Filter tasks to only show thoses from a single category

[adam-jw-casey]

This would be useful to get an at-a-glance view of each category/track.

Would pair well with #108

[adam-jw-casey]

How should the user interact with this? How will a category be selected? Clearing the filter should be easy, using the existing Filter struct (trait??)

[adam-jw-casey]

A persistent drop down at the top? But how would this interact with the displayed filter? Perhaps it disappears after you select a task, reappearing once you've cleared the selection? But then two filter to a different category you have to first clear the existing one, THEN select the new one.

But will this even happen enough to be annoying?

[adam-jw-casey]

Or perhaps (and this would be a perhaps uncomfortable UX), you open a task and click a button next to its category to filter to it. Embedding the filter in the tas UI makes it feel more like the calendar filter, and reinforces the "there is only one place to interact with X type" (i.e., only one way to select dates, only one place to select categories.

[adam-jw-casey]

It would be annoying to need to find a task of a certain category to filter to that category though. If you're looking for a single task out of 1000, ironically the filter will be the only efficient way to find it (which, in the proposal above, you wouldn't be able to use without first finding the task - Catch-22)

[adam-jw-casey]

Another alternative - persistently show the categories in a pane next to the tasks, link inboxes in an email service. This would make it very easy to filter to different categories, but would take up more screen room.

Perhaps an expandable tray, so it only appears when you want it? This would be even better if I could figure out how to do hotkeys.