[Gimp-developer] meta-data browser: EntryWidget + treemodel = chicken/egg problem

[Martin Nordholts]

On 07/12/2009 03:12 PM, Roman Joost wrote:
>   When I enter the first characters in the entry, the following happens:
>
>      1. the schema is set (row-changed signal is emitted)
>      2. the property *value* is set (another row-changed signal)
>
>   That raises actually to a big problem, because when I populate two
>   of my Entry widgets in the browser I get a pingpong going on between
>   the Entries. Funny, but not usable.
>    

When a listener makes changes to a the thing it listens to, it typically 
will want to have 
g_signal_handlers_block_by_func()/g_signal_handlers_unblock_by_func() 
around the piece of code that does the change, and/or "if (new_value == 
current_value) return;" at the beginning of the callback to prevent the 
pingpong you are describing. Sometimes it's tricky to get this right.

HTH,
Martin