Fixed HideNavBar functionality in GExperts

When Embarcadero added the Navigation Toolbar to the Delphi code editor in Delphi 10 there were a few people who didn’t like it because it took up some more of the vertical screen space. But there was no option to disable it.

Achim Kalwa wrote an expert to hide this toolbar and contributed the code, which I integrated into GExperts. Unfortunately it didn’t work reliably. The Navigation Toolbar came back whenever one opened a new edit window and went away again when switching between tabs, creating an annoying flicker.

Today I investigated the issue and found that apparently the IDE sets the control’s visible property to true whenever it opens a new editor tab. The fix was actually quite simple: Create a new panel, set its Parent to the toolbar’s original parent control and set the toolbar’s parent to this new panel. So it ends up between the toolbar and its parent. Then set this panel to be invisible instead of the toolbar. Since the IDE doesn’t know about this new panel, it does not change its visibility. Voila, problem solved.

Of course it was a bit more involved because I had to size the panel correctly and also make sure that I don’t insert a new panel every time I check for the visibility. But once I had the general principle it was just a matter of fine tuning the solution.

  if TryFindComponentByName(Ctrl, 'TEditorNavigationToolbar', C) then begin
    Ctrl := TWinControl(C);
    ParentCtrl := Ctrl.Parent;
    if Assigned(ParentCtrl) and (ParentCtrl is TPanel) and (ParentCtrl.Name = GX_HideNavbarPanel) then
      pnl := TPanel(ParentCtrl)
    else begin
      pnl := TPanel.Create(ParentCtrl);
      pnl.Parent := ParentCtrl;
      pnl.Name := GX_HideNavbarPanel;
      pnl.Align := alTop;
      pnl.BevelOuter := bvNone;
      pnl.Height := ctrl.Height;
      Ctrl.Parent := pnl;
    pnl.Visible := FIsNavbarVisible;
    pnl.Enabled := FIsNavbarVisible;
    if FIsNavbarVisible then
      Ctrl.Visible := True;
    Result := True;

I also found, that in Delphi 10.1 Berlin there is already an option to show or hide the Navigation Toolbar (Tools -> Options -> Editor Options -> Display), so I removed the functionality from GExperts for Delphi 10.1 again.