1735722 - Unify LinkAt in HyperTextAccessibleBase

Status: RESOLVED FIXED

(Core :: Disability Access APIs, task)

Description

[James Teh [:Jamie]]

LinkAt is needed to get embedded objects for hypertext clients. In particular, it's needed for NVDA to render a virtual buffer.

Comment 1

[James Teh [:Jamie]]

Attachment: Bug 1735722 part 1: Move EmbeddedChildAt into base Accessible.

This required renaming LocalAccessible::GetEmbeddedChildAt to EmbeddedChildAt.
LocalAccessible::EmbeddedChildAt uses a covariant return type to return a LocalAccessible* while still overriding the base method (which returns Accessible*).
Unfortunately, this can't be done for RemoteAccessible, since the Derived type isn't complete in time due to the templating.
There was only one caller of RemoteAccessible::EmbeddedChildAt, so I just changed it to call AsRemote.
Eventually, even that caller will use the unified tree anyway.

Comment 2

[James Teh [:Jamie]]

Attachment: Bug 1735722 part 2: Add HyperTextAccessibleBase::LinkAt.

This uses the unified Accessible::EmbeddedChildAt from the previous patch.
HyperTextAccessible::LinkAt still exists, since there are still some callers that depend on it returning a LocalAccessible.
xpcAccessibleHyperText has also been updated to call this, which means tests will work on Windows when the cache is enabled.

Comment 3

[James Teh [:Jamie]]

Attachment: Bug 1735722 part 3: Add test for HyperTextAccessibleBase::LinkAt.

Comment 4

[James Teh [:Jamie]]

Attachment: Bug 1735722 part 4: Support QueryInterface to IAccessibleHyperlink for RemoteAccessible.

We don't support any of the methods in this interface for RemoteAccessible yet.
However, IAccessibleHypertext::get_hyperlink returns an IAccessibleHyperlink, so we must support QI to it.

Comment 5

[James Teh [:Jamie]]

Attachment: Bug 1735722 part 5: Rename ia2AccessibleHypertext::TextAcc to LocalTextAcc.

This makes way for a new unified TextAcc method in a subsequent patch.

Strictly speaking, doing it like this isn't correct because methods will return CO_E_OBJNOTCONNECTED for a RemoteAccessible instead of E_NOTIMPL.
I fixed this for IAccessibleText, but I realised fixing this for all interfaces is going to involve a lot of churn which we're going to end up removing anyway once we unify everything.
Clients don't really care about the error code, so I think this situation is acceptable while this is still in early development.

Comment 6

[James Teh [:Jamie]]

Attachment: Bug 1735722 part 6: Support QueryInterface to IAccessibleHypertext and IAccessibleHypertext::get_hyperlink for RemoteAccessible.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/7d5b04d917ab
part 1: Move EmbeddedChildAt into base Accessible. r=morgan
https://hg.mozilla.org/integration/autoland/rev/f5d402b9c8e0
part 2: Add HyperTextAccessibleBase::LinkAt. r=morgan
https://hg.mozilla.org/integration/autoland/rev/3c9adcebbd98
part 3: Add test for HyperTextAccessibleBase::LinkAt. r=morgan
https://hg.mozilla.org/integration/autoland/rev/417190cd31c6
part 4: Support QueryInterface to IAccessibleHyperlink for RemoteAccessible. r=morgan
https://hg.mozilla.org/integration/autoland/rev/c4747685e885
part 5: Rename ia2AccessibleHypertext::TextAcc to LocalTextAcc. r=morgan
https://hg.mozilla.org/integration/autoland/rev/5ce097bae426
part 6: Support QueryInterface to IAccessibleHypertext and IAccessibleHypertext::get_hyperlink for RemoteAccessible. r=morgan

Comment 8

[Marian-Vasile Laza]

https://hg.mozilla.org/mozilla-central/rev/7d5b04d917ab
https://hg.mozilla.org/mozilla-central/rev/f5d402b9c8e0
https://hg.mozilla.org/mozilla-central/rev/3c9adcebbd98
https://hg.mozilla.org/mozilla-central/rev/417190cd31c6
https://hg.mozilla.org/mozilla-central/rev/c4747685e885
https://hg.mozilla.org/mozilla-central/rev/5ce097bae426