HP 39gII User Manual page 258

Redefining the
Views menu
Customizing an
app
248
The Views menu allows any app to define views in
addition to the standard seven views shown in the table
above. By default, each HP app has its own set of
additional views contained in this menu. The VIEWS
command allows you to redefine these views to run
programs you have created for an app. The syntax for
the VIEWS command is:
VIEWS "text"
By adding VIEWS "text", before the declaration of a
function, you will override the list of views for the app. For
example, if your app program defines 3 views
"SetSides", "RollDice" and "PlotResults", when the user
presses the Views key, he will see SetSides, RollDice, and
PlotResults instead of the app's default view list.
When an app is active, its associated program appears
as the first item in the Program Catalog. It is within this
program that you put functions to create a custom app. A
useful procedure for customizing an app is illustrated
below:
1. Decide on the HP app that you want to customize. For
example, you could customize the Function app or the
Statistics 1Var app. The customized app inherits all
the properties of the HP app. Go to the apps Catalog
and save the customized app with a unique name.
2. Customize the new app if you need to by configuring
the settings, for example by setting axes or angle
measures.
3. Develop the functions to work with your customized
app. When you develop the app's functions, use the
app naming conventions described above.
4. Put the VIEWS command into your program to modify
the app's Views menu.
5. Decide if your app will create new global variables.
If such variables are appropriate, you should EXPORT
them from a separate user program that is called from
the Start() function in the app program, so they
will not have their values lost.
6. Test the customized app and debug the associated
programs.
It is possible to link more than one app via programs. For
example, a program associated with the Function app
Programming