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{
fpGUI - Free Pascal Graphical User Interface
Copyright (C) 2000 - 2001 by
Areca Systems GmbH / Sebastian Guenther
Copyright (C) 2006 by Graeme Geldenhuys
member of the fpGUI development team.
Combobox class declarations
See the file COPYING.fpGUI, included in this distribution,
for details about the copyright.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
**********************************************************************}
{%mainunit fpgui.pp}
{$IFDEF read_interface}
{ Combobox widget declarations }
{ TCustomComboBox }
TComboBoxPopup = class(TPopupWindow)
private
FListBox: TListBox;
procedure ItemSelected(Sender: TObject);
public
constructor Create(AOwner: TComponent); override;
property ListBox: TListBox read FListBox;
end;
TCustomComboBox = class(TWidget)
private
FItemIndex: Integer;
FItems: TStrings;
FOnChange: TNotifyEvent;
procedure ButtonClick(Sender: TObject);
procedure DropDownDeactivate(Sender: TObject);
procedure DropDownDestroy(Sender: TObject);
procedure SetItemIndex(const AValue: Integer);
protected
FButton: TGenericButton;
// FDropDown: TCustomForm;
FDropDown: TComboBoxPopup;
lbl: TLabel;
procedure Click; override;
procedure Paint(Canvas: TFCanvas); override;
procedure CalcSizes; override;
procedure Resized; override;
function DistributeEvent(Event: TEventObj): Boolean; override;
property CanExpandWidth default True;
// property DropDownCount: integer read FDropDownCount write FDropDownCount;
property ItemIndex: Integer read FItemIndex write SetItemIndex default -1;
property OnChange: TNotifyEvent read FOnChange write FOnChange;
public
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
property Items: TStrings read FItems write FItems;
end;
TComboBox = class(TCustomComboBox)
published
property CanExpandWidth;
property CanExpandHeight;
property Enabled;
property Text;
property ItemIndex;
property OnChange;
end;
{$ENDIF read_interface}
{$IFDEF read_implementation}
{ Combobox widget implementation }
type
TArrowButton = class(TGenericButton)
protected
procedure Paint(Canvas: TFCanvas); override;
procedure CalcSizes; override;
end;
procedure TArrowButton.Paint(Canvas: TFCanvas);
begin
inherited Paint(Canvas);
Style.DrawComboBoxArrow(Canvas, Rect(0, 0, Width, Height),
(wsClicked in WidgetState) and (wsMouseInside in WidgetState),
wsEnabled in WidgetState);
end;
procedure TArrowButton.CalcSizes;
begin
FMinSize := Style.GetComboBoxArrowSize;
end;
procedure TComboBoxPopup.ItemSelected(Sender: TObject);
begin
Close;
end;
constructor TComboBoxPopup.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
WidgetStyle := WidgetStyle + [wsCaptureMouse, wsClickable, wsOpaque];
FListBox := TListBox.Create(self);
FListBox.Name := 'listbox';
FListBox.Parent := self;
FListBox.HotTrack := True;
// FListBox.OnClick := @ItemSelected; // Listbox needs OnSelect event
end;
// -------------------------------------------------------------------
// TCustomComboBox
// -------------------------------------------------------------------
constructor TCustomComboBox.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
FCanExpandWidth := True;
WidgetStyle := WidgetStyle + [wsCaptureMouse, wsClickable, wsOpaque];
FItems := TStringList.Create;
FItemIndex := -1;
FButton := TArrowButton.Create(Self);
FButton.Name := 'FButton';
FButton.Embedded := True;
FButton.CanExpandWidth := False;
FButton.OnClick := @ButtonClick;
FButton.Parent := Self;
end;
destructor TCustomComboBox.Destroy;
begin
FDropDown.Free;
inherited Destroy;
end;
procedure TCustomComboBox.Paint(Canvas: TFCanvas);
var
Pt: TPoint;
ItemRect: TRect;
ItemFlags: TItemFlags;
begin
ItemFlags := [];
Style.DrawEditBox(Canvas, Rect(0, 0, Width, Height));
if Text <> '' then
begin
Style.SetUIColor(Canvas, clWindowText);
Pt.x := 4;
Pt.y := (BoundsSize.cy - Canvas.FontCellHeight) div 2;
if (wsHasFocus in WidgetState) and FindForm.IsActive then
begin
Include(ItemFlags, ifFocused);
Include(ItemFlags, ifSelected);
end;
ItemRect := Rect(0, 0, (Width - FButton.Width), Height);
// InflateRect(ItemRect, -1, -1);
ItemRect.TopLeft := ItemRect.TopLeft + 1;
ItemRect.BottomRight := ItemRect.BottomRight - 2;
Style.DrawItemBefore(Canvas, ItemRect, ItemFlags);
Style.DrawText(Canvas, Pt, Text, WidgetState);
Style.DrawItemAfter(Canvas, ItemRect, ItemFlags);
end
else
begin
if (wsHasFocus in WidgetState) and FindForm.IsActive then
Style.DrawFocusRect(Canvas, Rect(0, 0, Width, Height));
end;
end;
procedure TCustomComboBox.CalcSizes;
begin
with Style.GetEditBoxBorders do
FMinSize := gfxBase.Size(FButton.MinSize.cx,
Max(FindForm.Wnd.Canvas.FontCellHeight, FButton.MinSize.cy)) +
TopLeft + BottomRight;
end;
procedure TCustomComboBox.Resized;
begin
with Style.GetEditBoxBorders do
FButton.SetBounds(Point(Width - Right - FButton.MinSize.cx, Top),
FButton.MinSize);
end;
function TCustomComboBox.DistributeEvent(Event: TEventObj): Boolean;
begin
Result := Event.SendToChild(FButton) or
inherited DistributeEvent(Event);
end;
procedure TCustomComboBox.ButtonClick(Sender: TObject);
var
l: TCustomListBox;
begin
if Assigned(FDropDown) and FDropDown.Visible then
begin
FDropDown.Close;
Exit; //==>
end;
if not Assigned(FDropDown) then
begin
FDropDown := TComboBoxPopup.Create(Self);
FDropDown.OnDeactivate := @DropDownDeactivate;
FDropDown.OnDestroy := @DropDownDestroy;
FDropDown.ListBox.Items.Text := FItems.Text;
FDropDown.ListBox.FItemIndex := FItemIndex;
FDropDown.ListBox.OnClick := @DropDownDeactivate;
end;
FDropDown.SetPosition(ClientToScreen(Point(0, Height)));
FDropDown.Show;
end;
procedure TCustomComboBox.DropDownDeactivate(Sender: TObject);
begin
LAYOUTTRACE('TCustomComboBox.DropDownDestroy for %s:%s', [Name, ClassName]);
ItemIndex := FDropDown.ListBox.ItemIndex;
FDropDown.Close;
SetFocus;
end;
procedure TCustomComboBox.DropDownDestroy(Sender: TObject);
begin
LAYOUTTRACE('TCustomComboBox.DropDownDestroy for %s:%s', [Name, ClassName]);
FDropDown := nil;
end;
procedure TCustomComboBox.SetItemIndex(const AValue: Integer);
begin
if FItemIndex <> AValue then
begin
if AValue < FItems.Count then
FItemIndex := AValue;
if FItemIndex = -1 then
Text := ''
else
Text := FItems[FItemIndex];
// fire event
if Assigned(OnChange) then
OnChange(Self);
end;
end;
{ This event causes the combobox to drop open when you click anywhere in the
component, or press the spacebar key. }
procedure TCustomComboBox.Click;
begin
ButtonClick(nil);
inherited Click;
end;
{$ENDIF read_implementation}
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