What's next for the meta-data browser

Hi folks,

I'm currently devoting some of my spare time on working on the metadata
browser and I'm wondering which should be worked on next. As a quick
background:

The metadata browser currently consists of seven tabs: Description,
Copyright, Origin, Camera 1, Camera 2, Advanced. Only two tabs "work":
Description and Advanced. The first tab shows dublin core metadata
fields, such as: title author, description, keywords. The last -
advanced - tab, shows schemas and their properties expanded as a tree.
Some of the property values can be edited by the user, some can't.


So, I picked as a next working target the description tab.

Two questions:

1. Do I have to be careful when entry callbacks write to the
XMPModel (or any other model or structure) everytime a user types in
a character (performance wise)?

2. I tried to find out how I can add callbacks to editable tree
items. Those callbacks should update the corresponding fields in the
description tab. E.g someone changes in the advanced tab the title
field. This change should then visible in the description tab and
the title has changed.
What am I looking for, when I want to add callbacks to those tree
columns? A pointer to documentation or some keywords I should look
out for would be helpful.

If there are more important changes for the browser than the description
tab, let me know. Maybe I should rather focus on make the advanced tab
more usable ... don't know.

If you need more information to provide useful help, let me know :)

Cheers!

Hi,

On Thu, 2009-07-02 at 11:53 +1000, Roman Joost wrote:

> Two questions:
>
> 1. Do I have to be careful when entry callbacks write to the
> XMPModel (or any other model or structure) everytime a user types in
> a character (performance wise)?

Usually this is not a problem. But if it turns out to be one (because
changing the model is expensive), then you might want to delay changes
to the model. You can do that for example by not connecting to 'changed'
but instead apply the changes when the dialog is closed. Or you could
connect to 'activate' and 'leave-notify-event' and apply the change when
the user presses Enter and when the focus leaves the entry.

> 2. I tried to find out how I can add callbacks to editable tree
> items. Those callbacks should update the corresponding fields in the
> description tab. E.g someone changes in the advanced tab the title
> field. This change should then visible in the description tab and
> the title has changed.
> What am I looking for, when I want to add callbacks to those tree
> columns? A pointer to documentation or some keywords I should look
> out for would be helpful.

You want to connect to the 'edited' signal of the GtkCellRendererText
object that is responsible for rendering the editable cell.


Sven

On Thu, Jul 02, 2009 at 09:58:33PM +0200, Sven Neumann wrote:
> > Two questions:
> >
> > 1. Do I have to be careful when entry callbacks write to the
> > XMPModel (or any other model or structure) everytime a user types in
> > a character (performance wise)?
>
> Usually this is not a problem. But if it turns out to be one (because
> changing the model is expensive), then you might want to delay changes
> to the model. You can do that for example by not connecting to 'changed'
> but instead apply the changes when the dialog is closed. Or you could
> connect to 'activate' and 'leave-notify-event' and apply the change when
> the user presses Enter and when the focus leaves the entry.
>
> > 2. I tried to find out how I can add callbacks to editable tree
> > items. Those callbacks should update the corresponding fields in the
> > description tab. E.g someone changes in the advanced tab the title
> > field. This change should then visible in the description tab and
> > the title has changed.
> > What am I looking for, when I want to add callbacks to those tree
> > columns? A pointer to documentation or some keywords I should look
> > out for would be helpful.
>
> You want to connect to the 'edited' signal of the GtkCellRendererText
> object that is responsible for rendering the editable cell.
Cheers for that response! Helped a lot!

Greetings,