285703 - Incorrect behavior for images with no ALT attribute or ALT=""

Status: RESOLVED FIXED

(Core :: Disability Access APIs, defect)

Description

[Aaron Leventhal]

To match IE:
- return "" when ALT="". This indicates to the AT that it should not attempt to
repair the ALT text, and that an empty string is intentional.
- return null when no ALT or TITLE attribute present. This indicates to the AT
that it may attempt to repair the missing ALT text

Comment 1

[Aaron Leventhal]

Attachment: 1) Put logic for GetName() in nsHTMLImageAccessible 2) Clean up AppendFlatStringFromContentNode(), 3) Return null if name.IsVoid()

This patch is a small step torward the ALT text repair patch from bug 277469,
because of the AppendFlatStringFromContentNode() cleanup and moving the
GetName() logic to nsHTMLImageAccessible.

Comment 2

[timeless]

Comment on attachment 177102 [details] [diff] [review]
1) Put logic for GetName() in nsHTMLImageAccessible 2) Clean up AppendFlatStringFromContentNode(), 3) Return null if name.IsVoid()

r=me with a few minor fixes

Comment 3

[Darin Fisher]

Comment on attachment 177102 [details] [diff] [review]
1) Put logic for GetName() in nsHTMLImageAccessible 2) Clean up AppendFlatStringFromContentNode(), 3) Return null if name.IsVoid()

>Index: accessible/src/base/nsAccessible.cpp

> nsresult nsAccessible::AppendFlatStringFromContentNode(nsIContent *aContent, nsAString *aFlatString)
> {
>+  if (aContent->IsContentOfType(nsIContent::eTEXT)) {

nit: I strongly recommend breaking this block out into a subroutine.
I think it would help readability.  Long functions are a pain ;)


>+    return NS_OK; // Not HTML and not XUL -- we don't handle it yet
>+  }
>+  else if (aContent->Tag() == nsAccessibilityAtoms::img) {

nit: else after return is a non-sequitor


>+    nsCOMPtr<nsIAccessibilityService> accService =
>+      do_GetService("@mozilla.org/accessibilityService;1");
>+    nsCOMPtr<nsIAccessible> accessible;
>+    accService->GetAccessibleInWeakShell(domNode, mWeakShell, getter_AddRefs(accessible));

nit: null check accService in case do_GetService fails?  (e.g., like
if this code happens to run after xpcom has shutdown.)


sr=darin

Comment 4

[Aaron Leventhal]

Checking in src/base/nsAccessibilityAtomList.h;
/cvsroot/mozilla/accessible/src/base/nsAccessibilityAtomList.h,v  <-- 
nsAccessibilityAtomList.h
new revision: 1.16; previous revision: 1.15
done
Checking in src/base/nsAccessible.cpp;
/cvsroot/mozilla/accessible/src/base/nsAccessible.cpp,v  <--  nsAccessible.cpp
new revision: 1.136; previous revision: 1.135
done
Checking in src/html/nsHTMLImageAccessible.cpp;
/cvsroot/mozilla/accessible/src/html/nsHTMLImageAccessible.cpp,v  <-- 
nsHTMLImageAccessible.cpp
new revision: 1.26; previous revision: 1.25
done

Comment 5

[Firefox Bug Husbandry Bot]

https://bugzilla.mozilla.org/show_bug.cgi?id=1527381