Evolution Attachment Rewrite

Today I finished a rewrite of Evolution's attachment handling code. What was supposed to be a short detour from a much larger ongoing project (more on that later) ballooned into a month-long overhaul. I had already sketched out plans for a rewrite a year ago. This was just preparation meeting opportunity.

The goals of the rewrite were primarily internal code cleanup, but there's some UI bling too:

• Attachment handling code is currently scattered throughout Evolution, with lots of duplication. The rewrite collects everything in one place.


• Migrate from GnomeIconList (deprecated) to GtkIconView, with a custom GtkTreeModel specifically for attachments. And throw in a GtkTreeView option just for kicks.


• Better utilize GIO for file operations, thumbnails, emblems, etc. Abstract away the distinction between local and remote files. Stop using threads, and make sure all blocking calls are asynchronous.


• Migrate the attachment popup menus to GtkUIManager.


• Kill off a couple frivolous attachment-related plugins and support the functionality directly. We ship way too many plugins as it is and I'm gradually killing off the silly ones.


• Make the whole thing extensible, to help resolve some cyclic dependencies within the application. The mailer now handles the mail-related parts, the calendar handles the calendar-related parts, and so on.

Here's a few screenshots. The first two show off the new icon and list views when composing email, and demonstrate simultaneously loading from or saving to remote stores (I used some big audio files here for better illustration of the progress bars). Both file operations are cancellable. The third screenshot shows off the attachment UI for received emails.