Creating the Config File

The package needs to have a config file - an `rc' file. For the composition package this will be named `compositionrc'. The file contains package dependencies, menu commands, and any user adjustable defaults.

For the composition package we do not need any dependencies. The package depends on gap4 and tk_utils, but both of these are already loaded. If we did need to use an additional package, or simply an additional dynamic library, then we could add further load_package commands to the start of the file.

Next we define the menu items. We could add an entirely new menu if the package defines many additional commands. In this example we'll simply add an extra command onto the standard Gap4 View menu.

# We want to add to the View menu a new command named "Test Command".
# This will call our TestCommand procedure with the contents of the global
# $io variable (used for accessing the gap database).
#
# The command itself should be greyed out when the database is not open or
# is empty.

add_command     {View.List Composition}       8 10 {Composition \$io}

This specifies that the Composition $io command is to be added to the View menu as 'List Composition'. It will be enabled only when the database is open and has data (8) and is disabled during busy modes and when the database has no data or is not open (10).

Next we add any defaults. For the composition package this is simply the dialogue values for the composition command.

# Now for the default values required by the composition command. Some of
# these are the sort of things that will be configured by users (eg the
# default cutoff score in a search routine) by creating their own .rc file
# (.compositionrc in this case). Others are values used entirely by the
# package itself. In our case  that's all we've got.

set_defx defs_c_in      WHICH.NAME      "Input contigs from"
set_defx defs_c_in      WHICH.BUTTONS   {list file {{all contigs}} single}
set_defx defs_c_in      WHICH.VALUE     3
set_defx defs_c_in      NAME.NAME       "List or file name"
set_defx defs_c_in      NAME.BROWSE     "browse"
set_defx defs_c_in      NAME.VALUE      ""

set_def COMPOSITION.WIN .composition
set_def COMPOSITION.INFILE $defs_c_in