Masayuki Nakano [:masayuki] (he/him)(JST, +0900) Reporter
	Description • 14 years ago

nsTextFrame uses IME specified selection colors/styles. However, there are some a11y problems:

1. If only foreground or background color is specified, nsTextFrame needs to check the contrast with its background color.

- When only foreground color is specified, should check whether the color has enough contrast with the frame background color. If it doesn't, use system color of input field's background color.

- When only background color is specified, should check whether the color has enough contrast with the frame foreground color. If it doesn't, use system color of input field's foreground color.

- After that, if the selection background color and frame's background don't have enough contrast, and if the selection type is "selected clause", we should revert the colors.

2. The underline color selection logic is wrong. Currently, nsTextFrame uses the specified underline color if it's specified. Otherwise, when foreground color is specified, it uses this. Otherwise, it uses its foreground color.

The better logic is: When both underline color and foreground color are specified and they are different color or only underline color is specified, should use the specified underline color. Otherwise, if foreground color or background color is defined, use computed foreground color by #1. Otherwise, use the frame foreground color.

But if only underline color is specified, should check the contrast with the frame background color.

	Masayuki Nakano [:masayuki] (he/him)(JST, +0900) Reporter
	Comment 1 • 14 years ago

See comment 0 for the detail of this patch.

	Robert O'Callahan (:roc) (email my personal email if necessary)
	Comment 2 • 14 years ago

The color selection code is already far too complicated :-(. I think we should factor it out into a separate file with a clean, documented interface.

It seems to me the interface should be:

Input:
-- the frame text color and background colors
-- the prescontext (so we can get access to nsITheme/nsILookAndFeel)
-- the preferred foreground color (if specified), text color (if specified) and decoration color (if specified) for the selection
-- the selection type?

Output: the actual foreground color, text color and decoration color for the selection

Does that sound right? A single function could do this.

	Masayuki Nakano [:masayuki] (he/him)(JST, +0900) Reporter
	Comment 3 • 14 years ago

OK, I agree. And it's better for me too. IME related code should be separated to other files in any level, it could protect from other developers who don't use IME.

	Masayuki Nakano [:masayuki] (he/him)(JST, +0900) Reporter
	Comment 4 • 14 years ago

I'm thinking about tests for this patch.

	Masayuki Nakano [:masayuki] (he/him)(JST, +0900) Reporter
	Comment 5 • 14 years ago

FYI: Ignore the widget part.

	Masayuki Nakano [:masayuki] (he/him)(JST, +0900) Reporter
	Comment 6 • 14 years ago

Hmm... I should still look for better rule of reverting IME selection color...

	Masayuki Nakano [:masayuki] (he/him)(JST, +0900) Reporter
	Comment 8 • 14 years ago

First test (prototype) passed. I'll add many test cases, create a test for nsITextRangeStyle, separate the patch to 3 bugs.