6.8.4 Agent Visuals

If you open a summary while unplugged and, Gnus knows from the group's active range that there are more articles than the headers currently stored in the Agent, you may see some articles whose subject looks something like `[Undownloaded article #####]'. These are placeholders for the missing headers. Aside from setting a mark, there is not much that can be done with one of these placeholders. When Gnus finally gets a chance to fetch the group's headers, the placeholders will automatically be replaced by the actual headers. You can configure the summary buffer's maneuvering to skip over the placeholders if you care (See gnus-auto-goto-ignores).

While it may be obvious to all, the only headers and articles available while unplugged are those headers and articles that were fetched into the Agent while previously plugged. To put it another way, "If you forget to fetch something while plugged, you might have a less than satisfying unplugged session". For this reason, the Agent adds two visual effects to your summary buffer. These effects display the download status of each article so that you always know which articles will be available when unplugged.

The first visual effect is the `%O' spec. If you customize gnus-summary-line-format to include this specifier, you will add a single character field that indicates an article's download status. Articles that have been fetched into either the Agent or the Cache, will display gnus-downloaded-mark (defaults to `+'). All other articles will display gnus-undownloaded-mark (defaults to `-'). If you open a group that has not been agentized, a space (` ') will be displayed.

The second visual effect are the undownloaded faces. The faces, there are three indicating the article's score (low, normal, high), seem to result in a love/hate response from many Gnus users. The problem is that the face selection is controlled by a list of condition tests and face names (See gnus-summary-highlight). Each condition is tested in the order in which it appears in the list so early conditions have precedence over later conditions. All of this means that, if you tick an undownloaded article, the article will continue to be displayed in the undownloaded face rather than the ticked face.

If you use the Agent as a cache (to avoid downloading the same article each time you visit it or to minimize your connection time), the undownloaded face will probably seem like a good idea. The reason being that you do all of our work (marking, reading, deleting) with downloaded articles so the normal faces always appear.

For occasional Agent users, the undownloaded faces may appear to be an absolutely horrible idea. The issue being that, since most of their articles have not been fetched into the Agent, most of the normal faces will be obscured by the undownloaded faces. If this is your situation, you have two choices available. First, you can completely disable the undownload faces by customizing gnus-summary-highlight to delete the three cons-cells that refer to the gnus-summary-*-undownloaded-face faces. Second, if you prefer to take a more fine-grained approach, you may set the agent-disable-undownloaded-faces group parameter to t. This parameter, like all other agent parameters, may be set on an Agent Category (see section 6.8.2 Agent Categories), a Group Topic (see section 2.16.5 Topic Parameters), or an individual group (see section 2.10 Group Parameters).