Add RelationType::CONTAINING_WINDOW to the RelationTypeMap. Note that
there is no implementation for this RelationType in place yet, but this
addition will fix off-by-one bugs when mapping newly-added relation types
to platform accessibility APIs.
MozReview-Commit-ID: LVML7EZaSYD
In non-e10s AccessibleWrap::HandleAccEvent, we special case our handling of
CARET_MOVED and FOCUS events with a call to UpdateSystemCaretFor. In e10s mode
we were not doing the same thing for proxied events sent from content. This
threw JAWS for a loop and presumably messes up other ATs as well.
This patch modifies the IPDL messages for these two events so that we may
send the caret rect along with the event, thus allowing us to update the
system caret for proxied events as well.
--HG--
extra : rebase_source : e1502c12b038739520afd5c7078d011e25ea669e
MozReview-Commit-ID: GTQF3x1pBtX
A general outline of the COM handler (a.k.a. the "smart proxy"):
COM handlers are pieces of code that are loaded by the COM runtime along with
a proxy and are layered above that proxy. This enables the COM handler to
interpose itself between the caller and the proxy, thus providing the
opportunity for the handler to manipulate an interface's method calls before
those calls reach the proxy.
Handlers are regular COM components that live in DLLs and are declared in the
Windows registry. In order to allow for the specifying of a handler (and an
optional payload to be sent with the proxy), the mscom library allows its
clients to specify an implementation of the IHandlerProvider interface.
IHandlerProvider consists of 5 functions:
* GetHandler returns the CLSID of the component that should be loaded into
the COM client's process. If GetHandler returns a failure code, then no
handler is loaded.
* GetHandlerPayloadSize and WriteHandlerPayload are for obtaining the payload
data. These calls are made on a background thread but need to do their work
on the main thread. We declare the payload struct in IDL. MIDL generates two
functions, IA2Payload_Encode and IA2Payload_Decode, which are used by
mscom::StructToStream to read and write that struct to and from buffers.
* The a11y payload struct also includes an interface, IGeckoBackChannel, that
allows the handler to communicate directly with Gecko. IGeckoBackChannel
currently provides two methods: one to allow the handler to request fresh
cache information, and the other to provide Gecko with its IHandlerControl
interface.
* MarshalAs accepts an IID that specifies the interface that is about to be
proxied. We may want to send a more sophisticated proxy than the one that
is requested. The desired IID is returned by this function. In the case of
a11y interfaces, we should always return IAccessible2_3 if we are asked for
one of its parent interfaces. This allows us to eliminate round trips to
resolve more sophisticated interfaces later on.
* NewInstance, which is needed to ensure that all descendent proxies are also
imbued with the same handler code.
The main focus of this patch is as follows:
1. Provide an implementation of the IHandlerProvider interface;
2. Populate the handler payload (ie, the cache) with data;
3. Modify CreateHolderFromAccessible to specify the HandlerPayload object;
4. Receive the IHandlerControl interface from the handler DLL and move it
into the chrome process.
Some more information about IHandlerControl:
There is one IHandlerControl per handler DLL instance. It is the interface that
we call in Gecko when we need to dispatch an event to the handler. In order to
ensure that events are dispatched in the correct order, we need to dispatch
those events from the chrome main thread so that they occur in sequential order
with calls to NotifyWinEvent.
--HG--
extra : rebase_source : acb44dead7cc5488424720e1bf58862b7b30374f
unfortunately because creating a DocAccessibleParent is not atomic one can be
created by AllocPDocAccessible(), but then RecvPDocAccessibleConstructor() can
fail. If that happens we will call actor destroyed on the new
DocAccessibleParent, however because the constructor messaged failed it will
not have a wrapper. That means this assert does not necessarily hold.