Peter MacDonaldPeter MacDonald$Revision: 1.4 $Tk

This TIP adds a 6th (and 7th element) to each option in the output of [path configure] for Tk widgets, indicating the type and modified status of each option respectively.

The configure subcommand of Tk widgets provides a powerful method for introspection of widget state information. Unfortunately, two important pieces of information are currently unavailable. Namely, the type Tk is expecting for an option and the whether a user has explicitly assigned a value. The type field is valuable in automating interfaces for editing the contents of widgets. The modified field is useful in changing styles (such as in tk_setPalette) where we update all widgets that are currently using default values.

The configure subcommand for Tk widgets, when invoked with no arguments, currently dumps out all options as a list with 5 elements per-option: optName, dbName, dbClass, defValue, optValue. This TIP proposes adding up to 2 additional values: optType and optModified. A 6th element, optType, is a string representation of the type field of Tk_ConfigSpec and Tk_OptionSpec.For widgets using the new Tk_OptionSpec, a 7th appended element indicates whether an option has been set by the user.

Perhaps optModified should be specified as an enumeration. For example: 1 = USER_MODIFIED2 = OPTION_DATABASE3 = SYSTEM_DEFAULT4 = TABLE_DEFAULT In addition, as much of the Tk core is still using Tk_ConfigSpec, would some form of compatibility interface make sense whereby a Tk_ConfigSpec could be used to dynamically produce a Tk_OptionSpec? (This last is out of the scope of this TIP.) Probably also need a way to change options such that the USER_MODIFIED flag does not get set. (eg. tk_setPalette)

Threre are a couple of small changes to tkConfig.c and tkOldConfig.c, plus a #define of TK_OPTION_VALUE_SET in tk.h

Scripts currently exploiting introspection and depending upon a list length of 5 may break.

There is a simple implementation of the above available as a patch against Tk 8.4.2[]. It does not implement a enumerated flag for optModified, and the type string lookup is rather crude.

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