Always show drop-down menu in TValueListEditor

Question

I am trying to improve the GUI by reducing the number of clicks required to complete some actions. However, one VCL component that bothers me is TValueListEditor, which contains a list of keys and values, all of which are controlled by drop-down lists. Three clicks are always required to select parameters, if only two are required:

At this point in time, the topmost line has focus, and the value can be changed using the drop-down list (two clicks). However, when the user wants to change another key, he must first change the focus to this key before he can use the drop-down list (three clicks).

Is there a way to show a down arrow for all rows to prevent an extra click?

Here is an example of the layout I want to achieve:

Answer 1

uses Vcl.Themes; type TValueListEditor = class(Vcl.ValEdit.TValueListEditor) private procedure DrawDropDownButton(ACol, ARow: Integer; ARect: TRect; AState: TGridDrawState); function MouseOverButton(X: Integer): Boolean; protected procedure DrawCell(ACol, ARow: Integer; ARect: TRect; AState: TGridDrawState); override; procedure DrawCellHighlight(const ARect: TRect; AState: TGridDrawState; ACol, ARow: Integer); override; procedure MouseDown(Button: TMouseButton; Shift: TShiftState; X, Y: Integer); override; end; { TValueListEditor } type TInplaceEditListAccess = class(Vcl.Grids.TInplaceEditList); procedure TValueListEditor.DrawCell(ACol, ARow: Integer; ARect: TRect; AState: TGridDrawState); begin inherited DrawCell(ACol, ARow, ARect, AState); DrawDropDownButton(ACol, ARow, ARect, AState); end; procedure TValueListEditor.DrawCellHighlight(const ARect: TRect; AState: TGridDrawState; ACol, ARow: Integer); var R: TRect; begin R := ARect; if ItemProps[ARow - FixedRows].HasPickList then Dec(R.Right, EditList.ButtonWidth); inherited DrawCellHighLight(R, AState, ACol, ARow); DrawDropDownButton(ACol, ARow, ARect, AState); end; procedure TValueListEditor.DrawDropDownButton(ACol, ARow: Integer; ARect: TRect; AState: TGridDrawState); var Details: TThemedElementDetails; begin if (ACol = 1) and (ARow >= FixedRows) and not (gdFocused in AState) and ItemProps[ARow - FixedRows].HasPickList then begin ARect.Left := ARect.Right - EditList.ButtonWidth; Details := StyleServices.GetElementDetails(tgDropDownButtonNormal); StyleServices.DrawElement(Canvas.Handle, Details, ARect); end; end; procedure TValueListEditor.MouseDown(Button: TMouseButton; Shift: TShiftState; X, Y: Integer); var ACol: Integer; ARow: Integer; begin inherited MouseDown(Button, Shift, X, Y); MouseToCell(X, Y, ACol, ARow); if (Button = mbLeft) and (ARow > FixedRows) and ItemProps[ARow - FixedRows].HasPickList and not EditList.ListVisible and MouseOverButton(X) then begin EditorMode := True; TInplaceEditListAccess(EditList).DropDown; end; end; function TValueListEditor.MouseOverButton(X: Integer): Boolean; begin Result := (UseRightToLeftAlignment and (X < EditList.ButtonWidth)) or (not UseRightToLeftAlignment and (X > ClientWidth - EditList.ButtonWidth)); end;