndex: TNavigateBtn;
    FNavStyle: TOSButtonStyle;
    FRepeatTimer: TTimer;
    procedure TimerExpired(Sender: TObject);
  protected
    procedure Paint; override;
    procedure MouseDown(Button: TMouseButton; Shift: TShiftState;
      X, Y: Integer); override;
    procedure MouseUp(Button: TMouseButton; Shift: TShiftState;
      X, Y: Integer); override;
  public
    destructor Destroy; override;
    property NavStyle: TOSButtonStyle read FNavStyle write FNavStyle;
    property Index : TNavigateBtn read FIndex write FIndex;
  end;

{ TOSDataLink }

  TOSDataLink = class(TDataLink)
  private
    FNavigator: TOldSchoolDBNavigator;
  protected
    procedure EditingChanged; override;
    procedure DataSetChanged; override;
    procedure ActiveChanged; override;
  public
    constructor Create(ANav: TOldSchoolDBNavigator);
    destructor Destroy; override;
  end;

function OkToChangeFieldAlignment(AField: TField; Alignment: TAlignment): Boolean;
function DBUseRightToLeftAlignment(AControl: TControl; AField: TField): Boolean;
procedure Register;

implementation

uses DBLogDlg, DBPWDlg, Clipbrd, DBConsts, VDBConsts, Dialogs, Math, Themes;

{$R DBCtrls.res}

{ BiDiMode support routines }

function OkToChangeFieldAlignment(AField: TField; Alignment: TAlignment): Boolean;
begin
  { dont change the alignment for these fields:
    ftSmallInt     ftInteger      ftWord         ftFloat        ftCurrency
    ftBCD          ftDate         ftTime         ftDateTime     ftAutoInc
    ftTimeStamp    ftFMTBcd}
  if Assigned(AField) then with AField do
    Result := (DataType < ftSmallInt) or
              (DataType = ftBoolean) or
              ((DataType > ftDateTime) and (DataType <> ftAutoInc)
              and (DataType <> ftFMTBcd))
  else
    Result := Alignment <> taCenter;
end;

{ AField is needed because TDBLookupComboBox, for its combobox, uses FListField
  for its alignment characteristics not FField }
function DBUseRightToLeftAlignment(AControl: TControl; AField: TField): Boolean;
var
  AAlignment: TAlignment;
begin
  if Assigned(AField) then
    AAlignment := AField.Alignment
  else
    AAlignment := taLeftJustify;
  Result := (SysLocale.MiddleEast) and (AControl.BiDiMode = bdRightToLeft) and
    (OkToChangeFieldAlignment(AField, AAlignment));
end;

{ TOldSchoolDBNavigator }

var
  BtnTypeName: array[TNavigateBtn] of PChar = ('FIRST', 'PRIOR', 'NEXT',
    'LAST', 'INSERT', 'DELETE', 'EDIT', 'POST', 'CANCEL', 'REFRESH');
  BtnHintId: array[TNavigateBtn] of Pointer = (@SFirstRecord, @SPriorRecord,
    @SNextRecord, @SLastRecord, @SInsertRecord, @SDeleteRecord, @SEditRecord,
    @SPostEdit, @SCancelEdit, @SRefreshRecord);

constructor TOldSchoolDBNavigator.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  ControlStyle := ControlStyle - [csAcceptsControls, csSetCaption] + [csOpaque];
  if not NewStyleControls then ControlStyle := ControlStyle + [csFramed];
  FDataLink := TOSDataLink.Create(Self);
  FVisibleButtons := [nbFirst, nbPrior, nbNext, nbLast, nbInsert,
    nbDelete, nbEdit, nbPost, nbCancel, nbRefresh];
  FHints := TStringList.Create;
  TStringList(FHints).OnChange := HintsChanged;
  InitButtons;
  InitHints;
  BevelOuter := bvNone;
  BevelInner := bvNone;
  Width := 241;
  Height := 25;
  ButtonWidth := 0;
  FocusedButton := nbFirst;
  FConfirmDelete := True;
  FullRepaint := False;
end;

destructor TOldSchoolDBNavigator.Destroy;
begin
  FDefHints.Free;
  FDataLink.Free;
  FHints.Free;
  FDataLink := nil;
  inherited Destroy;
end;

procedure TOldSchoolDBNavigator.InitButtons;
var
  I: TNavigateBtn;
  Btn: TOSButton;
  X: Integer;
  ResName: string;
begin
  MinBtnSize := Point(20, 18);
  X := 0;
  for I := Low(Buttons) to High(Buttons) do
  begin
    Btn := TOSButton.Create (Self);
    Btn.Flat := Flat;
    Btn.Index := I;
    Btn.Visible := I in FVisibleButtons;
    Btn.Enabled := True;
    Btn.SetBounds (X, 0, MinBtnSize.X, MinBtnSize.Y);
    FmtStr(ResName, 'dbn_%s', [BtnTypeName[I]]);
    Btn.Glyph.LoadFromResourceName(HInstance, ResName);
    Btn.NumGlyphs := 2;
    Btn.Enabled := False;
    Btn.Enabled := True;
    Btn.OnClick := ClickHandler;
    Btn.OnMouseDown := BtnMouseDown;
    Btn.Parent := Self;
    Buttons[I] := Btn;
    X := X + MinBtnSize.X;
  end;
  Buttons[nbPrior].NavStyle := Buttons[nbPrior].NavStyle + [nsAllowTimer];
  Buttons[nbNext].NavStyle  := Buttons[nbNext].NavStyle + [nsAllowTimer];
end;

procedure TOldSchoolDBNavigator.InitHints;
var
  I: Integer;
  J: TNavigateBtn;
begin
  if not Assigned(FDefHints) then
  begin
    FDefHints := TStringList.Create;
    for J := Low(Buttons) to High(Buttons) do
      FDefHints.Add(LoadResString(BtnHintId[J]));
  end;
  for J := Low(Buttons) to High(Buttons) do
    Buttons[J].Hint := FDefHints[Ord(J)];
  J := Low(Buttons);
  for I := 0 to (FHints.Count - 1) do
  begin
    if FHints.Strings[I] <> '' then Buttons[J].Hint := FHints.Strings[I];
    if J = High(Buttons) then Exit;
    Inc(J);
  end;
end;

procedure TOldSchoolDBNavigator.HintsChanged(Sender: TObject);
begin
  InitHints;
end;

procedure TOldSchoolDBNavigator.SetFlat(Value: Boolean);
var
  I: TNavigateBtn;
begin
  if FFlat <> Value then
  begin
    FFlat := Value;
    for I := Low(Buttons) to High(Buttons) do
      Buttons[I].Flat := Value;
  end;
end;

procedure TOldSchoolDBNavigator.SetHints(Value: TStrings);
begin
  if Value.Text = FDefHints.Text then
    FHints.Clear else
    FHints.Assign(Value);
end;

function TOldSchoolDBNavigator.GetHints: TStrings;
begin
  if (csDesigning in ComponentState) and not (csWriting in ComponentState) and
     not (csReading in ComponentState) and (FHints.Count = 0) then
    Result := FDefHints else
    Result := FHints;
end;

procedure TOldSchoolDBNavigator.GetChildren(Proc: TGetChildProc; Root: TComponent);
begin
end;

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

procedure TOldSchoolDBNavigator.SetVisible(Value: TButtonSet);
var
  I: TNavigateBtn;
  W, H: Integer;
begin
  W := Width;
  H := Height;
  FVisibleButtons := Value;
  for I := Low(Buttons) to High(Buttons) do
    Buttons[I].Visible := I in FVisibleButtons;
  SetSize(W, H);
  if (W <> Width) or (H <> Height) then
    inherited SetBounds (Left, Top, W, H);
  Invalidate;
end;

procedure TOldSchoolDBNavigator.CalcMinSize(var W, H: Integer);
var
  Count: Integer;
  I: TNavigateBtn;
begin
  if (csLoading in ComponentState) then Exit;
  if Buttons[nbFirst] = nil then Exit;

  Count := 0;
  for I := Low(Buttons) to High(Buttons) do
    if Buttons[I].Visible then
      Inc(Count);
  if Count = 0 then Inc(Count);

  W := Max(W, Count * MinBtnSize.X);
  H := Max(H, MinBtnSize.Y);

  if Align = alNone then W := (W div Count) * Count;
end;

procedure TOldSchoolDBNavigator.SetSize(var W: Integer; var H: Integer);