Display icon next to input box when the value is invalid

[bill]

As Owen pointed out, since changing the CSS of a input box to indicate error condition (ie, setting the border color) won't be visible in high contrast mode, should display an icon next to widgets that have an invalid value.

This should be in the template for each widget (or maybe generated; i'm not sure), and then the theme controls whether it shows up or not.

Oh, I guess for high contrast mode we shouldn't use an icon but rather a character, and then for themes like tundra, can use either a background-image or just not display anything. Basically, how Tree works.

Not sure what character to use; maybe the frowny face from "miscellaneous symbols" in ​http://www.unicode.org/charts/symbols.html :-). But I'm not sure if that shows up on all browsers.

[Becky Gibson]

I'm concerned about high contrast mode - this really should have some kind of title text because people may not easily interpret the character or symbol. I guess we could use an ascii 'x' for high contrast mode - that is a bit lame but if we use a symbol it really should include title text to describe it ("error") but then we get into i18n issues.

[davidb]

Is it okay if the page reflows? Or should the indicator space be reserved?

[davidb]

As per a11y chat today we will create a space for the icon even when not shown so that no reflow is necessary.

[bill]

Punting to 1.0. Note that the icon needs to appear for validation text boxes, combobox, dateTextBox, spinner, etc.

[Becky Gibson]

(In [10344]) fixes #3273 add icon to indicate validation error and display next to control