Improves the throughput of IME event handling by ensuring that
input events do not get serialized behind UI traversal and
drawing messages such as when the UI is animating.
Added support for creating an asynchronous Handler as part of a
HandlerCaller. It turns out we should be using an asynchronous
Handler not only in IME dispatch but also in accessibility and
wallpaper events where HandlerCaller is used. So fixed those
services to also use an asynchronous Handler.
Change-Id: I0b19140c9d5ca6ee300c1a150c48312fd55ed8eb
1. The screen magnification feature was implemented entirely as a part of the accessibility
manager. To achieve that the window manager had to implement a bunch of hooks for an
external client to observe its internal state. This was problematic since it dilutes
the window manager interface and allows code that is deeply coupled with the window
manager to reside outside of it. Also the observer callbacks were IPCs which cannot
be called with the window manager's lock held. To avoid that the window manager had
to post messages requesting notification of interested parties which makes the code
consuming the callbacks to run asynchronously of the window manager. This causes timing
issues and adds unnecessary complexity.
Now the magnification logic is split in two halves. The first half that is responsible
to track the magnified portion of the screen and serve as a policy which windows can be
magnified and it is a part of the window manager. This part exposes higher level APIs
allowing interested parties with the right permissions to control the magnification
of a given display. The APIs also allow a client to be registered for callbacks on
interesting changes such as resize of the magnified region, etc. This part servers
as a mediator between magnification controllers and the window manager.
The second half is a controller that is responsible to drive the magnification
state based on touch interactions. It also presents a highlight when magnified to
suggest the magnified potion of the screen. The controller is responsible for auto
zooming out in case the user context changes - rotation, new actitivity. The controller
also auto pans if a dialog appears and it does not interesect the magnified frame.
bug:7410464
2. By design screen magnification and touch exploration work separately and together. If
magnification is enabled the user sees a larger version of the widgets and a sub section
of the screen content. Accessibility services use the introspection APIs to "see" what
is on the screen so they can speak it, navigate to the next item in response to a
gesture, etc. Hence, the information returned to accessibility services has to reflect
what a sighted user would see on the screen. Therefore, if the screen is magnified
we need to adjust the bounds and position of the infos describing views in a magnified
window such that the info bounds are equivalent to what the user sees.
To improve performance we keep accessibility node info caches in the client process.
However, when magnification state changes we have to clear these caches since the
bounds of the cached infos no longer reflect the screen content which just got smaller
or larger.
This patch propagates not only the window scale as before but also the X/Y pan and the
bounds of the magnified portion of the screen to the introspected app. This information
is used to adjust the bounds of the node infos coming from this window such that the
reported bounds are the same as the user sees not as the app thinks they are. Note that
if magnification is enabled we zoom the content and pan it along the X and Y axis. Also
recomputed is the isVisibleToUser property of the reported info since in a magnified
state the user sees a subset of the window content and the views not in the magnified
viewport should be reported as not visible to the user.
bug:7344059
Change-Id: I6f7832c7a6a65c5368b390eb1f1518d0c7afd7d2
1. Added APIs for opening the quick settings to the StatusBarManagerService
and the local StatausBarManager. The new APIs are protected by the old
EXPAND_STATUS_BAR permission.
Renamed the expand* and collapse* non-public APIs that are expanding
the notifications to expandNotifications* collapseNotifications* to
better convey what they do given that this change adds
expandQuickSettings* and collapseQuickSettings*.
Added a global action to the accessibility layer to expand the quick
settings which is calling into the new status bar manager APIs.
bug:7030487
Change-Id: Ic7b46e1a132f1c0d71355f18e7c5a9a2424171c3
1. The feedback type provided by braille devices differs from all
already predefined types and this change defines braille
feedback type. Braille does not fit in the already predefined
categories.
bug:6998945
Change-Id: Ide6043bed03fdecd6d2ee45a08762f5bd07a2118
Okay this isn't entirely docs. I have un-hidden the new permission
for binding to accessibility services; we were going to go out with
it hidden since it didn't go into factory ROM, but now that we are
doing other things we might as well expose it.
Also changed a log from E to W, since it is not an error.
Change-Id: I9226c95e3b63e12218fe41dc3f4290d9824a9e5c
1. Every accessibility services targeting JellyBean or higher has
to request a special permission for the system to bind to it.
Change-Id: I6e579326bdf3597f148d6c67317455701ec8af68
1. The initial design was to have some accessibility gestures
being handled by the system if the gesture handling access
service does not consume the gesture. However, we are not
sure what a good default is and once we add a default handler
we cannot remove it since people may rely on it. Thus, we
take the simples approach and let the accessibility service
handle the gestures. If no gestures are handled the system
will work in explore by touch as before.
bug:5932640
Change-Id: I865a83549fa03b0141d27ce9713e9b7bb45a57b4
1. Delegating activation gestures has several issues that we should
decide how to handle if possible before allowing an accessibility
service to take over them:
A) It is needed that every view than can be clicked or long pressed on
reacts to such as a response to calling performClick and performLongPress
which is not necessary true since the view may watch the touch
events and do its own click long click detection. As a result it may
be possible that there are view a user cannot interact with in
touch exploration mode but can if not in that mode.
B) Clicking or long pressing on a different location in a view may yield
different results, for example NumberPicker. Ideally such views have
to implement AccessibilityNodeProvide which provider handles correctly
the request for click long press on virtual nodes. Some apps however
just fire different hover accessibility events when the user is over
a specific semantic portion of the view but do not provide virtual
nodes. Hence, a user will not be able to interact with such semantic
regions but the system can achieve that by sending the click/long click
at the precise location in the view that was last touch explored.
2. Adding a flag on accessibility service info to request explore by touch
mode. There is no need to put the device in this mode if node of the currently
enabled accessibility services supports it. Now the problem is inverted and
the service has to explicitly state its capability.
3. Fixing a bug where includeImportantViews was ignored for automation
services.
Change-Id: I3b29a19f24ab5e26ee29f974bbac2197614c9e2a
This problem was introduced in I74df9c24. The intention of the
change was still let UiTestAutomationBridge see the
non-important views, but there were bugs in the implementation:
1. AccessibilityManagerService was not really updating
mIncludeNotImportantViews when mIsAutomation is true
2. Wrong constant is used to set the flag
Change-Id: Ia0a2e9ed9720bd0ea3a563e0b492e870a6ec1586
1. Since we are using a stateless proxy accessibility service to
perform default accessibility gesture handling it shuld not
operate against not important views.
bug:6422069
Change-Id: I74df9c2415ab3b164d9ac5873f7004c0459e2bfa
1. The clockwise and counter clockwise circle gestures are difficult to
perform for a blind user. Some user studies have shown that so nuke them.
bug:6435260
Change-Id: I81d23bd3c450239fe17b4b8c60bafab00daa480a
1. A view that creates an accessibility node info may add to the info
a list of granularity labels. These are granularities by which the
source view can iterate over its content. For example a text view
may support character, word link while a web view may additionally
support buttons, tables, etc. There are actions on accessibility
node info to go to the next/previous at a given granularity which
is passesed as an argument.
2. Added Bundle argument to the APIs for performing accessibility
actions. This is generic and extensible.
bug:5932640
Change-Id: I328cbbb4cddfdee082ab2a8b7ff1bd7477d8d6f9
1. An accessibility service has to explicitly opt in to be notified
for gestures by the system. There is only one accessibility service
that handles gestures and in case it does not handle a gesture
the system performs default handling. This default handling ensures
that we have gesture navigation even if no accessibility service
would like to participate/customize the interaction model.
bug:5932640
Change-Id: Id8194293bd94097b455e9388b68134a45dc3b8fa
1. This APIs is useful for accessibility services since very often
they want to get access to the root node in the current window
to determine where accessibility focus is and subsequently find
a next view to take accessibility focus.
Change-Id: Ide5231f832d9ce2e9b14dc411dfd675f753a4edb
1. Added more gesture for accessibility. After a meeting
with the access-eng team we have decided that the current
set of gestures may be smaller than needed considering
that we will use four gestures for home, back, recents,
and notifications.
2. Adding actions for going back, home, opening the recents,
and opening the notifications.
3. Added preliminary mapping from some of the new gestures
to the new actions.
4. Fixed a bug in the accessibility interaction controller
which was trying to create a handled on the main looper
thread which may be null if the queried UI is in the
system process. Now the context looper of the root view
is used.
5. Fixed a bug of using an incorrect constant.
6. Added a missing locking in a couple of places.
7. Fixed view comparison for accessibilityt since it was
not anisymmetric.
bug:5932640
bug:5605641
Change-Id: Icc983bf4eafefa42b65920b3782ed8a25518e94f
Usefulness: Keep track of the current user location in the screen when
traversing the it. Enabling structural and directional
navigation over all elements on the screen. This enables
blind users that know the application layout to efficiently
locate desired elements as opposed to try touch exploring the
region where the the element should be - very tedious.
Rationale: There are two ways to implement accessibility focus One is
to let accessibility services keep track of it since they
have access to the screen content, and another to let the view
hierarchy keep track of it. While the first approach would
require almost no work on our part it poses several challenges
which make it a sub-optimal choice. Having the accessibility focus
in the accessibility service would require that service to scrape
the window content every time it changes to sync the view tree
state and the accessibility focus location. Pretty much the service
will have to keep an off screen model of the screen content. This
could be quite challenging to get right and would incur performance
cost for the multiple IPCs to repeatedly fetch the screen content.
Further, keeping virtual accessibility focus (i.e. in the service)
would require sync of the input and accessibility focus. This could
be challenging to implement right as well. Also, having an unlimited
number of accessibility services we cannot guarantee that they will
have a proper implementation, if any, to allow users to perform structural
navigation of the screen content. Assuming two accessibility
services implement structural navigation via accessibility focus,
there is not guarantee that they will behave similarly by default,
i.e. provide some standard way to navigate the screen content.
Also feedback from experienced accessibility researchers, specifically
T.V Raman, provides evidence that having virtual accessibility focus
creates many issues and it is very hard to get right.
Therefore, keeping accessibility focus in the system will avoid
keeping an off-screen model in accessibility services, it will always
be in sync with the state of the view hierarchy and the input focus.
Also this will allow having a default behavior for traversing the
screen via this accessibility focus that is consistent in all
accessibility services. We provide accessibility services with APIs to
override this behavior but all of them will perform screen traversal
in a consistent way by default.
Behavior: If accessibility is enabled the accessibility focus is the leading one
and the input follows it. Putting accessibility focus on a view moves
the input focus there. Clearing the accessibility focus of a view, clears
the input focus of this view. If accessibility focus is on a view that
cannot take input focus, then no other view should have input focus.
In accessibility mode we initially give accessibility focus to the topmost
view and no view has input focus. This ensures consistent behavior accross
all apps. Note that accessibility focus can move hierarchically in the
view tree and having it at the root is better than putting it where the
input focus would be - at the first input focusable which could be at
an arbitrary depth in the view tree. By default not all views are reported
for accessibility, only the important ones. A view may be explicitly labeled
as important or not for accessibility, or the system determines which one
is such - default. Important views for accessibility are all views that are
not dumb layout managers used only to arrange their chidren. Since the same
content arrangement can be obtained via different combintation of layout
managers, such managers cannot be used to reliably determine the application
structure. For example, a user should see a list as a list view with several
list items and each list item as a text view and a button as opposed to seeing
all the layout managers used to arrange the list item's content.
By default only important for accessibility views are regared for accessibility
purposes. View not regarded for accessibility neither fire accessibility events,
nor are reported being on the screen. An accessibility service may request the
system to regard all views. If the target SDK of an accessibility services is
less than JellyBean, then all views are regarded for accessibility.
Note that an accessibility service that requires all view to be ragarded for
accessibility may put accessibility focus on any view. Hence, it may implement
any navigational paradigm if desired. Especially considering the fact that
the system is detecting some standard gestures and delegates their processing
to an accessibility service. The default implementation of an accessibility
services performs the defualt navigation.
bug:5932640
bug:5605641
Change-Id: Ieac461d480579d706a847b9325720cb254736ebe
1. When the feedback type is set to TYPES_ALL_MASK the method
feedbackTypeToString was not generating a string with all
feedback types. Also the generated string sometimes could
have a comma appended after the last feedback type name
- this happens if the feedback type contains unknown type
flag.
Change-Id: I848c520cf7dae16dcd882f68275869c7ab656dd7
1. Now the thread is terminated in the disconnect() method
and also it is made demon since it has no pupose outside
the context of the bridge client.
bug:6053108
Change-Id: Idc25373fddf501eda4f875fea3e944367e4f04bf
1. Before there were two caches one in the app process that
kept track only the ids of infos that were given to a
querying client and one in the querying client that
holds the infos. This design requires precise sync
between the caches. Doing that is somehow complicated
since the app has cache for each window and it has
to intercept all accessibility events from that window
to manage the cache. Each app has to have a cache for
each querying client. This approach would guarantee that
no infos are fetched twice but due to its stateful nature
and the two caches is tricky to implement and adds
unnecessary complexity. Now there is only one cache in
the client and the apps are stateless. The client is
passing flags to the app that are a clue what nodes to
prefetch. This approach may occasionally fetch a node
twice but it is considerably simpler and stateless
from the app perspective - there is only one cache.
Fetching a node more than once does not cause much
overhead compared to the IPC.
Change-Id: Ia02f6fe4f82cff9a9c2e21f4a36747de0f414c6f
1. UiTestAutomationBridge was accessing the root node in the
active window by tracking the accessibility event stream
and keeping the last active window changing event. Now
the bridge is stateless and the root node is fetched by
passing special window and view id with the request to
the system.
2. AccessibilityNodeInfos that are cached were not finished,
i.e. not sealed, causing exception when trying to access
their children or rpedecessors.
3. AccessibilityManagerService was not properly restoring its
state after the UI automation bridge disconnects from it.
I particular the devices was still in explore by touch mode
event if no services are enabled and the sutomation bridge
is disconnected.
4. ViewRootImpl for the focused window now fires accessibility
events when accessibility is enabled to allow accessibility
services to determine the current user location.
5. Several missing null checks in ViewRootImpl are fixed since
there were scenraios in which a NPE can occur.
6. Update the internal window content querying tests.
7. ViewRootImpl was firing one extra focus event.
bug:6009813
bug:6026952
Change-Id: Ib2e058d64538ecc268f9ef7a8f36ead047868a05
1. Now when an interrogating client requires an AccessibilibtyNodeInfo
we aggressively prefetch all the predecessors of that node and its
descendants. The number of fetched nodes in one call is limited to
keep the APIs responsive. The prefetched nodes infos are cached in
the client process. The node info cache is invalidated partially or
completely based on the fired accessibility events. For example,
TYPE_WINDOW_STATE_CHANGED event clears the cache while
TYPE_VIEW_FOCUSED removed the focused node from the cache, etc.
Note that the cache is only for the currently active window.
The ViewRootImple also keeps track of only the ids of the node
infos it has sent to each querying process to avoid duplicating
work. Usually only one process will query the screen content
but we support the general case. Also all the caches are
automatically invalidated so not additional bookkeeping is
required. This simple strategy leads to 10X improving the
speed of the querying APIs.
2. The Monkey and UI test automation framework were registering a
raw event listener for accessibility events and hence perform
connection and cache management in similar way to an AccessibilityService.
This is fragile and requires the implementer to know internal framework
stuff. Now the functionality required by the Monkey and the UI automation
is encapsulated in a new UiTestAutomationBridge class. To enable this
was requited some refactoring of AccessibilityService.
3. Removed the *doSomethiong*InActiveWindow methods from the
AccessibilityInteractionClient and the AccessibilityInteractionConnection.
The function of these methods is implemented by the not *InActiveWindow
version while passing appropriate constants.
4. Updated the internal window Querying tests to use the new
UiTestAutomationBridge.
5. If the ViewRootImple was not initialized the querying APIs of
the IAccessibilityInteractionConnection implementation were
returning immediately without calling the callback with null.
This was causing the client side to wait until it times out. Now
the client is notified as soon as the call fails.
6. Added a check to guarantee that Views with AccessibilityNodeProvider
do not have children.
bug:5879530
Change-Id: I3ee43718748fec6e570992c7073c8f6f1fc269b3
1. AccessibilityServiceInfo loading the description string on
creation and using this value. Hence, changing the locale
results in reporting incorrectly localized string. Added a
new loadDescription method to return the localized version.
2. Deprecated the old method.
bug:5807616
Change-Id: Id82bda3c6a90fa6681b035d20da0b8688ed68da3
1. AccessibilityInteractionConnections were removed from the
AccessiiblityManagerService but their DeathRecipents were
not unregistered, thus every removed interaction connection
was essentially leaking. Such connection is registered in
the system for every ViewRootImpl when accessiiblity is
enabled and inregistered when disabled.
2. Every AccessibilityEvent and AccessiilbityEventInfo obtained
from a widnow content querying accessibility service had a
handle to a binder proxy over which to make queries. Hoewever,
holding a proxy to a remote binder prevents the latter from
being garbage collected. Therefore, now the events and infos
have a connection id insteand and the hindden singleton
AccessiiblityInteaction client via which queries are made
has a registry with the connections. This class looks up
the connection given its id before making an IPC. Now the
connection is stored in one place and when an accessibility
service is disconnected the system sets the connection to
null so the binder object in the system process can be GCed.
Note that before this change a bad implemented accessibility
service could cache events or infos causing a leak in the
system process. This should never happen.
3. SparseArray was not clearing the reference to the last moved
element while garbage collecting thus causing a leak.
bug:5664337
Change-Id: Id397f614b026d43bd7b57bb7f8186bca5cdfcff9
Added an interface that is the contract for a client to expose a virtual
view hierarchy to accessibility services. Clients impement this interface
and set it in the View that is the root of the virtual sub-tree. Adding
this finctionality via compostion as opposed to inheritance enables apps
to maintain backwards compatibility by setting the accessibility virtual
hierarchy provider on the View only if the API version is high enough.
bug:5382859
Change-Id: I7e3927b71a5517943c6cb071be2e87fba23132bf
Since the feedback type is an integer the bits of which correspond to a given
feedback type, the AccessibilityNodeInfo#feedbackTypeToString should return a
string representation of all feedback types. The current implementation
incorrectly assumes that the argument had only one flag set. Note that this
is a new ICS API and we would like to have this fixed.
bug:5486933
Change-Id: I5e461c385e199cce4c3054907ff0acf5e9d92afc
The content retrieval APIs are synchronous from a client's
perspective but internally they are asynchronous. The client thread
calls into the system requesting an action and providing a callback
to receive the result after which it waits up to a timeout for that
result. The system enforces security and then delegates the request
to a given view hierarchy where a message is posted (from a binder
thread) describing what to be performed by the main UI thread the
result of which it delivered via the mentioned callback. However,
the blocked client thread and the main UI thread of the target view
hierarchy can be the same one, for example an accessibility service
and an activity run in the same process, thus they are executed on the
same main thread. In such a case the retrieval will fail since the UI
thread that has to process the message describing the work to be done
is blocked waiting for a result is has to compute! To avoid this scenario
when making a call the client also passes its process and thread ids so
the accessed view hierarchy can detect if the client making the request
is running in its main UI thread. In such a case the view hierarchy,
specifically the binder thread performing the IPC to it, does not post a
message to be run on the UI thread but passes it to the singleton
interaction client through which all interactions occur and the latter is
responsible to execute the message before starting to wait for the
asynchronous result delivered via the callback. In this case the expected
result is already received so no waiting is performed.
bug:5138933
Change-Id: I382e2d8689f5189110226613c2387f553df98bd3
1. Events not generated by the user can change the interrogation allowing window
unpredicatably. For example when a ListView lays out its children it fires an
accessibility events and changes the currently active window while the user
interaction may be happening in another window say a dialog. Now the interrogation
allowing window is changed when a new window is shown or the user has touch
explored it.
bug:5074116
Change-Id: I8dde12bbec807d32445a781eedced9b95312b3e2
1. Upon registration of an accessibility client the latter received only
the accessiiblity state and waiting for the touch exploration state
to be sent by the system in async manner. This led the very first
check of touch exploration state is checked a wrong value to be reported.
Now a state of the accessibility layer is returned to the client
upon registration.
2. Removing the dependency on talking accessibility service to be enabled
for getting into touch exploration mode. What if the user wants to use
an accessibility service that shows a dialog with the text of the touched
view?
bug:5051546
Change-Id: Ib377babb3f560929ee73bd3d8b0d277341ba23f7
1. Seperated touch exploration to be a seperate setting rather being
magically enabled by the system of accessiiblity is on the there
is at leas one accessibility service that speaks enabled. Now
there is a setting for requesting touch exploration but still the
system will enabled it only if that makes sense i.e. accessibility
is on and one accessibility service that speaks is enabled.
2. Added public API for checking of touch exploration is enabled.
3. Added description attribute in accessibility service declaration
which will be shown to the user before enabling the service.
4. Added API for quick cloning of AccessibilityNodeInfo.
5. Added clone functionality to SparseArray, SparseIntArray, and
SparseBooleanArray.
bug:5034010
bug:5033928
Change-Id: Ia442edbe55c20309244061cd9d24e0545c01b54f
1. Added a new event type for notifying client accessibilitiy
services for changes in the layout. The event is fired at
most once for a given time frame and is delivered to clients
only if it originates from the window that can be interrogated.
2. Exposed the findByText functionality in AccessibilityNodeInfo.
This is very useful for an accessibility service since it allows
searching for something the user knows is on the screen thus
avoiding touch exploring the content. Touch exploring is
excellent for learning the apps but knowing them search is
much faster.
3. Fixed a bug causing an accessibiliby service not to receive
the event source in case of more than one service is registered
and one of them does not have paermission to interrogate the window.
The same event was dispatched to multiple services but if one
of them does not have interrogation permission the event is
modified to remove the source causing subsequent serivices not
to get the later.
4. Moved the getSource setSource methods to AccessibilityRecord
instead in AccessibilityEvent.
5. Hiden some protected members in AccessibilityRecod which should
not be made public since getters exist.
6. Added the View absolute coordinates in the screen to AccessibilityNodeInfo.
This is needed for fast computation of relative positions of
views from accessibility - common use case for the later.
7. Fixed a couple of marshalling bugs.
8. Added a test for the object contract of AccessibilityNodeInfo.
Change-Id: Id9dc50c33aff441e4c93d25ea316c9bbc4bd7a35
1. Views are represented as AccessibilityNodeInfos to AccessibilityServices.
2. An accessibility service receives AccessibilityEvents and can ask
for its source and gets an AccessibilityNodeInfo which can be used
to get its parent and children infos and so on.
3. AccessibilityNodeInfo contains some attributes and actions that
can be performed on the source.
4. AccessibilityService can request the system to preform an action
on the source of an AccessibilityNodeInfo.
5. ViewAncestor provides an interaction connection to the
AccessibiltyManagerService and an accessibility service uses
its connection to the latter to interact with screen content.
6. AccessibilityService can interact ONLY with the focused window
and all calls are routed through the AccessibilityManagerService
which imposes security.
7. Hidden APIs on AccessibilityService can find AccessibilityNodeInfos
based on some criteria. These API go through the AccessibilityManagerServcie
for security check.
8. Some actions are hidden and are exposes only to eng builds for UI testing.
Change-Id: Ie34fa4219f350eb3f4f6f9f45b24f709bd98783c
Note: This is a part of two CL change and contains the
system changes without updates to the settings.
1. Added a mechanism for configuring an accessibility service via
XML file specified in a meta-data tag (similar to IMEs).
2. Added property for specifying a settings activity for an
accessibility service.
3. Refactored the APIs in AccessibilityManager to return
lists of AccessiblityServiceInfo instead ServiceInfo
since the former describes an AccessibilityService in
particular (similar to IMEs).
Change-Id: Ie8781bb7e0cdb329e583b6702a612a507367ad7b
Also pretend to fix#2054990 (com.android.frameworktest: java.lang.NullPointerException
at android.accessibilityservice.AccessibilityService$IEventListenerWrapper.executeMessage(
AccessibilityService.java:215))... simply by making the variable that apparently was
null final, to assure myself that there is no possible way in the world for it to be
null. :p
Change-Id: I73e337d65b8360721896a0296691257b3e47564b
