README

HotKeyBox

Delphi's THotKey for Lazarus.

A box where the user presses a key combination, and it shows Shift+Ctrl+F9.

The class, its types, properties and defaults are Delphi's, so a Delphi form with a THotKey on it loads in Lazarus as it is. The control draws itself, so it is meant to look and work the same on every widgetset. It is one unit and needs the LCL alone.

ROADMAP.md says what is done and what is not.

Why

Lazarus has no shortcut entry control on the palette; the only one in the tree is TShortCutGrabBox inside the IDE's own package. The one re-creation of THotKey on GitHub is GPL-3 and uses the Windows unit.

Use

1. Install the package (below). THotKey appears on the Common Controls tab.
2. Drop a THotKey on a form.
3. Read HotKey in its OnChange event. It is a TShortCut, the type TMenuItem.ShortCut and TAction.ShortCut take:

procedure TForm1.HotKey1Change(Sender: TObject);
begin
  mnuSave.ShortCut := HotKey1.HotKey;
end;

With the Delphi defaults (InvalidKeys = [hcNone, hcShift], Modifiers = [hkAlt]) a key pressed alone gets Alt added: A is stored as Alt+A, Ctrl+A stays Ctrl+A. Set InvalidKeys to [] to store every combination as pressed. Backspace or Delete clears the box to None; Tab, Enter and Esc go to the form as usual.

demo/ has a box wired to a menu item and a second box with InvalidKeys = [].

Delphi forms

The class name, the types THKModifier, THKModifiers, THKInvalidKey and THKInvalidKeys, the property names and the defaults are Delphi's, so a .dfm with a THotKey loads without edits. hkExt, the Windows extended-key flag, is accepted and ignored. The box records Shift, Ctrl and Alt, the modifiers Delphi's TShortCut has; the macOS Command key is left out.

Current scope

Checked on Linux with GTK3: key handling, the InvalidKeys and Modifiers rules, streaming a Delphi form and an .lfm, drawing, and the height beside a TEdit. The package and demo also compile for Windows. Qt5, Win32 and Cocoa have not been looked at yet.

Install

Open hotkeyboxpkg.lpk in Lazarus, Compile, then Use > Install. The package needs the LCL and nothing else. src/hotkeybox.pas alone also works on a project's unit path.

License

0BSD. Copyright (c) 2026 Tony Stone.