# Use NamedKeyStrokes in a Custom Code Class **URL:** \ **Category:** Technical Support & Bugs\ **Created:** [October 26, 2021, 8:22pm UTC](https://forum.vassalengine.org/t/use-namedkeystrokes-in-a-custom-code-class/72882 "2021-10-26T20:22:04Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![drimmer](https://forum.vassalengine.org/letter_avatar_proxy/v4/letter/d/7993a0/32.png) [@drimmer](https://forum.vassalengine.org/u/drimmer)\ **Post date:** [October 26, 2021, 8:22pm UTC](https://forum.vassalengine.org/t/use-namedkeystrokes-in-a-custom-code-class/72882/1 "2021-10-26T20:22:04Z")
I want to implement a custom code class that uses NamedKeyStrokes. I am trying to use an existing class in my module (VASL) as a model but I cannot understand how it works. The buildFile entry for the model class (PieceLinker.java) is as follows: \ The class itself, contains the following: public class PieceLinker extends AbstractConfigurable implements KeyListener, CommandEncoder, GameComponent, Drawable { ``` [various declarations omitteed] private NamedKeyStroke linkKey = new NamedKeyStroke("71dd9846"); // CTL+ALT+L private NamedKeyStroke unlinkKey = new NamedKeyStroke("b385611"); // CTL+ALT+U ``` The net effect of this (and the rest of the class obviously) is that when CTRL+ALT+L is pressed and two counters are selected, those two counters are linked by a line drawn between them. Pressing CTRL+ALT+U removes the line. What I cannot understand is how the various inputs are determined and how they link to the desired keystrokes. More specifically: 1. in the buildFile, LinkKey=“76,650”, what do 76 and 650 represent and how would I know what to use if I want to used CTRL+ALT+S instead of CTRL+ALT+L? Or say SHIFT+L? 2. in the class code, new NamedKeyStroke(“71dd9846”), what does the 71dd9846 represent and how would I know what to use for a different keystroke? I can see how the NamedKeyStrokes are used by the class to actually manage the linking and unlinking. I just can’t figure out how the above lines work to create something that responds to the specific CTRL+ALT+L and CTRL+ALT+U keystrokes. TIA. Doug ---
**Author:** ![uckelman](https://forum.vassalengine.org/user_avatar/forum.vassalengine.org/uckelman/32/10020_2.png) [@uckelman](https://forum.vassalengine.org/u/uckelman)\ **Post date:** [October 26, 2021, 9:01pm UTC](https://forum.vassalengine.org/t/use-namedkeystrokes-in-a-custom-code-class/72882/2 "2021-10-26T21:01:17Z")
> [@drimmer](#): > > in the buildFile, LinkKey=“76,650”, what do 76 and 650 represent and how would I know what to use if I want to used CTRL+ALT+S instead of CTRL+ALT+L? Or say SHIFT+L? Those are the key code and modifiers, respectively. The key codes are defined in `java.awt.event.KeyEvent` and modifiers are defined in `java.awt.event.InputEvent`. ---
**Author:** ![uckelman](https://forum.vassalengine.org/user_avatar/forum.vassalengine.org/uckelman/32/10020_2.png) [@uckelman](https://forum.vassalengine.org/u/uckelman)\ **Post date:** [October 26, 2021, 9:02pm UTC](https://forum.vassalengine.org/t/use-namedkeystrokes-in-a-custom-code-class/72882/3 "2021-10-26T21:02:55Z")
> [@drimmer](#): > > in the class code, new NamedKeyStroke(“71dd9846”), what does the 71dd9846 represent and how would I know what to use for a different keystroke? The string argument is just the name of the `NamedKeyStroke`. You can make that whatever you want for identifying it. ---
**Author:** ![Cattlesquat](https://forum.vassalengine.org/user_avatar/forum.vassalengine.org/cattlesquat/32/241_2.png) [@Cattlesquat](https://forum.vassalengine.org/u/Cattlesquat)\ **Post date:** [October 26, 2021, 9:08pm UTC](https://forum.vassalengine.org/t/use-namedkeystrokes-in-a-custom-code-class/72882/4 "2021-10-26T21:08:14Z")
You can do this for constructing a NamedKeyStroke for a specific key sequence: > NamedKeyStroke.of(KeyEvent.VK\_S, InputEvent.ALT\_DOWN\_MASK) If you wanted multiple modifier keys you’d “or them together” in the second parameter. Brian ---
**Author:** ![drimmer](https://forum.vassalengine.org/letter_avatar_proxy/v4/letter/d/7993a0/32.png) [@drimmer](https://forum.vassalengine.org/u/drimmer)\ **Post date:** [October 30, 2021, 4:08pm UTC](https://forum.vassalengine.org/t/use-namedkeystrokes-in-a-custom-code-class/72882/5 "2021-10-30T16:08:30Z")
Thanks to you both. I will give this a go. ---
**Author:** ![drimmer](https://forum.vassalengine.org/letter_avatar_proxy/v4/letter/d/7993a0/32.png) [@drimmer](https://forum.vassalengine.org/u/drimmer)\ **Post date:** [March 6, 2022, 3:46pm UTC](https://forum.vassalengine.org/t/use-namedkeystrokes-in-a-custom-code-class/72882/6 "2022-03-06T15:46:53Z")
I was able to get this to work using Brian’s reference. Thanks for the continued help. ---
**Author:** ![Brent\_Easton](https://forum.vassalengine.org/user_avatar/forum.vassalengine.org/brent_easton/32/10_2.png) [@Brent\_Easton](https://forum.vassalengine.org/u/Brent_Easton)\ **Post date:** [March 10, 2022, 9:55pm UTC](https://forum.vassalengine.org/t/use-namedkeystrokes-in-a-custom-code-class/72882/7 "2022-03-10T21:55:20Z")
Just some further clarification, ```auto private NamedKeyStroke linkKey = new NamedKeyStroke("71dd9846"); // CTL+ALT+L ``` That comment at the end is meaningless, it bears no relationship at all to what that piece of code is doing. A NamedKeyStroke can be EITHER a specified real (can be typed)l keystroke OR a virtual named Keystroke. It can’t be both. So the above fragment is creating a virtual keystroke with the name “71dd9846”. Internally, in Vassal, this will be allocated an invisible Keystroke from a pool that is used by Vassal for all references to the Keystroke named “71dd9846”. This can never respond to CTRL+ALT+L or any other other type-able keystroke. The fragment alluded to by Brain ```auto private NamedKeyStroke linkKey = new NamedKeyStrokeKeyEvent.VK_L, InputEvent.ALT_DOWN_MASK + InputEvent.CTRL_DOWN_MASK); // CTL+ALT+L ``` Creates a Keystroke that responds to Ctrl-Alt-L being typed.