HotKeyManager, ver. 1.0.0

[Properties] [Methods] [Events] [Static methods]
[Known Bugs] [Hints] [Comments]

HotKeyManager is a component that allows you to add system hotkeys to your application.

A hotkey in Windows is a key combination which invokes a specific action. You can often use Ctrl+S from an application to save a file. However, a system hotkey allows your app. to invoke a custom action from anywhere. Your app. doesn't have to be in the foreground or even visible. The best known example of a system hotkey is probably Ctrl+Alt+Delete which pops up a system dialog.

Properties

No properties.

Methods

AddHotKey	function AddHotKey(HotKey: TShortCut): Word; Registers a hotkey with a specific key combination. NOTE: A return value of 0 means the specified key combination is already in use.	Returns an index or 0 if error
ChangeHotKey	function ChangeHotKey(Index: Word; NewHotKey: TShortCut): Word; Changes a hotkey to a new key combination. Provide the index received from AddHotKey as parameter. NOTE: This method returns a new index. The old index is no longer valid.	Returns an index or 0 if error
RemoveHotKey	function RemoveHotKey(HotKey: TShortCut): Boolean; Unregisters a hotkey by its key combination.	Returns true or false
RemoveHotKeyByIndex	function RemoveHotKeyByIndex(Index: Word): Boolean; Unregisters a hotkey by the index received from AddHotKey.	Returns true or false
ClearHotKeys	procedure ClearHotKeys; Unregisters all registered hotkeys.

Events

OnHotKeyPressed

type TOnHotKeyPressed = procedure(HotKey: TShortCut; Index: Word) of object;
Fired when then user presses one of the registered hotkeys. The event method provides the key combination pressed and the index the hotkey is registered under.

Static Methods

HotKeyAvailable	function HotKeyAvailable(HotKey: TShortCut): Boolean; Tests if the specified key combination is available for registration by your app. (or any other app.).	Returns true or false
SeparateHotKey	procedure SeparateHotKey(HotKey: Word; var Modifiers, Key: Word); Splits a key combination into a key (A, for instance) and its modifiers (shift, ctrl, alt, win).

Hints

How do you convert the string 'Ctrl+Alt+X' into a TShortCut value, or vice versa?
Delphi has some useful methods in the Menus unit, like TextToShortCut and ShortCutToText.

How do I test if a key combination contains the Ctrl modifier (like in Ctrl+Alt+X)?
You can use SeparateHotKey, then test the returned Modifier variable, like so:

  CtrlFound  := (Modifier and MOD_CONTROL) <> 0;
  AltFound   := (Modifier and MOD_ALT) <> 0;
  ShiftFound := (Modifier and MOD_SHIFT) <> 0;
  WinFound   := (Modifier and MOD_WIN) <> 0;    // Special Windows key

Can I use HotKeyManager in a DLL?
Yes, the component registers the hotkeys using indexes that are system-wide unique.
Tell me more about hotkeys?
See API documentation on RegisterHotKey, UnregisterHotKey, and WM_HOTKEY.

Known Bugs

None at this point.

Comments

HotKeyManager is freeware. Feel free to use and improve it, but please include all original files if you redistribute the zip-file. If you have any comments or corrections I would very much like to hear them.

Get the latest version from http://www3.ewebcity.com/troels/delphi.asp.

Troels Jakobsen
delphiuser@get2net.dk