CSTMENU: multilevel custom menu with soft keys

[ramon_ea1gth]

Feel the power of the customized soft keys of the HP Prime. CSTMENU is a compact and elegant program that allows the customization of the soft keys in a consistent manner, whether for the global environment or for each Prime app. Now it is possible to have at any entry window your preferred characters or commands, e.g., Greek characters for scientific writing, preferred units for fast unit conversion or fast access commands with customized entry. Menus are swiftly managed with the four ways of the directional pad (left/right/up/down).

Example of creation of a simple custom menu:
+ Download CSTMENU.hpprgm to the HP Prime
+ Create the two required variables, CSTpos and CST with your custom menu:
{1,1}▶CSTpos
{{"A","B","ALOG()","α","β","1","2","3"}}▶CST
(notice the double curly brackets {{ in CST)
+ Switch to User mode: [SHIFT][USER][SHIFT][USER]

Now, your menu is ready. Press the Menu key. Use the directional pad (left/right) to navigate the menu. Press the desired softkey to output it. Each time you press the Menu key, you return to the last menu used.

Multiple menu levels:
CST can include multiple menu levels, e.g., for two levels: {{"1","2","3","4","5","6","7","8"}{"A","B","C","D"}}▶CST
To navigate the levels, use the up/down arrows of the directional pad.

Soft key labels different to the output:
CST can include pairs of {"label","output_text"} to create a different output than the soft key label, e.g., for fast unit conversion with the [STO>] soft key you can prepare this menu:
{{{"m","_(m)"},{"cm","_(cm)"},"Hello",{"ALOG","ALOG()"}}}▶CST

A custom menu per app:
CSTMENU is very flexible, so you can prepare one customized menu per app if you use app variables, e.g.:
{1,1}▶AVars("CSTpos")
{{"A","B","ALOG()","α","β","1","2","3"}}▶AVars("CST")

And for you, the programmers, you can feel the flexibility of CSTMENU, so other programs can take advantage of it. Play with it to discover its power and have a customized HP Prime!

[Edit]:
Changelog
v1.01:
Added #pragma header to support multi-language separators