Add category dropdown to QuickPress in Dashboard

[jane]

This would make QuickPress more useful to people who use categories instead of tags, have been meaning to do this for years.

Adds Categories checkbox list to the QuickPress widget

Screenshot

This is really easy to implement, but there's definitely some UI considerations to be made (How many categories to show at once? Should some fields be hidden/collapsed by default to conserve space?)

Current patch still has one issue to be resolved, which is that the categories list seems to disappear after submitting the form.

FIY, here is another proposal for the improvement of the QuickPress widget: #21754.

I made a mockup variation that includes your categories list:

http://core.trac.wordpress.org/attachment/ticket/21754/quickpress-improved-02.png

In my proposal, the list is divided into columns - this should be quite easy to achieve with a CSS media query for the browsers that support it.

Replying to tar.gz:

FIY, here is another proposal for the improvement of the QuickPress widget: #21754.

I made a mockup variation that includes your categories list:

http://core.trac.wordpress.org/attachment/ticket/21754/quickpress-improved-02.png

In my proposal, the list is divided into columns - this should be quite easy to achieve with a CSS media query for the browsers that support it.

Mockup looks good. I brought this up in the UI group chat last week and there was some resistance to the idea of adding categories. Reason being that it might be a "slippery slope" toward adding too many things onto QuickPress/The Dashboard. We definitely want to make sure to keep clutter to a minimum. Still, if anything I think categories should take priority over tags anyway, as they're generally more important.