lcl: handle NullValueKey of TDBLookup* in KeyDown event instead of through a global handler. Fixes #19164

git-svn-id: trunk@30329 -

lcl/dbctrls.pp

@@ -145,7 +145,6 @@ Type
     FLookupCache: boolean;
     FLookupList: TLookupList;
     FNullValueKey: TShortcut;
-    FOnClearSelection: TNotifyEvent;
     procedure ActiveChange(Sender: TObject);
     procedure EditingChange(Sender: TObject);
     procedure FetchLookupData;
@@ -157,11 +156,10 @@ Type
     procedure SetListFieldName(const Value: string);
     procedure SetListSource(Value: TDataSource);
     procedure SetLookupCache(const Value: boolean);
-    procedure NullKeyHandler(Sender: TObject; var Key: Word; Shift: TShiftState);
+    function HandleNullKey(var Key: Word; Shift: TShiftState): Boolean;
   protected
     procedure Notification(AComponent: TComponent;
       Operation: TOperation); override;
-    procedure DoClearSelection;
   public
     constructor Create(AOwner: TComponent); override;
     destructor Destroy; override;
@@ -178,7 +176,6 @@ Type
     property ListFieldIndex: Integer read FListFieldIndex write FListFieldIndex default 0;
     property ListSource: TDataSource read GetListSource write SetListSource;
     property NullValueKey: TShortcut read FNullValueKey write FNullValueKey;
-    property OnClearSelection: TNotifyEvent read FOnClearSelection write FOnClearSelection;
   end;
 
   { TDBEdit }
@@ -454,10 +451,10 @@ Type
     procedure SetListFieldIndex(const Value: Integer);
     procedure SetListSource(const Value: TDataSource);
     procedure SetLookupCache(const Value: boolean);
-    procedure RemoveSelection(Sender: TObject);
     procedure SetNullValueKey(const AValue: TShortCut);
   protected
     procedure DataChange(Sender: TObject); override;
+    procedure KeyDown(var Key: Word; Shift: TShiftState); override;
     procedure InitializeWnd; override;
     procedure UpdateData(Sender: TObject); override;
   public
@@ -769,9 +766,9 @@ Type
     procedure SetListSource(const Value: TDataSource);
     procedure SetLookupCache(const Value: boolean);
     procedure SetNullValueKey(const AValue: TShortCut);
-    procedure RemoveSelection(Sender: TObject);
   protected
     procedure InitializeWnd; override;
+    procedure KeyDown(var Key: Word; Shift: TShiftState); override;
     procedure UpdateData(Sender: TObject); override;
     procedure UpdateText; override;
   public

lcl/include/dblookup.inc

@@ -75,7 +75,6 @@ begin
   FHasLookUpField:= False;
   FListLinkTmpSetActive := False;
   FLookupCache := False;
-  Application.AddOnKeyDownBeforeHandler(@NullKeyHandler, false);
 end;
 
 destructor TDBLookup.Destroy;
@@ -147,12 +146,17 @@ begin
     FLookupList := TLookupList.Create;
 end;
 
-procedure TDBLookup.NullKeyHandler(Sender: TObject; var Key: Word;
+{
-  Shift: TShiftState);
+Returns True if selection must be cleared
+If NullKey is detected set Key to VK_UNKNOWN
+}
+
+function TDBLookup.HandleNullKey(var Key: Word; Shift: TShiftState): Boolean;
 var
-  i:  Integer;
+  i: Integer;
 begin
-  if (FNullValueKey=KeyToShortCut(Key, Shift)) then
+  Result:=False;
+  if FNullValueKey=KeyToShortCut(Key, Shift) then
   begin
     // null associated field
     if Assigned(FControlLink) and (FDataFieldNames<>'') and FControlLink.Active then
@@ -161,11 +165,9 @@ begin
       for i:=0 to FDataFields.Count-1 do
         TField(FDataFields[i]).Clear;
     end else
-    if Assigned(FListLink.DataSet) and FListLink.DataSet.Active and Assigned(FListField) then
+      Result:=Assigned(FListLink.DataSet) and FListLink.DataSet.Active and Assigned(FListField);
-      // associated list is active, clear current selection
+    Key:=VK_UNKNOWN;
-      DoClearSelection;
   end;
-
 end;
 
 procedure TDBLookup.Notification(AComponent: TComponent; Operation: TOperation);
@@ -176,12 +178,6 @@ begin
       FListSource:= nil;
 end;
 
-procedure TDBLookup.DoClearSelection;
-begin
-  if Assigned(FOnClearSelection) then
-    OnClearSelection(Self);
-end;
-
 procedure TDBLookup.LinkGetBookMark;
 begin
   FListLinkTmpSetActive := not FListLink.DataSet.Active;

lcl/include/dblookupcombobox.inc

@@ -27,7 +27,6 @@ constructor TDBLookupComboBox.Create(AOwner: TComponent);
 begin
   inherited Create(AOwner);
   FLookup:= TDBLookup.Create(Self);
-  FLookup.OnClearSelection:=@RemoveSelection;
   FDataLink.OnActiveChange:= @ActiveChange;
 end;
 
@@ -55,6 +54,17 @@ begin
   ActiveChange(Self);
 end;
 
+procedure TDBLookupComboBox.KeyDown(var Key: Word; Shift: TShiftState);
+begin
+  if FLookup.HandleNullKey(Key, Shift) then
+  begin
+    //clear selection
+    ItemIndex := -1;
+    //Text := '';
+  end;
+  inherited KeyDown(Key, Shift);
+end;
+
 function TDBLookupComboBox.GetKeyField: string;
 begin
   Result := FLookup.KeyField;
@@ -133,10 +143,3 @@ begin
   FLookup.NullValueKey := AValue;
 end;
 
-procedure TDBLookupComboBox.RemoveSelection(Sender: TObject);
-begin
-  ItemIndex := -1;
-  Text := '';
-end;
-
-

lcl/include/dblookuplistbox.inc

@@ -26,7 +26,6 @@ constructor TDBLookupListBox.Create(AOwner: TComponent);
 begin
   inherited Create(AOwner);
   FLookup:= TDBLookup.Create(Self);
-  FLookup.OnClearSelection := @RemoveSelection;
   FDataLink.OnActiveChange:= @ActiveChange;
 end;
 
@@ -59,6 +58,19 @@ begin
   end;
 end;
 
+procedure TDBLookupListBox.KeyDown(var Key: Word; Shift: TShiftState);
+begin
+  if FLookup.HandleNullKey(Key, Shift) then
+  begin
+    //clear selection
+    if not assigned(FDatalink.DataSet) or not FDatalink.DataSet.Active or
+       not assigned(FDatalink.Field) then
+      GetItemIndex; // a list-only dblookuplist do not automatically update itemindex
+    ItemIndex := -1;
+  end;
+  inherited KeyDown(Key, Shift);
+end;
+
 procedure TDBLookupListBox.InitializeWnd;
 begin
   inherited InitializeWnd;
@@ -141,15 +153,6 @@ begin
   ActiveChange(Self);
 end;
 
-procedure TDBLookupListBox.RemoveSelection(Sender: TObject);
-begin
-  if not assigned(FDatalink.DataSet) or not FDatalink.DataSet.Active or
-     not assigned(FDatalink.Field) then
-  GetItemIndex; // a list-only dblookuplist do not automatically update itemindex
-
-  ItemIndex := -1;
-end;
-
 procedure TDBLookupListBox.SetNullValueKey(const AValue: TShortCut);
 begin
   FLookup.NullValueKey := AValue;