Thanks very much for these two - in particular the control version - I will add it to my list of controls. I took a slightly different approach in my implementation where I used the object part of the items list to identify if it was enabloed or disabled rather than maintain a separate list as you have suggested.
JohnB -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jeremy North Sent: 04 December 2007 00:09 To: Borland's Delphi Discussion List Subject: Re: Dumb question about ComboBoxes Here is the component version. If a disabled item is selected then the ItemIndex is set to -1. You can modify the code to take action accordingly. unit DisabledCombo; interface uses StdCtrls , Classes , Controls , Windows , Messages , Graphics ; type TCustomDisabledComboBox = class(TCustomComboBox) private FDisabledItems: TStrings; FShowDisabledFocus: Boolean; procedure SetDisabledItems(const Value: TStrings); procedure CNCommand(var Message: TWMCommand); message CN_COMMAND; protected function IsItemDisabled(const AIndex: Integer): Boolean; inline; procedure DrawItem(Index: Integer; Rect: TRect; State: TOwnerDrawState); override; property ShowDisabledFocus: Boolean read FShowDisabledFocus write FShowDisabledFocus default False; property DisabledItems: TStrings read FDisabledItems write SetDisabledItems; public constructor Create(AOwner: TComponent); override; destructor Destroy; override; end; TDisabledComboBox = class(TCustomDisabledComboBox) published property Align; property AutoComplete default True; property AutoCompleteDelay default 500; property AutoDropDown default False; property AutoCloseUp default False; property BevelEdges; property BevelInner; property BevelKind default bkNone; property BevelOuter; // property Style; {Must be published before Items} property Anchors; property BiDiMode; property CharCase; property Color; property Constraints; property Ctl3D; property DragCursor; property DragKind; property DragMode; property DropDownCount; property Enabled; property Font; property ImeMode; property ImeName; property ItemHeight; property ItemIndex default -1; property MaxLength; property ParentBiDiMode; property ParentColor; property ParentCtl3D; property ParentFont; property ParentShowHint; property PopupMenu; property ShowHint; property Sorted; property TabOrder; property TabStop; property Text; property Visible; property OnChange; property OnClick; property OnCloseUp; property OnContextPopup; property OnDblClick; property OnDragDrop; property OnDragOver; property OnDrawItem; property OnDropDown; property OnEndDock; property OnEndDrag; property OnEnter; property OnExit; property OnKeyDown; property OnKeyPress; property OnKeyUp; property OnMeasureItem; property OnMouseEnter; property OnMouseLeave; property OnSelect; property OnStartDock; property OnStartDrag; property Items; { Must be published after OnMeasureItem } property DisabledItems; property ShowDisabledFocus; end; procedure Register; implementation uses SysUtils ; procedure Register; begin RegisterComponents('Samples', [TDisabledComboBox]); end; { TCustomDisabledComboBox } procedure TCustomDisabledComboBox.CNCommand(var Message: TWMCommand); begin case Message.NotifyCode of CBN_SELCHANGE: begin // if the user selects a disabled item, clear the selection if not IsItemDisabled(ItemIndex) then begin Text := Items[ItemIndex]; Click; Select; end else ItemIndex := -1; end; else inherited; end; end; constructor TCustomDisabledComboBox.Create(AOwner: TComponent); begin inherited; Style := csOwnerDrawFixed; FDisabledItems := TStringList.Create; FShowDisabledFocus := False; end; destructor TCustomDisabledComboBox.Destroy; begin FDisabledItems.Free; inherited; end; procedure TCustomDisabledComboBox.DrawItem(Index: Integer; Rect: TRect; State: TOwnerDrawState); var lDrawFlags: Cardinal; lStr: string; begin TControlCanvas(Canvas).UpdateTextFlags; Canvas.Brush.Style := bsSolid; // setup background color if (odSelected in State) and not IsItemDisabled(Index) then Canvas.Brush.Color := clHighlight else Canvas.Brush.Color := Color; Canvas.FillRect(Rect); Canvas.Brush.Style := bsClear; // setup font color if (odSelected in State) and not IsItemDisabled(Index) then Canvas.Font.Color := clHighlightText else if IsItemDisabled(Index) then Canvas.Font.Color := clGrayText else Canvas.Font.Color := Font.Color; InflateRect(Rect, -2, -2); lDrawFlags := DT_LEFT or DT_VCENTER or DT_SINGLELINE or DT_NOPREFIX or DT_END_ELLIPSIS; lStr := Items[Index]; DrawText(Canvas.Handle, PChar(lStr), Length(lStr), Rect, lDrawFlags); // comment this out if you want the focus rect to be draw even when a // disabled item has focus if (odSelected in State) and IsItemDisabled(Index) and not ShowDisabledFocus then begin InflateRect(Rect, 2, 2); DrawFocusRect(Canvas.Handle, Rect); end; end; function TCustomDisabledComboBox.IsItemDisabled(const AIndex: Integer): Boolean; begin result := FDisabledItems.IndexOf(IntToStr(AIndex)) > -1; end; procedure TCustomDisabledComboBox.SetDisabledItems(const Value: TStrings); begin FDisabledItems.Assign(Value); end; end. _______________________________________________ Delphi mailing list -> [email protected] http://lists.elists.org/cgi-bin/mailman/listinfo/delphi _______________________________________________ Delphi mailing list -> [email protected] http://lists.elists.org/cgi-bin/mailman/listinfo/delphi
