The GtkImageView widget

The project I have been working on lately is to create a general purpose image viewer widget for GTK . For my personal project, which will be a commercial product to be sold, I needed such a widget.

After searching around a bit, I concluded that there was no such widget [ 1 ] .

So, what I have created is such a general purpouse widget named GtkImageView. I think that there is a great use for such a widget in GNOME and that it will be just as useful as the GtkSourceView widget has been.

There are quite a few programs in GNOME that display an image inside a pane which you can zoom and drag around. Atleast both gThumb , Eye of GNOME and GIMP has such widgets. But the image display widget in these three programs is implemented independently and are incompatible to each other. Each behave slightly differently from the other. Different keybindings, different zoom factor levels and different graphic adornments.

This is where GtkImageView comes into the picture. It is an attempt to unify these three different widget implementations into one that they all can use. The gains are obvious:

less code duplication

Less code for each project to maintain means less bugs.

Uniform UI

The same set of keybindings in all programs means that a user does not have to relearn each program.

Usable by third parties

If you today want to create an application that has a widget that can pane and zoom on an image you have to create it from scratch. You would probably look at, for example, gThumb's source and then cut and paste that. Then you would have to spend some time integrating their widget in your own programs. Time that would be better spent doing something else.

Right now, GtkImageView is almost fully coded. What remains is to upload it to bjourne.webfactional.com and make it world-readable. The following tasks are not yet done:

• API documentation needs to be written.
• There needs to be example programs.
• Patches must be written for EOG and gThumb.
• Must announce intention to the GNOME community and get buy-in from EOG and gThumb's maintainers.
• Need to upload code and publish documentation online.

[ 1 ]

Which was wrong, as I found out later.