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
This was initially about the Clock widget crashing repeatedly on some
devices with multiple users. Turned out that there were race conditions
when switching users that could result in remote views of one user calling
back to the RemoteViewsAdapter in keyguard that in turn sent an incorrect widget id
to a different user's widget, resulting in a crash.
Since KeyguardHostView is instantiated in the same process for different users,
it needs to carry a user identity to pass along to AppWidgetService so that
remote views services were bound to the correct user and callbacks were attached and
detached properly.
Added some aidl calls that take the userId to do the binding properly. A more
complete fix might be needed in the future so that all calls from Keyguard carry
the user id.
Also, there was a problem in comparing host uid for secondary users, since Settings
for a secondary user has a different uid than keyguard. Not an issue on single-user
systems. Changed the host.uid comparison to accomodate for the secondary user.
Bug: 7450247
Change-Id: Idbc36e3c60023cac74174f6cb7f2b2130dd3052c
After finding a window in the window list we turn around and look in
the AppWindowToken.windows list for it. If it is a child of a window
in that list we should use the parent windows index as the search
result. Instead we gave up and ended up inserting the window at the
beginning of the windows list.
Bug 7357465 fixed.
Change-Id: If77f343b8597bfbb0b7fa41dedf7972d78d03020
There is this stupid fudge factor applied to window transformations
when doing a screen rotation animation. We need this when rotating,
but when not rotating it causes very visible artifacts. Historically
the non-rotation case only happened due to configuration changes, so
wasn't that big a deal. Now however that we use this when switching
users, it is more annoying. So get rid of it for such cases.
Change-Id: I6b343866c1bad9b16984b4a629917c2f1bb37b9e
...android.os.Parcel.nativeAppendFrom(Native Method)
The failing stack trace is:
11-20 20:29:04.365 19154 19170 E AndroidRuntime: java.lang.IllegalArgumentException
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.os.Parcel.nativeAppendFrom(Native Method)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.os.Parcel.appendFrom(Parcel.java:428)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.os.Bundle.writeToParcel(Bundle.java:1613)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.os.Parcel.writeBundle(Parcel.java:605)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.location.Location.writeToParcel(Location.java:903)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.os.Parcel.writeParcelable(Parcel.java:1254)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.os.Parcel.writeValue(Parcel.java:1173)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.os.Parcel.writeMapInternal(Parcel.java:591)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.os.Bundle.writeToParcel(Bundle.java:1619)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.os.Parcel.writeBundle(Parcel.java:605)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.location.Location.writeToParcel(Location.java:903)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.os.Parcel.writeParcelable(Parcel.java:1254)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.os.Parcel.writeValue(Parcel.java:1173)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.os.Parcel.writeMapInternal(Parcel.java:591)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.os.Bundle.writeToParcel(Bundle.java:1619)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.os.Parcel.writeBundle(Parcel.java:605)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.content.Intent.writeToParcel(Intent.java:6660)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at android.app.ApplicationThreadProxy.scheduleReceiver(ApplicationThreadNative.java:763)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at com.android.server.am.BroadcastQueue.processCurBroadcastLocked(BroadcastQueue.java:230)
11-20 20:29:04.365 19154 19170 E AndroidRuntime: at com.android.server.am.BroadcastQueue.processNextBroadcast(BroadcastQueue.java:777)
This is odd because where we do Bundle.writeToParcel(), we are just writing the Parcel
we have with its current length. There is no way this should be able to fail like this...
unless the Bundle is changed while we are running?
Hm.
It looks like the location manager is holding on to Location objects which have a
Bundle of extras. It is that Bundle of extras that the crash is happening on.
And the bundle extras can be changed as it operates. And there are places where
the raw Location object is returned from the location manager, which means the
caller can be olding on to a Location object whose extras can be changed at any
time by other threads in the location manager.
So that seem suspicious.
This change should take care of all these places in the location manager, by
making sure to copy the location object before it goes out of the location
manager.
In addition, add some code to the activity manager to not bring down the entire
system if there is a problem trying to send one of these broadcasts. There is
no need, we can just skip the broadcast as bad.
Change-Id: I3043c1e06f9d2931a367f831b6a970d71b0d0621
