Bug #2352


Preferences System needs to be resolved

Added by Christopher Brooks almost 17 years ago. Updated almost 17 years ago.

Target version:
Start date:
Due date:
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Estimated time:


I'm creating a bug for this because
"add welcome screen for release 1.0" depends on it.
I wrote:

Hi Edward,
I'm hacking up the Welcome window and would like to have a way
the window so it has a "Please don't show me this dialog again"
checkbox and I have some questions about VergilPreferences.

- vergil.VergilPreferences should probably be renamed to
PtolemyPreferences and moved to so that the
actor.gui.WelcomeWindow class can get at it and does
not depend on vergil.

In fact, getting a preference is a fairly basic task, so this
should go in some non-gui base class. If we use plain old java
properties, then perhaps we could have a preferences class in
ptolemy.util? I'd like to be able to get at preferences without
requiring moml.
Another preference I'd like to see is a way for the user to adjust
how much detail the GraphicalMessageHandler window initially shows.
GraphicalMessageHandler is in ptolemy.gui and only imports
ptolemy.util, so MoML is not available.

- We need a way to access a global property when we don't have a
container. In general, I think the Kepler developers are confused
about how we should get a Configuration from anywhere in the code.
So, we need a preferenceValue(String preferenceValue) that
does not require a context or container and gets the value of
the global preference.


I've included some email below that has further details


To: Matthew Brooke <>
From: "Christopher Brooks" <>
Subject: Re: [Bug 2343] - add welcome screen for release 1.0
In-reply-to: Your message of Fri, 20 Jan 2006 16:28:29 -0800.
Date: Sat, 21 Jan 2006 18:07:54 -0800

I've taken the liberty of ccing Edward here.

Matthew Brook writes:


Perhaps Edward's preferences manager
(ptolemy.vergil.VergilPreferences) can be used?

When i started the SVG icon stuff, I needed to access properties files
from various parts of the code, and spent a lot of time trying to use
ptII's existing configuration.xml, to no avail. I finally figured it
just wasn't 'available' for enough of the codebase at runtime, without
hard-coding paths in order to re-load it (or maybe I'm just too

Right this is a problem in general. It is not always easy to get
at the configuration, you usually need a model that was read in.

So - I went ahead and used java's built-in
resourcebundle/properties classes for storing prefs. This is
overkill/inappropriate in some places (for example, many of the settings
are not localizable, so do not really need resourcebundle files), but it
works marvelously. I guess in the meantime, Edward created the
VergilPreferences thing, which I haven't looked at - so now we have a
proliferation on our hands... :-(

Anyway - I have put all the ui-related settings in .properties files in
configs/ptolemy/configs/kepler/, and they all have names like:
***.properties. The 'main' one is

Up to now, these only contain application settings (ie read-only) rather
than user settings - so we still need to create a user-settings file for
these read/write props. Is that what VergilPreferences currently does?
if it's ultra-simple to use, and easy to get a reference to the props
class (say via a static method somewhere) let's use it! If not, then
let's use POJ!


Right, VergilPreferences saves its perferences in
or c:/Documents and Settings/username/ptolemyII/VergilPreferences.xml

I think it is fine to have the ui read only settings in

The primary entry point in VergilPreferences is:
/** Check to see whether a preference of the specified name is
  • defined in the specified context, and if it is, return it's value.
  • Note that if there is an error in the expression for the preference,
  • then this method will return null and report the error to standard ou\


  • This is done because we assume the error will normally be caught
  • before this method is called.
  • @param context The context for the preference.
  • @param preferenceName The name of the preference.
  • @return The value of the preference, or null if it is not set.
    public static Token preferenceValue(NamedObj context, String preferenceNa\


) {

I'm not sure what the context would be for the "Show this dialog at
startup". This is sort of a global context.

Perhaps we should extend VergilPreferences to provide a default global
context with a static accessor? Also, it would be nice to have
a static method that returns a String:
public static String preferenceValueAsString(String preferenceName);

Also, I don't see how I add a new preference? (Edward?)

I'm not particularly wedded to using .xml for the global preferences, but
using xml makes sense in this context, where we are setting things
like Relation size, Link bend radius and Show Parameters, and we want
these things to be inherited and overridden in the model hierarchy.

However, there is quite a bit of appeal to using Plain Old Java (POJ)
properties, like what we do with ptII/lib/, which
is created by configure and contains POJ properties that
are merged in by VergilApplication. POJ properties do not
require MoMLParser, so they are more useful for codegen runtime
and other small footprint programs.

BTW - Perhaps we should use ptII/lib/ for global
properties and first load ptII/lib/ and then load
~/.ptolemyII/ (if it exists) so we can override these

Anyway, seems like we have lots of properties systems, we should
hash something out and use it.

1) We could extend VergilPreferences:
- static accessor without a context
- static accessor that returns a String
- static setter of new Properties (with automagic save?)

2) Hack up
- configure sets properties, but we need to make it easy for
users to override
- static setter of new Properties (with automagic save?)

3) Hack up the Kepler properties system
- Make it useful in Ptolemy only



Actions #1

Updated by Christopher Brooks almost 17 years ago

I'm closing this bug because
"add welcome screen for release 1.0"
is now complete

I don't think we have the perfect solution to the Preferences problem.
However, I was able to use Edward's preferences system to save the global
"Show this window next time" preference for the Welcome Window.
See $PTII/ptolemy/actor/gui/ for details.
To do the preferences work, I had to add some code to the Preferences system,
but I think we are in a good place for shipping Kepler-1.0 and
Ptolemy II 6.0.

Thus, I'm closing this bug.

Actions #2

Updated by Redmine Admin almost 10 years ago

Original Bugzilla ID was 2352


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