begin
  inherited;

  // mouse is in control ?
  P := ClientToScreen(Point(X, Y));
  if (MouseInControl <> Self) and (FindDragTarget(P, True) = Self) then
  begin
    if Assigned(MouseInControl) then
      MouseInControl.MouseLeave;
    // the application is active ?
    if (GetActiveWindow <> 0) then
    begin
      if MouseTimer.Enabled then
        MouseTimer.Enabled := False;
      MouseInControl := Self;
      MouseTimer.OnTimer := MouseTimerHandler;
      MouseTimer.Enabled := True;
      MouseEnter;
    end;
  end;

  if FDragging then
  begin
    if not FDown then
      NewState := bsUp
    else
      NewState := bsExclusive;
    if (X >= 0) and (X < ClientWidth) and (Y >= 0) and (Y <= ClientHeight) then
      if FDown then
        NewState := bsExclusive
      else
        NewState := bsDown;
    if NewState <> FState then
    begin
      FState := NewState;
      Invalidate;
    end;
  end;
end;

procedure TFlatButton.MouseUp (Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
var
  DoClick: Boolean;
begin
  inherited MouseUp(Button, Shift, X, Y);
  if FDragging then
  begin
    FDragging := False;
    DoClick := (X >= 0) and (X < ClientWidth) and (Y >= 0) and (Y <= ClientHeight);
    if FGroupIndex = 0 then
    begin
      // Redraw face in-case mouse is captured
      FState := bsUp;
      FMouseInControl := False;
      if DoClick and not (FState in [bsExclusive, bsDown]) then
        Invalidate;
    end
    else
      if DoClick then
      begin
        SetDown(not FDown);
        if FDown then Repaint;
      end
      else
      begin
        if FDown then FState := bsExclusive;
        Repaint;
      end;
    if DoClick then Click else MouseLeave;
    UpdateTracking;
  end;
end;

procedure TFlatButton.Click;
begin
  if Parent <> nil then
    GetParentForm(self).ModalResult := FModalResult;
  inherited Click;
end;

function TFlatButton.GetPalette: HPALETTE;
begin
  Result := FGlyph.Palette;
end;

procedure TFlatButton.SetColors (Index: Integer; Value: TColor);
begin
  case Index of
    0: FFocusedColor := Value;
    1: FDownColor := Value;
    2: FBorderColor := Value;
    3: FColorHighlight := Value;
    4: FColorShadow := Value;
  end;
  Invalidate;
end;

procedure TFlatButton.CalcAdvColors;
begin
  if FUseAdvColors then
  begin
    FFocusedColor := CalcAdvancedColor(Color, FFocusedColor, FAdvColorFocused, lighten);
    FDownColor := CalcAdvancedColor(Color, FDownColor, FAdvColorDown, darken);
    FBorderColor := CalcAdvancedColor(Color, FBorderColor, FAdvColorBorder, darken);
  end;
end;

procedure TFlatButton.SetAdvColors (Index: Integer; Value: TAdvColors);
begin
  case Index of
    0: FAdvColorFocused := Value;
    1: FAdvColorDown := Value;
    2: FAdvColorBorder := Value;
  end;
  CalcAdvColors;
  Invalidate;
end;

procedure TFlatButton.SetUseAdvColors (Value: Boolean);
begin
  if Value <> FUseAdvColors then
  begin
    FUseAdvColors := Value;
    ParentColor := Value;
    CalcAdvColors;
    Invalidate;
  end;
end;

procedure TFlatButton.SetGlyph (value: TBitmap);
begin
  if value <> FGlyph then
  begin
    FGlyph.Assign(value);
    if not FGlyph.Empty then
    begin
      if FGlyph.Width mod FGlyph.Height = 0 then
      begin
        FNumGlyphs := FGlyph.Width div FGlyph.Height;
        if FNumGlyphs > 4 then FNumGlyphs := 1;
      end;
    end;
    Invalidate;
  end;
end;

procedure TFlatButton.SetNumGlyphs (value: TNumGlyphs);
begin
  if value <> FNumGlyphs then
  begin
    FNumGlyphs := value;
    Invalidate;
  end;
end;

procedure TFlatButton.UpdateExclusive;
var
  Msg: TMessage;
begin
  if (FGroupIndex <> 0) and (Parent <> nil) then
  begin
    Msg.Msg := CM_BUTTONPRESSED;
    Msg.WParam := FGroupIndex;
    Msg.LParam := Longint(Self);
    Msg.Result := 0;
    Parent.Broadcast(Msg);
  end;
end;

procedure TFlatButton.SetDown (Value: Boolean);
begin
  if FGroupIndex = 0 then Value := False;
  if Value <> FDown then
  begin
    if FDown and (not FAllowAllUp) then Exit;
    FDown := Value;
    if Value then
    begin
      if FState = bsUp then Invalidate;
      FState := bsExclusive
    end
    else
    begin
      FState := bsUp;
      Repaint;
    end;
    if Value then UpdateExclusive;
  end;
end;

procedure TFlatButton.SetGroupIndex (Value: Integer);
begin
  if FGroupIndex <> Value then
  begin
    FGroupIndex := Value;
    UpdateExclusive;
  end;
end;

procedure TFlatButton.SetLayout (Value: TButtonLayout);
begin
  if FLayout <> Value then
  begin
    FLayout := Value;
    Invalidate;
  end;
end;

procedure TFlatButton.SetMargin (Value: Integer);
begin
  if (Value <> FMargin) and (Value >= -1) then
  begin
    FMargin := Value;
    Invalidate;
  end;
end;

procedure TFlatButton.SetSpacing (Value: Integer);
begin
  if Value <> FSpacing then
  begin
    FSpacing := Value;
    Invalidate;
  end;
end;

procedure TFlatButton.SetAllowAllUp (Value: Boolean);
begin
  if FAllowAllUp <> Value then
  begin
    FAllowAllUp := Value;
    UpdateExclusive;
  end;
end;

procedure TFlatButton.WMLButtonDblClk (var Message: TWMLButtonDown);
begin
  inherited;
  if FDown then DblClick;
end;

procedure TFlatButton.CMEnabledChanged (var Message: TMessage);
begin
  inherited;
  if not Enabled then
  begin
    FMouseInControl := False;
    FState := bsDisabled;
    RemoveMouseTimer;
  end;
  UpdateTracking;
  Invalidate;
end;

procedure TFlatButton.CMButtonPressed (var Message: TMessage);
var
  Sender: TFlatButton;
begin
  if Message.WParam = FGroupIndex then
  begin
    Sender := TFlatButton(Message.LParam);
    if Sender <> Self then
    begin
      if Sender.Down and FDown then
      begin
        FDown := False;
        FState := bsUp;
        Invalidate;
      end;
      FAllowAllUp := Sender.AllowAllUp;
    end;
  end;
end;

procedure TFlatButton.CMDialogChar (var Message: TCMDialogChar);
begin
  with Message do
    if IsAccel(CharCode, Caption) and Enabled then
    begin
      Click;
      Result := 1;
    end else
      inherited;
end;

procedure TFlatButton.CMFontChanged (var Message: TMessage);
begin
  Invalidate;
end;

procedure TFlatButton.CMTextChanged (var Message: TMessage);
begin
  Invalidate;
end;

procedure TFlatButton.CMSysColorChange (var Message: TMessage);
begin
  if FUseAdvColors then
  begin
    ParentColor := True;
    CalcAdvColors;
  end;
  Invalidate;
end;

procedure TFlatButton.CMParentColorChanged (var Message: TWMNoParams);
begin
  inherited;
  if FUseAdvColors then
  begin
    ParentColor := True;
    CalcAdvColors;
  end;
  Invalidate;
end;

procedure TFlatButton.MouseEnter;
begin
  if Enabled and not FMouseInControl then
  begin
    FMouseInControl := True;
    Repaint;
  end;
end;

procedure TFlatButton.MouseLeave;
begin
  if Enabled and FMouseInControl and not FDragging then
  begin
    FMouseInControl := False;
    RemoveMouseTimer;
    Invalidate;
  end;
end;

procedure TFlatButton.MouseTimerHandler (Sender: TObject);
var
  P: TPoint;
begin
  GetCursorPos (P);
  if FindDragTarget(P, True) <> Self then
    MouseLeave;
end;

procedure TFlatButton.RemoveMouseTimer;
begin
  if MouseInControl = Self then
  begin
    MouseTimer.Enabled := False;
    MouseInControl := nil;
  end;
end;

end.