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(* |
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* IBX For Lazarus (Firebird Express) |
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* |
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* The contents of this file are subject to the Initial Developer's |
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* Public License Version 1.0 (the "License"); you may not use this |
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* file except in compliance with the License. You may obtain a copy |
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* of the License here: |
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* |
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* http://www.firebirdsql.org/index.php?op=doc&id=idpl |
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* |
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* Software distributed under the License is distributed on an "AS |
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* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or |
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* implied. See the License for the specific language governing rights |
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* and limitations under the License. |
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* |
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* The Initial Developer of the Original Code is Tony Whyman. |
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* |
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* The Original Code is (C) 2011 Tony Whyman, MWA Software |
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* (http://www.mwasoftware.co.uk). |
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* |
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* All Rights Reserved. |
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* |
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* Contributor(s): ______________________________________. |
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* |
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*) |
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unit IBLookupComboEditBox; |
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|
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{$mode objfpc}{$H+} |
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|
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interface |
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|
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uses |
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Classes, SysUtils, LResources, Forms, Controls, Graphics, Dialogs, DbCtrls, |
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ExtCtrls, IBSQLParser, DB, StdCtrls; |
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|
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type |
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|
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{TIBLookupComboEditBox is a TDBLookupComboBox descendent that implements "autocomplete" |
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of typed in text and "autoinsert" of new entries. Autocomplete uses SQL manipulation |
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to revise the available list and restrict it to items that are prefixed by the |
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typed text (either case sensitive or case insenstive). Autoinsert allows a |
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newly typed entry to be added to the list dataset and included in the available |
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list items. } |
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|
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TAutoInsert = procedure(Sender: TObject; aText: string; var NewKeyValue: variant) of object; |
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TCanAutoInsert = procedure (Sender: TObject; aText: string; var Accept: boolean) of object; |
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|
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TIBLookupComboEditBox = class; |
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|
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{ TIBLookupComboDataLink } |
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|
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TIBLookupComboDataLink = class(TDataLink) |
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private |
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FOwner: TIBLookupComboEditBox; |
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protected |
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procedure ActiveChanged; override; |
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procedure DataEvent(Event: TDataEvent; Info: Ptrint); override; |
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procedure RecordChanged(Field: TField); override; |
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procedure UpdateData; override; |
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public |
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constructor Create(AOwner: TIBLookupComboEditBox); |
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end; |
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|
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|
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{ TIBLookupComboEditBox } |
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|
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TIBLookupComboEditBox = class(TDBLookupComboBox) |
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private |
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FCanAutoInsert: TCanAutoInsert; |
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{ Private declarations } |
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FDataLink: TIBLookupComboDataLink; |
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FAutoComplete: boolean; |
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FAutoInsert: boolean; |
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FKeyPressInterval: integer; |
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FOnCanAutoInsert: TCanAutoInsert; |
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FRelationName: string; |
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FTimer: TTimer; |
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FFiltered: boolean; |
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FOnAutoInsert: TAutoInsert; |
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FOriginalTextValue: string; |
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FUpdating: boolean; |
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FInserting: boolean; |
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FExiting: boolean; |
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FLastKeyValue: variant; |
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procedure DoActiveChanged(Data: PtrInt); |
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function GetAutoCompleteText: TComboBoxAutoCompleteText; |
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function GetListSource: TDataSource; |
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function GetRelationNameQualifier: string; |
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procedure HandleTimer(Sender: TObject); |
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procedure ResetParser; |
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procedure RecordChanged(Sender: TObject; aField: TField); |
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procedure SetAutoCompleteText(AValue: TComboBoxAutoCompleteText); |
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procedure SetListSource(AValue: TDataSource); |
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procedure UpdateList; |
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procedure UpdateSQL(Sender: TObject; Parser: TSelectSQLParser); |
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procedure HandleEnter(Data: PtrInt); |
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procedure UpdateLinkData(Sender: TObject); |
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protected |
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{ Protected declarations } |
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procedure ActiveChanged(Sender: TObject); |
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procedure CheckAndInsert; |
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procedure DoEnter; override; |
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procedure DoExit; override; |
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procedure KeyUp(var Key: Word; Shift: TShiftState); override; |
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procedure SetItemIndex(const Val: integer); override; |
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procedure UpdateShowing; override; |
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public |
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{ Public declarations } |
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constructor Create(TheComponent: TComponent); override; |
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destructor Destroy; override; |
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procedure EditingDone; override; |
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published |
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{ Published declarations } |
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property AutoInsert: boolean read FAutoInsert write FAutoInsert; |
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property AutoComplete: boolean read FAutoComplete write FAutoComplete default true; |
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property AutoCompleteText: TComboBoxAutoCompleteText read GetAutoCompleteText |
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write SetAutoCompleteText; |
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property ItemHeight; |
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property ItemWidth; |
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property ListSource: TDataSource read GetListSource write SetListSource; |
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property KeyPressInterval: integer read FKeyPressInterval write FKeyPressInterval default 500; |
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property RelationName: string read FRelationName write FRelationName; |
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property OnAutoInsert: TAutoInsert read FOnAutoInsert write FOnAutoInsert; |
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property OnCanAutoInsert: TCanAutoInsert read FOnCanAutoInsert write FOnCanAutoInsert; |
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end; |
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|
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|
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implementation |
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|
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uses IBQuery, IBCustomDataSet, LCLType, Variants, LCLProc; |
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|
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{ TIBLookupComboDataLink } |
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|
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procedure TIBLookupComboDataLink.ActiveChanged; |
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begin |
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FOwner.ActiveChanged(self) |
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end; |
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|
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procedure TIBLookupComboDataLink.DataEvent(Event: TDataEvent; Info: Ptrint); |
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begin |
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{If we are not visible then avoid unnecessary work} |
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if not FOwner.Showing then Exit; |
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|
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if (Event = deCheckBrowseMode) and (Info = 1) and not DataSet.Active then |
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begin |
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if (DataSet is TIBDataSet) then |
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FOwner.UpdateSQL(self,TIBDataSet(DataSet).Parser) |
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else |
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if (DataSet is TIBQuery) then |
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FOwner.UpdateSQL(self,TIBQuery(DataSet).Parser) |
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end |
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else |
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inherited DataEvent(Event, Info); |
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end; |
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|
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procedure TIBLookupComboDataLink.RecordChanged(Field: TField); |
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begin |
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FOwner.RecordChanged(self,Field); |
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end; |
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|
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procedure TIBLookupComboDataLink.UpdateData; |
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begin |
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FOwner.UpdateLinkData(self) |
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end; |
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|
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constructor TIBLookupComboDataLink.Create(AOwner: TIBLookupComboEditBox); |
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begin |
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inherited Create; |
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FOwner := AOwner |
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end; |
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|
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{ TIBLookupComboEditBox } |
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|
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procedure TIBLookupComboEditBox.HandleTimer(Sender: TObject); |
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var ActiveState: boolean; |
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begin |
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FTimer.Interval := 0; |
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FFiltered := Text <> ''; |
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UpdateList |
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end; |
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|
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function TIBLookupComboEditBox.GetListSource: TDataSource; |
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begin |
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Result := inherited ListSource; |
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end; |
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|
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function TIBLookupComboEditBox.GetRelationNameQualifier: string; |
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begin |
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if FRelationName <> '' then |
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Result := FRelationName + '.' |
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else |
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Result := '' |
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end; |
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|
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procedure TIBLookupComboEditBox.ActiveChanged(Sender: TObject); |
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begin |
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if not FInserting and not FUpdating then |
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Application.QueueAsyncCall(@DoActiveChanged,0); |
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end; |
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|
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procedure TIBLookupComboEditBox.DoActiveChanged(Data: PtrInt); |
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begin |
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if AppDestroying in Application.Flags then Exit; |
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|
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if (DataSource = nil) and assigned(ListSource) and assigned(ListSource.DataSet) |
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and ListSource.DataSet.Active then |
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begin |
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begin |
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if varIsNull(FLastKeyValue) and (ItemIndex = -1) then |
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KeyValue := ListSource.DataSet.FieldByName(KeyField).AsVariant |
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else |
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begin |
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KeyValue := FLastKeyValue; |
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UpdateData(self); {Force auto scroll} |
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if varIsNull(KeyValue) then {Value not present} |
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Text := ListSource.DataSet.FieldByName(ListField).AsString |
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end; |
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end; |
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end |
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else |
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if (DataSource <> nil) and assigned(DataSource.DataSet) and |
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(DataSource.DataSet.Active) and (DataField <> '') then |
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begin |
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ResetParser; |
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KeyValue := Field.AsVariant; |
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end |
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else |
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Text := ''; |
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FOriginalTextValue := Text; |
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end; |
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|
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function TIBLookupComboEditBox.GetAutoCompleteText: TComboBoxAutoCompleteText; |
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begin |
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Result := inherited AutoCompleteText; |
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if AutoComplete then |
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Result := Result + [cbactEnabled] |
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end; |
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|
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procedure TIBLookupComboEditBox.ResetParser; |
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begin |
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if FFiltered then |
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begin |
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FFiltered := false; |
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UpdateList; |
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UpdateData(self); {Force Scroll} |
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end; |
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end; |
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|
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procedure TIBLookupComboEditBox.RecordChanged(Sender: TObject; aField: TField); |
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begin |
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{Make sure that we are in sync with other data controls} |
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if DataSource = nil then |
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begin |
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KeyValue := ListSource.DataSet.FieldByName(KeyField).AsVariant; |
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if VarIsNull(KeyValue) then {Probable deletion} |
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begin |
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UpdateList; |
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KeyValue := ListSource.DataSet.FieldByName(KeyField).AsVariant; |
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end; |
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end; |
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end; |
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|
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procedure TIBLookupComboEditBox.SetAutoCompleteText( |
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AValue: TComboBoxAutoCompleteText); |
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begin |
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if AValue <> AutoCompleteText then |
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begin |
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FAutoComplete := cbactEnabled in AValue; |
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inherited AutoCompleteText := AValue - [cbactEnabled] |
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end; |
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end; |
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|
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procedure TIBLookupComboEditBox.SetListSource(AValue: TDataSource); |
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begin |
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if AValue <> inherited ListSource then |
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begin |
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FDataLink.DataSource := AValue; |
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inherited ListSource := AValue; |
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end; |
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end; |
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|
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procedure TIBLookupComboEditBox.UpdateList; |
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{ Note: Algorithm taken from TCustomComboBox.KeyUp but modified to use the |
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ListSource DataSet as the source for the autocomplete text. It also runs |
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after a delay rather than immediately on keyup |
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} |
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var |
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iSelStart: Integer; // char position |
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sCompleteText, sPrefixText, sResultText: string; |
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curText: string; |
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begin |
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if assigned(ListSource) and assigned(ListSource.DataSet) and (ListSource.DataSet is TIBCustomDataSet) |
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and ListSource.DataSet.Active then |
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begin |
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FUpdating := true; |
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try |
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iSelStart := SelStart;//Capture original cursor position |
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if ((iSelStart < UTF8Length(Text)) and |
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(cbactEndOfLineComplete in AutoCompleteText)) then |
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Exit; |
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curText := Text; |
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sPrefixText := UTF8Copy(Text, 1, iSelStart); |
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ListSource.DataSet.Active := false; |
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ListSource.DataSet.Active := true; |
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Text := curText; |
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if not FExiting and Focused and (Text <> '')then |
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begin |
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if ListSource.DataSet.Active and (ListSource.DataSet.RecordCount > 0) then |
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begin |
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sCompleteText := ListSource.DataSet.FieldByName(ListField).AsString; |
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if (sCompleteText <> Text) then |
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begin |
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sResultText := sCompleteText; |
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if ((cbactEndOfLineComplete in AutoCompleteText) and |
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(cbactRetainPrefixCase in AutoCompleteText)) then |
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begin//Retain Prefix Character cases |
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UTF8Delete(sResultText, 1, iSelStart); |
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UTF8Insert(sPrefixText, sResultText, 1); |
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end; |
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Text := sResultText; |
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SelStart := iSelStart; |
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SelLength := UTF8Length(Text); |
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end; |
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end; |
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end; |
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finally |
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FUpdating := false |
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end; |
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end; |
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end; |
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|
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procedure TIBLookupComboEditBox.UpdateSQL(Sender: TObject; |
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Parser: TSelectSQLParser); |
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var FieldPosition: integer; |
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begin |
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if FFiltered then |
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begin |
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if cbactSearchCaseSensitive in AutoCompleteText then |
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Parser.Add2WhereClause(GetRelationNameQualifier + '"' + ListField + '" Like ''' + Text + '%''') |
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else |
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Parser.Add2WhereClause(GetRelationNameQualifier + 'Upper("' + ListField + '") Like Upper(''' + Text + '%'')'); |
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|
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end; |
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if cbactSearchAscending in AutoCompleteText then |
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begin |
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FieldPosition := Parser.GetFieldPosition(ListField); |
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if FieldPosition = 0 then Exit; |
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|
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Parser.OrderByClause := IntToStr(FieldPosition) + ' ascending'; |
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end; |
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end; |
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|
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procedure TIBLookupComboEditBox.HandleEnter(Data: PtrInt); |
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begin |
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SelectAll |
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end; |
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|
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procedure TIBLookupComboEditBox.UpdateLinkData(Sender: TObject); |
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begin |
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if FInserting then |
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ListSource.DataSet.FieldByName(ListField).AsString := Text |
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end; |
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|
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procedure TIBLookupComboEditBox.CheckAndInsert; |
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var Accept: boolean; |
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NewKeyValue: variant; |
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begin |
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if AutoInsert and (Text <> '') and assigned(ListSource) and assigned(ListSource.DataSet) |
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and ListSource.DataSet.Active and (ListSource.DataSet.RecordCount = 0) then |
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try |
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{Is it OK to insert a new list member?} |
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Accept := true; |
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if assigned(FOnCanAutoInsert) then |
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OnCanAutoInsert(self,Text,Accept); |
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if not Accept then |
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begin |
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ResetParser; |
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Text := FOriginalTextValue; |
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SelectAll; |
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Exit; |
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end; |
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|
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FInserting := true; |
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try |
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{New Value} |
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FFiltered := false; |
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if assigned(FOnAutoInsert) then |
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begin |
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{In an OnAutoInsert handler, the client is expected to insert the new |
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row into the List DataSet and to set the KeyValue property to the |
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value of the primary key of the new row.} |
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OnAutoInsert(self,Text,NewKeyValue); |
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end |
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else |
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begin |
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ListSource.DataSet.Append; |
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{The new KeyValue should be determined by an external generator or |
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in the "OnInsert" handler. If it is the same as the ListField, then |
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it will be set from the UpdateLinkData method} |
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try |
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ListSource.DataSet.Post; |
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except |
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ListSource.DataSet.Cancel; |
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raise; |
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end; |
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NewKeyValue := ListSource.DataSet.FieldByName(KeyField).AsVariant; |
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end; |
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UpdateList; |
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KeyValue := NewKeyValue; |
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UpdateData(nil); {Force sync with DataField} |
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finally |
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FInserting := false |
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end; |
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except |
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Text := FOriginalTextValue; |
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ResetParser; |
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raise; |
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end; |
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end; |
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|
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procedure TIBLookupComboEditBox.DoEnter; |
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begin |
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inherited DoEnter; |
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FOriginalTextValue:= Text; |
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ResetParser; |
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Application.QueueAsyncCall(@HandleEnter,0); |
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end; |
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|
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procedure TIBLookupComboEditBox.DoExit; |
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begin |
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FExiting := true; |
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try |
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CheckAndInsert; |
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ResetParser; |
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FTimer.Interval := 0; |
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finally |
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FExiting := false; |
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end; |
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inherited DoExit; |
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end; |
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|
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procedure TIBLookupComboEditBox.KeyUp(var Key: Word; Shift: TShiftState); |
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begin |
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inherited KeyUp(Key, Shift); |
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if Key = VK_RETURN then |
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EditingDone |
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else |
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if Key = VK_ESCAPE then |
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begin |
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SelStart := UTF8Length(Text); {Ensure end of line selection} |
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ResetParser; |
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Text := FOriginalTextValue; |
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SelectAll; |
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end |
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else |
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if (IsEditableTextKey(Key) or (Key = VK_BACK)) |
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and AutoComplete and (Style <> csDropDownList) and |
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(not (cbactEndOfLineComplete in AutoCompleteText) or (SelStart = UTF8Length(Text))) then |
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FTimer.Interval := FKeyPressInterval |
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else |
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FTimer.Interval := 0 |
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end; |
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|
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procedure TIBLookupComboEditBox.SetItemIndex(const Val: integer); |
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begin |
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inherited SetItemIndex(Val); |
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FLastKeyValue := KeyValue; |
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end; |
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|
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procedure TIBLookupComboEditBox.UpdateShowing; |
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begin |
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inherited UpdateShowing; |
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if Showing then {Ensure up-to-date as we were ignoring any changes} |
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ActiveChanged(nil); |
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end; |
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|
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constructor TIBLookupComboEditBox.Create(TheComponent: TComponent); |
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begin |
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inherited Create(TheComponent); |
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FDataLink := TIBLookupComboDataLink.Create(self); |
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FKeyPressInterval := 500; |
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FAutoComplete := true; |
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FTimer := TTimer.Create(nil); |
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FTimer.Interval := 0; |
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FTimer.OnTimer := @HandleTimer; |
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FLastKeyValue := NULL; |
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end; |
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|
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destructor TIBLookupComboEditBox.Destroy; |
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begin |
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if assigned(FDataLink) then FDataLink.Free; |
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if assigned(FTimer) then FTimer.Free; |
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inherited Destroy; |
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end; |
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|
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procedure TIBLookupComboEditBox.EditingDone; |
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begin |
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CheckAndInsert; |
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inherited EditingDone; |
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end; |
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|
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end. |