[Dev] New rules for icons for collections in the sidebar

[John Anderson]

Hi:

I tried to change the rules for icon names for the collections in the 
sidebar to avoid many of the duplicate images. The new rules for naming 
icons are still very complicated, which is a reflection of complexity of 
our sidebar design, so I though I should try to summaries the new rules:

Names are made up of the following pieces:

"Sidebar", ButtonName, IconName, "Checked", "MouseOver", ".png"

They all begin with "Sidebar", followed by ButtonName. Today, we only 
have two buttons named: "Icon", and "SharingIcon".

The  ButtonName is followed by IconName. IconName is a property of the 
collection, e.g. the AllCollection has an IconName of "All". The In, 
Out, and Trash collections have names "In", "Out" and "Trash" 
respectively. Currently, new collections have no icon name, so the 
IconName can be empty. Another property of the collection is whether or 
not the IconName has a kind variation, in which case the IconName is 
appended with the Kind, e.g. CalendarEventMixin, MailMessageMixin, 
TaskMixin. Currently, only the All collection has this property, so the 
IconNames for the AllCollection are "All", "AllCalendarEventMixin", 
"AllMailMessageMixin" and "AllTaskMixin".

A property of a button in the siebar is whether or not it is checkable. 
Today the Icon button is checkable and the SharingIcon isn't. For 
checkable buttons, the IconName is followed by "Checked", for the 
checked image.

Next comes "MouseOver" if a different image is necessary for the state 
when the mouse is over the item.

Here are the new rules for defaults:

First we lookup the fully qualified name, e.g. "Sidebar", ButtonName, 
IconName, "Checked", "MouseOver", ".png"

If we don't find an image by that name we next lookup the name without 
the IconName, e.g. "Sidebar", ButtonName, "Checked", "MouseOver", 
".png". This allows us to specify a default icon for Checked and 
MouseOver that is applied by default if you don't have a special one for 
a particular icon.

If we still don't find an image, we next lookup the full image name 
without MouseOver, e.g. "Sidebar", ButtonName, IconName, "Checked", 
".png". So if you don't have MouseOver icons they don't get displayed.

Finally if we still don't have an image, we try to lookup the name 
without an IconName or MouseOver, e.g "Sidebar", ButtonName, "Checked", 
".png". This allows us to have a default for checkable buttons without 
MouseOver.

John