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root/public/ibx/trunk/ibcontrols/IBLookupComboEditBox.pas
Revision: 21
Committed: Thu Feb 26 10:33:34 2015 UTC (9 years, 8 months ago) by tony
Content type: text/x-pascal
File size: 14748 byte(s)
Log Message:
Committing updates for Release R1-2-0

File Contents

# Content
1 (*
2 * IBX For Lazarus (Firebird Express)
3 *
4 * The contents of this file are subject to the Initial Developer's
5 * Public License Version 1.0 (the "License"); you may not use this
6 * file except in compliance with the License. You may obtain a copy
7 * of the License here:
8 *
9 * http://www.firebirdsql.org/index.php?op=doc&id=idpl
10 *
11 * Software distributed under the License is distributed on an "AS
12 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
13 * implied. See the License for the specific language governing rights
14 * and limitations under the License.
15 *
16 * The Initial Developer of the Original Code is Tony Whyman.
17 *
18 * The Original Code is (C) 2011 Tony Whyman, MWA Software
19 * (http://www.mwasoftware.co.uk).
20 *
21 * All Rights Reserved.
22 *
23 * Contributor(s): ______________________________________.
24 *
25 *)
26 unit IBLookupComboEditBox;
27
28 {$mode objfpc}{$H+}
29
30 interface
31
32 uses
33 Classes, SysUtils, LResources, Forms, Controls, Graphics, Dialogs, DbCtrls,
34 ExtCtrls, IBSQLParser, DB, StdCtrls;
35
36 type
37
38 {TIBLookupComboEditBox is a TDBLookupComboBox descendent that implements "autocomplete"
39 of typed in text and "autoinsert" of new entries. Autocomplete uses SQL manipulation
40 to revise the available list and restrict it to items that are prefixed by the
41 typed text (either case sensitive or case insenstive). Autoinsert allows a
42 newly typed entry to be added to the list dataset and included in the available
43 list items. }
44
45 TAutoInsert = procedure(Sender: TObject; aText: string; var NewKeyValue: variant) of object;
46 TCanAutoInsert = procedure (Sender: TObject; aText: string; var Accept: boolean) of object;
47
48 TIBLookupComboEditBox = class;
49
50 { TIBLookupComboDataLink }
51
52 TIBLookupComboDataLink = class(TDataLink)
53 private
54 FOwner: TIBLookupComboEditBox;
55 protected
56 procedure ActiveChanged; override;
57 procedure DataEvent(Event: TDataEvent; Info: Ptrint); override;
58 procedure RecordChanged(Field: TField); override;
59 procedure UpdateData; override;
60 public
61 constructor Create(AOwner: TIBLookupComboEditBox);
62 end;
63
64
65 { TIBLookupComboEditBox }
66
67 TIBLookupComboEditBox = class(TDBLookupComboBox)
68 private
69 FCanAutoInsert: TCanAutoInsert;
70 { Private declarations }
71 FDataLink: TIBLookupComboDataLink;
72 FAutoComplete: boolean;
73 FAutoInsert: boolean;
74 FKeyPressInterval: integer;
75 FOnCanAutoInsert: TCanAutoInsert;
76 FRelationName: string;
77 FTimer: TTimer;
78 FFiltered: boolean;
79 FOnAutoInsert: TAutoInsert;
80 FOriginalTextValue: string;
81 FUpdating: boolean;
82 FInserting: boolean;
83 FExiting: boolean;
84 FLastKeyValue: variant;
85 procedure DoActiveChanged(Data: PtrInt);
86 function GetAutoCompleteText: TComboBoxAutoCompleteText;
87 function GetListSource: TDataSource;
88 function GetRelationNameQualifier: string;
89 procedure HandleTimer(Sender: TObject);
90 procedure ResetParser;
91 procedure RecordChanged(Sender: TObject; aField: TField);
92 procedure SetAutoCompleteText(AValue: TComboBoxAutoCompleteText);
93 procedure SetListSource(AValue: TDataSource);
94 procedure UpdateList;
95 procedure UpdateSQL(Sender: TObject; Parser: TSelectSQLParser);
96 procedure HandleEnter(Data: PtrInt);
97 procedure UpdateLinkData(Sender: TObject);
98 protected
99 { Protected declarations }
100 procedure ActiveChanged(Sender: TObject);
101 procedure CheckAndInsert;
102 procedure DoEnter; override;
103 procedure DoExit; override;
104 procedure KeyUp(var Key: Word; Shift: TShiftState); override;
105 procedure SetItemIndex(const Val: integer); override;
106 procedure UpdateShowing; override;
107 public
108 { Public declarations }
109 constructor Create(TheComponent: TComponent); override;
110 destructor Destroy; override;
111 procedure EditingDone; override;
112 published
113 { Published declarations }
114 property AutoInsert: boolean read FAutoInsert write FAutoInsert;
115 property AutoComplete: boolean read FAutoComplete write FAutoComplete default true;
116 property AutoCompleteText: TComboBoxAutoCompleteText read GetAutoCompleteText
117 write SetAutoCompleteText;
118 property ItemHeight;
119 property ItemWidth;
120 property ListSource: TDataSource read GetListSource write SetListSource;
121 property KeyPressInterval: integer read FKeyPressInterval write FKeyPressInterval default 500;
122 property RelationName: string read FRelationName write FRelationName;
123 property OnAutoInsert: TAutoInsert read FOnAutoInsert write FOnAutoInsert;
124 property OnCanAutoInsert: TCanAutoInsert read FOnCanAutoInsert write FOnCanAutoInsert;
125 end;
126
127
128 implementation
129
130 uses IBQuery, IBCustomDataSet, LCLType, Variants, LCLProc;
131
132 { TIBLookupComboDataLink }
133
134 procedure TIBLookupComboDataLink.ActiveChanged;
135 begin
136 FOwner.ActiveChanged(self)
137 end;
138
139 procedure TIBLookupComboDataLink.DataEvent(Event: TDataEvent; Info: Ptrint);
140 begin
141 {If we are not visible then avoid unnecessary work}
142 if not FOwner.Showing then Exit;
143
144 if (Event = deCheckBrowseMode) and (Info = 1) and not DataSet.Active then
145 begin
146 if (DataSet is TIBDataSet) then
147 FOwner.UpdateSQL(self,TIBDataSet(DataSet).Parser)
148 else
149 if (DataSet is TIBQuery) then
150 FOwner.UpdateSQL(self,TIBQuery(DataSet).Parser)
151 end
152 else
153 inherited DataEvent(Event, Info);
154 end;
155
156 procedure TIBLookupComboDataLink.RecordChanged(Field: TField);
157 begin
158 FOwner.RecordChanged(self,Field);
159 end;
160
161 procedure TIBLookupComboDataLink.UpdateData;
162 begin
163 FOwner.UpdateLinkData(self)
164 end;
165
166 constructor TIBLookupComboDataLink.Create(AOwner: TIBLookupComboEditBox);
167 begin
168 inherited Create;
169 FOwner := AOwner
170 end;
171
172 { TIBLookupComboEditBox }
173
174 procedure TIBLookupComboEditBox.HandleTimer(Sender: TObject);
175 var ActiveState: boolean;
176 begin
177 FTimer.Interval := 0;
178 FFiltered := Text <> '';
179 UpdateList
180 end;
181
182 function TIBLookupComboEditBox.GetListSource: TDataSource;
183 begin
184 Result := inherited ListSource;
185 end;
186
187 function TIBLookupComboEditBox.GetRelationNameQualifier: string;
188 begin
189 if FRelationName <> '' then
190 Result := FRelationName + '.'
191 else
192 Result := ''
193 end;
194
195 procedure TIBLookupComboEditBox.ActiveChanged(Sender: TObject);
196 begin
197 if not FInserting and not FUpdating then
198 Application.QueueAsyncCall(@DoActiveChanged,0);
199 end;
200
201 procedure TIBLookupComboEditBox.DoActiveChanged(Data: PtrInt);
202 begin
203 if AppDestroying in Application.Flags then Exit;
204
205 if (DataSource = nil) and assigned(ListSource) and assigned(ListSource.DataSet)
206 and ListSource.DataSet.Active then
207 begin
208 begin
209 if varIsNull(FLastKeyValue) and (ItemIndex = -1) then
210 KeyValue := ListSource.DataSet.FieldByName(KeyField).AsVariant
211 else
212 begin
213 KeyValue := FLastKeyValue;
214 UpdateData(self); {Force auto scroll}
215 if varIsNull(KeyValue) then {Value not present}
216 Text := ListSource.DataSet.FieldByName(ListField).AsString
217 end;
218 end;
219 end
220 else
221 if (DataSource <> nil) and assigned(DataSource.DataSet) and
222 (DataSource.DataSet.Active) and (DataField <> '') then
223 begin
224 ResetParser;
225 KeyValue := Field.AsVariant;
226 end
227 else
228 Text := '';
229 FOriginalTextValue := Text;
230 end;
231
232 function TIBLookupComboEditBox.GetAutoCompleteText: TComboBoxAutoCompleteText;
233 begin
234 Result := inherited AutoCompleteText;
235 if AutoComplete then
236 Result := Result + [cbactEnabled]
237 end;
238
239 procedure TIBLookupComboEditBox.ResetParser;
240 begin
241 if FFiltered then
242 begin
243 FFiltered := false;
244 UpdateList;
245 UpdateData(self); {Force Scroll}
246 end;
247 end;
248
249 procedure TIBLookupComboEditBox.RecordChanged(Sender: TObject; aField: TField);
250 begin
251 {Make sure that we are in sync with other data controls}
252 if DataSource = nil then
253 begin
254 KeyValue := ListSource.DataSet.FieldByName(KeyField).AsVariant;
255 if VarIsNull(KeyValue) then {Probable deletion}
256 begin
257 UpdateList;
258 KeyValue := ListSource.DataSet.FieldByName(KeyField).AsVariant;
259 end;
260 end;
261 end;
262
263 procedure TIBLookupComboEditBox.SetAutoCompleteText(
264 AValue: TComboBoxAutoCompleteText);
265 begin
266 if AValue <> AutoCompleteText then
267 begin
268 FAutoComplete := cbactEnabled in AValue;
269 inherited AutoCompleteText := AValue - [cbactEnabled]
270 end;
271 end;
272
273 procedure TIBLookupComboEditBox.SetListSource(AValue: TDataSource);
274 begin
275 if AValue <> inherited ListSource then
276 begin
277 FDataLink.DataSource := AValue;
278 inherited ListSource := AValue;
279 end;
280 end;
281
282 procedure TIBLookupComboEditBox.UpdateList;
283 { Note: Algorithm taken from TCustomComboBox.KeyUp but modified to use the
284 ListSource DataSet as the source for the autocomplete text. It also runs
285 after a delay rather than immediately on keyup
286 }
287 var
288 iSelStart: Integer; // char position
289 sCompleteText, sPrefixText, sResultText: string;
290 curText: string;
291 begin
292 if assigned(ListSource) and assigned(ListSource.DataSet) and (ListSource.DataSet is TIBCustomDataSet)
293 and ListSource.DataSet.Active then
294 begin
295 FUpdating := true;
296 try
297 iSelStart := SelStart;//Capture original cursor position
298 if ((iSelStart < UTF8Length(Text)) and
299 (cbactEndOfLineComplete in AutoCompleteText)) then
300 Exit;
301 curText := Text;
302 sPrefixText := UTF8Copy(Text, 1, iSelStart);
303 ListSource.DataSet.Active := false;
304 ListSource.DataSet.Active := true;
305 Text := curText;
306 if not FExiting and Focused and (Text <> '')then
307 begin
308 if ListSource.DataSet.Active and (ListSource.DataSet.RecordCount > 0) then
309 begin
310 sCompleteText := ListSource.DataSet.FieldByName(ListField).AsString;
311 if (sCompleteText <> Text) then
312 begin
313 sResultText := sCompleteText;
314 if ((cbactEndOfLineComplete in AutoCompleteText) and
315 (cbactRetainPrefixCase in AutoCompleteText)) then
316 begin//Retain Prefix Character cases
317 UTF8Delete(sResultText, 1, iSelStart);
318 UTF8Insert(sPrefixText, sResultText, 1);
319 end;
320 Text := sResultText;
321 SelStart := iSelStart;
322 SelLength := UTF8Length(Text);
323 end;
324 end;
325 end;
326 finally
327 FUpdating := false
328 end;
329 end;
330 end;
331
332 procedure TIBLookupComboEditBox.UpdateSQL(Sender: TObject;
333 Parser: TSelectSQLParser);
334 var FieldPosition: integer;
335 begin
336 if FFiltered then
337 begin
338 if cbactSearchCaseSensitive in AutoCompleteText then
339 Parser.Add2WhereClause(GetRelationNameQualifier + '"' + ListField + '" Like ''' + Text + '%''')
340 else
341 Parser.Add2WhereClause(GetRelationNameQualifier + 'Upper("' + ListField + '") Like Upper(''' + Text + '%'')');
342
343 end;
344 if cbactSearchAscending in AutoCompleteText then
345 begin
346 FieldPosition := Parser.GetFieldPosition(ListField);
347 if FieldPosition = 0 then Exit;
348
349 Parser.OrderByClause := IntToStr(FieldPosition) + ' ascending';
350 end;
351 end;
352
353 procedure TIBLookupComboEditBox.HandleEnter(Data: PtrInt);
354 begin
355 SelectAll
356 end;
357
358 procedure TIBLookupComboEditBox.UpdateLinkData(Sender: TObject);
359 begin
360 if FInserting then
361 ListSource.DataSet.FieldByName(ListField).AsString := Text
362 end;
363
364 procedure TIBLookupComboEditBox.CheckAndInsert;
365 var Accept: boolean;
366 NewKeyValue: variant;
367 begin
368 if AutoInsert and (Text <> '') and assigned(ListSource) and assigned(ListSource.DataSet)
369 and ListSource.DataSet.Active and (ListSource.DataSet.RecordCount = 0) then
370 try
371 {Is it OK to insert a new list member?}
372 Accept := true;
373 if assigned(FOnCanAutoInsert) then
374 OnCanAutoInsert(self,Text,Accept);
375 if not Accept then
376 begin
377 ResetParser;
378 Text := FOriginalTextValue;
379 SelectAll;
380 Exit;
381 end;
382
383 FInserting := true;
384 try
385 {New Value}
386 FFiltered := false;
387 if assigned(FOnAutoInsert) then
388 begin
389 {In an OnAutoInsert handler, the client is expected to insert the new
390 row into the List DataSet and to set the KeyValue property to the
391 value of the primary key of the new row.}
392 OnAutoInsert(self,Text,NewKeyValue);
393 end
394 else
395 begin
396 ListSource.DataSet.Append;
397 {The new KeyValue should be determined by an external generator or
398 in the "OnInsert" handler. If it is the same as the ListField, then
399 it will be set from the UpdateLinkData method}
400 try
401 ListSource.DataSet.Post;
402 except
403 ListSource.DataSet.Cancel;
404 raise;
405 end;
406 NewKeyValue := ListSource.DataSet.FieldByName(KeyField).AsVariant;
407 end;
408 UpdateList;
409 KeyValue := NewKeyValue;
410 UpdateData(nil); {Force sync with DataField}
411 finally
412 FInserting := false
413 end;
414 except
415 Text := FOriginalTextValue;
416 ResetParser;
417 raise;
418 end;
419 end;
420
421 procedure TIBLookupComboEditBox.DoEnter;
422 begin
423 inherited DoEnter;
424 FOriginalTextValue:= Text;
425 ResetParser;
426 Application.QueueAsyncCall(@HandleEnter,0);
427 end;
428
429 procedure TIBLookupComboEditBox.DoExit;
430 begin
431 FExiting := true;
432 try
433 CheckAndInsert;
434 ResetParser;
435 FTimer.Interval := 0;
436 finally
437 FExiting := false;
438 end;
439 inherited DoExit;
440 end;
441
442 procedure TIBLookupComboEditBox.KeyUp(var Key: Word; Shift: TShiftState);
443 begin
444 inherited KeyUp(Key, Shift);
445 if Key = VK_RETURN then
446 EditingDone
447 else
448 if Key = VK_ESCAPE then
449 begin
450 SelStart := UTF8Length(Text); {Ensure end of line selection}
451 ResetParser;
452 Text := FOriginalTextValue;
453 SelectAll;
454 end
455 else
456 if (IsEditableTextKey(Key) or (Key = VK_BACK))
457 and AutoComplete and (Style <> csDropDownList) and
458 (not (cbactEndOfLineComplete in AutoCompleteText) or (SelStart = UTF8Length(Text))) then
459 FTimer.Interval := FKeyPressInterval
460 else
461 FTimer.Interval := 0
462 end;
463
464 procedure TIBLookupComboEditBox.SetItemIndex(const Val: integer);
465 begin
466 inherited SetItemIndex(Val);
467 FLastKeyValue := KeyValue;
468 end;
469
470 procedure TIBLookupComboEditBox.UpdateShowing;
471 begin
472 inherited UpdateShowing;
473 if Showing then {Ensure up-to-date as we were ignoring any changes}
474 ActiveChanged(nil);
475 end;
476
477 constructor TIBLookupComboEditBox.Create(TheComponent: TComponent);
478 begin
479 inherited Create(TheComponent);
480 FDataLink := TIBLookupComboDataLink.Create(self);
481 FKeyPressInterval := 500;
482 FAutoComplete := true;
483 FTimer := TTimer.Create(nil);
484 FTimer.Interval := 0;
485 FTimer.OnTimer := @HandleTimer;
486 FLastKeyValue := NULL;
487 end;
488
489 destructor TIBLookupComboEditBox.Destroy;
490 begin
491 if assigned(FDataLink) then FDataLink.Free;
492 if assigned(FTimer) then FTimer.Free;
493 inherited Destroy;
494 end;
495
496 procedure TIBLookupComboEditBox.EditingDone;
497 begin
498 CheckAndInsert;
499 inherited EditingDone;
500 end;
501
502 end.